Orendurff Michael S, Segal Ava D, Berge Jocelyn S, Flick Kevin C, Spanier David, Klute Glenn K
Center of Excellence for Limb Loss Prevention and Prosthetic Engineering, Motion Analysis Laboratory, Rehabilitation Research and Development, Veterans Administration Puget Sound Health Care System, Seattle, WA 98108, USA.
Gait Posture. 2006 Jan;23(1):106-11. doi: 10.1016/j.gaitpost.2004.12.008.
The biomechanics of changing direction while walking has been largely neglected despite its obvious relevancy to functional mobility. The world is filled with turns that must be negotiated. These turns carry an increased risk of injury due to a decrease in stability. A VICON 612 system measured joint kinematics and kinetics on 10 normal subjects for straight line walking (ST); turning, inside foot strike (IN); and turning, outside foot strike (OUT). All trials were completed at a self-selected walking speed and across a range of speeds from 0.6 to 1.3 m/s; the turn radius was 1 m. Significant differences between the conditions were detected using a mixed effects repeated measures ANCOVA with walking speed as a covariate. The most pronounced differences were demonstrated in the mediolateral ground reaction force impulse: in straight walking the impulses tended to shift the body toward the contralateral limb. In turning, the IN and OUT impulses shifted the body toward the ipsilateral and contralateral limbs, respectively. Knee flexion during stance was increased on the IN limb, while ankle plantarflexion increased on the OUT limb consistent with body lean during turning; differences in joint kinetics during turning were negligible. Self-selected turning was significantly slower than walking straight ahead (0.96+/-0.12 m/s versus 1.61+/-0.22 m/s) and turning at very slow speeds showed a non-uniform center of mass trajectory. Understanding the mechanisms of turning will provide insights driving design, therapy and intervention to increase functional navigation in amputees, the elderly and individuals with neuromuscular pathologies.
尽管行走时改变方向的生物力学与功能移动性明显相关，但在很大程度上被忽视了。现实世界中充满了必须应对的转弯。由于稳定性降低，这些转弯会带来更高的受伤风险。一个VICON 612系统测量了10名正常受试者在直线行走（ST）、转弯（内脚先着地，IN）和转弯（外脚先着地，OUT）时的关节运动学和动力学。所有试验均以自我选择的步行速度完成，速度范围为0.6至1.3米/秒；转弯半径为1米。使用以步行速度作为协变量的混合效应重复测量方差分析检测不同条件之间的显著差异。最明显的差异体现在内外侧地面反作用力冲量上：在直线行走时，冲量倾向于使身体向对侧肢体移动。在转弯时，IN和OUT冲量分别使身体向同侧和对侧肢体移动。站立时，IN侧肢体的膝关节屈曲增加，而OUT侧肢体的踝关节跖屈增加，这与转弯时身体倾斜一致；转弯时关节动力学的差异可忽略不计。自我选择的转弯速度明显慢于直线行走（0.96±0.12米/秒对1.61±0.22米/秒），并且在非常慢的速度下转弯时，质心轨迹不均匀。了解转弯机制将为推动设计、治疗和干预提供见解，以提高截肢者、老年人和患有神经肌肉疾病个体的功能导航能力。
