NeuroMuscular Electrical Stimulation to Facilitate Perturbation-based REACtive Balance Training for Fall Risk Reduction Post-stroke: The REACTplusNMES Trial
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 46
- 试验地点
- 2
- 主要终点
- Change in Vertical Limb support
研究概览
简要总结
The aim of this study is to compare the effectiveness of 6-weeks of reactive balance training (REACT) with and without neuromuscular electrical stimulation (NMES) to paretic lower limb muscles on biomechanical, clinical, neuromuscular and neuroplastic outcomes of reactive balance control. This project is a Phase-I study and incorporates a double-blinded, randomized controlled trial design.
Methods: Forty-six individuals with chronic stroke will be recruited and screened for determining their eligibility for the study. Once enrolled, they will be randomized into either of the two groups: intervention group (23 participants) and control group (23 participants). Both groups will undergo series of pre-training assessments which includes a postural disturbance in the form of a slip- or trip-like perturbations and walking tests in laboratory environment. After the pre-training assessment, individuals will undergo 6-weeks of training (2 hour per session, 2 sessions per week). The intervention group will receive NMES with the REACT training and the control group will receive ShamNMES. NMES will be applied to the different muscle groups of the paretic lower limb using an advanced software which is able to synchronize muscle activation with the time of perturbation onset and according to the phases of gait. After training, both groups will again be tested on all the assessments performed pre training.
This study will help us understand the immediate therapeutic and mechanistic effects of REACT+NMES and inform stroke rehabilitation research and clinical practice. Our study will provide foundational evidence for future use of NMES to implement clinically applicable neuromodulation adjuvants to reactive balance training, which could be leveraged for designing more effective future interventions for fall-risk reduction.
详细描述
1.0 Background/Scientific Rationale Interventions such as conventional balance and exercise training constitute a major part of stroke rehabilitation and improve volitional balance control and gait in people with chronic hemiparetic stroke (PwCHS). However, they seldom target reactive balance (compensatory postural responses such as stepping) that forms the first line of defense while recovering from a balance loss. Reactive balance in PwCHS is affected by deficits in perturbation-evoked neuromuscular and biomechanical responses especially during gait. Further, previous research has shown that stability and adaptions to repeated perturbations is more affected on paretic compared to non-paretic limb. Thus, paretic limb deficits are postulated to be key contributors of falls in ambulatory PwCHS. Perturbation-based reactive balance training (REACT) is widely recognized as an intervention that reduces falls by improving fall-resisting skills. In the past five years, there is a 3-fold increase in perturbation training research in PwCHS (mostly low impairment). Thus, limited evidence exists for PwCHS with severe motor impairment who might not show similar tolerance or learning abilities.
Complementing REACT with interventions known to facilitate paretic limb performance and motor learning (i.e., neuromuscular electrical stimulation, NMES) can improve therapeutic effects of REACT and hence its clinical translation for PwCHS and other populations that could benefit from fall-risk reduction. While it is established that REACT programs and NMES can induce motor learning in behavioral variables, there is limited evidence on neuroplastic changes and exact neural mechanisms underlying these behavioral changes (especially during REACT). Similar to the precision medicine approach, modifiable causative factors, contributors, and mediators to falls must be targeted when designing effective falls prevention interventions that reduce training times and/or facilitate the inclusion of persons with high impairment.
This project aims to describe whether a specific pattern of lower limb muscle stimulation could modify the recovery response after an unexpected perturbation in the form of a slip and/or trip in individuals with stroke. Also, this study aims to examine the effectiveness of 6-weeks of reactive balance training (REACT) with and without neuromuscular electrical stimulation (NMES) to paretic lower limb muscles on biomechanical, clinical, neuromuscular and neuroplastic outcomes of reactive balance control.
2.0 Objectives/Aims
The specific aims of this study are below:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Double (Participant, Outcomes Assessor)
盲法说明
Subjects will be blinded to group existence and assignment and outcome assessors will be blinded to group assignment
入排标准
- 年龄范围
- 18 Years 至 90 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Age group: 18-90 years.
- •Presence of hemiparesis.
- •Onset of stroke (> 6 months).
- •Ability to walk at least for 2 minutes on the treadmill with or without ankle foot orthosis.
- •Can understand and communicate in English.
- •Cognitively and behaviorally capable of complying with the regimen (Mini-Mental State Examination > 25/30).
- •No history or recent use (i.e., past 6 weeks) of any Neuromuscular electrical stimulation device to leg muscles during walking (e.g., Bioness, Walkaide).
排除标准
- •Subjects will not proceed with the test if any of the following occurs at baseline measurement: 1) HR > 85% of age-predicted maximal heart rate (HRmax) (HRmax = 220 - age), 2) systolic blood pressure (SBP) > 165 mmHg and/or diastolic blood pressure (DBP) > 110 mmHg during rest, or 3) oxygen saturation (measured by pulse oximeter) < 95% during rest.
- •Body weight of more than 250 lbs.
- •Spasticity (Ashworth scale > 2).
- •Loss of protective sensations on the paretic leg (indicated by inability to perceive the 5.07/10 g on Semmes-Weinstein Monofilament) or inability to feel the NMES.
- •Severe osteoporosis (indicated by T score < -2)
- •Cognitive impairment (indicated by Mini-Mental State Exam score<25)
- •Global Aphasia (indicated by <71% on the Mississippi Aphasia Screening Test).
- •Subjects with Chedoke McMaster Leg Assessment Scale score (> 4).
研究组 & 干预措施
REACT-NMES: Intervention condition
The REACT-NMES group will undergo 6 weeks of reactive balance training with NMES involving 12 one-hour sessions (twice a week). Each session will begin with NMES parameter setup where the current amplitude will be customized to individual "maximal tolerable" levels for a strong yet comfortable experience. NMES settings will include moderate to high intensity (30-50mA) and low frequency (20-45Hz) to target motor nerve thresholds. The REACT-NMES group will wear a footswitch on their paretic shoe for triggering the slips during walking and for NMES synchronization. NMES will be delivered to the paretic limb quadriceps muscles for 500 milliseconds after slip onset.
干预措施: Reactive balance training with Neuromuscular Electrical Stimulation (Behavioral)
REACT: Control condition
The REACT group will undergo 6 weeks involving 12 one-hour sessions (twice a week) of reactive balance training with ShamNMES. To prevent psychological bias and unblinding, sub-sensory stimulation will be used. ShamNMES will employ low intensity (0-10mA) and high frequency (50-100Hz), staying 20% below the sensory nerve threshold without inducing muscle contraction. The REACT group will wear a footswitch on their paretic shoe for triggering the slips during walking and for ShamNMES synchronization. ShamNMES (control) will be delivered after compensatory step touchdown to avoid interference with balance recovery.
干预措施: Reactive balance training without Neuromuscular Electrical Stimulation (Behavioral)
结局指标
主要结局
Change in Vertical Limb support
时间窗: Pre-training (during week 2 i.e., Session 2), Post-training (during week 9 i.e., Session 16)
Vertical limb support (dimensionless) is quantified by the quotient of hip vertical velocity to its height (VZhip/ Zhip). Zhip will be obtained as the vertical distance of the bilateral hip midpoint to the surface of the platform and its vertical velocity (VZhip), as the first-order differentiation of hip height. Its positive direction is upward. Higher values indicate better vertical limb support.
Change in Perturbation-evoked potentials
时间窗: Pre-training (during week 2 i.e., Session 2), Post-training (during week 9 i.e., Session 16)
Data from different midline electroencephalographic (EEG) channels overlying lower limb frontal, sensorimotor and parietal regions will be used to extract the perturbation-evoked potentials (P1, N1, P2 and N2) to assess their spatio-temporal parameter (amplitude: microvolts, latency: seconds)
Change in time-frequency power
时间窗: Pre-training (during week 2 i.e., Session 2), Post-training (during week 9 i.e., Session 16)
Data from different midline electroencephalographic channels overlying lower limb frontal, sensorimotor, and parietal regions will be used to extract the alpha, beta, theta, and gamma power (decibels). Higher values indicate more frequency power.
Change in Falls
时间窗: Pre-training (during week 2 i.e., Session 2), Post-training (during week 9 i.e., Session 16)
A fall will be detected when the force exerted through the safety-harness load cell exceeds 30% of a person's body weight and verified with video analysis. Otherwise, the trial will be a balance recovery. Higher percentages indicate more falls.
Change in Reactive Stability
时间窗: Pre-training (during week 2 i.e., Session 2), Post-training (during week 9 i.e., Session 16)
Reactive stability (dimensionless) will be measured at the time point of compensatory limb touchdown after slipping. Stability will be calculated as the shortest distance from the COM state to the backward balance loss threshold. The instantaneous COM state is determined by its position and velocity (computed from filtered marker data) relative to the BOS, normalized respectively to foot length and the square root of the product of gravitational acceleration and body height. Higher values indicate better reactive stability.
Change in Muscle synergies
时间窗: Pre-training (during week 2 i.e., Session 2), Post-training (during week 9 i.e., Session 16)
To assess the muscular synergies, electromyography sensors will be applied to four muscle groups on both lower limbs. The muscle groups include tibialis anterior, gastrocnemius, quadriceps and hamstring group of muscles. Higher values indicate more muscle synergies.
Change in Proactive Stability
时间窗: Pre-training (during week 2 i.e., Session 2), Post-training (during week 9 i.e., Session 16)
Proactive stability (dimensionless) will be measured at the time point of slipping limb touchdown i.e., before slipping. Stability will be calculated as the shortest distance from the COM state to the backward balance loss threshold. The instantaneous COM state is determined by its position and velocity (computed from filtered marker data) relative to the BOS, normalized respectively to foot length and the square root of the product of gravitational acceleration and body height. Higher values indicate better proactive stability.
次要结局
- Change in Step length(Pre-training (during week 2 i.e., Session 2), Post-training (during week 9 i.e., Session 16))
- Change in Margin of Stability(Pre-training (during week 2 i.e., Session 2), Post-training (during week 9 i.e., Session 16))
- Change in Step initiation time(Pre-training (during week 2 i.e., Session 2), Post-training (during week 9 i.e., Session 16))
研究者
Tanvi Bhatt
Full Professor
University of Illinois at Chicago