Acute effects of passive stretching on the electromechanical delay and evoked twitch properties: a gender comparison

J Appl Biomech. 2012 Dec;28(6):645-54. doi: 10.1123/jab.28.6.645.

Abstract

This study examined the acute effects of passive stretching on electromechanical delay (EMD), peak twitch force (PTF), rate of force development (RFD), and peak-to-peak M-wave (PPM) for the soleus muscle during evoked isometric plantar flexion muscle actions. Fourteen men (mean age ± SD = 21.2 ± 2.4 years; body mass = 80.0 ± 14.9 kg; height = 176.9 ± 7.2 cm) and 20 women (20.9 ± 2.5 years; 61.3 ± 8.9 kg; 165.3 ± 7.5 cm) volunteered for the study. Five single-square, supramaximal transcutaneous electrical stimuli (each separated by 5 s) were delivered to the tibial nerve before and after passive stretching. A time × gender interaction was observed for EMD, and the post hoc dependent-samples t tests indicated that EMD increased 4% for the women (p = .023), but not for the men (p = .191). There were no other stretching-related changes for PTF, RFD, or p-p M-wave for either the men or women (p > .05). These findings tentatively suggested that mechanical factors related to the stiffness of the muscle-tendon unit may contribute to the explanation for why stretching caused an acute increase in the EMD during evoked twitches in the women, but not in the men.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Female
  • Humans
  • Isometric Contraction / physiology*
  • Male
  • Motor Neurons / physiology*
  • Muscle Stretching Exercises / methods*
  • Neural Conduction / physiology*
  • Neuromuscular Junction / physiology*
  • Sex Factors