Biofeedback to Increase Propulsion during Walking after Stroke

 描述(由申请人提供)： 背景/目的：每年约有15,000名退伍军人因中风住院。运动控制障碍和随之而来的步行功能受限是最常见的表现，恢复行走能力是中风老兵幸存者的首要目标。身体重心的向前推进是步态的一个基本特征，它依赖于产生适当的前后地面反作用力。通过模拟和横断面研究，中风幸存者瘫痪肢体所产生的推进力减少已被确定为步行功能障碍的主要因素。来自治疗师的外部语言反馈是步态再训练中用来改善推进力生成的标准方法。然而，治疗师不能直接观察到步态的这一关键组成部分，而且由于内在反馈受损，尤其是躯体感觉和本体感觉的缺陷，患者往往无法感觉到推进的产生，阻碍了瘫痪患者推进能力的恢复，并影响了行走功能。本研究的目的是提供初步证据表明，生物反馈作为治疗师语言反馈的辅助手段，将改善退伍军人中风后的推进能力和步行功能。研究对象：30名卒中后6个月的患者。其他研究标准包括：1)在没有身体帮助的情况下行走以推进或支撑瘫痪的腿；2)Fugl-Meyer运动评估的32分确认为单侧腿部瘫痪；3)步长不对称(偏瘫和非偏瘫的步长)；4)没有辅助或矫形装置的步行。方法：参与者将被随机分为两组，一组将接受来自市场上可获得的压敏鞋垫传感器的推进生物反馈训练(生物反馈组，n=15)，另一组将仅接受标准治疗师提供的语言反馈训练(标准组，n=15)。12个疗程(每周3次，为期4周)的步态训练干预将由物理治疗师领导的团队提供。对于生物反馈组的参与者，在第一次干预之前，将确定晚期站立时瘫痪的前足施加的基准量。当压力超过基线压力的5%时，前脚下面的鞋垫区域将被校准以产生音调。在整个干预期间，这一阈值将以定期的间隔逐步增加，以确保参与者在他们的挑战点进行训练，以改善瘫痪肢体的推进能力。为了对称和舒适，在非瘫痪腿的鞋子中将穿上类似厚度的鞋垫，但在干预过程中不会产生音调。标准组的患者在干预期间不会穿鞋垫，但在步态训练期间只会收到关于瘫痪肢体推进的口头反馈。治疗师提供的口头反馈将用于指导参与者实现和/或保持有助于推动生成的适当运动模式。对于这两组人，治疗师将从标准化的步态活动库中进行选择， 适合每个参与者的能力水平。每场比赛的总步行时间的目标是50分钟：每场比赛5-10分钟，每场比赛之间休息2分钟。观察指标：偏瘫肢体推进能力是我们的主要结果指标。次级测量包括六分钟步行测试、功能步态评估、跌倒自我效能、时间距离步态测量和步态运动学，所有这些都将在干预前后进行测量。数据分析计划：将为所有结果衡量标准提供描述性统计数据。为了确定干预的效果，将计算每组培训前和培训后评估之间的差异(即变化分数)。为了检验我们的假设，我们将对生物反馈组和标准组的变化分数进行独立样本t检验。假设检验将在两面p&lt；0.05水平上进行。

 DESCRIPTION (provided by applicant): Background/Purpose: Approximately 15,000 Veterans are hospitalized for stroke each year. Impairments of motor control and the subsequent functional limitations in ambulation are the most common manifestations and regaining the ability to walk is the number one stated goal of Veteran stroke survivors. Forward propulsion of the body's center of mass is a cardinal feature of gait that depends on the generation of appropriate anterior- posterior ground reaction forces. Decreased propulsive force generation by the paretic limb of stroke survivors has been identified through both simulation and cross-sectional studies as a major contributor to walking dysfunction. Extrinsic verbal feedback from a therapist is the standard approach used during gait retraining to improve propulsion generation. However, this key component of gait is not directly observable by therapists and patients are often unable to sense propulsion generation due to impaired intrinsic feedback, specifically deficits in somatosensation and proprioception, hindering recovery of paretic propulsion and compromising walking function. The objective of this study is to provide preliminary evidence that biofeedback as an adjuvant to therapists' verbal feedback will improve propulsion and enhance walking function for Veterans post-stroke. Subjects: Thirty individuals > 6-months post-stroke will participate. Additional study criteria include: 1) Ambulation of household distances without physical assistance to advance or support the paretic leg; 2) Unilateral leg paresis confirmed by a score of < 32 on the Fugl-Meyer Motor Assessment; 3) Step length asymmetry (paretic > non-paretic step length); 4) Ambulation without an assistive or orthotic device. Methods: Participants will be randomized to either an experimental group that will train with propulsion biofeedback from commercially available pressure-sensitive insole sensors (Biofeedback group; n=15) or a control group that will train with standard therapist-provided verbal feedback alone (Standard group; n=15). The 12 session (3X/week for 4 weeks) gait training intervention will be delivered by a physical therapist-led team. For participants in the Biofeedback group, prior to the first intervention session, the baseline amount of pressure exerted by the paretic forefoot during late stance will be determined. The insole area underlying the forefoot will then be calibrated to produce a tone when pressure exceeds 5% of this baseline pressure. This threshold will be progressively increased at regular intervals throughout the intervention period to ensure participants are training at their challenge-point to improve propulsion of the paretic limb. An insole of similar thickness will be worn in the shoe of the non-paretic leg for symmetry and comfort but will not produce a tone during the intervention. Those in the Standard group will not wear insoles during intervention but will receive verbal feedback alone regarding propulsion of the paretic limb during gait training. Therapist-provided verbal feedback will be used to instruct participants on achieving and/or maintaining appropriate movement patterns that contribute to propulsion generation. For both groups, the therapist will choose from a standardized bank of gait activities, suitable to each participant's ability level. The goal for total walking time for each session willbe 50 minutes: 5, 10-minute bouts with a 2-minute rest between each bout. Outcome Measures: Paretic limb propulsion is our primary outcome measure. Secondary measures include the Six Minute Walk Test, Functional Gait Assessment, Fall Self-Efficacy, temporal-distance gait measures and gait kinematics, all of which will be measured pre- and post-intervention. Data Analysis Plan: Descriptive statistics will be provided for all outcome measures. To identify the effect of the intervention, differences between the pre- and post-training assessment within each group (i.e. change scores) will be calculated. To test our hypotheses, we will apply independent sample t-tests to the change scores of the Biofeedback and Standard group. Hypothesis testing will be conducted at a two-sided p < 0.05 level.