Static Stretching Intensity Does Not Influence Acute Range of Motion, Passive Torque, and Muscle Architecture

Abstract

Context: Although stretching exercises are commonly used in clinical and athletic practice, there is a lack of evidence regarding the methodological variables that guide the prescription of stretching programs, such as intensity. Objective: To investigate the acute effects of different stretching intensities on the range of motion (ROM), passive torque, and muscle architecture. Design: Two-group pretest–posttest design. Setting: Laboratory. Participants: Twenty untrained men were allocated into the low- or high-intensity group. Main Outcome Measures: Subjects were evaluated for initial (ROMinitial) and maximum (ROMmax) discomfort angle, stiffness, viscoelastic stress relaxation, muscle fascicle length, and pennation angle. Results: The ROM assessments showed significant changes, in both groups, in the preintervention and postintervention measures both for the ROMinitial (P < .01) and ROMmax angle (P = .02). There were no significant differences for stiffness and viscoelastic stress relaxation variables. The pennation angle and muscle fascicle length were different between the groups, but there was no significant interaction. Conclusion: Performing stretching exercises at high or low intensity acutely promotes similar gains in flexibility, that is, there are short-term/immediate gains in ROM but does not modify passive torque and muscle architecture.

The Relationship between Stretching Intensity and Changes in Passive Properties of Gastrocnemius Muscle-Tendon Unit after Static Stretching

“…Previous studies have reported that higher-intensity SS affects ROM changes and muscle-tendon stiffness when compared within same subjects [9,11]. On the other hand, as described above, no significant difference was observed between ROM changes and stretching intensity when compared between each subject [10]. Therefore, it was hypothesized that a higher relative intensity of SS is more effective in inducing changes in ROM and passive properties, but absolute intensity of SS might not be related to changes in ROM and passive properties.…”

“…A previous study has reported that 120% ROM stretching intensity affects ROM and the passive properties compared to 100% ROM stretching intensity for the same subjects, i.e., relative intensity. Conversely, a previous study has reported that there is no significant difference in ROM change between the stretching intensity defined as the angle when high or low sensation of stretching felt for each subjects as the stretching intensity [10]. Therefore, it is possible that the difference in setting stretching intensity could influence the effects of SS on ROM and passive property.…”

“…Similarly, Kataura et al (2017) have reported that a high-intensity SS has a greater effect on changes in ROM and passive stiffness than low-intensity SS [ 9 ]. Conversely, Santos et al (2019) have reported that ROM significantly increases after SS, but no significant difference was observed in ROM change between high- and low-intensity SS [ 10 ]. Therefore, no consensus was found on the effect of stretching intensity on ROM and muscle-tendon stiffness.…”

High-Intensity Static Stretching in Quadriceps Is Affected More by Its Intensity Than Its Duration

“…The stress of static stretching increases with stretching duration and intensity. Santos et al (2020) reported that the muscle-tendon unit stiffness of the hamstrings did not change after 3-min of high-intensity static stretching at the intensity of the numerical rating scale (NRS) Levels 9–10 (an NRS of Level 10 indicates the worst possible discomfort). On the other hand, Kataura et al (2017) showed that 3-min of static stretching at the intensity of 120% ROM (NRS Level 5) effectively decreased the muscle-tendon unit stiffness of the hamstrings.…”

Strength training is as effective as stretching for improving range of motion: A systematic review and meta-analysis.

“…[16] Stretching techniques include static (active or passive), dynamic, or proprioceptive neuromuscular facilitation (PNF), all of which can improve ROM. [1,[17][18][19][20] However, reduced ROM and muscle weakness are deeply associated. [21][22][23] Therefore, although strength training (ST) primarily addresses muscle weakness through methods such as resistance training or similar protocols, it has been shown to increase ROM in athletic populations, [24,25] as well as in healthy elderly people [26] and women with chronic nonspecific neck pain.…”