Effects of a High-Volume 7-Week Pectoralis Muscle Stretching Training on Muscle Function and Muscle Stiffness

Abstract

Background There is evidence that high-volume static stretching training of the lower limbs can increase the range of motion (ROM) while decreasing muscles stiffness. However, to date, there is no evidence on the effects of upper limb stretching training or its effect mechanism. Therefore, this study aimed to investigate the effects of a comprehensive 7-week static stretching training program of the pectoralis major muscle (PMa) on glenohumeral joint ROM, muscle force, and muscle stiffness. Methods Thirty-eight healthy, physically active participants (23 male, 15 female) were randomly assigned to either the PMa-static stretching intervention (PMa-SS) group or the control group. The PMa-SS group performed a 7-week intervention comprising three sessions a week for 15 min per session, including three static stretching exercises of the PMa for 5 min each. Before and after the intervention period, shoulder extension ROM, muscle stiffness of the PMa (pars clavicularis), and maximal voluntary isometric contraction (MVIC) peak torque (evaluated at both long (MVIClong) and short (MVICshort) muscle lengths) were investigated on a custom-made testing device at 45° shoulder abduction. Results In the PMa-SS group, the shoulder extension ROM (+ 6%; p < 0.01; d = 0.92) and the MVIClong (+ 11%; p = 0.01; d = 0.76) increased. However, there were no significant changes in MVICshort or in PMa muscle stiffness in the PMa-SS group. In the control group, no changes occurred in any parameter. Conclusion In addition to the increase in ROM, we also observed an improved MVIC at longer but not shorter muscle lengths. This potentially indicates an increase in fascicle length, and hence a likely increase in sarcomeres in series.

Effects of chronic static stretching interventions on jumping and sprinting performance–a systematic review with multilevel meta-analysis

“…The meta-analytical approaches might be seen as a supplementation to quantify results. Although some short duration stretching interventions sufficiently increased maximal strength ( Nelson et al, 2012 ; Mizuno 2019 ), consistent stretch-induced strength and muscle size increases were reported after longer stretching durations (≥10 min per session) ( Chen et al, 2011 ; Wohlann et al, 2023 ; Wohlann et al, 2024 , Warneke et al, 2022a , Reiner et al, 2023 ; Warneke et al, 2022). However, stretching durations of the included studies primarily used short stretching durations of a few minutes.…”

Seven weeks of pectoralis muscle stretching does not induce non‐local effects in dorsiflexion ankle range of motion

“…Indeed, the applied stretching stimulus of the pectoralis muscles is enough to induce local changes in ROM (i.e., shoulder extension) as have been shown in a previous study (Reiner et al, 2023).…”

Comparison of Supervised versus Self-Administered Stretching on Bench Press Maximal Strength and Force Development

“…Assuming a dose–response relationship, recent research enhanced the stretching duration up to 2 h per day for 6 weeks [ 30 ], showing highly consistent results in the plantar flexors. Similarly, upper-body-muscle static stretching induced pectoralis muscle hypertrophy [ 17 ] and strength increases [ 17 , 20 , 21 ].…”

“…Nevertheless, the plantar flexors can be considered a comparatively small muscle group with comparably low impact on multi-articular, complex (athletic) movements [ 15 , 16 ]. While Wohlann et al [ 17 ], Ikeda and Ryushi [ 18 ] and Chen et al [ 19 ] reported stretch-induced strength increases in the thigh muscles, Reiner et al [ 20 ], Warneke et al [ 21 ] and Wohlann et al [ 17 ] showed transferability to the upper body. Wohlann et al [ 17 ] pointed out that 15 min of supervised stretching has the potential to substitute high-intensity pectoralis resistance training.…”