Stretching combined with repetitive small length changes of the plantar flexor muscles enhances their passive extensibility for longer duration than conventional static stretching, while not compromising strength

Abstract

accompanied by a significantly larger muscle elongation but not tendon elongation. Elevated 36 dorsiflexion range of motion was maintained until 30 min after the local vibration stretching 37 while it returned to baseline level (pre-intervention) in 15 min after the static stretching. 38All variables remained unchanged in the control condition. In conclusion, local vibration 39 stretching improves extensibility of the muscle belly without decreasing strength, and the 40 increased flexibility is retained longer than static stretching.

Minute oscillation stretching: A novel modality for reducing musculo‐tendinous stiffness and maintaining muscle strength

“…For the MOS condition, the dynamic stretching device was used for plantar flexion and dorsiflexion of the ankle joint by approximately 5° (Figure 1), which was repeated at a frequency of 15 Hz for 1 minute. 12 For the control condition, the subjects were instructed to rest in a sitting position on the dynamometer for 6 minutes, which was the same time allocated to the SS and MOS interventions, and to avoid stretching the plantar flexors.…”

“…Muscle function is known to be attenuated after SS of over 60 seconds per muscle group, 3,9,11 which may be attributed to the reduction in neuromuscular activity during force production in the stretching target muscle group. 11,18,19 MOS does not decrease muscle strength, which is unlike SS 12 ; thus, it may be presumed that neuromuscular activity during force production remains unchanged after MOS. The calculated RTD derived from the torque-duration curve during explosive force exertion is decreased after SS; that is, muscle force exertion becomes slower.…”

“…[5][6][7][8] However, SS has been shown to temporarily decrease muscle functions such as maximal muscle strength and explosive power exertion (often observed in sports, including the rate of torque development [RTD] or jump performance). 3,4,[9][10][11][12] Therefore, it is desirable to perform stretching that reduces musculo-tendinous stiffness and does not decrease muscle function.…”

“…We have reported that the MOS modality improves flexibility as well as SS without decreasing maximal muscle strength, unlike SS. 12 MOS is a modality of conditioning the MTU that provides repetitive small longitudinal length changes (stretch-shortening) to the plantar flexors by ankle joint movement undergoing passive stretch (dorsiflexion of approximately 5°, which is likely passive DS in the form of oscillation) ( Figure 1).…”

“…7,8,12,13 Moreover, the tendinous tissue stiffness, often assessed by the linear slope of the load-elongation relationship of the tendinous tissue during isometric force exertion, 5,6,14 is affected by tendinous tissue extensibility and is decreased after long-duration SS (>3 minutes). 5,6,15 A previous study has also shown that MOS increases gastrocnemius muscle elongation during passive dorsiflexion; however, it does not increase Achilles tendon elongation, 12 which differs from the findings for SS. However, this study only evaluated part of the load-elongation relationship of the tendinous tissue, while the change in tendinous tissue stiffness represented by the slope of the linear region under higher tension has not been verified yet.…”