Gait Analysis and Abnormalities

Normal gait requires the coordinated integration of four neuroanatomical systems: (1) the motor cortex and corticospinal tract (voluntary motor planning and execution — damage causes upper motor neuron spastic gait with circumduction), (2) the basal ganglia (movement initiation, speed regulation, and automatic motor programs — dysfunction causes Parkinsonian festinating gait with bradykinesia and loss of arm swing), (3) the cerebellum (coordination, balance, and error correction — damage causes wide-based ataxic gait with irregular step length and inability to tandem walk), and (4) the peripheral sensory system including proprioception (dorsal columns carry position sense from muscle spindles and joint receptors — loss causes sensory ataxia with positive Romberg sign, where patients compensate with visual input). The gait cycle consists of stance phase (60% of cycle — heel strike, midstance, toe-off) and swing phase (40% — acceleration, midswing, deceleration). Pathological gait patterns localize neurological lesions: antalgic gait (shortened stance on painful side — musculoskeletal pain), Trendelenburg gait (pelvic drop on swing side from contralateral gluteus medius weakness — L5 radiculopathy or superior gluteal nerve injury), steppage gait (exaggerated hip/knee flexion to clear...