title: Decrements in stiffness are restored within 10 min.
abstract: The purpose of this study was to clarify the temporal course of stiffness in the muscle-tendon unit after stretching. In 11 male participants, displacement of the myotendinous junction on the gastrocnemius medialis muscle was measured ultrasonographically during the passive-dorsiflexion test, with the ankle was passively dorsiflexed at 1 °/s to the end of the range of motion. Passive torque, representing resistance to stretch, was also measured using an isokinetic dynamometer. On 4 different days, passive-dorsiflexion tests were performed before and immediately, 5, 10 or 15 min after stretching, which comprised dorsiflexion to end range of motion and holding that position for 1 min, 5 times. As a result, end range of motion and passive torque at end range of motion were significantly increased after stretching (P<0.05) as compared with each previous value. Although stiffness of the muscle-tendon unit was significantly decreased immediately and 5 min after stretching (P<0.05), this change recovered within 10 min. These results suggest that static stretching for 5 min results in significantly increased range of motion over 30 min, but significant decreases in stiffness of the muscle-tendon unit returned to baseline levels within 5-10 min.
authors.affiliation: Chukyo University, School of Health and Sport Sciences, Toyota, Japan. taka.mizuno82@gmail.com
authors.forename: T
authors.initials: T
authors.lastname: Mizuno
authors.forename: M
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Y
authors.initials: Y
authors.lastname: Umemura
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D053581:Muscle Strength Dynamometer; D052580:Muscle Stretching Exercises; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000502:physiology; D016059:Range of Motion, Articular / Q000502:physiology*; D013710:Tendons / Q000000981:diagnostic imaging / Q000502:physiology*; D013997:Time Factors; D019415:Torque; D014463:Ultrasonography; D055815:Young Adult