TY - JOUR
T1 - Altered Triceps Surae Muscle-Tendon Unit Properties after 6 Months of Static Stretching
AU - Moltubakk, Marie M
AU - Villars, Fabienne O
AU - Magulas, Melina M
AU - Magnusson, Stig P
AU - Seynnes, Olivier R
AU - Bojsen-Møller, Jens
N1 - Copyright © 2021 by the American College of Sports Medicine.
PY - 2021/9/1
Y1 - 2021/9/1
N2 - INTRODUCTION: This study examined the effects of 24 wk of daily static stretching of the plantarflexors (unilateral 4 × 60-s stretching, whereas the contralateral leg served as a control; n = 26) on joint range of motion (ROM), muscle-tendon unit morphological and mechanical properties, neural activation, and contractile function.METHODS: Torque-angle/velocity was obtained in passive and active conditions using isokinetic dynamometry, whereas muscle-tendon morphology and mechanical properties were examined using ultrasonography.RESULTS: After the intervention, ROM increased (stretching, +11° ± 7°; control, 4° ± 8°), and passive torque (stretching, -10 ± 11 N·m; control, -7 ± 10 N·m) and normalized EMG amplitude (stretching, -3% ± 6%; control, -3% ± 4%) at a standardized dorsiflexion angle decreased. Increases were seen in passive tendon elongation at a standardized force (stretching, +1.3 ± 1.6 mm; control, +1.4 ± 2.1 mm) and in maximal passive muscle and tendon elongation. Angle of peak torque shifted toward dorsiflexion. No changes were seen in tendon stiffness, resting tendon length, or gastrocnemius medialis fascicle length. Conformable changes in ROM, passive dorsiflexion variables, tendon elongation, and angle of peak torque were observed in the nonstretched leg.CONCLUSIONS: The present findings indicate that habitual stretching increases ROM and decreases passive torque, altering muscle-tendon behavior with the potential to modify contractile function.
AB - INTRODUCTION: This study examined the effects of 24 wk of daily static stretching of the plantarflexors (unilateral 4 × 60-s stretching, whereas the contralateral leg served as a control; n = 26) on joint range of motion (ROM), muscle-tendon unit morphological and mechanical properties, neural activation, and contractile function.METHODS: Torque-angle/velocity was obtained in passive and active conditions using isokinetic dynamometry, whereas muscle-tendon morphology and mechanical properties were examined using ultrasonography.RESULTS: After the intervention, ROM increased (stretching, +11° ± 7°; control, 4° ± 8°), and passive torque (stretching, -10 ± 11 N·m; control, -7 ± 10 N·m) and normalized EMG amplitude (stretching, -3% ± 6%; control, -3% ± 4%) at a standardized dorsiflexion angle decreased. Increases were seen in passive tendon elongation at a standardized force (stretching, +1.3 ± 1.6 mm; control, +1.4 ± 2.1 mm) and in maximal passive muscle and tendon elongation. Angle of peak torque shifted toward dorsiflexion. No changes were seen in tendon stiffness, resting tendon length, or gastrocnemius medialis fascicle length. Conformable changes in ROM, passive dorsiflexion variables, tendon elongation, and angle of peak torque were observed in the nonstretched leg.CONCLUSIONS: The present findings indicate that habitual stretching increases ROM and decreases passive torque, altering muscle-tendon behavior with the potential to modify contractile function.
KW - Electromyography
KW - Female
KW - Humans
KW - Male
KW - Muscle Contraction/physiology
KW - Muscle Stretching Exercises/physiology
KW - Muscle, Skeletal/diagnostic imaging
KW - Range of Motion, Articular/physiology
KW - Ultrasonography
KW - Young Adult
UR - http://www.scopus.com/inward/record.url?scp=85111599803&partnerID=8YFLogxK
U2 - 10.1249/MSS.0000000000002671
DO - 10.1249/MSS.0000000000002671
M3 - Journal article
C2 - 34398062
SN - 0195-9131
VL - 53
SP - 1975
EP - 1986
JO - Medicine and Science in Sports and Exercise
JF - Medicine and Science in Sports and Exercise
IS - 9
ER -