Gait Analysis and Alignment

Hip-Leveling Guide

• A device that uses a bubble level to determine if the pelvis is level

Dynamic Alignment

• Walking in a safe environment, often using parallel bars, to identify and correct gait deviations
• Aims to achieve a more efficient gait technique

Prosthetic Gait - Transtibial

• Initial contact: lateral border of heel, knee flexed by 20°
• Loading response: medial aspect of forefoot touches ground, medial border of foot parallel to line of progression
• Midstance: dorsiflexion increases, knee moves over foot
• Pre-swing: heel comes off ground, prosthesis rolls forward over toe, and lifts off ground
• Sufficient ground clearance is required

Gait Deviations - Transtibial

• Excessive inversion or eversion of foot: misalignment of prosthesis
• Excessive knee flexion: foot too far posterior, too dorsiflexed, or heel too rigid
• Insufficient knee flexion: knee fully extended at heel strike, heel too soft, or foot too far anterior
• Excessive varus: socket too far inset, foot too outset, or excessive external rotation
• Foot excessive internal rotation: socket excessively adducted

Gait Phases - Transtibial

• Initial contact:
  • External rotation: foot too far outset or excessive toe-out
  • Internal rotation: excessively inset or internally rotated foot
• Midstance:
  • Abducted gait: lateral trunk bending, lateral gapping of socket
  • Choppy or segmented midstance: differences in flexibility, lack of stability
• Swing phase:
  • Insufficient ground clearance/toe-drag: faulty suspension, plantar flexed foot
  • Medial whip: misalignment of knee axis, irregular loading of limb
• Climbing hill/ramp:
  • Drop off: excessive descent of center of mass, diminished heel rise
  • Early heel off: pelvic rise, foot too plantar flexed, toes too stiff

Prosthetic Gait - Transfemoral

• Initial contact: heel, compression of prosthetic heel simulates loading response
• Midstance: weight bearing forces move anteriorly to medial forefoot
• Terminal stance: foot prosthetic simulates toe extension and heel rise
• Pre-swing: individual rolls over toe and moves into knee flexion for effective limb clearance

Gait Deviations - Transfemoral

• Unstable prosthetic knee during stance phase: hip extensor weakness, hip flexion contracture
• Lateral trunk bending: excessive pressure in perineum
• Excessive knee flexion/heel rise in early swing: delays extension, lateral whip
• Medial whip: foot swing in medial arc, excessive external rotation
• Improper donning or suspension: vaulting, too long prosthesis

Bench Alignment - Transtibial

• Side view (Sagittal plane):
  • Plumb line passes through anatomic knee center and junction point of posterior third and anterior 2/3 of foot
  • Socket aligned with knee flexed 5° to 10° to facilitate heel strike and place quadriceps on stretch
  • Foot position: center of heel and big toe aligned along line bisecting socket from anterior view
• Anterior view (Coronal plane):
  • Plumb line passes through mid-patella and center of heel
  • Socket placed in 2° to 5° of varus (adduction) to protect head of fibula and encourage lateral shift
  • Foot externally rotated by 3° to 5° for smooth rollover from heel to toe

Dynamic Alignment - Transtibial

• Smooth rollover from heel to toe with good control of knee
• Consistent base of support width: 5-10 cm
• Toe clearance in swing phase
• Comfortable weight bearing on prosthesis
• Level hips
• Equal and adequate step length

Bench Alignment - Transfemoral

• Aims:
  • Stability in double-limb stance
  • Adequate lateral shift in single-limb stance
  • Narrow base of support (5 cm)
• Anterior view:
  • Socket adjusted with hip in 2° to 5° of adduction according to length of femur and strength of hip muscles