Russell Esposito Elizabeth, Choi Harmony S, Darter Benjamin J, Wilken Jason M
Center for the Intrepid, Brooke Army Medical Center, JBSA, Ft. Sam Houston, Texas, United States of America.
Extremity Trauma and Amputation Center of Excellence, Ft. Sam Houston, Texas, United States of America.
PLoS One. 2017 Feb 9;12(2):e0171786. doi: 10.1371/journal.pone.0171786. eCollection 2017.
The metabolic demand of walking generally increases following lower extremity amputation. This study used real-time visual feedback to modify biomechanical factors linked to an elevated metabolic demand of walking in individuals with transtibial amputation. Eight persons with unilateral, traumatic transtibial amputation and 8 uninjured controls participated. Two separate bouts of real-time visual feedback were provided during a single session of gait retraining to reduce 1) center of mass sway and 2) thigh muscle activation magnitudes and duration. Baseline and post-intervention data were collected. Metabolic rate, heart rate, frontal plane center of mass sway, quadriceps and hamstrings muscle activity, and co-contraction indices were evaluated during steady state walking at a standardized speed. Visual feedback successfully decreased center of mass sway 12% (p = 0.006) and quadriceps activity 12% (p = 0.041); however, thigh muscle co-contraction indices were unchanged. Neither condition significantly affected metabolic rate during walking and heart rate increased with center-of-mass feedback. Metabolic rate, center of mass sway, and integrated quadriceps muscle activity were all not significantly different from controls. Attempts to modify gait to decrease metabolic demand may actually adversely increase the physiological effort of walking in individuals with lower extremity amputation who are young, active and approximate metabolic rates of able-bodied adults.
下肢截肢后，行走的代谢需求通常会增加。本研究使用实时视觉反馈来改变与经胫截肢者行走时代谢需求升高相关的生物力学因素。8名单侧创伤性经胫截肢者和8名未受伤的对照者参与了研究。在单次步态再训练过程中提供了两次单独的实时视觉反馈，以减少1）重心摆动和2）大腿肌肉激活幅度及持续时间。收集了基线和干预后的数据。在以标准化速度进行稳态行走期间，评估了代谢率、心率、额面重心摆动、股四头肌和腘绳肌活动以及共同收缩指数。视觉反馈成功地使重心摆动降低了12%（p = 0.006），股四头肌活动降低了12%（p = 0.041）；然而，大腿肌肉共同收缩指数没有变化。两种情况均未对行走时的代谢率产生显著影响，且心率随重心反馈而增加。代谢率、重心摆动和股四头肌综合肌肉活动与对照组均无显著差异。试图改变步态以降低代谢需求，实际上可能会对年轻、活跃且代谢率接近健全成年人的下肢截肢者行走时的生理努力产生不利影响。
