Comparison of Hip and Low Back Loads between Normal Gait, Axillary Crutch Ambulation and Walking with a Hands-free Crutch in a Healthy Population

BACKGROUND: Instead of using axillary crutches, using a hands-free crutch (HFC) has been associated with higher functional outcome scores. However, hip and back pain have been reported as side effects. PURPOSE/HYPOTHESIS: The purpose of this study was to compare range of motion and joint reaction forces at the hip and low back between HFC walking, normal walking, and standard crutch walking. It was hypothesized that hip joint reaction forces and low back joint reaction forces would be higher with HFC walking compared with normal walking and axillary crutch walking. STUDY DESIGN: Controlled Laboratory Study METHODS: Using 3D motion analysis and force plates, kinematics and ground reaction forces were measured in 12 healthy subjects during gait, crutch ambulation and HFC walking. Gait speed, hip and trunk range of motion, and hip and low back reaction forces, were compared using repeated-measures ANOVA. RESULTS: Gait speed during HFC ambulation was reduced 33% compared to crutch ambulation (P<0.001) and 44% compared to normal gait (p<0.001). Hip range of motion was reduced during both crutch conditions compared to gait (p<0.001). Trunk range of motion was greatest during HFC walking compared to both gait and crutch ambulation (p<0.001). Peak hip joint reaction force during HFC walking was 11% lower than during gait (p=0.026) and 30% lower than during crutch walking (p<0.001). Peak low back reaction force during HFC walking was 18% higher than during gait (p=0.032) but not different than during crutch walking. CONCLUSION: Hip joint reaction forces during HFC walking did not exceed those during gait or axillary crutch ambulation. However, a reduction in hip motion using the HFC was associated with increases in trunk motion and low-back loading. These could be a cause for reports of low-back pain accompanying HFC usage. LEVEL OF EVIDENCE: Level 3