Effects of repeated ankle plantar-flexions on H-reflex and body sway during standing

Citation

Laudani L, Wood L, Casabona A, Giuffrida R & De Vito G (2009) Effects of repeated ankle plantar-flexions on H-reflex and body sway during standing. Journal of Electromyography and Kinesiology, 19 (1), pp. 85-92. https://doi.org/10.1016/j.jelekin.2007.06.012

Abstract
The study investigated relations between effects of repeated ankle plantar-flexion movements exercise on the soleus Hoffmann (H) reflex and on postural body sway when maintaining upright stance. Ten young volunteers performed five sets of ankle plantar-flexions of both lower limbs. Assessment of the feet centre-of-pressure (COP) displacement and H-reflex tests were carried out in quiet stance before, during and after the exercise. H-max and M-max responses were obtained in 8 subjects and reported as the peak-to-peak amplitudes of the right soleus muscle electromyographic waves. Mean dispersion of COP along the antero-posterior direction increased significantly during the exercise; whilst the overall H-reflex response indicated a reduction without a concomitant modification in the M-max response. H-reflex responses, however, varied between participants during the first sets of exercise, showing two main trends of modulation: either depression or early facilitation followed by reduction of the H-reflex amplitude. The extent of reflex modulation in standing position was correlated to the concentric work performed during the exercise (r=0.85; p

Keywords
Dynamic contractions; Stretch reflex; Post-exercise potentiation; Stance; Physical fitness; Posture; Standing position; Human mechanics

Journal
Journal of Electromyography and Kinesiology: Volume 19, Issue 1