Hand palpation muscle bulk is assessed in which regions?

• A. Thenar and hypothenar eminences
• B. Thenar only
• C. Hypothenar only
• D. Carpal tunnel area

Answer: (A)

Assessing hand intrinsic muscle bulk is done by palpating the thenar and hypothenar eminences. These two bulges reflect the main intrinsic muscle groups: the thenar eminence near the thumb houses muscles like the abductor pollicis brevis and opponens pollicis, while the hypothenar eminence near the little finger houses muscles like the abductor digiti minimi. Evaluating their bulk helps detect atrophy from nerve injuries: atrophy of the thenar region points to median nerve involvement affecting thumb muscles, whereas atrophy of the hypothenar region suggests ulnar nerve involvement. The carpal tunnel area is important for assessing median nerve compression, but it is not where you judge intrinsic hand muscle bulk.