Lower Limb Inter-Joint Coordination of Unilateral Transfemoral Amputees: Implications for Adaptation Control

• Published in: Applied sciences Vol. 10; no. 12; p. 4072
• Main Authors: Xu, Zhi, Wong, Duo Wai-Chi, Yan, Fei, Chen, Tony Lin-Wei, Zhang, Ming, Jiang, Wen-Tao, Fan, Yu-Bo
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.06.2020
• Subjects: Adaptive control; Amputation; Amputations of leg; amputee gait; Amputees; Angular speed; Angular velocity; Ankle; Care and treatment; compensation strategy; continuous relative phase; Control; Coordination; Correlation analysis; Data analysis; Decomposition; decomposition index; Gait; inter-joint coordination; Joints (anatomy); Kinematics; Knee; Limbs; Methods; phase portrait; Physiological aspects; Prostheses; Standard deviation; Time series; Trans-femoral amputees; Velocity; Walking; Hong Kong; United Kingdom > UK
• ISSN: 2076-3417; 2076-3417
• DOI: 10.3390/app10124072

The gait of transfemoral amputees can be made smoother by adjusting the inter-joint coordination of both lower limbs. In this study, we compared the inter-joint coordination of the amputated and non-amputated limbs of unilateral amputees to able-bodied controls. Eight amputees and eight able-bodied control participants were recruited. Walking speed, stance–swing time ratio, joint angle, joint angular velocity, and inter-joint coordination parameters—including continuous relative phase (CRP) and decomposition index (DI)—of the lower-limb joint pairs in stance and swing phases were investigated. Similarity of the CRP between groups was evaluated using cross-correlation measures and root-mean-square, and the variability of the CRP was examined by deviation phase (DP). There were significant differences between the amputated limbs and controls in CRP of hip–knee and knee–ankle in stance and swing, DP of knee–ankle and hip–ankle in stance, and DI of hip–knee in swing. For the non-amputated limbs, there were significant differences in CRP and DP of knee–ankle, and DI of hip–knee in swing compared to controls. The amputees utilized unique inter-joint coordination patterns for both limbs—particularly the hip joint—to compensate for the support-capability impairment due to limb salvage and ensure foot placement accuracy.