Applied Anatomy Of Muscles Of Upper Limb

APPLIED ANATOMY OF MUSCLES OF UPPER LIMB

1. Pectoralis major is the most common muscle to be congenitally absent (POLAND SYNDROME).

• Sternocostal origin is the most commonly missing part.

2. Winging of scapula is caused most commonly by serratus anterior palsy.

• This is typically caused by damage to long thoracic nerve (nerve to SA).
• Secondary to serratus anterior palsy, a winged scapula is also caused by trapezius palsy and rhomboid palsy,  involving spinal accessory nerve & the dorsal scapular nerve respectively.
• To test the Winged scapula due to serratus anterior palsy, with the arm flexed & the elbow extended the outstretched hand is pushed against a wall.

3. Dropped shoulder is caused by paralysis of trapezius.

4. Muscles which cross both shoulder & elbow:– biceps & triceps (only long head)

5. Bicipital aponeurosis passes superficial to the brachial artery & median nerve. It lies deep to the superficial veins.

6. Muscles with dual nerve supply (hybrid muscles):

• Brachialis : Supplied by radial nerve (proporioception) & musculocutaneous (motor).
• Pectoralis major & minor : Supplied by medial & lateral pectoral) nerve.
• Flexor digitorum profundus: Supplied by ulnar nerve (medial half) & median nerve (lateral half).
• Flexor pollicis brevis: Supplied by median nerve (superficial head) & deep branch of ulnar nerve (deep head).
• Subscapularis: Supplied by upper & lower subscapular nerves.

7. Palmar brevis is a remnant of panniculus carnosus.

8. Third head of coracobrachialis is denoted as struther’s ligament.

9. Rotator cuff consists of supraspinatus, infraspinatus, teres minor & subscapularis.

• Most commonly tendon damaged among rotators is supraspinatus.