title: Effects of a 4-week static stretch training program on passive stiffness of human gastrocnemius muscle-tendon unit in vivo.
abstract: Static stretch is commonly used to prevent contracture and to improve joint mobility. However, it is unclear whether the components of the muscle-tendon unit are affected by a static stretch training program. This study investigated the effect of a four-week static stretch training program on the viscoelastic properties of the muscle-tendon unit and muscle. The subjects comprised 18 male participants (mean age 21.4 ± 1.7 years). The range of motion (ROM), passive torque, myotendinous junction (MTJ) displacement and, muscle fascicle length of the gastrocnemius muscle were assessed using both ultrasonography and a dynamometer while the ankle was passively dorsiflexed. After the initial test, the participants were assigned either to a group that stretched for 4 weeks (N = 9) or to a control group (N = 9). The tests were repeated after the static stretch training program. The ROM and MTJ displacement significantly increased, and the passive torque at 30° significantly decreased, in the stretching group after the study period. However, there was no significant increase in muscle fascicle length. These results suggest that a 4-week static stretch training program changes the flexibility of the overall MTU without causing concomitant changes in muscle fascicle length.
authors: Human Health Sciences, Graduate School of Medicine, Kyoto University, 53 Shogoin-Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan. M.Nakamura@ky5.ecs.kyoto-u.ac.jp
authors: Masatoshi
authors: M
authors: Nakamura
authors: Tome
authors: T
authors: Ikezoe
authors: Yohei
authors: Y
authors: Takeno
authors: Noriaki
authors: N
authors: Ichihashi
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000502:physiology*; D055119:Elastic Modulus / Q000502:physiology; D006801:Humans; D008297:Male; D052580:Muscle Stretching Exercises / Q000379:methods*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D013710:Tendons / Q000033:anatomy & histology / Q000502:physiology*; D014783:Viscosity