School of Sport and Health Sciences, University of Exeter, UK.
Gait Posture. 2021 Jun;87:11-18. doi: 10.1016/j.gaitpost.2021.01.018. Epub 2021 Jan 23.
The locomotor system is proposed to be able to adapt to asymmetric conditions, which reflects the interaction between interlimb control and task constraints. However, this adaptability may be confounded by intrinsic differences between age groups.
What are the effects of mechanical asymmetry on kinematic symmetry in healthy younger and older adults?
Two groups of 10 participants (age 18-25 and 58-65 years) walked (3 km h -1) and ran (9 km h -1) on a treadmill normally, and with unilateral ankle weights (UW). Lower-body kinematic data was collected. Symmetry Index (SI) and bilateral cyclograms were used to evaluate spatiotemporal step-cycle characteristics and joint angles.
Step-cycle characteristics were not significantly different between all comparisons. In running gait, asymmetry in range of motion (SI_RoM) of the knee and bilateral cyclogram minimum bounding box length (L) of the ankle was greater with UW compared to the normal condition. Ankle angle characteristics (SI_RoM ankle and minimum ankle angle) were more asymmetrical for older compared to younger adults, regardless of the UW condition. Interaction effects between age and UW were observed. In running gait, L knee and SI_RoM hip were greater with UW for younger adults, and smaller with UW for older adults. In walking gait, ankle angle at touchdown was greater with UW for younger adults, but smaller with UW for older adults.
For both age groups walking and running with UW, symmetry appears to be preserved in step-cycle characteristics, but not in joint angle measures. While adapting to unilateral perturbation, older adults show greater asymmetry in some ankle kinematic measures compared to younger adults while running, suggesting that some kinematic solutions are altered with age, while the majority of symmetry values about the lower limbs were not.
运动系统被认为能够适应不对称条件，这反映了肢体间控制与任务约束之间的相互作用。然而，这种适应性可能会受到年龄组内在差异的影响。
机械不对称对健康年轻和老年成年人的运动学对称性有什么影响？
两组各 10 名参与者（18-25 岁和 58-65 岁）在跑步机上正常和单侧踝重（UW）条件下以（3 公里/小时）和（9 公里/小时）的速度行走和跑步。收集下肢运动学数据。使用对称性指数（SI）和双边循环图评估时空步周期特征和关节角度。
在所有比较中，步周期特征没有显著差异。在跑步步态中，与正常状态相比，UW 时膝关节运动幅度（SI_RoM）和踝关节双边循环图最小包围盒长度（L）的不对称性更大。与年轻成年人相比，无论 UW 条件如何，踝关节角度特征（SI_RoM 踝关节和最小踝关节角度）在老年成年人中更为不对称。观察到年龄和 UW 之间的交互效应。在跑步步态中，UW 时年轻成年人的 L 膝和 SI_RoM 髋更大，而老年成年人的 L 膝和 SI_RoM 髋更小。在步行步态中，UW 时年轻成年人的踝关节触地点角度更大，但 UW 时老年成年人的踝关节触地点角度更小。
对于两组年龄组，在行走和跑步时使用 UW，在步周期特征中似乎保持了对称性，但在关节角度测量中没有。在适应单侧干扰时，与年轻成年人相比，老年成年人在跑步时某些踝关节运动学指标的不对称性更大，这表明一些运动学解决方案随着年龄的增长而改变，而下肢的大多数对称性值没有改变。
