Sobotta Atlas vol-1

M uscles -> T o p o g ra p h y -► S ections

Shoulder blade

Incisura scapulae Acrom ion
M argo superior
Angulus superior Proc. coracoideus Tuberculum supraglenoidale
A crom ion Proc. coracoideus
Fossa
s u p ra s p in a ta

S p in a
s c a p u la e

C a v ita s C a vitas glen oid alis
g le n o id a lis Tuberculum infraglenoidale
A n g u lu s Facies c o s ta l is
C ollum scapulae M argo lateralis

M argo lateralis

Fossa infraspinata

Angulus inferior

A crom ion Proc. coracoideus
Facies articularis clavicularis Incisura scapulae

C a vitas glen oid alis M argo superior
C ollum scapulae Fossa subscapularis
Facies costalis

Figs. 3.13 to 3.15 Shoulder blade. Scapula, right side; dorsal The dorsal T-shaped protrusion, the Spina scapulae, serves as an im-
(-* Fig. 3.13), lateral (-» Fig. 3.14), and ventral (-» Fig. 3.15) view . portant apophysis fo r the attachm ent o f muscles.
The shoulder blade is a fla t bone w ith three m argins and three angles.

Clinical Remarks of th e nerve w ith weakening of the dependent m uscles (M. sup-
raspinatus and M . infraspinatus). These m uscles are im portant for
The N. suprascapularis passes through the Incisura scapu­ abduction and external rotation of the arm.
lae, w hich is bridged by the Lig. transversum scapulae superius
(-► Fig. 3.28). O ssification o f th e ligam ent can result in com pression

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Humerus

S ulcus intertubercularis C aput hum eri
Tuberculum m ajus C ollum anatom icum
Tuberculum m inus
C ollum chirurgicum

C rista tu b e rc u li m ajoris tr C rista tu b e rc u li m inoris

C orpus hum eri

Tuberositas delto id ea

M argo lateralis M argo medialis
Facies anterolateralis Facies anterom edialis

Crista supraepicondylaris Fossa coronoidea
lateralis Crista supraepicondylaris
m e d ia lis
Fossa radialis Epicondylus m edialis
Epicondylus lateralis
Trochlea hum eri
C a p itu lu m h u m e r i -------------

C ondylus hum eri

Fig. 3.16 Bone of th e upper arm . Hum erus, right side; ventral retroto rsion o f 15o-3 0 ° and a po sterior rotation relative to th e axis
vie w . through the distal condyles. The Tuberculum majus and the Tubercu­
The humeral head form s an angle of 150°-180° w ith the axis of the lum minus are located laterally and m edially on the proximal shaft, re­
humeral sh a ft (collodiaphyseal angle). In addition, th e head sh o w s a spectively.

138

M uscles -> T o p o g ra p h y -► S ections Humerus

C ollum anatom icum
C ollum chirurgicum

S u lcu s nervi radialis Tuberculum m inus Sulcus intertubercularis
C ollum anatom icum
Facies posterior Tuberculum m ajus
C aput humeri Tendinous insertions:
Fossa olecrani 1 M . supraspinatus
S ulcus nervi ulnaris Trochlea humeri 2 M . infraspinatus
3 M. teres minor
3.17

Fig. 3.17 and Fig. 3.18 Bone o f th e upper arm , H um erus, righ t m erus guiding th e N. radialis. The po sterior side o f th e Epicondylus
side; dorsal (-► Fig. 3.17) and proxim al (-► Fig. 3.18) view . m edialis show s the Sulcus nervi ulnaris w here the N. ulnaris may be
The Sulcus nervi radialis spirals around the dorsal shaft of the Hu- irritated mechanically ("funny bone").

r- Clinical Rem arks------------------------------------ lesion (radial nerve paralysis). In th is region, the nerve may also be
damaged by compression ("park bench paralysis" or "Saturday
As a result of falls, fractures of the Hum erus are relatively com m on. night palsy"). Distal fractures may cause dam age to the N. ulna­
S upplying blood vessels (Aa. circum flexae hum eri anterior and ris in th e Sulcus ulnaris (-» p. 207). Since th e nerve is extrem e ly ex­
posterior) and th e N. axillaris w h ic h loop around th e H um erus may posed at th is location, lesions o f th e N. ulnaris in th is area represent
be dam aged in proxim al fractures (-» p. 200). The N. radialis may the m ost com m on nerve lesions of the upper extremity.
be injured during fractures in th e sh aft area or surgical tre a tm e n t of
such fra cture s (-» p. 203), resulting in a clinically obvious N. radialis

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3 Upper Extremity Surface a n a to m y -► D e ve lo p m e n t Skeleton -♦ Im aging

Ulna

O lecranon Incisura trochlearis
C rista m usculi supinatoris
Incisura trochlearis Proc. coronoideus
In cis u ra radialis T uberositas ulnae Facies posterior

M a rg o interosseus O lecranon

Foramen nutricium Proc.
Facies anterior c o ro n o id e u s

C orpus ulnae

M argo posterior

Circum ferentia Facies m edialis C a p u t ulnae
a rtic u la r is Proc. styloideus ulnae
C a p u t ulnae Circum ferentia
3.19 3.21 a rtic u la r is

Proc. styloideus ulnae Facies posterior

3.20

Figs. 3.19 to 3.21 Ulna, U lna righ t side; ventral (-» Fig. 3.19), M atching an isolated Ulna to one side o f the body is aided by the posi­
dorsal (-* Fig. 3.20), and radial (-» Fig. 3.21) view . tion o f the Incisura radialis w hich points laterally.

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M uscles -> T o p o g ra p h y -► S ections

C a p u t radii, Radius
Circum ferentia articularis
3.24
C o llu m radii

Tu b e ro sitas radii

Foramen nutricium Circum ferentia C a p u t radii
M a rg o interosseus a rtic u la r is C ollum radii
C o rp u s radii
M argo anterior
Facies anterior Facies lateralis

M a rg o interosseus
M argo posterior

Facies posterior

P roc. sty lo id e u s radii

Tuberculum

3.23

Figs. 3.22 to 3.24 Radius, Radius rig h t side; ventral (-► Fig. 3.22), position o f the Proc. styloideus radii w hich points laterally. The Incisura
dorsal (-» Fig. 3.23), and ulnar (-» Fig. 3.24) view . radialis, how ever, points in an ulnar direction.
M a tching an isolated Radius to one side o f th e body is aided by th e * grooves and bony crests fo r the extensor tendons

Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Skeleton of the hand

Fig. 3.25 Skeleton of th e hand. Ossa m anus, right side; palmar the w ris t form the Sulcus carpi w hich builds th e base of the carpal tun­
vie w . nel (-► Fig. 3.125). The carpal tunnel is bordered by th e scaphoid (Os
The hand (Manus) consists o f th e w ris t (Carpus w ith Ossa carpi), the scaphoideum ) and th e trapezium (Os trapezium ) on th e radial side and
metacarpus (Metacarpus w ith Ossa metacarpi) and the digits (Digiti by the pisiform (Os pisiform e) and the ham ate (Os hamatum) on the
w ith Ossa digitorum ). Digits consist of several phalanges. The bones of ulnar side.

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M uscles -> T o p o g ra p h y -► S ections

Skeleton of the hand

Radius

——O s lu n a tu m ' O s scaphoideum
M TO s tr iq u e tr u m j------------ êê
\ j
v Os tra p e ziu m
WÊBÉ WFO s p is if o r m e ---------- p
M ~.
O s h a m a t u m ---------------- 93*4*' j B s l r
X ' --------------- O s tr a p e z o id e u m
flra:

O s capitatum

proxim alis

P halanx m edia
P halanx distalis
Tuberositas phalangis distalis

Fig. 3.26 S keleton of th e hand. Ossa m anus, rig h t side; dorsal (Os sesam oideum ) fo r the tendon o f the M. flexor carpi ulnaris. The
view. distal ro w com prises o f th e trapezium (Os trapezium ), th e trapezoid (Os
The w ris t (Carpus) com prises a proxim al and a distal row. From radial to trapezoideum), the capitate (Os capitatum ), and the hamate (Os hama-
ulnar the proximal ro w contains scaphoid (Os scaphoideum), lunate (Os tum ).
lunatum ) and triq u e tru m (Os triq uetrum ). The pisiform (Os pisiform e) is For many years, students have used m nem onics to help them m em o­
adjacent to the triquetrum on the palmar side. S trictly speaking, the Os rising the sequence of the carpal bones:
pisiform e is not part o f the Ossa carpi but serves as a sesam oid bone Som e Lovers Try Positions That They Can't Handle.

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3 Upper Extremity Surface a n a to m y -► D e ve lo p m e n t Skeleton -► Im aging

Clavicular joints

D iscus articularis

Capsula articularis Lig. c o sto cla vic u lare
Cartilago co sta lis I Lig. s tern o clavicu lare anterius
M anubrium sterni

Fig. 3.27 M edial clavicular jo int, A rticulatio sternoclavicularis; m ovem ents. The strong ligam ents com prise the Ligg. sternoclavicula-
ventral view of both joints. ria anterius and posterius spanning both bony com pone nts on th e ven­
The m edial clavicular jo in t is th e o n ly articulating connection o f th e up­ tral and dorsal side, and the Lig. interclaviculare connecting both clavi­
per extrem ity w ith the skeleton o f the trunk. The socket o f the sternum cles cranially. The Lig. costoclaviculare spans betw een the cartilage of
and th e ball o f th e clavicle are separated by a D iscus articularis o f fi­ rib I and the sternal end of the clavicle; the M. subclavius extends to the
brous cartilage w h ic h fu n ctio n s in balancing th e traction force o f lateral acromial end of the clavicle.

144

M uscles -» T o p o g ra p h y -► S ections Clavicular joints

A rticulatio acrom ioclavicularis, Lig. corac o c la v ic u lare ,
Lig. a cro m io c la v ic u la re Lig. tra p e zo id e u m
Lig. corac o c la v ic u lare ,
Proc. coracoideus Lig. con o id eu m
Lig. transversum scapulae superius

Fig. 3.28 Lateral clavicular jo in t, A rt. acrom ioclavicularis, righ t stabilise the acromioclavicular joint. This ligam ent consists of tw o
side; ventral view. separate ligam ents, w hich independently connect the coracoid process
The lateral clavicular jo in t connects th e clavicle and th e Scapula. The w ith th e Scapula. The Lig. conoideum reaches th e Tuberculum conoi­
frequently present Discus articularis of fibrous cartilage incom pletely deum medially. The Lig. trapezoideum inserts laterally on the inferior
separates th e cavity o f th e joint. The jo in t capsule is supported by th e and acrom ial aspect o f th e clavicle along th e Linea trapezoidea (-» Fig.
Lig. acrom ioclaviculare. In addition, th e Lig. coracoclaviculare helps to 3.12).

r- Clinical Rem arks-----------------------------------------------------------------------------------------------------

The sternoclavicular jo in t is w e ll protecte d fro m injuries by its stro ng jo in t, also called AC joint, occur fre q u e n tly (e.g. as a result o f a fall;
ligam entous support. H ow ever, injuries to th e acrom ioclavicular -» Fig. 3.57).

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3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Shoulder joint

A crom ion Facies articularis clavicularis
Bursa subacrom ialis M. supraspinatus
Lig. coracohum erale
M . b ic e p s b ra c h ii, C aput longum , Tendo
Labrum glen o id ale
C avitas glen oid alis

C aput hum eri

Vagina tendinis intertubercularis S c a p u la
M . b ic e p s b ra c h ii, C aput longum , Tendo (R ecessus axillaris)

H u m e ru s

Lig. acrom ioclaviculare Clavicula
A crom ion
J g . trapezoideum Lig. coracoclaviculare
M . biceps brachii, Lig. conoideum
C a p u t longum , Tendo
Proc. coracoideus
C a vitas glen oid alis Lig. c o rac o a cro m iale

Labrum g len oid ale

M . tric ep s brachii, C a p u t longum

Fig. 3.29 and Fig. 3.30 Shoulder jo int, A rticulatio hum eri, right shoulder joint, w hile the long head of the triceps (Caput longum of M.
side; section in th e scapular plane, ventral (-» Fig. 3.29) and lateral triceps brachii) has its origin at the Tuberculum infraglenoidale outside
v ie w on to th e jo in t socke t (-» Fig. 3.30). of the shoulder jo in t capsule. The capsule inserts at the Collum anato-
The Cavitas glenoidalis o f th e Scapula to g e th e r w ith th e glenoid labrum m icum o f the Humerus, leaving Tuberculum m ajus and Tuberculum
(Labrum glenoidale) o f fibrous cartilage form the socket o f the glenohu­ m inus extra-articular. Inferiorly, the joint capsule extends to form a fold
m eral joint. It is a classical ball and socke t jo in t w h e re th e hum eral head (Recessus axillaris). Various ligam ents (-» Fig. 3.31) and inserting te n ­
articulates w ith th e glenoid fossa o f th e Scapula. The jo in t capsule dons o f th e rotator c u ff m uscles (-» Figs. 3.34 und 3.65) sup port the
(Capsula articularis) originates fro m the Labrum glenoidale and includes joint capsule on the posterior, superior, and anterior side. The roof of
at the superior aspect of the Labrum glenoidale the tendon o f Caput th e shoulder com prises the Proc. coracoideus, th e Acrom ion, and the
longum of the M . biceps brachii. Originating from the Tuberculum connecting Lig. coracoacromiale.
supraglenoidale, the long head of the biceps projects through the

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M uscles -> T o p o g ra p h y -► S ections

Shoulder joint

A rticulatio acrom ioclavicularis, - äT - . Lig. coracoclaviculare,
Lig. acrom ioclaviculare Lig. trapezoideum

A crom ion Bursa synovialis
Lig. c o rac o a cro m iale
M. supraspinatus, Tendo Lig. coracoclaviculare,
Proc. coracoideus Lig. conoideum
Lig. co rac o h u m e rale
Tuberculum m ajus transversum scapulae
s u p e riu s
M . subscapularis, Tendo
Incisura scapulae
M. biceps brachii,
C a pu t long urn Bursa subtendinea m usculi
s u b s c a p u la ris
r■
Capsula articularis,
Ligg. g len ohum eralia:
- (superius)
- (m edium)
- (in fe riu s )

Fig. 3.31 S ho ulder jo in t, A rticu latio hum eri, rig h t side; ventral tions, th e w eakn ess o f th e inferior jo in t capsule is evident. The Lig.
view. coracoacromiale, together w ith the Proc. coracoideus and the Acrom i­
The jo in t capsule (Capsula articularis) is supported by various ligam ents on, form the roof of th e shoulder outside o f the jo in t capsule. The roof
and by tendons of the rotator c u ff muscles. The Lig. coracohum erale of the shoulder functions as an additional support fo r the glenoid fossa
is positioned cranially, originates fro m the Proc. coracoideus, and radi­ by stabilizing the humeral head superiorly against pressure from the
ates into the posterior aspect of the capsule. The Ligg. glenohum era­ arm. The structural elem ents of the shoulder roof also lim it elevation of
lia consist o f diffe ren t collagen fibre system s and stabilise the anterior th e arm above th e horizontal plane (Elevation), unless th e Scapula is
part of the capsule. Since the tendons of the rotator cu ff m uscles also rotated, too.
radiate into th e capsule fro m anterior, superior, and posterior direc­

i- Clinical Rem arks-----------------------------------------------------------------------------------------------------

The glenoid fossa o f the shoulder jo in t is relatively small. Thus, this tions (luxations) o f the shoulder jo in t are am ong the m ost com m on
jo in t has a large range o f m otion but is also prone to injury. Disloca- dislocations o f th e body (-» p. 159).

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Upper Extremity Surface a n a to m y -► D e ve lo p m e n t Skeleton -♦ Im aging

Shoulder joint

Lig. transversum scapulae superius Proc. coracoideus

Lig. co rac o h u m e rale

S pina scapulae

Tuberculum m ajus

Fig. 3.32 Shoulder jo int, A rticulatio hum eri, right side; dorsal
view.

Figs. 3.33a to c Range of m o v e m e n t in th e shoulder jo in t w ith
and w ith o u t contributions of th e clavicular joints, (according to
[1]).
a, b The shoulder jo in t is a ball and socket jo in t w ith three de­

grees of freedom of m ovem ent and the highest range of
m ovem ent o f all joints o f the human body. W hen m otions are
exclusively perform ed in the glenohum eral joint, th e e xte n t
o f abduction and anteversion is re stricted by th e shoulder
roof (thin lines). But if considering com bined m ovem ents of
shoulder and clavicular joints, allow ing th e Scapula to rotate,
then a m uch higher range o f m o ve m e n t is possible (thick
lines). This also allows fo r the elevation of the arm above the
horizontal plane. Rotation o f th e Scapula is m ediated by the
M . serratus anterior and M . trapezius and already becomes
effective at the beginning of abduction of the arm.
c To determ ine rotational m ovem ents o f the shoulder joint (see
o° below ) th e forearm , w h ic h can be vie w e d like an indicator,
has to be positioned in a 90° flexion o f th e elbow . W ith the
arm extended, one m ostly detects a com bined rotation of the
shoulder joint and the forearm.

Range of m o v e m e n t in th e shoulder jo in t alone:
• abduction-adduction: 9 0 °- 0 °- 40°
• anteversion-retroversion: 9 0 °- 0 °- 40°
• external rotation-internal rotation: 6 0 °- 0 °- 70°
Range of m o ve m en t in th e shoulder and clavicular jo ints co m ­
bined:
• abduction-adduction: 180°- 0 ° - 40°
• anteversion-retroversion: 17 0°- 0 °- 40°
• external rotation-internal rotation: 9 0 °- 0 °- 100°

M uscles -> T o p o g ra p h y -► S ections

Shoulder joint

Bursa subacrom ialis M . supraspinatus

Acrom ion Lig. coracoacrom iale
M . supraspinatus, Tendo Proc. coracoideus

Tuberculum m ajus Lig. coracohum erale
M . infraspinatus, Tendo M . subscapularis, Tendo
Vagina tendinis intertubercularis
M . te res m inor M. biceps brachii, C aput longum , Tendo
M . subscapularis

Fig. 3.34 S ho ulder jo in t, A rticu latio hum eri, rig h t side; lateral tensions o f the joint. The Bursa subcoracoidea w hich is positioned un­
view. derneath the Proc. coracoideus frequently com m unicates w ith the Bur­
Several m uscles contribute to the stabilisation o f the shoulder joint sa subtendinea m usculi subscapularis. The latter cushions the tendon
through insertion of their tendons into the joint capsule. These muscles o f th e M. subscapularis (-» Fig. 3.31) and o fte n also com m unica tes w ith
are collectively called the rotator cuff: M . subscapularis supports the th e articular cavity (-* Fig. 3.64). The Bursa subacrom ialis is positioned
joint capsule from the ventral, M . supraspinatus from the superior, on top o f the supraspinatus tendon and is connected w ith the Bursa
and M . infraspinatus and M . teres m inor from the dorsal aspect. subdeltoidea. Thus, these tw o bursae together form the accessory
Thus, th e infe rior asp ect is th e w e a k e s t part o f th e jo in t capsule. subacromial joint. These bursae enable a friction-free m ovem ent of the
Several synovial cushions (Bursae) are associated w ith the shoulder head of the Hum erus and of the tendons o f the rotator cu ff muscles
joint. Some of them com m unicate w ith the joint capsule and form ex­ beneath the Acrom ion.

Clinical Remarks

Degenerative alterations affecting the tendon of M. supraspinatus addition, degenerativ charges due to calcifications in the accessory
are com m on. Patients present w ith pain w h e n liftin g th e arm. A b­ subacromial joint can be the cause of painful restrictions of shoulder
duction betw een 60-120° causes com pression of the tendon un­ m o ve m e n ts.
derneath th e ro of o f th e shoulder (im p in g e m e n t syndrom e). In

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3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Elbow joint

E picondylus lateralis Trochlea hum eri H u m e ru s
C apitulum
hum eri C a p s u la articularis, Lig. c o lla te rale
M em brana fibrosa ulnare
Incisura trochlearis
C ircum ferentia Proc. coronoideus Lig. c o lla te rale radiale Chorda obliqua
Incisura radialis Lig. a n u la re radii
a rticularis Tuberositas ulnae C ollum radii

Tuberositas M. b icep s brachii, Tendo
radii

Radius

3.36

Fig. 3.35 A rticulating bones of th e elb ow jo int, A rticulatio cubiti;
ventral view. Articulating areas covered by hyaline cartilage are
illustrated in blue.

H u m e ru s

H um erus E p ico n d ylu s E p ic o n d y lu s E p ic o n d y lu s
Lig. a n u la re radii m e d ia lis m e d ia lis lateralis
C ollum radii Lig. co llaterale
M. biceps brachii, Tendo C apsula ra d ia le
Bursa bicipitoradialis a rticularis
Radius Lig. a n u lare radii

O lecranon C ollum radii

Tuberositas ulnae Lig. c o lla te ra le ulnare,
(Pars posterior)
3.37
Lig. c o lla te rale ulnare,
(Pars anterior)

Figs. 3.36 to 3.38 E lbo w jo in t, A rticu latio cubiti, rig h t side; The jo in t capsule (Capsula articularis) encloses the cartilaginous articu­
ventral (-* Fig. 3.36), m edial (-» Fig. 3.37), and dorsal (-» Fig. 3.38) lating surfaces o f all th re e bones. The capsule is reinforced by accesso­
vie w . ry ligam ents. T w o co llateral lig am ents are responsible fo r lateral
The e lb o w jo in t is a com posite jo in t (A rticulatio com posita), w ith the stabilisation o f th e e lb o w joint. Medially, the Lig. c o lla te ra l ulnare con­
Hum erus, the Radius and the Ulna articulating in three partial joints. nects the Epicondylus m edialis o f th e Hum erus w ith the Proc. coronoi­
deus (Pars anterior) and th e O lecranon (Pars posterior) o f th e Ulna. The
A rticulatio hum eroulnaris: hinge jo in t w ith the Trochlea humeri Lig. c o lla te ra l radiale originates fro m the lateral aspect o f the Epicon­
fo rm in g th e ball and th e Incisura trochlearis o f the Ulna fo rm in g the dylus lateralis and radiates o u t to join the anular lig am en t (Lig. anulare
socket radii) w h ic h is attached to th e an terior and po sterior side o f th e Ulna to
• A rticu latio hum eroradialis: m ultiaxial ball and socket jo in t loop the Caput o f the Radius. The anular ligam ent allow s fo r guided
involving th e C apitulum hum eri (ball) und th e Fovea articularis o f the rotational m ovem ents in the proximal radio-ulnar joint.
Radius (socket)
A rticu latio radioulnaris proxim alis: pivot jo in t involving th e Cir­
cum fere ntia articularis o f th e Caput radii (ball) and th e Incisura radia­
lis o f the Ulna (socket).

150

M uscles -> T o p o g ra p h y -► S ections Elbow joint

90°

b

Figs. 3.39a and b Range of m ovem ent in th e elbow joint. The rotational m o ve m e n ts are guided by th e Lig. anulare radii (b). Rota­
(according to [1]) tion o f the Radius around the Ulna not only requires m ovem ents in the
The elbo w joint enables tw o distinct m ovem ents: hinge m ovem ents proxim al b u t also in th e distal radio-ulnar jo in t (-» Fig. 3.44). Starting
betw een H um erus and Ulna and betw een H um erus and Radius and from the neutral-null position and w ith the thu m b pointing upwards the
rotational m o ve m e n ts b e tw een H um erus and Radius and b e tw een Ra­ rotational m o vem en t in th e radio-ulnar jo in t can result in supination
dius and Ulna. Thus, the partitions o f the e lb o w joint function as hinge (palm facing upwards) or pronation (palm facing downw ards) o f the
rotation joint (trochoginglymus) w hen acting together. The joint forearm . Despite the fact that the articular surfaces of the humero-ulnar
b e tw e e n H um erus and Ulna is largely guided by bones. In con trast to jo in t have th e shape o f a multi-axial ball and socke t joint, th e hum ero-
the inhibition of arm flexion by so ft tissues of the flexor muscles, exten­ ulnar jo in t is fun ctiona lly con fined to hinge m o vem ents. The circular
sion o f the arm is lim ited by th e bony structure o f the Olecranon. The anular ligam ent firm ly tie s the Radius to the Ulna and prevents abduc­
transverse axis o f m o vem en t in th e e lb o w jo in t is positioned w ith in the tion and adduction m ovem ents.
Trochlea hum eri (a).
Range of m o v e m e n t in th e e lb o w joint:
• extension-flexion: 10 °- 0 °-1 50°
• supination-pronation: 9 0 ° -0 ° -9 0 °

Figs. 3.40a and b HUETER's triangle. tion s may result in deviations fro m th is triangular orientation o f the epi­
In th e extended position o f th e e lb o w joint, th e epicondyles o f th e Hu­ condyles.
m erus are in line w ith th e O lecranon (a). In flexe d position, how ever,
th e epicondyles fo rm an equilateral triangle (HUETER's triangle, b). The * clinical term : HUETER's triangle
H ueter's triangle has radiological relevance since fractures and disloca­

151

3 Upper Extremity Surface a n a to m y -► D e ve lo p m e n t Skeleton -♦ Im aging

Conjunctions between the bones of the forearm

Lig. anulare radii Incisura trochlearis
Circum ferentia articularis
A rticulatio radioulnaris Tuberositas radii
M. biceps brachii, proxim alis

C h orda obliqua

Radius

M em b ran a interossea
a n te b ra c h ii

ra diou lnaris distalis, 3.42 Proc. styloideus
C apsula a rticularis

Facies articularis carpalis

Fig. 3.41 and Fig. 3.42 Conjunctions of th e bones of th e right fro m the Radius proxim ally to the Ulna distally. Proximally, the Chorda
fo re arm in supination (-* Fig. 3.41) and pronation position obliqua courses w ith an opposite orientation. The figures dem onstrate
(-» Fig. 3.42); ventral view . the rotation o f the Radius around the Ulna. Radius and Ulna are posi­
The bones o f th e forearm are connected by th e tou gh M em brana in- tion ed in parallel during supination o f th e forearm but th e y cross during
terossea antebrachii w hose collagen fibres are predom inantly oriented pronation of the forearm .

O lecranon

A rticu latio Incisura Proc. styloideus Proc. styloideus
ra d io u ln a ris tro c h le a ris radii ulnae
C aput ulnae
proxim alis Proc. Facies articu la ris carpalis D iscus a rticularis
c o ro n o id e u s
Lig. anulare A rticu latio radiou lnaris distalis
ra d ii

C ollum radii

Fig. 3.43 Proxim al radio-ulnar joint, A rticulatio radioulnaris Fig. 3.44 Distal radio-ulnar jo in t, A rticu latio radioulnaris
proxim alis, right side; proximal and ventral view. distalis; distal and dorsal view.
The proxim al radio-ulnar jo in t is a pivot jo in t and part o f th e e lb o w joint. The distal radio-ulnar jo in t is a pivot jo in t as w e ll and is located adjacent
The com m on axis fo r both the proximal and the distal radio-ulnar joints to the proximal w ris t joint. This jo in t com prises the Caput ulnae and
is th e diagonal axis o f th e forearm connecting th e Caput radii w ith the th e Incisura ulnaris o f th e Radius. In th e proxim al w ris t jo in t th e Facies
Caput ulnae. articularis carpalis o f the distal Radius and th e articular disc o f the distal
radio-ulnar joint articulate w ith the proximal carpal bones.

152

M uscles -> T o p o g ra p h y -► S ections Joints of Carpus and metacarpus

Radius Ulna
Proc. styloideus radii A rticulatio radioulnaris distalis
Proc. styloideus ulnae
O s lunatum Lig. u ln o c arp a le pa lm a re
Lig. ra d io c a rp a le p a lm a re Os pisiform e
Lig. p iso h am atu m
Lig. c arp i radiatum Lig. p iso m e ta c arp a le
A rticu latio carp o m e ta ca rp a lis Ham ulus ossis hamati

pollicis Lig. c a rp o m e ta c a rp a le palm are
Os capitatum
Ligg. m etacarpalia palm aria

O ssa sesam oidea Ligg. palm aria
Ligg. m etacarpalia transversa profunda

Fig. 3.45 Jo ints and lig am ents of th e righ t hand, A rticulationes
and Ligam enta manus, right side; palmar view.

O s lunatum Radius radioulnaris distalis
A rticu latio radiocarpalis
D iscus a rticularis
Os capitatum Os triquetrum
Lig. c o lla te rale c arp i ulnare
Os scaphoideum A rticu latio m ed io carp alis
O s ham atum
Lig. c o lla te rale c arp i ra d ia le Lig. in te rca rp a le interosseum
A rtic u latio n es c arp o m e ta ca rp a le s
O s trapezoideum
O s trapezium
A rticu latio carp o m e ta ca rp a lis
pollicis
Os m etacarpi I

Ligg. m e tac a rp alia in terossea

Fig. 3.46 Joints of th e right carpus and m etacarpus, A rticulatio­ • The distal w ris t jo in t (A rticulatio m ediocarpalis) also fu n ctio n s as
nes carpi, righ t side; v ie w fro m palmar, section parallel to the a condyloid joint. Carpal bones o f the proximal ro w articulate w ith
dorsum of the hand. carpal bones o f the distal row.
In addition to sm a lle r jo in ts b e tw e e n th e d iffe re n t bones o f th e carpus
and metacarpus these consit o f tw o w rist joints. • The A rticu latio nes carpom etacarpales II—V b e tw een carpal and
• The proxim al w ris t jo in t (A rticulatio radiocarpalis) is a condyloid metacarpal bones and the Articulationes intermetacarpales be­
tw ee n the bases of the metacarpal bones are tig h t am phi-arthroses
jo in t and connects the bones o f the forearm (socket) w ith the car­ allow ing only very lim ited m o vem ents. In contrast, th e saddle jo in t
pus (joint head). B etw een Ulna and Os triq uetrum resides a Discus of th e th u m b (Articulatio carpometacarpalis pollicis) is highly m obile
articularis (-* Fig. 3.44). and allows flexion and extension as w ell as abduction and adduction
m o ve m e n ts.

153

3 Upper Extremity Surface a n a to m y -► D e ve lo p m e n t Skeleton -♦ Im aging

Joints of carpus and metacarpus

U ln a Radius Ligaments of Carpus and Metacarpus
Proc. styloideus
Lig. ra d io c a rp ale dorsale • Ligg. radiocarpalia palmare and dorsale,
ulnae Proc. styloideus radii and Lig. ulnocarpale palmare
Lig. c o lla te rale c arp i ulnare Lig. c o lla te rale c arp i radiale
Os scaphoideum • Ligg. collateralia carpi radiale and
Ligg. in te rca rp a lia Ligg. in te rca rp a lia d orsalia ulnare: fro m the Procc. styloidei
d o rs a lia Os trapezoideum
• Ligg. intercarpalia palmaria, dorsalia,
Os triquetrum Ligg. c arp o m e ta ca rp a lia and interossea
O s ham atum d o rs a lia
O s capitatum • Lig. carpi radiatum: ligam ents radiating
Ligg. collateralia from the Os capitatum
Ligg. m e tac a rp alia
d o rs a lia • Lig. pisoham atum : continuation o f the
flexor carpi ulnaris tendon to the Os
A rticulation es h a m a tu m
m etac a rp o p h a la n g e ae
• Lig. pisom etacarpale: continuation of
the flexor carpi ulnaris tendon to the
Ossa m etacarpi IV and V

• Ligg. carpometacarpalia palmaria and
dorsalia

• Ligg. metacarpalia palmaria, dorsalia,
and interossea

Fig. 3.47 Joints and ligam ents of th e hand, Articulationes and
Ligam enta m anus, right side; dorsal view.

Figs. 3.48a and b Range of m o v e m e n t in th e w ris t joints. active p a s s iv e
(according to [1]) active Dorsal extension
Proximal and distal w ris t joints function as condyloid (ellipsoid) joints
and contribute both to the m ovem ents of the hand. Thus, the axes of Palm ar flexion
m ovem ents fo r both joints are described as com bined axes through the p a s s iv e
Os capitatum . A bduction o f Radius and Ulna occurs m ainly in th e proxi­
mal w ris t joint w ith a com bined dorsopalm ar axis of m ovem ents run­
ning through th e cen tre o f th e Os cap itatum (a).
The palm ar flexion is predom inantly m ediated by the proxim al w ris t
joint, and th e dorsal extension by th e distal w ris t jo in t (m nem onic, b).
The transverse axis of these m ovem ents also runs through the centre
of the Os capitatum . M o st other joints of the carpus and metacarpus
are am phi-arthroses and th e ir range o f m otion is negligible. In contrast,
the saddle joint of the thum b shows a great freedom o f movements
allow ing not only flexion and extension but also adduction and abduc­
tion. These m ovem ents can be com bined fo r circum duction and oppo­
sition o f the thum b, both o f w hich are im portant to grasp objects.

Range of m ovem ent in th e carpal joints:
• ulnar abduction - radial abduction: 3 0 ° - 0 ° - 30°
• dorsal extension - palm ar flexion: 6 0 °- 0 ° - 60°

Range of m o v e m e n t in th e saddle jo in t of th e th um b:
• extension-flexion: 3 0 °- 0 °- 40°
• ab duction -ad ductio n: 10 ° - 0 ° - 40°

154

M uscles -> T o p o g ra p h y -► S ections

Finger joints

Fig. 3.49 Finger joints, A rticu latio nes dig ito ru m , righ t side; Fig. 3.50 Ligam ents o f th e fin ger joints, A rticulationes digiti,
lateral view , sagittal section. righ t side; lateral view .
They com prise the metacarpophalangeal and interphalangeal joints. • Ligg. collateralia: medial and lateral
The m etacarpophalangeal joints (Articulationes metacarpophalan- • Lig. palmare: ventral
geales) are condyloid joints in w hich the distal parts o f the metacarpal • Lig. metacarpale transversum profundum : connects palm ar liga­
bones articulate w ith the bases o f the proximal phalanges. The m eta­
carpophalangeal jo in t o f the thum b, however, is a hinge joint. m e nts at th e metacarpophalangeal jo in ts (-» Fig. 3.45).
The proxim al and distal interphalangeal joints (Articulationes inter-
phalangeae manus proxim ales and distales) betw een the heads and
the bases of the respective digital bones are hinge joints.

Figs. 3.51a to c Range o f m o v e m e n t in th e fin g e r joints.
(according to [1])
The m etacarpophalangeal jo in ts a llo w flexion and extension as w e ll as
radial and ulnar abduction. Rotational m o ve m e n ts are only possible pas­
sively if fingers are in extension. The saddle joint o f the thum b exclu­
sively enables hinge m ovem ents. The same applies fo r the proximal
and distal interphalangeal joints w hich exclusively enable flexion.

Range of m ovem ent in th e m etacarpophalangeal joints:
• dorsal extension-palm ar flexion: 3 0 °- 0 °- 90°
• ulnar abduction-radial abduction: (20 - 4 0 )°- 0 ° - (20 - 40)°
Range of m ovem ent in th e proxim al interphalangeal joints:
• dorsal extension-palm ar flexion: 0 °- 0 °-1 00°
Range of m ovem ent in th e distal interphalangeal joints:
• dorsal extension-palm ar flexion: 0 °- 0 °- 90°

r- Clinical Remarks---------------------------------

A bbreviations and te rm s com m only used in the clinical setting:
• MCP joint = metacarpophalangeal joint
• PIP jo in t = proxim al interphalangeal jo in t
• DIP joint = distal interphalangeal joint

3 Upper Extremity Surface a n a to m y -► D e ve lo p m e n t Skeleton -♦ Im a g in g -►

Shoulder joint and humerus

A rtic u la tio Clavicula
acrom ioclavicularis Proc. coracoideus

Acrom ion C avitas glenoidalis
C ollum scapulae
C aput humeri Tuberculum infraglenoidale

Tuberculum m ajus M argo lateralis

Tuberculum m inus
Sulcus intertubercularis

Fig. 3.52 Shoulder joint, A rticulatio hum eri, right side; radiograph
in an terioposterior (AP) beam projection.

H um erus

Figs. 3.53a and b Radiographs sh ow in g fractures of th e b Fracture of th e head o f th e H um erus, w h ich m ay result in injury

Humerus. to th e axillary nerve. [4]

a Fracture of th e shaft of th e Hum erus, w hich may result in injury

to th e radial nerve. [8]

Clinical Remarks-----------------------------------------------------------------------------------------------------

Conventional radiographs are suitable fo r th e identification of frac- be detected by radiographic imaging but instead require the use of
tures and dislocations (luxations) leading to alterations in the posi- ultrasound or magnetic resonance imaging (MRI) as diagnostic tools,
tion of skeletal elem ents. Injuries to the ligam ents, however, cannot

156

M uscles -> T o p o g ra p h y -► S ections

Elbow joint

Crista supraepicondylaris Crista supraepicondylaris
lateralis m e d ia lis
Epicondylus medialis
E picondylus lateralis O lecranon
Capitulum humeri Trochlea humeri
C a pu t radii Proc. coronoideus
C ollum radii
Tuberositas radii
Fossa olecrani
O lecranon H um erus

Incisura trochlearis Fossa coronoidea
Proc. coronoideus
C aput radii
C ollum radii
Radius
Ulna

Fig. 3.54 and Fig. 3.55 E lbo w jo in t, A rticu latio cubiti, righ t side; Clinical Remarks---------------------------------
radiographs in an terioposterior (AP; -» Fig. 3.54) and lateral (-» Fig. 3.55)
beam projections. In the extended position o f th e e lb o w joint, both epicondyles of
th e H um erus are in line w ith th e O lecranon o f th e Ulna. Fractures
o r dislocations m ay result in deviations fro m th e normal position
( - Fig. 3.40).

157

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im a g in g ->

Hand

Proc. styloideus ulnae Radius
Tuberculum ossis scaphoidei
Ham ulus ossis hamati
Ossa m etacarpi Os trapezium
O s trapezoideum
Basis ossis m etacarpi

Phalanx m edia
Phalanx distalis

Fig. 3.56 Hand, M anus, righ t side; radiograph in anterioposterior
(AP) beam projection.

i- Clinical Remarks------------------------------------ necrosis o f th e scaphoid bone and sh o w a reduced bone de nsity in
radiographic im ages. In addition, injuries m ay cause degenerative
The fracture o f the distal Radius is the m o st com m on fracture occur­ alterations such as arthrosis of the hand and finger joints. Typical
ring in hum ans. The diagnosis o f a distal Radius fra cture based on radiological signs o f arthrosis are the de velopm ent o f bony out­
the radiographic image requires profound know ledge o f the radiolo­ grow ths (osteophytes) and destruction of the articular surfaces.
gical anatom y of the w ris t joint.
Fractures of the carpus frequently involve the scaphoid bone.
C onco m itan t injuries o f th e supplying blood vessels m ay result in

158

M uscles -> T o p o g ra p h y -► S ections

Dislocations of the shoulder

Fig. 3.57 Injury of th e acrom ioclavicular jo in t ("shoulder Fig. 3.58 Dislocation (luxation) of th e shoulder joint.
separation"), (according to [1]) (according to [1])
A fte r dislocation (luxation) of the acromioclavicular joint and associated Dislocation o f the shoulder is th e m ost com m on luxation in the body.
rupture of the Ligg. coracoclaviculare and acromioclaviculare, the lateral The shoulder jo in t is prone to luxation because o f th e w eak bony and
part o f th e clavicle is pulled up by th e M . trapezius and th e shoulder ligam entous guidance fo r the m ovem ents of the head of Humerus. The
"d ro p s" (w eight o f the arm). The classification o f the severity is done m o st com m on (90% ) fo rm is th e Luxatio subcoracoidea (as sho w n on
according to TOSSY: th e right side) w ith po sitioning o f th e Hum eral head beneath th e Proc.
coracoideus. The contour o f the shoulder (dome) is reduced and the
I overextension of the ligaments upper arm appears longer.
II partial rup tu re o f th e ligam ents
• III co m p lete rupture o f both com ponents, the Lig. coracoclavicu­
lare and the Lig. acromioclaviculare. This TOSSY-III injury requires
surgical stabilisation.

Fig. 3.59 Reposition of a dislocated shoulder, (according to [1]) Fig. 3.60 Luxatio subcoracoidea. [4]
The procedure according to ARLT requires the injured arm to be posi- This type o f luxation means tha t the head of the Humerus snaps to a
tioned over a cushioned back o f a chair. The physician pulls th e flexed position beneath th e Proc. coracoideus. The dom e o f th e shoulder is
arm in th e direction o f th e H um erus until th e head o f th e H um erus pops reduced and the arm appears longer,
back into the glenoid fossa.

159

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Muscles of shoulder and arm

Fig. 3.61 V entral m uscles of th e shoulder and arm , righ t side;
ventral view.

-►T 2 4 -3 8

160

M uscles -» T o p o g ra p h y -► S ections Muscles of shoulder and arm

M. trapezius Acrom ion
M. infraspinatus M. deltoideus

M. teres minor M. triceps brachii
M . teres m ajor M . brachioradialis

M. latissim us dorsi M . extensor carpi radialis longus
M . extensor carpi radialis brevis
M. anconeus M. extensor digitorum
M. extensor carpi ulnaris M . a b d u cto r pollicis longus
M. extensor p ollicis brevis
M. extensor pollicis longus, Tendo
M m . interossei dorsales

Fig. 3.62 Dorsal m uscles o f th e shoulder and arm , righ t side;
dorsal view.

- * T 24-38

Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► S keleton -► Im a g in g ->

Muscles of the arm

M. trapezius M. sternocleidom astoideus
M . pectoralis m ajor
Spina scapulae M. deltoideus
M. trapezius M. serratus anterior
Fascia infraspinata
M. teres minor M . obliquus externus abdom inis
M. teres major
M. trice p s brachii, C aput longum M. e xtensor carpi radialis longus
M. trice p s brachii, C a pu t laterale M . extensor carpi radialis brevis
M. latissim us dorsi

S e p tu m in te rm u scu la re b ra ch ii la terale

O lecranon
M .anconeus
M . extensor digitorum

M . extensor digitorum , Tendines M. a bd ucto r p ollicis longus
Retinaculum m usculorum extensorum M . extensor p ollicis brevis
M. extensor pollicis longus, Tendo
M m . interossei dorsales
M. adductor pollicis

Fig. 3.63 Muscles of th e arm and thorax, right side; lateral view.
-►T 2 4 -3 8

162

M uscles -» T o p o g ra p h y -► S ections

Rotator cuff

Lig. coracoacrom iale Lig. acrom ioclaviculare
Bursa subacrom ialis brachii, C aput longum , Tendo
M . supraspinatus Lig. trapezoideum
M. deltoideus Lig. coracohum erale
Acrom ion
Fascia p e c to ra l is
M . infraspinatus
Capsula articularis Fascia pectoralis,
(Hiatus venae cephalicae)
M . te res m inor Lig. conoideum
C avitas glenoidalis Proc. coracoideus

Labrum glenoidale (Bursa m usculi coracobrachialis)
Bursa subtendinea
m usculi subscapularis
M . coracobrachialis
M . b icep s brachii, C aput breve

M . subscapularis

M. trice p s brachii, C a pu t longum Fig. 3.64 Shoulder jo in t and shoulder m uscles, righ t side; lateral
view after removal of the M. deltoideus and the Caput humeri.

—►T 2 6 , 28

Fig. 3.65 Muscles of th e rotator cuff; lateral view. Acrom ion Lig. coracoacrom iale
The extensive range o f m o vem en t in the shoulder joint is an essential M . infraspinatus Proc. coracoideus
prerequisite fo r the touch and grip function of the upper extrem ity.
Based on the strong guidance by m uscles and the highly flexible posi­ M . te res m inor M . supraspinatus
tion in g o f th e Scapula, th e shoulder jo in t o n ly requires little sup port by Tuberculum m ajus
bones and ligam ents. H ow ever, w h e n neurom uscular problem s arise,
such as in nerve injuries or w ith a dysbalance b e tw e e n th e ro tator c u ff M . subscapularis
muscles, the contact of the articular surfaces cannot be guaranteed M . b icep s brachii,
anymore. Dislocations occur w hen shear forces act tangentially to the C aput longum , Tendo
Cavitas glenoidalis, in particular during a fall. Humerus, Corpus
The tendons of those m uscles directly adjacent to the shoulder joint
radiate into the joint capsule and form a tough rotator cu ff around the
head of the Humerus. A m ong these m uscles are the M . subscapularis
(ventral), the M . supraspinatus (superior), M . infraspinatus (dorsal su­
perior), and th e M . teres m inor (dorsal inferior). W ith the exception of
th e M. subscapularis, w h ic h inserts on th e Tuberculum m inus, and in
addition to the ir connection to the jo in t capsule, all m uscles o f the rota­
to r c u ff insert at th e Tuberculum majus. The M. deltoideus is not part of
the rotator c u ff because there is no connection to the joint capsule.

Clinical Remarks

In addition to th e ir role in th e various m o ve m e n ts (kinem atics), the th e hum eral head occurs as a result of m uscular imbalance, es­
relevance o f th e ro tator c u ff m uscles is to ensure th e correct posi­ pecially a relative w eakness o f the adductory (inferior) parts o f the
tion o f th e hum eral head in th e glenoid fossa (statics). E levation of m u s c le s .

163

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► S keleton -► Im aging

M uscles of the shoulder girdle

M. trapezius, Pars descendens M . levator scapulae

M . trapezius, M . rhom boideus m inor
Pars transversa M. rhom boideus m ajor

M. trapezius,
Pars ascendens

Figs. 3.66a and b Muscles of th e shoulder girdle, trapezius, the M . levator scapulae, and th e M m . rhomboidei. Ventral
a M . trapezius m uscles are the M . serratus anterior, the M . pectoralis minor, and the
b M . levator scapulae and M m . rhom boidei M. subclavius (-» Fig. 3.68). Fixation o f th e Scapula to th e tru n k is pre­
The shoulder has tw o functional m uscle groups. The m uscles of the dom inantly accom plished by the M . levator scapulae and the M m .
shoulder girdle originating fro m th e Scapula o r clavicle prim arily move rhomboidei, w ith additional support from the M. serratus anterior and
th e shoulder girdle and only indirectly m ove th e arm. In contrast, the the M . trapezius.
m uscles o f the shoulder originating fro m the Humerus directly move The dorsal m uscles o f the shoulder girdle are also illustrated as super­
the arm. These m uscle groups can be subdivided according to their ficial m uscles o f th e back (-* pp. 74 and 75). The ventral m uscles are
position. The dorsal muscles of the shoulder girdle com prise the M. also sho w n w ith th e ventral w all o f th e tru n k (-» pp. 86-88).

—»T 27

164

M uscles -» T o p o g ra p h y -► S ections

M uscles of the shoulder girdle

M. subclavius
M. pectoralis m inor

M. serratus anterior

Figs. 3.66c and d Muscles of th e shoulder girdle, ing as auxiliary m uscle of inspiration sim ilar to th e M . serratus anterior.
c M . serratus anterior The M . subclavius acts as an active strap in the stabilisation o f the
d M . pectoralis m inor and M . subclavius sternoclavicular joint.
M. serratus anterior, M . pectoralis minor, and M . subclavius belong to The dorsal m uscles are also illustrated as superficial m uscles of the
the ventral m uscles o f the shoulder girdle. The main function o f the M. back (-* pp. 74 and 75). The ventral m uscles are shown w ith the ventral
serratus anterior and the M. trapezius is the rotation o f the Scapula, a w all o f th e tru n k (-» pp. 86 - 88).
require m en t fo r th e elevation o f th e arm above th e horizontal plane. In
addition to its fun ction in low ering th e Scapula, th e M . pectoralis m inor -► T24
supports the elevation o f the ribs w hen the arm is fixed, thus, function­

165

Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Muscles of the shoulder

M. latissim us dorsi

M . subscapularis

s

Figs. 3.67a to c Muscles of the shoulder, The M . latissimus dorsi enables a strong retroversion m ovem ent of
a M . latissimus dorsi the anteverted arm (such as raising the trunk to the arm w hen clim bing
b M . infraspinatus, M . teres minor, M . teres m ajor o r pe rform ing chin-ups). H ow ever, w ith th e arm s fixed its action aids in
c M . subscapularis th e com pression o f th e tho rax (e.g. w h e n coughing; pa tients w ith
In con trast to m uscles o f th e shoulder girdle, shoulder m uscles directly COPD develop a strong M . latissim us dorsi).
act on the arm. They can be subdivided into a dorsal and a ventral group The M . subscapularis is th e m o s t im po rtan t m edial rotator o f th e arm
o f m uscles and an additional lateral group o f m uscles w hich is defined and its action is necessary in order to cross w h e n crossing th e arms
as a part o f the dorsal group in som e textbooks. The group o f dorsal behind the back. Its fun ctiona l antagonist is th e M . infraspinatus en­
shoulder m uscles com prises the M. latissim us dorsi, M. infraspinatus, abling a strong lateral rotation o f the arm. M. teres m ajor and M . teres
M. teres m inor, M . teres major, and M . subscapularis, the only muscle m inor are functionally less im portant on their ow n but support the ac­
o f th is group positioned on th e ventral side o f th e Scapula. tion of the other shoulder muscles.

T 28

166

M uscles -» T o p o g ra p h y -► S ections

M uscles of shoulder and shoulder girdle

M. supraspinatus M . deltoideus,
Pars clavicularis
M. deltoideus,
Pars spinalis M . deltoideus,
Pars acrom ialis

M . pectoralis major, M . p e c to ra lis major,
Pars clavicularis Pars sternocostalis

Figs. 3.67d to f Muscles of th e shoulder, M . p ectoralis major,
d M. supraspinatus Pars abdom inalis
e M. deltoideus
f M . pectoralis m ajor
The group of lateral shoulder m uscles com prises the M. supraspinatus
and th e M . deltoideus. The M . pectoralis m ajor is th e o n ly one in a
ventral position. The M . pectoralis m ajor is th e stro nge st m uscle fo r
anteversion and adduction o f the arm. Its action is essential to cross
th e arm s in fro n t o f th e tru n k (ventrally). In addition to th e M . latissim us
dorsi, the M . pectoralis m ajor supports a strong retroversion m ovem ent
of the arm w hen started from an anteverted position.
The M . delto ideu s is th e m o st im po rtan t ab ducto r o f th e arm and sup­
ports all o th e r m o ve m e n ts o f th e shoulder jo in t through its fun ctiona lly
distinct parts. The M . supraspinatus supports the action of the M.
deltoideus in abduction.

-♦ T 25, 26

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

M uscles of shoulder and shoulder girdle

M . pectoralis m ajor M . trapezius
M . levator scapulae
M . delto id eu s M. scalenus m edius
M. b icep s brachii, M. scalenus anterior

C aput longum M . scalenus posterior
M . om ohyoideus, Venter inferior

M . biceps brachii, Mm. sternocleidom astoidei
C aput breve M . subclavius
M m . intercostales interni
M. coracobrachialis M m . intercostales externi
M . te res m ajor
M . subscapularis

M . s erratu s an terio r

M . latissim us dorsi M . pectoralis m inor
M. pectoralis major

M. rectus abdom inis

M. o bliquus externus
abdom inis

Fig. 3.68 Muscles of th e shoulder girdle and th e shoulder, right tion o f the M . trapezius are illustrated. The M. pectoralis m ino r is reflec­
side; ventral view , corresponding ribs are labeled w ith Roman ted anteriorly to provide a better vie w of the M. serratus anterior and its
numerals. origins on ribs I to IX. The abduction position o f th e arm allow s a good
This ventral vie w mainly show s the ventral m uscle group o f the shoul­ vie w of the M . subscapularis w hich broadly covers the ventral area of
der girdle (M. serratus anterior, M . pectoralis m inor, and M. subclavius). th e Scapula.
O f the dorsal group, only the M . levator scapulae and part o f th e inser­

M. biceps brachii C a pu t longum H u m e ru s
C aput breve
Lig. c o ra c o a c ro m ia le
Clavicula
A crom ion
Proc. coracoideus M. infraspinatus
A rticulatio acrom ioclavicularis
N. suprascapularis
Lig. transversum scapulae superius

M. subscapularis
M . supraspinatus

Fig. 3.69 Position o f th e M . supraspinatus in relation to th e roof o f th e shoulder. Therefore th e ten don can be com pressed in abducted
of the shoulder. position of the arm and frequently painful degenerative conditions of
A crom ion and Proc. coracoideus form the roof o f the shoulder. They the supraspinatus tendon are observed.
are connected by the Lig. coracoacromiale. Prior to its insertion into the
joint capsule, the tendon of M. supraspinatus courses beneath the roof —>T 26, 28, 29

168

M uscles -» T o p o g ra p h y -► S ections

M uscles of shoulder and shoulder girdle

Clavicula M. subclavius
Proc. coracoideus
M . trapezius
A rticulatio acrom ioclavicularis
Lig. coracoclaviculare, Lig. trapezoideum
Lig. coracoacrom iale Lig. coracoclaviculare, Lig. conoideum
M . pectoralis m inor M. levator scapulae
M. biceps brachii, C aput breve M. om ohyoideus, Venter inferior
M . coracobrachialis M . serratus anterior
M. rhom boideus m inor
Q uad rangular axillary space M . supraspinatus
M . latissim us dorsi, Tendo Lig. transversum scapulae
s u p e riu s
T riang ular axillary space
M . tric e p s brachii, C aput laterale M . subscapularis

M. b icep s brachii, C a pu t longum M. rhom boideus m ajor

M. coracobrachialis M . te res m ajor
M. serratus anterior

3 70 M . biceps brachii, C aput breve C ap u t longum

M. levator scapulae M. om ohyoideus,
M. trapezius Venter inferior
M . rhom boideus m inor
M . supraspinatus Acrom ion
S pina scapulae Bursa subdeltoidea
M . deltoideus
Hum erus

M. rhom boideus m ajor A rticulatio humeri
M . infraspinatus Q u ad ran g u lar axillary space
M . te res m inor
T riang ular axillary space M . tric ep s brachii,
M . te res m a jo r C ap u t longum
M . latissim us dorsi

_ M . serratus

Fig. 3.70 and Fig. 3.71 M uscles of th e shoulder girdle and th e This illustration also visualises the axillary gaps betw een M. teres major
shoulder, rig h t side; ventral (-► Fig. 3.70) and dorsal (-» Fig. 3.71) and M . teres m inor w ith the Hum erus as their lateral border. Both m u­
view. scles diverge in a Y-shaped w a y fro m th e ir origins on th e Scapula and
Except fo r their origins, the muscles o f th e shoulder girdle are removed leave a gap w hich is divided by the long head o f the M . triceps brachii
to visualise the shoulder muscles. The ventral vie w particularly show s into a m edially positioned triangular axillary space (Spatium axillare
the com plete course o f the M. subscapularis and the M . teres major. mediale) and the laterally positioned quadrangular axillary space
From its origin at the Angulus inferior o f the Scapula, the latter crosses (Spatium axillare laterale). The (medial) triangular axillary space serves
the Humerus anteriorly before inserting on the Crista tuberculi minoris. as passage fo r th e A. and V. circum flexa scapulae to th e dorsal side of
On th e dorsal side o f th e Scapula, th e M. supraspinatus is in part co­ th e Scapula. The (lateral) quadrangular axillary space is traversed by the
vered by the M . trapezius and courses (not visible here) under the roof N. axillaris and by th e A. and V. circum flexa hum eri posterior.
o f the shoulder to insert on the upper portion o f the Tuberculum majus.
Beneath are the insertions of M. infraspinatus and M. teres minor. —►T 25, 2 6 ,2 8 , 30

169

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Muscles of the upper arm

M. coracobrachialis

C a pu t longum C a pu t laterale
C aput m ediale

M .anconeus

3.72a C aput longum C aput breve

A poneurosis m usculi b icip itis brachii

3.72b

Figs. 3.72a and b Ventral muscles of the In contrast to th e M. coracobrachialis and M. Fig. 3.73 Dorsal muscles of th e upper
upper arm , right side; ventral view, brachialis, both the M. biceps brachii and the arm, M. triceps brachii and M. anconeus,
a M . coracobrachialis and M . brachialis M. trice ps brachii (-» Fig. 3.73) span tw o right side; dorsal view.
b M . biceps brachii joints and thus are able to prom ote move­ The M. triceps brachii is positioned on the dor­
The ventrally positioned M. coracobrachialis m e nts in th e shoulder and th e e lb o w joints. sal side of the upper arm. Its Caput longum
has its origins at the Proc. coracoideus and in­ The M. triceps brachii is the m ost im portant originates fro m the Tuberculum infraglenoida-
serts m edially at th e H um erus. In contrast to m uscle on th e dorsal side o f th e arm. The Ca­ le, w hereas th e Caput laterale and Caput m e­
the other tw o ventral m uscles of the upper put breve of the M. biceps brachii originates diate have a broad origin on the dorsal side of
arm , its action is re stricted to th e shoulder fro m the Proc. coracoideus and has sim ilar th e H um erus. In addition to its supportive
joint contributing to m ovem ents of adduction, fu n c tio n s as th e M. coracobrachialis. The Ca­ fun ction in adduction and retroversion o f the
medial rotation, and anteversion w ith o u t a put longum originates fro m the Tuberculum shoulder joint, th e M. triceps brachii is the
major im pact on these m ovem ents of the supraglenoidale o f th e Scapula and fun ctions m ost im portant extensor of the elbow
arm. Originating distally from the anterior sur­ as abductor of the arm. However, its m ost im­ jo in t due to its com m on insertion on the Ole­
face of the Humerus, the M . brachialis inserts portant action is on the elbo w joint. W ith its cranon. This fu n ctio n is sup ported to a certain
into th e joint capsule and the Tuberositas ul­ m ajor insertion at th e Tuberositas radii, th e M. extent by the action of the M. anconeus which
nae. The M . brachialis exclusively acts on the biceps brachii serves as the m ost im portant spans fro m th e Condylus lateralis o f the Hu­
elbow jo in t by supporting its flexion. fle xo r in th e e lb o w jo in t and th e stro nge st merus to the Olecranon and the dorsal side of
su pin ato r o f th e fo re arm in a flexe d position. th e Ulna.

- f T 29, 30

170

M uscles -► T o p o g ra p h y -► S ections Muscles of the upper arm

Clavicula M. supraspinatus
M. subclavius M. om ohyoideus, Venter inferior
Lig. coracoclaviculare Lig. transversum scapulae superius
Proc. coracoideus M. subscapularis
M. pectoralis m inor M. teres m ajor
M . coracobrachialis
M. deltoideus M . tric e p s brachii, C aput longum

M. p ectoralis major, Tendo M . trice p s brachii, C aput m ediale
S eptum interm usculare brachii m ediale
M . b ic e p s b ra c h ii, C aput longum M . brachialis
M . b ice p s b ra ch ii, C aput breve Epicondylus medialis
A poneurosis m usculi bicipitis brachii
M . brachialis Fascia antebrachii
M . biceps brachii, Tendo

Fig. 3.74 V entral m uscles of th e upper arm , rig h t side; ventral berositas radii, the Aponeurosis m usculi bicipitis brachii radiates into
view. th e fascia o f th e forearm (Fascia antebrachii). The M . brachialis is posi­
The M . coracobrachialis is positioned ventrally to the M . biceps brachii. tioned beneath the M. biceps brachii and is only visible w ith its muscle
The short head (Caput breve) of the M . biceps brachii originates from belly on both sides of the biceps tendon.
the Proc. coracoideus, the long head (Caput longum) from the Tubercu-
lum supraglenoidale. In addition to its principal insertion site at th e Tu­ -► T 29, 30

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Muscles of the upper arm

M. C lavicula
M. pectoralis m inor M. subscapularis
M. deltoideus
M . coracobrachialis
Vagina tendinis intertubercularis M. trice p s brachii, C aput longum
M . b ice p s b ra ch ii, C aput breve
M . b ic e p s b ra c h ii, C aput longum

N . m usculocutaneus
M. deltoideus

C orpus humeri

M . brachialis M. triceps brachii, C aput mediate
M. brachioradialis S eptum interm usculare brachii mediate

E picondylus m edialis
Fascia antebrachii
A poneurosis m usculi b icip itis brachii

M. biceps brachii

Fig. 3.75 Ventral muscles of th e upper arm , right side; ventral by the N. m usculocutaneus, the nerve w hich innervates all three m us­
view ; after removal o f the M. biceps brachii. cles o f the ventral side of the upper arm (M. biceps brachii, M. coraco­
The M . biceps brachii w as rem oved to dem onstrate the underlying M. brachialis, and M . brachialis).
brachialis. The M . coracobrachialis is easily identified since it is pierced
-► T 29, 30

172

M uscles -» T o p o g ra p h y -► S ections Muscles of the upper arm

M. supraspinatus M. trapezius
Clavicula
Fascia infraspinata
M . te res m ajor M . delto id eu s
M . pectoralis m ajor
M . latissim us dorsi
M . tric e p s b ra c h ii, C a pu t longum M . biceps brachii
M . tric e p s b ra c h ii, C a pu t laterale M . brachialis

S eptum interm usculare brachii laterale M . brachioradialis
M . trice p s brachii, C aput mediale M . e x te n s o r carp i radialis longus
E p ic o n d y lu s M . e xten s o r c arp i radialis brevis
O lecranon

Fig. 3.76 Dorsal m uscles o f th e shoulder and upper arm , and radial exte nsor m uscles o f th e forearm have th e ir origins on th e lateral
ventral m uscles of th e upper arm , righ t side; dorsolateral view . aspect of the distal upper arm. From proxim ally to distally, these com ­
The M. triceps brachii alm ost com pletely covers the posterior aspect of prise the M . brachioradialis, M . extensor carpi radialis longus, and M.
the upper arm. Visible here are Caput longum and Caput laterale which extensor carpi radialis brevis. The follow ing shoulder m uscles are also
both cover the Caput mediale. All three heads o f this m uscle have a visible here: M . deltoideus, M. teres major, M. latissim us dorsi and M.
com m on insertion at the Olecranon. The M. triceps brachii is separated supraspinatus.
by the Septum interm usculare laterale fro m the flexor m uscles (M. bra-
chialis, M. biceps brachii) on the ventral side o f the upper arm. The —►T 26, 28, 29, 33

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Muscles of the upper arm

M. infraspinatus M. deltoideus
M . tric ep s brachii,
M. teres minor
C a p u t longum H um erus
M. teres minor M . biceps brachii, C aput longum ,
Tendo
T riang ular axillary gap M . pectoralis major, Tendo
Q uad rangular axillary gap
M . deltoideus
M . te res m ajor
Triceps slit S ulcus nervi radialis

M . triceps brachii, C a p u t laterale M. biceps brachii
M . brachialis
M . tric ep s b rachii, C a p u t m ediale M. brachioradialis

S eptum interm usculare brachii laterale M. extensor carpi radialis longus
M . trice p s brachii, Tendo
O lecranon M. extensor carpi radialis brevis
M. anconeus

Fig. 3.77 Dorsal muscles of th e shoulder and upper arm , right triangular and the quadrangular spaces (axillary gaps) are visible
side; dorsolateral view ; the Caput laterale of the M. triceps brachii b e tw e e n th e M . teres m inor and M. teres m ajor (-» Figs. 3.70 and
w as cut. 3.71), w hich are separated by the Caput longum. Distal of the M . teres
The Caput longum of the M. triceps brachii originates from the Tuber­ m ajor th e triceps slit is visible w h ich is used by th e N. radialis to reach
culum infraglenoidale o f the Scapula. The Caput laterale originates pro­ the dorsal side o f the Humerus.
xim al and lateral o f th e Sulcus nervi radialis. W hen th e Caput laterale is
cut open, the Caput mediale can be seen w hich originates from the -►T 28, 30
H um erus distal and m edial o f th e Sulcus nervi radialis. In addition, the

174

M uscles -» T o p o g ra p h y -► S ections 3

Muscles of the forearm

M. flexor
carpi ulnaris

M. palm aris
longus

M. flexor carpi M. flexor
d ig ito ru m
M. p ro fu n d u s
pollicis longus

M . fle xor digitorum
s u p e rfic ia lis

Figs. 3.78a to d V entral muscles of th e fo re arm , righ t side; ulnar abduction and th e M. fle xo r carpi radialis enables radial abduction,
ventral view. b m iddle layer
The flexors of the forearm are positioned on the ventral side. They are The M . flexor digitorum superficialis m akes up the m iddle layer. The
separated by the radial and ulnar neurovascular bundles into a super­ tendons of its fo u r parts insert on the palmar aspects of th e m iddle
ficial and a deep group o f m uscles. Each o f th e se tw o groups consists phalanges o f the second to fifth fingers. Thus, this m uscle also flexes
again of tw o layers, thus, four distinct layers can be separated: the m iddle interphalangeal joints and, w ith lesser strength, the m e­
• superficial layer tacarpo phalan geal joints, in addition to its sup port in flexion o f the
• m iddle layer elbow and w rist joints,
• deep layer c deep layer
• deepest layer The deep layer com prises th e M . fle xo r pollicis longus on th e radial
a superficial layer side and the M . flexor digitorum profundus on th e ulnar side. Both
From radial to ulnar, th e superficial layer consists o f M . pronator teres, m uscles originate from the ventral aspect of the bones of the forearm
M . flexo r carpi radialis, M . palmaris longus, and M . flexor carpi ulnaris. A s their tendons reach the palmar aspects of the distal phalanges, they
All these m uscles have their origin at the Epicondylus m edialis of the do not act on the elbow joint but flex the w rist and the distal interpha­
Humerus and function as flexors of the elbow joint and, w ith the ex­ langeal joints of fingers and th um b and to a lesser extent the m eta­
ception o f the M. pronator teres, also of the w rist. The M . pronator carpophalangeal and proximal interphalangeal joints,
teres crosses th e diagonal axis o f th e forearm and th e re fo re is the d deepest layer
m ost im p o rta n t pronator, to g e th e r w ith th e M. pronator quadratus in Beneath the tendons of the long flexor m uscles of the forearm the M.
the deepest layer. The M . palmaris longus may be m issing uni- or bila­ p ron ato r quadratus connects th e ventral aspects o f Radius and Ulna.
terally in up to 20% o f the people and functions in stretching the palmar
aponeurosis in addition to flexing th e w ris t. W hen acting to g e th e r w ith —» T 31, 32
its antagonist on the extensor side, the M. flexor carpiulnaris mediates

175

Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Muscles of the forearm

Mi

M. biceps brachii M. trice p s brachii,
C aput m ediale
A poneurosis m usculi b icip itis brachii
M. biceps brachii, Tendo S eptum interm usculare
brachii m ediale
M. brachialis

E picondylus medialis
M . pronator teres

M. brachioradialis M . p a lm a ris longus
M . fle x o r c arp i radialis
M . extensor carpi radialis brevis M . fle x o r carpi ulnaris
M. extensor carpi radialis longus M . fle x o r d igitorum superficialis
M . fle x o r dig ito ru m superficialis
M . fle x o r c arp i ulnaris, Tendo
M. a b d u cto r pollicis longus M . p alm aris longus, Tendo
M. brachioradialis, Tendo
M. fle xor pollicis longus fle x o r c arp i radialis, Tendo

M . a b d u cto r pollicis longus, Tendo
M. pronator quadratus

Retinaculum m usculorum extensorum

Fig. 3.79 Superficial layer of th e ventral muscles of th e forearm , group o f m uscles of the forearm functionally belongs to the extensors
righ t side; ventral view . o f the w ris t and lies on the radial side in relation to the superficial
From radial to ulnar, the superficial m uscle layer o f the forearm consists flexors.
o f M . pronator teres, M . flexo r carpi radialis, M . palmaris longus, and M.
flexor carpi ulnaris. Parts of the M . flexor digitorum s u p e rfic ia l of the —►T 31
m iddle layer are visible betw een th e M . palmaris longus and M. flexor
carpi ulnaris and b e tw een th e ten don s o f th e o th e r m uscles. The radial

176

M uscles -» T o p o g ra p h y -► S ections

Muscles of the forearm

M. brachialis M. trice p s brachii,
C aput mediale
M. brachioradialis
M. brachialis, Tendo S eptum interm usculare
brachii m ediale
M. supinator
Bursa bicipitoradialis E picondylus medialis

M. extensor carpi radialis longus M. biceps brachii, Tendo
M . pronator teres
M . p a lm a ris longus
M . fle x o r dig ito ru m superficialis, M . fle x o r carpi ulnaris
C a p u t radiale M . fle x o r carp i radialis
M . fle x o r dig ito ru m superficialis,
M. abd ucto r pollicis longus C aput hum eroulnare
M. fle xor p ollicis longus
M. pronator quadratus M . fle x o r d igitorum superficialis

M . extensor p ollicis brevis, M . fle x o r c arp i radialis, Tendo
Tendo M . palm aris longus, Tendo

M. brachioradialis, Tendo

Fig. 3.80 M iddle layer of th e ventral muscles of th e forearm , M . flexor digitorum superficialis originates from the Epicondylus medi-
righ t side; ventral view ; M. flexo r carpi radialis and M . palmaris alis o f the Hum erus and fro m the Proc. coronoideus o f the ulna. Its
longus w ere partially removed. Caput radiale has its origin at th e anterior aspect o f the Radius.
The M . pronator teres is visible in its full length after removal o f the S trictly speaking, the diffe ren t m uscle bulges of M . flexor digitorum
Aponeurosis m usculi bicipitis brachii and reflection of the M . brachiora- superficialis are not positioned exactly in one plane. Thus, th is illustra­
dialis. Beneath the superficial flexors, the m iddle layer of ventral m us­ tion only show s th e m uscle parts fo r the third and fourth fingers w hich
cles o f th e forearm is visible w h ic h consists o f th e fo u r m uscle bellies cover the m uscle parts of the second and fifth fingers.
of the M . flexor digitorum superficialis. Its w hole dim ension can only be
appreciated upon removal or deviation of the M . flexor carpi radialis and —» T 31
M. palmaris longus, as illustrated here. The Caput hum eroulnare o f the

177

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Muscles of the forearm

M. brachialis M. trice p s brachii,
M. brachioradialis C aput mediale

S eptum interm usculare
brachii mediale

M. supinator Epicondylus medialis
M. biceps brachii, Tendo M . pronator teres

M. extensor carpi radialis longus M . fle x o r c arp i radialis
M . p a lm a ris longus

M . pronator teres M . fle x o r c arp i ulnaris
M . fle x o r dig ito ru m superficialis

M . a bd ucto r pollicis longus M . fle x o r c arp i radialis, Tendo
M . p alm aris longus, Tendo
M . fle xor pollicis longus

M. pronator quadratus
M. a bd ucto r p ollicis longus, Tendo

M. brachioradialis, Tendo

Fig. 3.81 M iddle layer of th e ventral muscles of th e forearm , cialis. The Caput humeroulnare originates from the Epicondylus media-
righ t side; ventral v ie w ; M . fle x o r carpi radialis, M . palm aris longus, lis o f the Hum erus and fro m the Proc. coronoideus o f th e Ulna. The
and M. pronator teres w ere alm ost com pletely removed. Caput radiale has its origin at the anterior aspect o f the Radius.
In contrast to th e illustration in -» Fig. 3.80, th e M . pronator teres w as
also cut to dem onstrate the origins of the M. flexor digitorum superfi- —►T 31

i- Clinical Remarks------------------------------------ w rite r's cramp, and som etim es only a single m uscle belly such as of
the M. flexor digitorum superficialis. To enable targeted treatm ent,
A bn orm al increase in m uscle to n e in th e fo rm of spasticity may such as the inhibition o f signal transm ission at the m otor end plates
occur a fte r stroke o r dam age to th e central nervous system (CNS). by injection of botulinum toxin, a very precise understanding of the
An increase in m uscle ton e may also occur w ith o u t m ajor injury w ith function and the topography o f the m uscles is necessary.
dystonia. Spasticity often affects entire m uscle groups. However,
dystonia m ay a ffe c t selectively individual fle x o r m uscles, such as in

178

M uscles -» T o p o g ra p h y -► S ections Muscles of the forearm

M. brachialis S eptum interm usculare
brachii m ediale

M. biceps brachii, Tendo Epicondylus medialis
M. supinator
M. p ro na tor teres, C a pu t ulnare
Radius, Facies anterior M. fle xor d igitorum superficialis
M . extensor carpi radialis longus
A .; V. in te ro sse a p o s te rio r
M. p ronator teres M. flexor digitorum profundus
M . fle x o r pollicis longus,
M . fle x o r p ollicis longus C a p u t h u m e r o u ln a r e (Var.)
M . fle xor digitorum superficialis, M. fle xor carpi ulnaris

C aput radiale M. fle xor d igitorum profundus,
Tendines
M . fle xo r pollicis longus, Tendo
M. brachioradialis, Tendo M. fle xor d igitorum superficialis,
Tendines
M . pronator quadratus M. palm aris longus, Tendo
M. fle xor carpi radialis, Tendo

Fig. 3.82 Deep and deepest layer of th e ventral muscles of the o f the Radius and in up to 40% o f all cases w ith an additional Caput
forearm , right side; ventral view ; after removal of the superficial humeroulnare from the Epicondylus m edialis and the Proc. coronoide-
flexors. us. The M . pronator quadratus is covered by th e ten don s o f th e flexor
W ith th e rem oval o f all superficial flexors, th e deep flexo rs becom e m uscles and connects Radius and Ulna at the distal forearm .
visible as show n here. The M. flexo r digitorum profundus has its origin
at the anterior aspect o f the Ulna and the M em brana interossea ante- T 32
brachii. The M . flexor pollicis longus originates fro m the anterior aspect

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Muscles of the forearm

M. supinator

M . extensor digitorum

M . extensor digiti
m inim i

M . extensor carpi
ulnaris

M . brachioradialis

M . extensor carpi
radialis longus

M . extensor carpi
radialis brevis

M . extensor M. abductor
p ollicis longus pollicis longus

M. extensor M . extensor 3.84c
in d ic is pollicis brevis
3.84a

3.84b

Fig. 3.83 Radial muscles of th e forearm , right side; dorsal view. extensor carpi ulnaris. The M. extensor digitorum and M . extensor digi­
From proxim al to distal, th e radial group o f m uscles com prises the M. ti m inim i radiate into the dorsal aponeuroses of digits tw o to five.
brachioradialis and the M m . extensores carpi radialis longus and brevis. Therefore, these m uscles serve as extensors of the w rist, the metacar­
These m uscles originate fro m the lateral aspect of the Hum erus and pophalangeal joints, and th e proximal interphalangeal joints. As the dor­
run anterior to the transversal axis o f the elbow joint w hich m akes them sal aponeurosis ends at the m iddle phalanges, these m uscles do not
flexors of this joint. The M. brachioradialis inserts at the distal end of participate in extension o f th e distal interphalangeal joints,
the Radius and, thus, only spans one joint. Its function depends on the b and c deep layer
given position of the forearm and may support supination or pronation. From radial to ulnar, the distal layer consists o f the M. abductor pollicis
The M m . extensores carpi radialis longus and brevis function as exten­ longus, M . extensor pollicis brevis, M . extensor pollicis longus, and M.
sors o f the w ris t joints and enable radial abduction. exte nsor indicis H Fig. 3.84b). The M. ab ducto r pollicis longus abducts
in the saddle jo in t o f the thum b, and the M m . extensores pollicis brevis
—►T 33 and longus extend this join t as w ell as the interphalangeal joint of the
thum b. The M . extensor indicis extends the metacarpophalangeal and
Figs. 3.84a to c Dorsal muscles of th e forearm , right side; dorsal the proximal interphalangeal joints of the index finger. Proximal, the
view. deep layer of extensor m uscles com prises the M . supinator
a superficial layer (-► Fig. 3.84c) w h ich w in d s around th e Radius. It is the stro n g e st supi­
All superficial extensors have a com m on origin at the Epicondylus late­ nator during extension of the elbow joint.
ralis. Excessive use o f th e exte nsor ten don s may cause intensive pain
in th e e lb o w ("te n n is e lb o w "). From radial to ulnar, th is m uscle group —* T 34, 35
com prises the M . extensor digitorum , M. extensor digiti minim i, and M.

180

M uscles -► T o p o g ra p h y -► S ections

Muscles of the forearm

M . tric e p s brachii, C a pu t laterale M. biceps brachii
S eptum interm usculare brachii laterale M. brachialis
M . brachioradialis
M. trice p s brachii, C aput m ediale M . e x te n s o r c arp i ra d ia lis longus
E picondylus lateralis
O lecranon
M .anconeus M . e xten s o r c arp i radialis brevis

M . fle xor carpi ulnaris

M. extensor p ollicis brevis M. a bd ucto r p ollicis longus

M . exten s o r digitorum , M. a bd ucto r p ollicis longus, Tendo
Tendines M. extensor pollicis brevis, Tendo
Radius
M . e xten s o r digiti m inim i,
Tendo

M . exten s o r carpi ulnaris
Ulna

M . e xtensor p ollicis longus, Tendo
Retinaculum m usculorum
e x te n s o ru m

Fig. 3.85 Superficial layer of th e dorsal m uscles of th e forearm are visible (thus, they are not com pletely covered by the superficial
and distal part of upper arm , right side; lateral view. extensors). In th is illustration, th e fascia o f th e M. anconeus at th e dis­
The lateral v ie w best show s the radial group of muscles. From proxi­ tal part of the upper arm w as removed. The M . anconeus belongs to
mal to distal there are the M . brachioradialis, and the M m . extensores the extensor m uscles of the upper arm.
carpi radialis longus and brevis. Further to the ulnar side, the superfi­
cial extensor m uscles are positioned (M . exte nsor digitorum , M. -» T 33-35
extensor digiti m inim i, and M. extensor carpi ulnaris). D istally betw een
these m uscle groups the distal parts of the deep extensor muscles

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Muscles of the forearm

M. trice p s brachii, M. brachialis
C aput laterale M . brachioradialis
M. e xtensor carpi radialis longus
S eptum interm usculare
brachii laterale E picondylus lateralis

M . trice p s brachii, C aput mediale M. e xtensor carpi radialis brevis

O lecranon
M .anconeus

M. fle xor carpi ulnaris

M . e xten s o r c arp i ulnaris M . exten s o r digitorum
M . e xten s o r digiti m inim i
M . a bd ucto r pollicis longus
U ln a
R etinaculum m usculorum M. extensor pollicis brevis
M. e xtensor digitorum , Tendines
e x te n s o ru m M. extensor carpi radialis brevis, Tendo
M. extensor carpi radialis longus, Tendo
Radius

Fig. 3.86 Superficial layer of th e dorsal muscles of th e forearm On th e ulnar side, the M. flexor carpi ulnaris of the superficial flexor
and distal part of upper arm , right side; dorsal view. group is adjacent to th e M . exte nsor carpi ulnaris.
The superficial extensor muscles of the forearm com prise the M . ex­
tensor digitorum , M . extensor digiti m inim i, and M . extensor carpi ulna­ —►T 34
ris.

182

M uscles -» T o p o g ra p h y -► S ections Muscles of the forearm

M . trice p s brachii, Tendo S eptum interm usculare brachii laterale
M . triceps brachii, C aput m ediale M . brachioradialis
E picondylus lateralis
O lecranon M. extensor carpi radialis longus
M .anconeus
Mm . extensores d igitorum et d igiti m inim i
M. fle xor carpi ulnaris M. e xtensor carpi radialis brevis
M. extensor carpi ulnaris M . supinator
Radius
M . e x te n s o r d ig ito ru m , Tendines M. p ronator teres, Tendo
M . exten s o r carpi ulnaris, Tendo M . a b d u c to r pollicis longus

Ulna M . e x te n s o r pollicis longus
M . e x te n s o r indicis
R etinaculum m usculorum extensorum M . e xten s o r pollicis brevis
M . exten s o r carpi ulnaris, Tendo Radius
M . exten s o r digiti m inim i, Tendo M . e xten s o r c arp i radialis brevis, Tendo

M . e xten s o r carpi radialis longus, Tendo
M . exten s o r pollicis brevis, Tendo

exten s o r pollicis longus, Tendo

Fig. 3.87 Deep layer o f th e dorsal muscles of th e fo re arm , right Osseofibrous tunnels on the dorsum of the hand, from radial to
side; dorsal view ; after partial removal of the M m . extensores ulnar:
digitorum and digiti minimi. • first tunnel: M. abductor pollicis longus and M. extensor pollicis
Removal of the superficial extensors of the forearm enables the view
o f proximal parts of the deep extensor m uscles. The deep layer con­ brevis
sists proxim ally o f th e M . supinator, and distally fro m radial to ulnar of • second tunnel: M m . extensores carpi radialis longus and brevis
the M. abductor pollicis longus, M . extensor pollicis brevis, M . extensor • third tunnel: M. extensor pollicis longus
pollicis longus, and M . extensor indicis. • fourth tunnel: M. extensor digitorum and M . extensor indicis
The Retinaculum m usculorum extensorum form s six osseofibrous • fifth tunnel: M . extensor digiti minimi
tunnels fo r the passage o f the extensor m uscle tendons to the dorsum • sixth tunnel: M. extensor carpi ulnaris
of the hand. This illustration show s the third, fourth, and fifth osseofib­
rous tunnel cut open. —» T 35

3 Upper Extremity S urface a n a to m y -► D e ve lo p m e n t -► Skeleton -► Im aging

Muscles of the forearm

O lecranon Lig. c o lla te ra le ra d ia le
E picondylus lateralis Lig. a n u lare radii
M. e xtensor carpi radialis brevis
M. anconeus
M . supinator
M. fle xor carpi ulnaris
C o rp u s radii
C orpus ulnae M . p ronator teres, Tendo

M . e x te n s o r pollicis longus M . a b d u c to r pollicis longus

M . e xten s o r indicis e xten s o r pollicis brevis
M em b ran a interossea antebrachii a b d u cto r pollicis longus, Tendo
M. extensor pollicis brevis, Tendo
M . e xtensor carpi ulnaris, Tendo e xtensor carpi radialis brevis, Tendo
C aput ulnae

R etinaculum m usculorum extensorum

Fig. 3.88 Deep layer of th e dorsal muscles of th e forearm , right side o f Radius and Ulna and fro m the M em brana interossea antebra-
side; dorsal view ; after com plete removal of the superficial extensor chii. Their tendons pass through the firs t osseofibrous tunnel. The tw o
m u s c le s . m uscles on th e ulnar side (M. extensor pollicis longus and M. extensor
Superficial extensor m uscles have been com pletely rem oved to visua­ indicis) originate exclusively fro m the Ulna and th e M em brana interos­
lise the origins of the deep extensor muscles. The M . supinator origins sea. Their tendons pass through the third and fourth osseofibrous tun­
fro m th e Epicondylus lateralis o f th e H um erus, th e radial ligam ents (Lig. nel, respectively. The illustration here show s all osseofibrous tunnels
c o lla te ra l radiale and Lig. anulare radii) and fro m th e Crista m. supina- opened.
toris o f the Ulna. The m uscle then w inds around the Radius above and
be lo w the Tuberositas radii. Both m uscles on th e radial side (M . abduc­ —►T 35
to r pollicis longus, M . extensor pollicis brevis) originate from the dorsal

184

M uscles -» T o p o g ra p h y -» S ections

Muscles of the forearm

M . brachioradialis N. m edianus M. brachioradialis H u m e ru s
M . biceps brachii M. biceps brachii
N . m edianus
N . r a d ia lis , R. p ro fu n d u s N. radialis,
M . biceps brachii, M . pronator teres,
Tendo M. palm aris longus C ap u t ulnare
M . supinator M . pronator quadratus M . pronator teres,
M. pronator teres C a p u t hum erale
M. fle xor carpi radialis M . palm aris longus
Radius M. fle xor carpi radialis

M. pronator quadratus

Fig. 3.89 Forearm , A ntebrach ium , in supination position, righ t Fig. 3.90 Forearm , A ntebrach ium , in pron ation position, righ t
side; ventral and palm ar view. A rrow s indicate the traction vectors for side; ventral v ie w near th e e lb o w and dorsal v ie w near th e hand.
th e m ost im portant supinators. A rrow s indicate the traction vectors for the m ost im portant pronators.
In general, all m uscles capable o f prom otin g pronation o r supination The m ost im portant pronators are the M .pronator teres, M. pronator
cross th e diagonal axis of th e forearm (-» Fig. 3.8) w hich corresponds- quadratus, and M . brachioradialis (from a supinated position). The M.
its rotational axis. In addition, all im po rtan t supinator and pronator m us­ flexor carpi radialis and M . palmaris longus also w eakly prom ote prona­
cles insert on th e Radius. Im portant supinators are the M . biceps bra­ tion.
chii (from a flexed position), M . supinator (w ith extended arm), and M. The N. m edianus passes b e tw e e n th e tw o heads o f th e M . pronator
brachioradialis (from a pronated position). The M. supinator is pierced teres b u t is rarely com pressed at th is location (-» p. 205).
by th e Ramus profundus o f th e radial nerve (N. radialis) w h ic h m ay be
com pressed at this location w ith resulting paralysis of the deep exten­ -» T 32, 33, 35
sor m uscles (-» p. 203).

Upper Extremity S urface a n a to m y -» D e ve lo p m e n t -► Skeleton -» Im aging

Tendons of the dorsum of the hand

M . e xten s o r d igitorum , Tendines Radius
C aput ulnae
M . extensor carpi radialis brevis, Tendo
M. e xtensor carpi ulnaris, M . extensor carpi radialis longus, Tendo
Tendo (Fovea radialis)
M . exten s o r pollicis brevis, Tendo
M . extensor digiti minim i M . exten s o r pollicis longus, Tendo

C onnexus intertendinei M . in terosse us d o rsa lis II
M. interosseus dorsalis I

Dorsal aponeurosis: m edial tracts
Dorsal aponeurosis: lateral tracts

Fig. 3.91 Tendons of th e dorsum of th e hand. Dorsum manus, According to their developm ental origins and innervation, the M m .
rig h t side; dorsal view . interossei dorsales belong to th e palm ar m uscles. W hen th e th u m b is
The tendons o f the extensor m uscles run beneath the Retinaculum extended, tendons of the M. extensor pollicis brevis and M. extensor
m usculorum extensorum to reach the dorsum of the thum b and the pollicis longus fo rm th e borders o f an indented space w h ic h is referred
dorsal aponeuroses o f the digits. The distinct tendons o f the M. exten­ to as the anatom ical snu ff box (Tabatière).
sor digitorum are linked by intertendinous connections (Connexus inter­
tendinei) w hich lim it the separate m obility o f each finger. There are no -» T 34, 35, 37
intrinsic m uscles at the dorsum of the hand.

186