Locomotor Kinematics and Kinetics Following High-Intensity Stepping Training in Variable Contexts Poststroke

Abstract

Background and Purpose Previous studies suggest individuals post-stroke can achieve substantial gains in walking function following high-intensity locomotor training (LT). Recent findings also indicate practice of variable stepping tasks targeting locomotor deficits can mitigate selected impairments underlying reduced walking speeds. The goal of this study was to investigate alterations in locomotor biomechanics following three different LT paradigms. Methods This secondary analysis of a randomized trial recruited individuals 18–85 years old and >6 months post-stroke. We compared changes in spatiotemporal, joint kinematics and kinetics following up to 30 sessions of high-intensity (>70% heart rate reserve [HRR]) LT of variable tasks targeting paretic limb and balance impairments (high-variable, HV), high-intensity LT focused only on forward walking (high-forward, HF), or low-intensity LT (<40% HRR) of variable tasks (low-variable, LV). Sagittal spatiotemporal and joint kinematics, and concentric joint powers were compared between groups. Regressions and principle component (PC) analyses were conducted to evaluate relative contributions or importance of biomechanical changes to between and within groups. Results Biomechanical data were available on 50 participants who could walk ≥0.1 m/s on a motorized treadmill. Significant differences in spatiotemporal parameters, kinematic consistency, and kinetics were observed between HV and HF vs LV. Resultant PC analyses were characterized by paretic powers and kinematic consistency following HV, while HF and LV were characterized by non-paretic powers. Conclusion High-intensity LT results in greater changes in kinematics and kinetics as compared to lower-intensity interventions. The results may suggest greater paretic-limb contributions with high-intensity variable stepping training that targets specific biomechanical deficits.