Limb Length Discrepancy: Understanding Impact & Physiotherapy Management

Limb Length Discrepancy: Clinical Impact and Physiotherapy Solutions

A difference in leg length — whether from actual bone asymmetry or functional muscle imbalance — creates a cascade of biomechanical compensations throughout the entire kinetic chain. Understanding which type is present determines the correct treatment approach.

How LLD Causes Pain

When one leg is functionally shorter, the body compensates at every joint level:

• Foot/Ankle: Excessive pronation (rolling inward) on the shorter leg side
• Knee: Increased valgus stress, predisposing to patellofemoral pain and IT band syndrome
• Hip: Pelvic drop (Trendelenburg pattern) on the shorter side, or hiking on the opposite side
• Lumbar Spine: Compensatory scoliosis with muscle asymmetry and facet joint loading
• Sacroiliac Joint: Asymmetrical loading often generates chronic SI joint dysfunction

Physiotherapy Assessment

A comprehensive LLD assessment includes:

1. True leg length measurement: ASIS to medial malleolus in supine
2. Apparent leg length measurement: Navel to medial malleolus (detects pelvic obliquity component)
3. Functional assessment: Observe single-leg stance, gait analysis, and hip drop during walking
4. Hip Thomas test: Identifies hip flexor contracture contributing to functional LLD
5. Sacroiliac joint assessment: Standing flexion test and ASIS symmetry check

Treatment Protocol

For Functional LLD:

• Hip flexor stretching (Thomas stretch, kneeling lunge)
• Quadratus lumborum release (side-lying, with foam roller)
• Gluteus medius strengthening (clam shells, hip abduction, single-leg squat)
• Pelvic alignment re-training: Active correction exercises in standing
• Gait re-education: Teaching equal stride length and symmetric trunk movement

For Structural LLD:

• Heel lift orthotic: 3mm–10mm lift inside shoe on the short-leg side (start with 50% correction)
• Spinal decompression exercises: Reduce asymmetric facet loading
• Strengthening program: Address secondary muscle weaknesses that developed from compensation