Department of Mechanical Engineering, University of Alberta, Donadeo Innovation Centre for Engineering, Edmonton, Alberta, T6G 1H9, Canada.
CIUSSS du Centre-Sud-de-l'Île-de-Montréal (Installation Gingras-Lindsay), Montreal, QC, Canada; School of Rehabilitation, Université de Montréal, Montreal, QC, Canada; SCI Mobility Lab, KITE, Toronto Rehabilitation Institute-University Health Network, Toronto, ON, Canada.
Gait Posture. 2021 Jan;83:152-159. doi: 10.1016/j.gaitpost.2020.10.027. Epub 2020 Oct 27.
Up to one-third of individuals with a recent spinal cord injury (SCI) and most of the individuals with an incomplete lesion are able to regain partial balance and walking ability after the first-year post-injury. However, most individuals experience injurious falls while standing and frequent losses of balance post-rehabilitation, which can result in physical injuries and a fear of falling.
Control of balance during quiet standing depends on the integration of sensory information. Since SCI causes sensory and motor impairments, understanding the underlying mechanisms of how postural control is regulated is of significant importance for targeted and guided rehabilitation post-SCI.
We characterized the impact of a variety of challenging conditions on the standing balance for eight participants with incomplete SCI with walking ability compared to twelve age-matched able-bodied individuals using a waist-mounted inertial measurement unit (IMU). We compared balance biomarkers derived from IMUs' readouts under conditions that challenged balance by affecting somatosensory (i.e., standing on hard vs. foam surfaces) and visual (i.e., eyes open vs. closed) inputs. We performed a three-way ANOVA or a Kruskal-Wallis test to characterize changes in postural control post-SCI based on reliance on somatosensory and visual information using balance biomarkers.
We observed a reduced stability performance, an increased control demand, and a less effective active correction post-SCI in all standing conditions. Due to impaired somatosensory feedback, individuals with incomplete SCI showed a higher and lower reliance on visual and somatosensory information, respectively, for maintaining balance (p < 0.05).
Using a single waist-mounted IMU, the proposed method could characterize standing balance in individuals with incomplete SCI compared to able-bodied participants. Having high clinical utility and sufficient resolution with discriminatory ability, our method could be used in the future to objectively evaluate the effectiveness of rehabilitative interventions on the balance performance of individuals with SCI.
多达三分之一的近期脊髓损伤 (SCI) 患者和大多数不完全性损伤的患者，在损伤后一年都能恢复部分平衡和行走能力。然而，大多数患者在站立时会遭受伤害性跌倒，并且在康复后经常失去平衡，这可能导致身体受伤和跌倒恐惧。
在安静站立时，平衡的控制取决于感觉信息的整合。由于 SCI 会导致感觉和运动障碍，因此了解姿势控制是如何调节的潜在机制对于 SCI 后的有针对性和指导性康复非常重要。
我们使用腰部安装的惯性测量单元 (IMU) ，比较了 8 名具有行走能力的不完全性 SCI 患者与 12 名年龄匹配的健康个体在各种挑战性条件下对站立平衡的影响。我们比较了在影响躯体感觉（例如，站在硬表面与泡沫表面）和视觉（例如，睁眼与闭眼）输入的情况下，IMU 读数得出的平衡生物标志物。我们使用平衡生物标志物，根据对躯体感觉和视觉信息的依赖程度，进行三因素方差分析或 Kruskal-Wallis 检验，以描述 SCI 后姿势控制的变化。
我们观察到，在所有站立条件下，SCI 后稳定性表现降低，控制需求增加，主动纠正效果降低。由于躯体感觉反馈受损，不完全性 SCI 患者表现出更高和更低的对视觉和躯体感觉信息的依赖，以维持平衡（p<0.05）。
使用单个腰部安装的 IMU，该方法可以比较健康个体与不完全性 SCI 患者的站立平衡。具有较高的临床实用性和足够的分辨率以及区分能力，我们的方法将来可以用于客观评估康复干预对 SCI 患者平衡表现的有效性。
