Transfemoral bone-anchored limb use changes dynamic hip muscle forces during walking

Area of Science:

• Biomechanics
• Orthopedics
• Rehabilitation Engineering

Background:

• Transfemoral amputation often causes residual limb pain and musculoskeletal injuries due to compensatory movement patterns.
• While bone-anchored limbs normalize joint loading, their impact on hip muscle forces remains unclear.

Purpose of the Study:

• To compare dynamic hip muscle forces in three planes of motion during walking before and after transfemoral bone-anchored limb implantation.
• To investigate the effects of bone-anchored limbs on hip muscle function and joint loading.

Main Methods:

• Collected overground walking motion capture data from 19 participants before and 12 months after bone-anchored limb implantation.
• Estimated bilateral hip muscle forces using subject-specific musculoskeletal models.
• Resolved muscle forces into anteroposterior, mediolateral, and superoinferior components for comparison.

Main Results:

• Increased amputated-side hip abductor muscle forces throughout stance post-implantation.
• Decreased amputated-side hip flexor posterior muscle forces during terminal stance.
• More symmetric hip abductor forces during single limb support and more asymmetric flexor forces post-implantation.

Conclusions:

• Bone-anchored limb implantation alters hip muscle function during walking in transfemoral amputees.
• Findings suggest potential benefits for reducing aberrant muscle function and hip joint loading.
• Implications for mitigating hip osteoarthritis development and progression in this population.