Which of the following movements of thumb are not affected in radial nerve injury:

A i.e. Opposition; C i.e. Adduction; B i.e. Flexion Posterior interosseous branch of radial nerve supplies extensor pollicis longus & brevis (EPL & EPB) and abductor pollicis longus (AbPL)Q (3) thumb muscles. So radial nerve injury weakens (affects) abduction & extension movements of thumb and spares flexion, adduction & oppositionQ Movements of Thumb Movements Extension Flexion Abduction Adduction Opposition Muscle - Extensor pollicis longus - Flexor pollicis longus (FPL) - Abductor pollicis - Aductor pollicis - Opponens & (EPL) /PIN /M longus (AbPL)/ (AdP)/U pollicis (OP) /M Nerve - Extensor pollicis brevis - Flexor pollicis brevis PIN - ls, dorsal - Flexor pollicis (EPB)/ PIN - Abductor pollicis longus (FPB)/M & U - Opponens pollicis (OP) /M - Abductor pollicis brevis (AbPB)/M interosseous /U brevis /M & U (AbPL) / PIN * PIN = posterior interosseous nerve (br of radial nerve); M= Median & U = Ulnar nerve * Flexor pollicis brevis has dual nerve supply i.e. superficial head from median and deep hed from ulnar nerve.