The hand

Look

Skin

Look for tight bands in the palm leading up to the fingers or even thumb (Dupuytren’s contracture) (Fig. 20.36).

Soft tissue

Check for thenar and hypothenar wasting (see previous section on ‘The wrist’) but also check for wasting in the clefts between the fingers dorsally (damage to the ulna nerve or Ti).

Bone

Look for Heberden’s nodes (Fig. 20.37) over the distal inter­phalangeal joints dorsally (associated with osteoarthritis). Look for swan neck and boutonniere (Fig. 20.38) deformities. Swan neck deformities have an extension at the middle interphalangeal joint with flexion at the distal interpha­langeal joint. Boutonniere deformity is extension at the distal interphalangeal joint with flexion at the middle interpha­langeal joint.

Both of these are associated with rheumatoid arthritis. Look also for dropped fingers. If one finger lies lower than the others when the hands are held out, test for rupture of the extensor tendon by asking the patient to extend the finger against resistance. Look for subluxation of the metacarpal phalangeal joints and for ulna drift of the fingers (also associated with rheumatoid arthritis) (Fig. 20.39).

Feel

Skin

Feel for loss of sensation in the tips of the fingers. Review the sensory distribution of the median, ulna and radial nerves. If there is any doubt about the sensation then proceed to test two-point discrimination.

Soft tissues

Check for capillary filling in the fingertips.

Feel for wasting in the first dorsal interosseous on the radial side of the first metacarpal. This muscle is plump and easily palpable. Damage to the ulna nerve or to the Ti nerve root can be detected from wasting in this muscle.

Bone

Feel for swelling and tenderness over the metacarpal phalangeal and interphalangeal joints.

Move

Active

Test roll-up of the fingers from full extension to full flexion. Test flexion of the metacarpal phalangeal joints in isolation while keeping the proximal and distal interphalangeal joints extended. This tests the patient’s control of the intrinsic muscles. Test abduction of the fingers (a further test of small muscles in the hand).

Passive, stability and resisted

Test the power of the extensors, individually pushing down on each finger.

Superficialis tendon test. Flexor digitorum profundus usually has only one muscle belly supplying the tendons to all of the fingers. Profundus can therefore be immobilised by holding all the fingers bar the one being tested in full extension, grasping them in your hand. If the test finger is still able to flex, then superficialis to that finger is active (Fig. 20.40).

Profundus test. Flexor digitorum profundus is the only tendon that inserts in the distal phalanx. If the finger is held by the middle phalanx, the power of the profundus tendon can be tested (Fig. 20.41).

Intrinsics. The power of the intrinsic muscles of the hand is tested by asking the patient to abduct the fingers against resistance, and feeling for contraction in the first dorsal

interosseous muscle on the index finger side of the web space (Fig. 20.42).

Froment’s test. The patient is asked to grip a sheet of paper between the index finger and thumb of both hands. If the intrinsic muscles of the hand are normal the patient can grip firmly with the thumb in extension. However, if there is weakness, particularly of the adductor pollicis, the thumb cannot remain straight while flexor hallucis longus contracts hard, so the thumb flexes (Fig. 20.43).

Abductors of thumb. The abductors of the thumb are supplied by the median nerve. Power is tested by asking the patient to raise the thumb from the palm against resistance (Fig. 20.44).