There are four dorsal interossei in each hand.
Guttering interosseous atrophy.
Ulnar nerve entrapment at the elbow is one of the most common entrapment neuropathies encountered in clinical practice.
Interossei weakness atrophy and claw hands may be noted in severe cases.
The position of the insertion site is dependent on which digit is involved.
When assessed by needle emg the first dorsal interosseous is the muscle most likely to be affected followed by the abductor digit quinti and flexor carpi ulnaris.
Examine the functions of the muscles supplied by the ulnar nerve.
Electrodiagnostic studies are able to differentiate une from radiculopathies and lower trunk plexopathy.
Palmar interossei ask the patient hold a card between two fingers while you attempt to pull it away using the same two fingers.
Wasting of the interossei prominent guttering of the back of the hand of the web space between thumb and index finger and softening and flattening of the hypothenar eminence with sparing of abductor pollicis brevis indicates an ulnar nerve lesion.
Waldman md jd in atlas of common pain syndromes fourth edition 2019.
The dorsal interosseous muscles are bipennate with each muscle arising by two heads from the adjacent sides of the metacarpal bones but more extensively from the metacarpal bone of the finger into.
Each muscle is bipennate in shape and extends from the proximal ends of adjacent metacarpals to the proximal phalanx and dorsal digital expansion of the appropriate finger.
They are specified as dorsal to contrast them with the palmar interossei which are located on the anterior side of the metacarpals.