Quality, kinematics, and self-reported comfort of gait during body weight support in young adults with gait impairments - A cross-sectional study

Background: Body weight support (BWS) technologies offer effective gait training for individuals with neurological gait impairments. However, varying dynamic BWS levels may impact specific gait kinematics, potentially introducing maladaptive movement patterns. Aim: To investigate the acute impact of different levels of dynamically modulated BWS during overground walking at a self-selected speed on gait quality, kinematic gait patterns, and self-reported gait comfort in young adults with gait impairments. Methods: Three-dimensional gait analysis was conducted on 18 individuals with neurological gait impairments during overground walking with 0, 10, 20, 30, 40, and 50 % BWS using a novel robotic unloading device. Gait quality, expressed as Gait Deviation Index (GDI), lower limb joint kinematics, and spatiotemporal parameters were obtained for one representative stride per participant at each BWS level. Gait comfort was reported on a visual analogue scale (VAS) for each unload level. Time-continuous data were analysed using statistical parametric mapping; discrete data were compared between BWS levels using paired t-tests. Results: Compared with habitual gait (0 % BWS), GDI was unaltered with increasing BWS. The relative shapes of kinematic trajectories were largely unaffected, with minor reductions in amplitude and a limited impact on temporal effects with increasing BWS. Most spatiotemporal parameters were unaltered by changes in BWS, although negative impacts on walking speed, cadence, and step length emerged at 40 % BWS, with a more pronounced impact at 50 % BWS. Gait comfort improved at 20-30 % BWS by up to 20 mm on a 0-100 mm VAS. Conclusion: Participants maintained habitual (0 % BWS) biomechanical gait patterns with 10-30 % BWS, experiencing increased gait comfort at 20-30 % BWS. Dynamically modulated BWS can be applied in task- specific gait training to offer vertical body support and increased comfort with little to no impact on biomechanical movement patterns.