Acute effects of passive stretching on the electromechanical delay and evoked twitch properties

Abstract

The purpose of this study was to investigate the acute effects of passive stretching on the electromechanical delay (EMD), peak twitch force (PTF), rate of force development (RFD), and compound muscle action potential (M-wave) amplitude during evoked twitches of the plantar flexor muscles. 16 men (mean age +/- SD = 21.1 +/- 1.7 years; body mass = 75.9 +/- 11.4 kg; height = 176.5 +/- 8.6 cm) participated in this study. A single, square-wave, supramaximal transcutaneous electrical stimulus was delivered to the tibial nerve before and after passive stretching. The stretching protocol consisted of nine repetitions of passive assisted stretching designed to stretch the calf muscles. Each repetition was held for 135 s separated by 5-10 s of rest. Dependent-samples t tests (pre- vs. post-stretching) were used to analyze the EMD, PTF, RFD, and M-wave amplitude data. There were significant changes (P < or = 0.05) from pre- to post-stretching for EMD (mean +/- SE = 4.84 +/- 0.31 and 6.22 +/- 0.34 ms), PTF (17.2 +/- 1.3 and 15.6 +/- 1.5), and RFD (320.5 +/- 24.5 and 279.8 +/- 28.2), however, the M-wave amplitude did not change (P > 0.05). These findings suggested that passively stretching the calf muscles affected the mechanical aspects of force production from the onset of the electrically evoked twitch to the peak twitch force. These results may help to explain the mechanisms underlying the stretching-induced force deficit that have been reported as either "mechanical" or "electrical" in origin.

Age-related mobility loss is joint-specific: an analysis from 6,000 Flexitest results

“…Although, flexibility or stretching routines are currently recommended as part of an exercise session, surprisingly the prescription tend to be general and non-individualized. On the other hand, more often these exercises are included at the end of the session, attempting to avoid potential deleterious effects on strength performance (Costa et al 2011(Costa et al , 2010Gleim and McHugh 1997;Rubini et al 2007).…”

Electromechanical Delay of the Vastus Medialis Obliquus and Vastus Lateralis in Individuals With Patellofemoral Pain Syndrome

“…5 In addition, the duration of EMD is dependent on the mechanical properties of tendon structures. 24 It is speculated that a decrease in stiffness of tendon structures, which means a decrease in the ability to transmit muscle force, plays an important role in increasing the duration of the EMD.…”

“…EMD is affected by muscle fatigue, 29 muscle length, 21 muscle training, 11,17,19 passive muscle stretching, 5 and the type of muscle activation. 15 Indeed, it has been reported that VL and peroneus longus EMDs were significantly longer in patients with anterior cruciate ligament reconstruction 15 and unstable ankles, 13,20 respectively, compared to healthy individuals.…”

“…All individuals with PFPS had anterior knee pain when performing at least 2 of the following activities: stair climbing, prolonged sitting, kneeling, squatting, running and hopping, or jumping. 6 All patients were referred by an orthopaedic physician. Twenty-six healthy age-and gendermatched volunteers participated in the study as a control group.…”

Validação do instrumento de medida da resistência da musculatura espástica flexora de punho e dedos

“…Além do reflexo do estiramento muscular dependente da velocidade em que há o aumento da resistência à movimentação passiva, a espasticidade tem como consequências a restrição da amplitude articular, o que interfere na função motora dificultando atividades, causando dor, desconforto muscular, deformidades ou mesmo contraturas (CHEN, et al, 2005;COSTA et al, 2010;LEE et al, 2008;RODGERS et al, 2010;TIEVE;ZONTA;KUMAGAI, 1998).…”