Soft tissue anatomy

This is an excerpt from Clinical Guide to Surface Palpation 2nd Edition With HKPropel Online Video, A by Michael Masaracchio & Chana Frommer.

Several groups of muscles surround the elbow and forearm.

• Anteriorly, the elbow flexors consist of the biceps brachii, brachialis, and brachioradialis.
• Posteriorly, the triceps brachii and anconeus compose the elbow extensor group (figure 5.3).
• The medial elbow is covered by the flexor–pronator group of muscles.
• The lateral elbow is occupied by the extensor–supinator group of muscles.

Anatomically, these muscle groups are separated into layers, and knowing the relative depth of these muscles during palpation is an important consideration so that proper force can be applied for structure identification.

The posterior forearm is divided into two layers:

• The superficial layer contains the brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris (figure 5.4, superficial).
• The deep layer is composed of the supinator, abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, and the extensor indicis (figure 5.4, deep).

All muscles of the posterior forearm are innervated by the radial nerve.²

The anterior forearm muscles are broken into superficial, intermediate, and deep layers (figure 5.5).

• The superficial layer consists of the pronator teres, flexor carpi radialis, palmaris longus, and flexor carpi ulnaris.
• The intermediate layer consists of the flexor digitorum superficialis.
• The deepest layer consists of the flexor digitorum profundus, the flexor pollicis longus, and the pronator quadratus.