Singer Jonathan C, Mansfield Avril, Danells Cynthia J, McIlroy William E, Mochizuki George
Heart and Stroke Foundation Centre for Stroke Recovery, Toronto, ON, Canada; Sunnybrook Research Institute, Toronto, ON, Canada.
Clin Biomech (Bristol). 2013 Oct;28(8):921-6. doi: 10.1016/j.clinbiomech.2013.07.010. Epub 2013 Jul 25.
Challenges in stability control are common post-stroke. Although lower-limb spasticity is a common sensorimotor consequence post-stroke, its potential to further complicate stability control among stroke-survivors remains largely unknown. Advancing such understanding can help inform strategies to reduce fall risk and increase independence among these individuals. The purpose of this study was to characterise the extent of limb-specific dyscontrol among individuals with spasticity.
A retrospective analysis of 131 patients assessed for spasticity was performed. Patients selected for inclusion were categorised into two groups, with (n=19) or without (n=63) unilateral lower-limb spasticity. Two force platforms were used to determine the individual-limb and net centres of pressure in both anteroposterior and mediolateral directions during 30s of quiet standing. Limb-specific dyscontrol was assessed by calculating weight-bearing symmetry ratios, cross-correlation coefficients at zero phase-shift (temporal synchrony) and ratios of individual-limb root-mean-square displacements (spatial symmetry). Total body postural control was assessed by examining the root-mean-square of the net centre of pressure displacement.
The group with spasticity bore less weight on the affected limb and exhibited reduced temporal synchrony of centre of pressure displacements. There were no differences in inter-limb root-mean-square centre of pressure ratios or in the root-mean-square of the net centre of pressure displacement.
Individuals with lower-limb spasticity may have additional challenges with stability control, specifically linked to the ability to modify the location of the centre of pressure beneath the affected limb, in a time-sensitive manner so as to contribute beneficially to the control of whole body stability.
中风后稳定性控制面临的挑战很常见。尽管下肢痉挛是中风后常见的感觉运动后果，但其在中风幸存者中使稳定性控制进一步复杂化的可能性在很大程度上仍不为人知。增进这种理解有助于为降低这些个体跌倒风险和提高其独立性的策略提供依据。本研究的目的是描述痉挛患者肢体特异性控制失调的程度。
对131例接受痉挛评估的患者进行回顾性分析。入选患者分为两组，一组有（n=19）单侧下肢痉挛，另一组无（n=63）单侧下肢痉挛。使用两个测力平台在安静站立30秒期间确定前后方向和内外侧方向上的单肢和净压力中心。通过计算负重对称率、零相位偏移时的互相关系数（时间同步）和单肢均方根位移比（空间对称）来评估肢体特异性控制失调。通过检查净压力中心位移的均方根来评估全身姿势控制。
痉挛组患侧肢体负重较少，且压力中心位移的时间同步性降低。肢体间压力中心均方根比或净压力中心位移的均方根无差异。
下肢痉挛患者在稳定性控制方面可能面临额外挑战，特别是与以时间敏感方式改变患侧肢体下方压力中心位置的能力相关，以便对全身稳定性控制做出有益贡献。
