School of Physiotherapy, Dalhousie University, 5981 University Avenue, Halifax, NS, B3H 1W2, Canada.
Eur J Appl Physiol. 2012 Feb;112(2):439-49. doi: 10.1007/s00421-011-1990-4. Epub 2011 May 15.
The purpose of this study was to determine the effect of impaired quadriceps function on knee joint biomechanics and neuromuscular function during gait. Surface electromyograms, three-dimensional motion and ground reaction forces were collected during gait before and after 20 healthy adults completed a high intensity quadriceps fatigue protocol. Pattern recognition techniques were utilized to examine changes in amplitude and temporal characteristics of all gait variables. The fatigue protocol resulted in decreased knee extensor torque generation and quadriceps median power frequencies for 18 of 20 participants (p < 0.05). The gait data from these 18 participants was analyzed. The knee external rotation angle increased (p < 0.05), the net external flexion and external rotation moments decreased (p < 0.05), and the net external adduction moment increased (p < 0.05). Post-fatigue changes in periarticular muscle activation patterns were consistent with the biomechanical changes, but were not significantly altered. Even for this low demand task of walking the knee motion and loading characteristics were altered following a high intensity fatigue protocol in a manner that may place the knee joint at greater risk for joint pathology and injury.
本研究旨在确定股四头肌功能障碍对步态中膝关节生物力学和神经肌肉功能的影响。20 名健康成年人完成高强度股四头肌疲劳方案前后，在步态期间收集表面肌电图、三维运动和地面反作用力。利用模式识别技术检查所有步态变量的幅度和时间特征的变化。疲劳方案导致 20 名参与者中的 18 名（p < 0.05）的膝关节伸肌扭矩产生和股四头肌中值功率频率降低。对这 18 名参与者的步态数据进行了分析。膝关节外旋角度增加（p < 0.05），净外部弯曲和外部旋转力矩减小（p < 0.05），净外部内收力矩增加（p < 0.05）。关节周围肌肉激活模式的疲劳后变化与生物力学变化一致，但没有明显改变。即使对于行走这样低需求的任务，在高强度疲劳方案之后，膝关节的运动和加载特征也会发生改变，这可能会使膝关节更容易发生关节病理和损伤。
