Video 57: Foot Eversion, Inversion - neuroexam.com

57. Foot Eversion, Inversion

What Is Being Tested?

A detailed discussion of patterns of muscle weakness and localization is provided in KCC 6.3 and in Chapters 8 and 9 in Neuroanatomy through Clinical Cases 3e. In Tables 3.4 and 3.5 below, we briefly summarize some of the main actions, muscle groups, peripheral nerves, and nerve roots tested during the motor exam.

Table 3.4 Upper Extremity Strength Testing

Action	Muscles	Nerves	Nerve Roots
Finger extension at metacarpophalangeal joints	Extensor digitorum, extensor indicis, extensor digiti minimi	Radial nerve (posterior interosseous nerve)	C7, C8
Thumb abduction in plane of palm	Abductor pollicis longus	Radial nerve (posterior interosseous nerve)	C7, C8
Finger abduction	Dorsal interossei, abductor digiti minimi	Ulnar nerve	C8, T1
Finger and thumb adduction in plane of palm	Adductor pollicis, palmar interossei	Ulnar nerve	C8, T1
Thumb opposition	Opponens pollicis	Median nerve	C8, T1
Thumb abduction perpendicular to plane of palm	Abductor pollicis brevis	Median nerve	C8, T1
Flexion at distal interphalangeal joints, digits 2, 3	Flexor digitorum profundus to digits 2, 3	Median nerve (anterior interosseous nerve)	C7, C8
Flexion at distal interphalangeal joints, digits 4, 5	Flexor digitorum profundus to digits 4, 5	Ulnar nerve	C7, C8
Wrist flexion and hand abduction	Flexor carpi radialis	Median nerve	C6, C7
Wrist flexion and hand adduction	Flexor carpi ulnaris	Ulnar nerve	C7, C8, T1
Wrist extension and hand abduction	Extensor carpi radialis	Radial nerve	C5, C6
Elbow flexion (with forearm supinated)	Biceps, brachialis	Musculocutaneous nerve	C5, C6
Elbow extension	Triceps	Radial nerve	C6, C7, C8
Arm abduction at shoulder	Deltoid	Axillary nerve	C5, C6

Table 3.5 Lower Extremity Strength Testing

Action	Muscles	Nerves	Nerve Roots
Hip flexion	Iliopsoas	Femoral nerve and L1–L3 nerve roots	L1, L2, L3, L4
Knee extension	Quadriceps	Femoral nerve	L2, L3, L4
Knee flexion	Hamstrings (semitendinosus, semimembranosus, biceps femoris)	Sciatic nerve	L5, S1, S2
Leg abduction	Gluteus medius, gluteus minimus, tensor fasciae latae	Superior gluteal nerve	L4, L5, S1
Leg adduction	Obturator externus, adductor longus, magnus, and brevis; gracilis	Obturator nerve	L2, L3, L4
Toe dorsiflexion	Extensor hallucis longus, extensor digitorum longus	Deep fibular (peroneal) nerve	L5, S1
Foot dorsiflexion	Tibialis anterior	Deep fibular nerve	L4, L5
Foot plantar flexion	Triceps surae (gastrocnemius, soleus)	Tibial nerve	S1, S2
Foot eversion	Peroneus longus, peroneus brevis	Superficial fibular nerve	L5, S1
Foot inversion	Tibialis posterior	Tibial nerve	L4, L5