Z FASCIZ AND MUSCLES OF THE FOREARM AND HAND. 3 
bo 
mr 
Table of Muscles acting on the Elbow Joint. 
| Flexors. Extensors. 
| 
Biceps Triceps 
_ Brachialis anticus Anconeus | 
Brachio-radialis Extensors of wrist and fingers (in supination) 
Pronator radii teres 
| Flexors of wrist and fingers 
Extensors of wrist (in pronation) 
(2) Subordinate and accessory movements are performed by all the muscles of this group 
except the brachialis anticus. The biceps supinates the forearm, flexes the elbow, and with the 
aid of the coraco-brachialis adducts and flexes the humerus at the shoulder joint. The triceps 
through its scapular head adducts and extends the humerus, besides extending the elbow joint. 
FASCIA AND MUSCLES OF THE FOREARM AND HAND. 
FASCLA. 
The superficial fascia in the forearm presents no exceptional features. On 
the dorsum of the hand it is loose and thin; in the palm it is generally well 
furnished with fat, forming pads for the protection of the vessels and nerves. It is 
closely adherent to the palmar fascia, and to the skin, especially along the lines of 
flexure. 
The palmaris brevis is a quadrilateral subcutaneous muscle occupying the 
inner side of the hand under the superficial fascia. It arises from the inner border 
of the thick central portion of the palmar fascia, and is inserted into the skin of the 
inner border of the hand for a variable distance. It covers the ulnar artery and 
nerve, branches of which supply it. Its action is to wrinkle the skin of the inner 
border of the Collateral digital branches Collateral digital 
hand, and by of the median nerve branches of the 
raising up the —— ulnar nerve 
skin and super- 
ficial fascia, to 
deepen the hol- 
low of the hand. 
The deep 
Becta. of Ghie ~ cccons soso: 
Merearmandhand  ADDUCTOR THANE” 
5 5 VERSUS POLLICIS 
1s continuous Digital branches 
above with the (median nerve) 
deep fascia of the 
orm. At the \ Ss 
upper part of the ABDUCTOR POLLICIS ASS \)) \ i —— j 
forearm it is “ Wi 
strengthened by 
additional fibres 
around the el- 
Palmar 
fascia 
ABDUCTOR 
MINIMI DIGITI 
_.PALMARIS 
Ss BREVIS 
EN 
f | Ulnar nerve 
F- j e 
OPPONENS POLLICIS 
bow : in front by Superficial volar artery Ben 
PALMARIS LONGUS TENDON Sen 
fibres from the Saas ae ‘annular 
ligament 
semilunar fascia 
of the biceps, 
behind by the re Z 
fascial insertions 
otf the triceps, 
and laterally by fibres derived from the humeral condyles in relation to the 
common tendons of origin of the flexor and extensor muscles of the forearm. It 
closely invests and gives origin to these muscles. It is attached to the posterior 
border of the ulna in the whole length of the forearm, and affords increased 
21 
Fig. 238.—THE PALM oF THE HaND (SUPERFICIAL DISSECTION). 
