BACKGROUND While therapy is an important part of the recovery process, there is a lack of quantitative data detailing the "dosage" of therapy received due to the limitations on in/outpatient accessibility and mobility. Advances in wearable sensor technology have allowed us to obtain an unprecedented glimpse into joint-level kinematics in an unobtrusive manner. The objective of this observational longitudinal pilot study was to evaluate the relations between lower body joint kinematics during therapy and functional gait recovery over the first three months after stroke. METHODS Six individuals with subacute stroke (< 1 month) were monitored for a total of 59 one-hour physical therapy sessions including gait and non-gait activities. Participants donned a heart rate monitor and an inertial motion capture system to measure full lower body joint kinematics during each therapy session. Linear mixed regression models were used to examine relations between functional gait recovery (speed) and activity features including total joint displacements, defined as amount of motion (AoM), step number, change in heart rate (∆HR), and types of tasks performed. RESULTS All activity features including AoM, step number, types of tasks performed (all p < 0.01), and ∆HR (p < 0.05) showed strong associations with gait speed. However, AoM (R2 = 32.1%) revealed the greatest explained variance followed by step number (R2 = 14.1%), types of tasks performed (R2 = 8.0%) and ∆HR (R2 = 5.8%). These relations included both gait and non-gait tasks. Contrary to our expectations, we did not observe a greater relation of functional recovery to motion in the impaired limb (R2 = 27.8%) compared to the unimpaired limb (R2 = 32.9%). CONCLUSIONS This proof-of-concept study shows that recording joint kinematics during gait therapy longitudinally after stroke is feasible and yields important information for the recovery process. These initial results suggest that compared to step number, more holistic outcome measures such as joint motions may be more informative and help elucidate the dosage of therapy.

中文翻译：

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使用下半身运动学量化物理疗法的剂量：一项针对中风后早期个体的纵向试验研究。

背景技术尽管治疗是恢复过程的重要组成部分，但是由于在住院/门诊可及性和活动性方面的限制，缺乏详细描述接受的治疗“剂量”的定量数据。可穿戴式传感器技术的进步使我们能够以一种不引人注目的方式对关节级运动学进行前所未有的了解。这项纵向观察性前瞻性研究的目的是评估中风后前三个月治疗期间下半身关节运动学与功能步态恢复之间的关系。方法监测6例亚急性中风（<1个月）个体，共进行59个小时的一小时物理治疗，包括步态和非步态活动。参与者穿戴了心率监测器和惯性运动捕获系统，以在每次治疗期间测量下半身的运动学。线性混合回归模型用于检查功能步态恢复（速度）与活动特征之间的关系，包括总关节位移，定义为运动量（AoM），步数，心率变化（∆HR）和执行的任务类型。结果所有活动特征包括AoM，步数，执行的任务类型（所有p <0.01）和∆HR（p <0.05）均与步态速度密切相关。但是，AoM（R2 = 32.1％）显示最大的解释方差，其次是步数（R2 = 14.1％），执行的任务类型（R2 = 8.0％）和∆HR（R2 = 5.8％）。这些关系包括步态和非步态任务。与我们的期望相反，与未受损的肢体（R2 = 32.9％）相比，我们没有观察到肢体受损（R2 = 27.8％）中功能恢复与运动的更大关系。结论：该概念验证研究表明，在中风后纵向记录步态治疗期间的关节运动学是可行的，并且可以为康复过程提供重要信息。这些初步结果表明，与步数相比，更全面的结局指标（例如关节运动）可能更有用，并有助于阐明治疗剂量。