Upper Extremity. Deltoid. Absence of deformity, which is averted by weight of arm. Inability to raise arm. Sometimes subluxation. Frequent association with paralysis, biceps, brachialis anticus, and supinator longus.
Lower Extremity. Ilio-psoas. Rare except with total paralysis. Associated with paralysis, sartorius. Loss of flexion of thigh. Limb extended (if glutæi intact).
Glutæi. Thigh adducted. Outward rotation lost. Lordosis on standing. Frequent association with paralysis of extensors of back.
Quadriceps extensor. Flexion and adducting of leg (if hamstrings intact). Loss of extension of leg. Frequent association with paralysis of tibialis anticus.
Tibialis anticus. Often concealed if extensor communis intact. If both paralyzed, then fall of point of foot in equinus. Dragging point of foot on ground in walking. Big toe in dorsal flexion (if extensor pollicis intact). The tendons prominent. Hollow sole of foot (if perineus longus intact).
Extensor communis. Nearly always associated with that of tibialis anticus. Toes in forced flexion.
Peroneus longus. Sole of foot flattened. Point turned inward. Internal border elevated.
Sural muscles. Heel depressed. Foot in dorsal flexion (calcaneus). Sole hollowed if perineus longus intact; flattened if paralyzed. Point turned outward (calcaneo-valgus).
Extensors of back. Lordosis on standing. Projection backward of shoulders. Plumb-line falls behind sacrum (unilateral). Trunk curved to side. Trunk cannot be moved toward paralyzed side.