Revising the stretch reflex threshold method to measure stretch hyperreflexia in cerebral palsy.

Autor:	Valadão P; Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland., Bar-On L; Department of Rehabilitation Sciences, Ghent University, Gent, Belgium.; Department of Rehabilitation Medicine, Amsterdam Movement Sciences, Amsterdam University Medical Centers, Amsterdam, Netherlands., Cenni F; Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland., Piitulainen H; Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.; Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland.; Motion Analysis Laboratory, Children and Adolescents, Helsinki University Hospital, Helsinki, Finland., Avela J; Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland., Finni T; Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
Jazyk:	angličtina
Zdroj:	Frontiers in bioengineering and biotechnology [Front Bioeng Biotechnol] 2022 Nov 23; Vol. 10, pp. 897852. Date of Electronic Publication: 2022 Nov 23 (Print Publication: 2022).
DOI:	10.3389/fbioe.2022.897852
Abstrakt:	Hyper-resistance is an increased resistance to passive muscle stretch, a common feature in neurological disorders. Stretch hyperreflexia, an exaggerated stretch reflex response, is the neural velocity-dependent component of hyper-resistance, and has been quantitatively measured using the stretch reflex threshold (i.e., joint angle at the stretch reflex electromyographic onset). In this study, we introduce a correction in how the stretch reflex threshold is calculated, by accounting for the stretch reflex latency (i.e., time between the stretch reflex onset at the muscle spindles and its appearance in the electromyographic signal). Furthermore, we evaluated how this correction affects the stretch reflex threshold in children and young adults with spastic cerebral palsy. A motor-driven ankle dynamometer induced passive ankle dorsiflexions at four incremental velocities in 13 children with cerebral palsy (mean age: 13.5 years, eight males). The stretch reflex threshold for soleus and medial gastrocnemius muscles was calculated as 1) the joint angle corresponding to the stretch reflex electromyographic onset (i.e., original method); and as 2) the joint angle corresponding to the electromyographic onset minus the individual Hoffmann-reflex latency (i.e., latency corrected method). The group linear regression slopes between stretch velocity and stretch reflex threshold differed in both muscles between methods ( p < 0.05). While the original stretch reflex threshold was velocity dependent in both muscles ( p < 0.05), the latency correction rendered it velocity independent. Thus, the effects of latency correction on the stretch reflex threshold are substantial, especially at higher stretch velocities, and should be considered in future studies. Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. (Copyright © 2022 Valadão, Bar-On, Cenni, Piitulainen, Avela and Finni.)
Databáze:	MEDLINE
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