Differential effects of an acute bout of passive stretching on maximal voluntary torque and the rate of torque development of the calf muscle-tendon unit

Issue title: Selected papers and Abstracts of the "XXXIVèmes Entretiens de Mèdecine Physique et Réadaptation", Isokinetics 2007: An update, Montpellier, France, March 2007

Article type: Research Article

Authors: Maisetti, O.^{a; b} | Sastre, J.^a | Lecompte, J.^{b; c} | Portero, P.^{a; b}

Affiliations: [a] UFR SESS/STAPS, Université Paris XII, 61 avenue du Général de Gaule, 94010 Créteil, France | [b] Institute of Myology, Groupe Hospitalier Pitié-Salpêtrière, 83 boulevard de l'Hôpital, 75651 Paris Cedex 13, France | [c] Airforce Aerospace Medical Research Institute (IMASSA) BP 73, Bretigny-sur-Orge 91223, France

Note: [] Address for correspondence: Pr Pierre Portero, Service de Rééducation Neuro-Orthopédique, Inserm U731/UPMC, Hôpital Rothschild, 33 Boulevard de Picpus, 75012 Paris, France. Tel.: +33 140193097; Fax: +33 140193205; E-mail: [email protected]

Abstract: This study was aimed to examine the impact of acute stretching on the rate of force development (RFD) of the plantar flexors (PF). Eleven physically active female subjects participated in the study. The right calf muscle-tendon unit was stretched during five passive cyclic slow stretches (5°/s) that consisted of a dynamic ascending stretch phase to a pre-determined final joint angle (80% of maximal dorsiflexion angle) and a 15~s hold phase. Maximal isometric torque (MVC) of PF and dorsiflexors (DF) and the RFD of PF were determined before, immediately and 30min following stretching. Changes in passive stiffness, passive resistive torque and torque relaxation of PF were computed during stretching. Passive characteristics decreased significantly during stretching (−11 to −27%, P<0.01). DF MVC did not change following stretching but there was a significant decrease in PF MVC immediately and after 30 min of recovery (−10%, P< 0.001). In contrast, PF RFD remained unaltered following stretching (P>0.05). These results indicate that passive stretching (< 5 min) can be applied without altering the capacity to develop torque rapidly under isometric condition up to 75% of MVC despite significant MVC impairment. These findings may have practical implications for stretching undertaken during rehabilitation or sport training.

Keywords: Acute stretching, rate of force development, passive stiffness, recovery

DOI: 10.3233/IES-2007-0265

Journal: Isokinetics and Exercise Science, vol. 15, no. 1, pp. 11-17, 2007