Influences on Gait and Causes of Pathological Gait

Study Notes

Pain, posture, flexibility, endurance, base of support, inter-limb coordination, leg length, gender, pregnancy, obesity, age, and displacement of the center of gravity (COG) are factors that influence gait.

Deformity (congenital or acquired), impaired motor control or spasticity, sensory loss, pain, muscle weakness, and other factors can cause pathological gait.

Club foot (talipes equino varus) or supinated foot: plantar flexion, inversion, and adduction
Talipes calcino valgus or pronated foot: dorsiflexion, eversion, and abduction

Plantar flexion contracture: blocks progression of the limb over the supporting foot and inhibits floor clearance during swing
Knee flexion contracture: blocks progression during stance and increases the activity of quadriceps
Knee extension contracture: increases the energy cost of walking by requiring additional body maneuvers for floor clearance during swing
Hip flexion contracture: impairs hip stability during stance and introduces strain on the back muscles and hip extensors

Hip flexor spasticity: restricts progression in mid and terminal stance
Sustained quadriceps action: inhibits pre-swing preparation for limb advancement
Plantar flexors spasticity: leads to persistent ankle plantar flexion and inability to rise on the metatarsal heads
Hamstring spasticity: leads to persistent knee flexion and limits thigh advancement in stance and terminal swing

Prevents the patient from knowing the position of the hip, knee, ankle, or foot
Moderate sensory loss causes slow walking
Greater sensory loss may obstruct walking as it causes the patient to be unable to trust the motions that occur

Major causes of musculoskeletal pain: excessive tissue tension, joint distension related to trauma or arthritis
Pain can cause antalgic gait (limping gait)

When the patient's muscle strength is insufficient to meet the demands of walking
Can be caused by disuse muscular atrophy or neurological impairment
Patients with muscle weakness can modify the timing of muscle action to avoid threatening postures, induce protective alignment during stance, and walk at a slower speed

Normal function: counteracts flexion moment during single-limb support
Effect of weakness on gait: inability to counteract flexion moment, excessive hip flexion, and tendency for anterior pelvic tilt
Possible compensation: leaning the trunk backward to shift the ground reaction force vector (GRFV) behind the axis of the hip joint
Long-term effects of compensation: excessive lumbar lordosis, shifting the lumbosacral joint anterior to the hip joint, and mechanical lower back pain

Normal function: counteracts adduction moment during single-limb support
Effect of weakness on gait: inability to counteract adduction moment, resulting in loss of balance and a positive Trendelenberg sign
Possible compensation: leaning the trunk laterally toward the weak limb, resulting in a gluteus medius gait or waddling gait
Long-term effects of compensation: lateral spinal curve (functional scoliosis)

Normal function: counteracts flexion moment during loading response
Effect of weakness on gait: inability to counteract flexion moment, resulting in excessive knee flexion during loading response, decreased shock absorption, and knee joint instability
Possible compensation: leaning the trunk forward to shift the GRFV anterior to the knee joint, creating an extension moment, and placing the knee in hyperextension

Normal function: counteracts dorsiflexion moment during mid-stance and terminal stance
Effect of weakness on gait: inability to counteract dorsiflexion moment, resulting in excessive ankle dorsiflexion and uncontrolled tibial advancement
Possible compensation: increased demand on quadriceps to counteract tibial instability, delayed heel rise, and loss of knee extension during terminal stance

Normal function: counteracts dorsiflexion moment during mid-stance, terminal stance, and pre-swing
Effect of weakness on gait: inability to counteract dorsiflexion moment, resulting in excessive ankle dorsiflexion and uncontrolled tibial advancement
Possible compensation: increased demand on quadriceps to counteract tibial instability, delayed heel rise, and loss of knee extension during terminal stance