Effect of robotic exoskeleton training on lower limb function, activity and participation in stroke patients: a systematic review and meta-analysis of randomized controlled trials

Useless!  You didn't exactly specify which ones worked and the protocols to go with them.

Effect of robotic exoskeleton training on lower limb function, activity and participation in stroke patients: a systematic review and meta-analysis of randomized controlled trials

Juncong Yang^1†‡Yongxin Zhu^1†‡Haojie Li²Kun Wang¹Dan Li¹Qi Qi^1,3*‡

• ¹Shanghai YangZhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Shanghai, China
• ²School of Exercise and Health, Shanghai University of Sport, Shanghai, China
• ³School of Medicine, Tongji University, Shanghai, China

Background: The current lower limb robotic exoskeleton training (LRET) for treating and managing stroke patients remains a huge challenge. Comprehensive ICF analysis and informative treatment options are needed. This review aims to analyze LRET’ s efficacy for stroke patients, based on ICF, and explore the impact of intervention intensities, devices, and stroke phases.

Methods: We searched Web of Science, PubMed, and The Cochrane Library for RCTs on LRET for stroke patients. Two authors reviewed studies, extracted data, and assessed quality and bias. Standardized protocols were used. PEDro and ROB2 were employed for quality assessment. All analyses were done with RevMan 5.4.

Results: Thirty-four randomized controlled trials (1,166 participants) were included. For function, LRET significantly improved motor control (MD = 1.15, 95%CI = 0.29–2.01, p = 0.009, FMA-LE), and gait parameters (MD = 0.09, 95%CI = 0.03–0.16, p = 0.004, Instrumented Gait Velocity; MD = 0.06, 95%CI = 0.02–0.09, p = 0.002, Step length; MD = 4.48, 95%CI = 0.32–8.65, p = 0.04, Cadence) compared with conventional rehabilitation. For activity, LRET significantly improved walking independence (MD = 0.25, 95%CI = 0.02–0.48, p = 0.03, FAC), Gait Velocity (MD = 0.07, 95%CI = 0.03–0.11, p = 0.001) and balance (MD = 2.34, 95%CI = 0.21–4.47, p = 0.03, BBS). For participation, social participation (MD = 0.12, 95%CI = 0.03–0.21, p = 0.01, EQ-5D) was superior to conventional rehabilitation. Based on subgroup analyses, LRET improved motor control (MD = 1.37, 95%CI = 0.47–2.27, p = 0.003, FMA-LE), gait parameters (MD = 0.08, 95%CI = 0.02–0.14, p = 0.006, Step length), Gait Velocity (MD = 0.11, 95%CI = 0.03–0.19, p = 0.005) and activities of daily living (MD = 2.77, 95%CI = 1.37–4.16, p = 0.0001, BI) for the subacute patients, while no significant improvement for the chronic patients. For exoskeleton devices, treadmill-based exoskeletons showed significant superiority for balance (MD = 4.81, 95%CI = 3.10–6.52, p < 0.00001, BBS) and activities of daily living (MD = 2.67, 95%CI = 1.25–4.09, p = 0.00002, BI), while Over-ground exoskeletons was more effective for gait parameters (MD = 0.05, 95%CI = 0.02–0.08, p = 0.0009, Step length; MD = 6.60, 95%CI = 2.06–11.15, p = 0.004, Cadence) and walking independence (MD = 0.29, 95%CI = 0.14–0.44, p = 0.0002, FAC). Depending on the training regimen, better results may be achieved with daily training intensities of 45–60 min and weekly training intensities of 3 h or more.

Conclusion: These findings offer insights for healthcare professionals to make effective LRET choices based on stroke patient needs though uncertainties remain. Particularly, the assessment of ICF participation levels and the design of time-intensive training deserve further study.

Systematic review registration: https://www.crd.york.ac.uk/PROSPERO, Unique Identifier: CRD42024501750.

Introduction

Stroke, the second leading global cause of death and a significant contributor to disability (1, 2), often leaves survivors grappling with long-term issues like impaired movement and reduced participation (3). Among these challenges, lower limb motor impairment stands out as a common residual symptom, marked by problems like slow gait velocity, hemiparetic gait, balance dysfunction and lack of endurance and poor mobility (4, 5). Of these, over 80% of stroke patients suffer from walking impairment (6), significantly impacting their independence and quality of life, ultimately preventing their participation in activities of daily living (7). Consequently, improving ambulation has become the primary goal of lower extremity rehabilitation for stroke patients. And the rehabilitation process should focus on changes in function, activity and participation levels at the same time, in order to more comprehensively help patients regain their walking independence and improve their quality of life and return to the society.

In recent years, lower limb exoskeleton robots have become a hotspot in both research and clinical applications. They offer standardized rehabilitation training and aid daily activities to enhance participation (8, 9). Compared with conventional rehabilitation methods, LRET strengthens the functional connections between the central nervous system and the lower limbs (10, 11). Through providing patients with correct proprioceptive inputs in ergonomic posture, these robots guides patients in mimicking natural walking patterns (4, 12, 13). Exoskeletons also provide repetitive, quantitative training, high-dosage and task-oriented training, overcoming limitations of conventional rehabilitation. They have advantages such as conserving therapist energy and ensuring patient safety during movement (10, 14, 15).

However, the effectiveness of LRET for stroke patients varies, with previous meta-analyses yielding inconsistent results. While some studies examined a wide range of robotic devices, they lacked detailed analysis of exoskeletal robots (16, 17). Others focused on functional or activity levels, neglecting stroke-specific outcomes (18). Moreover, subjective measures were often used, which may introduce bias (11, 12, 19). Objective measures, such as gait velocity, are crucial for assessing walking function and mobility after stroke, and appropriate gait velocity is also a key factor in social participation (20). Measurements of gait velocity include clinical walking tests or gait analysis. Clinical walking tests focus on assessing the overall walking ability of patients, usually conducted in a controlled environment to measure the maximum stable gait velocity. Gait analysis is a more comprehensive evaluation method that uses advanced technology to analyze the biomechanical characteristics of walking in detail, including multiple parameters such as step length, cadence, stride length, step width and detailed characteristics of each stage. Gait analysis can reveal the specific causes of walking disorders and provide more precise guidance for treatment (21). However, none of the current meta-analyses have distinguished between them (16, 17, 22). Recent systematic reviews have shown that high-quality clinical data and convincing evidence are very limited in clinical studies on LRET (4), emphasizing the need for rigorous RCTs and objective outcome measures.

Currently, treating and managing stroke patients remains a challenge. While numerous methods exist to improve lower limb dysfunction post-stroke, they all require individualization(Well then find the commonalities and write those protocols. That excuse you are using is a fireable offense!), complicating standardization in clinical studies and leading to inconsistent findings (4, 12). Differences in effectiveness across studies might hinge on factors such as training intensity, frequency and duration (14, 23). High-intensity exercises have demonstrated effectiveness in enhancing physiotherapy outcomes (24, 25). However, sustaining high intensity poses a significant challenge due to time and cost constraints for therapists and patients alike (26). Although existing Lower limb exoskeleton robots can provide repetitive high-intensity task-oriented training for stroke patients, the optimal frequency and duration of such training have not been systematically analyzed (23). Therefore, further examination of the differential effects of various training regimens is necessary to maximize the effectiveness of lower limb exoskeleton robots in aiding stroke patients’ recovery. This will play a crucial role in improving lower limb function, activity, and participation.

The aim of this systematic review and meta-analysis is threefold: Firstly, to focus and update the rehabilitative effects across three levels of the International Classification of Functioning, Disability, and Health (ICF) on LRET of stroke patients (27). Secondly, by focusing on objective primary outcomes, we will conduct subgroup analyses on training intensity, providing valuable insights for clinical therapists in devising training protocols. Lastly, we will analyze data from different stroke phases (subacute, chronic) and various devices (treadmill-based, over-ground) to inform clinical decision-making, facilitating the creation of more individualized and targeted training protocols for stroke patients.

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