Research Projects

Asymmetric gait in stroke patients is commonly associated with slow walking speeds and poor gait economy. The paretic limb often produces a longer step length compared to the non-paretic limb in response to reduced propulsive force of the paretic limb, leading to step length asymmetry and other spatiotemporal gait imbalances. Long-term consequence of untreated gait asymmetry includes reduced dynamic balance stability, musculoskeletal imbalances causing pain and joint degeneration, and lower activity levels. Gait training aims to relearn and to adapt new movement patterns through controlled training paradigm, a process called gait motor adaptation. Split-belt treadmill training method in stroke patients has shown to improve step length symmetry by exaggerating step length asymmetry i.e., augmenting error during training. The error augmentation through split-belt training achieved by moving one leg faster than other is the key principle strategy to invoke the sensorimotor system to correct the induced asymmetry. This strategy works better than the intervention that corrects the movement errors through feed forward methods such as through robotic assistive devices. This is because error augmentation allows the patients nervous system to actively engage and respond to the induced error (asymmetry). Despite its benefits, split-belt treadmill training method has major drawbacks. The retentions post training from the split-belt treadmill is short lived and after effects are poorly translated to the overground real-life walking scenario, reducing its practical utility. Also, treadmill is bulky, costly, and often confined to rehabilitation centers, limiting accessibility for many patients. These challenges underscore the need for alternative solutions. In this project, I propose passive hip exosuit as a promising alternative and practical solution for the real-life overground asymmetry training in stroke patients. Unlike treadmills, the exosuit is lightweight, portable, and affordable, making it suitable for clinical and home use. It uses elastic resistance bands to create moment at the hip joint. Placement of the elastic bands in the asymmetric settings across the hip joint could produce split-belt treadmill like gait adaptation effects. By targeting hip joint torque asymmetry, the exosuit may facilitates spatiotemporal gait adjustment including step length adjustments thus improving gait symmetry through error augmentation. This enhances the practical transfer of training benefits to real-world activities. In this project, first I aim to develop passive hip exosuit and then to test the feasibility of different asymmetric settings of the exosuit in inducing gait asymmetry. In the last, I aim to investigate the effect of the exosuit training and the effectiveness of the training transfer to overground walking among stroke patients.