Abstract Rationale Chronic respiratory disease is among the most prevalent diseases with disabling consequences. Many with advanced CRD cannot support the metabolic energy demands of walking causing them to walk slower and stop often. A powered wearable exoskeleton could assume part of the energy of walking. Assisting the legs will lower the metabolic energy demand and, therefore, the ventilation required, thereby allowing them to walk longer. In a previous study (Dolmage and Goldstein 2022), the weight of the exoskeleton compromised walking tolerance. The current study investigates a lighter commercially available exoskeleton. This study is a series of single-case experiments comparing walking endurance with and without a powered hip exoskeleton assist. Each case (n = 1) stands alone as a prospective analyzable and interpretable experiment. The aim of this study is to determine the efficacy the exoskeleton on walking endurance in ventilatory limited patients with CRD. We present preliminary results here. Methods This is a prospective longitudinal, self-controlled, single-case repeated measures alternating treatment, randomized and counterbalanced cross-over experimental trial design (N of 1 trials), comparing walking endurance without (control) and with a powered exoskeleton. The exoskeleton includes a rigid outer frame, sensors that detect a user’s desired movements, a computerized controller and motors to provide assist at the hip joints powered by a lightweight battery. The primary outcome is the difference in the time limit of endurance determined using equal constant speed endurance walk test. Walk speed was achieved immediately to a speed considered a brisk walk for the individual and conducted along a 40 m, indoor, stadium shaped track with markers at every 5 meters. In each test, the participant kept pace with the investigator walking at the individualized set speed guided by an audio signal. When the participant stopped, the endurance time was recorded. Results The results of 6 participants (mean±SD: age 64±8; mMRC=2.7±1.5; Usual Walk speed=63.3±14.8 m/min; 6MWT distance=392±60 m) are presented in the Figure. The control walks averaged 6.71±1.89 min. Three of 6 participants demonstrated a statistically significant (p 0.10) effect of exoskeleton assist. However, no participant consistently exceeded an approximated practical meaningful improvement (2.83–4.70 min). Conclusions Advances applied to the design of this exoskeleton demonstrate, using Level 1 evidence (Phillips, Ball et al. 1998), the potential to improve walking tolerance in individuals with CRD. An exoskeleton could be a novel immediate and long term strategy to augment walking as part of the spectrum of pulmonary rehabilitation and community reintegration. This abstract is funded by: supported by West Park Healthcare Foundation Robert J. Harman Respirology Research Fund and the National Sanitarium Association Chair in Respiratory Rehabilitation Research at West Park Health Care Centre (UHN)
Dolmage et al. (Fri,) studied this question.