Timing of propulsion-related biomechanical variables is impaired in individuals with post-stroke hemiparesis

• Published in: Gait & posture 2022-07, Vol.96, p.275-278
• Main Authors: Alam, Zahin, Rendos, Nicole K., Vargas, Alex M., Makanjuola, Joseph, Kesar, Trisha M.
• Format: Article
• Language: English
• Subjects: Biomechanical Phenomena; Gait; Gait training; Humans; Paresis - etiology; Post-stroke Hemiparesis; Propulsion; Push-off; Stroke - complications; Stroke gait biomechanics; Stroke Rehabilitation; Walking
• ISSN: 0966-6362; 1879-2219
• DOI: 10.1016/j.gaitpost.2022.05.022

In individuals with post-stroke hemiparesis, reduced paretic leg propulsion, measured through anterior ground reaction forces (AGRF), is a common and functionally-relevant gait impairment. Deficits in other biomechanical variables such as plantarflexor moment, ankle power, and ankle excursion contribute to reduced propulsion. While reduction in the magnitude of propulsion post-stroke is well studied, here, our objective was to compare the timing of propulsion-related biomechanical variables. Are there differences in the timing of propulsion and propulsion-related biomechanical variables between able-bodied individuals, the paretic leg, and non-paretic leg of post-stroke individuals? Nine able-bodied and 13 post-stroke individuals completed a gait analysis session comprising treadmill walking trials at each participant’s self-selected speed. Two planned independent sample t-tests were conducted to detect differences in the timing of dependent variables between the paretic versus non-paretic leg post-stroke and paretic leg versus the dominant leg of able-bodied individuals. Post-stroke individuals demonstrated significantly earlier timing of peak AGRF of their paretic leg versus their non-paretic leg and able-bodied individuals. Post-stroke participants displayed earlier timing of peak power of their paretic leg versus their non-paretic leg and able-bodied individuals, and earlier timing of peak ankle moment of the paretic leg versus able-bodied. No significant differences were detected in the timing of peak ankle angle. The earlier onset of peak AGRF, peak ankle power, and peak ankle moment may be an important, under-studied biomechanical factor underlying stroke gait impairments, and a potential therapeutic target for stroke gait retraining. Future investigations can explore the use of interventions such as gait biofeedback to normalize the timing of these peaks, thereby improving propulsion and walking function post-stroke. •We show earlier onset of peak AGRF, power, and moment during the gait cycle in the stroke paretic leg.•Abnormal timing may be an under-studied yet important stroke gait impairment.•Future studies can investigate if biofeedback may normalize abnormal timing.