de Kam Digna, Kamphuis Jip F, Weerdesteyn Vivian, Geurts Alexander C H
Radboud University Medical Center, Donders Centre for Neuroscience, Department of Rehabilitation, Nijmegen, The Netherlands.
RMC Groot Klimmendaal, Arnhem, The Netherlands.
Gait Posture. 2017 Mar;53:5-10. doi: 10.1016/j.gaitpost.2016.12.019. Epub 2016 Dec 21.
After stroke, weight-bearing asymmetry (WBA) towards the non-paretic side is associated with postural instability. It remains unknown whether WBA is a cause or consequence of postural instability, as both phenomena depend on stroke severity. We investigated the effect of WBA on the ability to recover from balance perturbations in people with stroke. Fourteen people in the chronic phase of stroke underwent multidirectional translational perturbations at three levels of initial WBA (0, 10 and 20% of body weight unloading of the paretic leg). We iteratively determined the highest perturbation intensity that could be sustained with a feet-in-place response (i.e. stepping threshold) for each WBA condition and in four perturbation directions (forward, backward, towards paretic and towards non-paretic side). For perturbations above the stepping threshold we determined the choice of stepping leg. WBA increased the stepping threshold for perturbations towards the paretic side, whereas it decreased the stepping threshold for perturbations towards the non-paretic side (p<0.05). No effects of WBA were found on forward or backward stepping thresholds. Yet, the frequency of stepping with the paretic leg in the anteroposterior directions increased with greater WBA. Similarly, greater initial WBA resulted in a larger number of side steps towards the paretic side. In conclusion, the results suggest that people with stroke can benefit from some paretic leg unloading when perturbed towards the paretic side. It remains to be investigated, however, to what extent these benefits outweigh the potentially detrimental effects of WBA that were observed when recovering from perturbations in the other directions.
中风后，向非瘫痪侧的负重不对称（WBA）与姿势不稳有关。WBA是姿势不稳的原因还是结果仍不清楚，因为这两种现象都取决于中风的严重程度。我们研究了WBA对中风患者从平衡扰动中恢复能力的影响。14名处于中风慢性期的患者在三种初始WBA水平（患侧腿卸载体重的0%、10%和20%）下接受了多方向平移扰动。我们迭代确定了在每种WBA条件下以及四个扰动方向（向前、向后、向患侧和向非患侧）下，能够通过原地踏步反应维持的最高扰动强度（即踏步阈值）。对于高于踏步阈值的扰动，我们确定了踏步腿的选择。WBA增加了向患侧扰动的踏步阈值，而降低了向非患侧扰动的踏步阈值（p<0.05）。未发现WBA对向前或向后踏步阈值有影响。然而，在前后方向上患侧腿踏步的频率随着WBA的增加而增加。同样，更大的初始WBA导致向患侧的侧步数量增加。总之，结果表明，当中风患者向患侧受到扰动时，患侧腿适当卸载体重可能有益。然而，这些益处能在多大程度上超过从其他方向的扰动中恢复时观察到的WBA的潜在有害影响，仍有待研究。
