Biomechanical responses to repeated stretches in human hamstring muscle in vivo

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Bibliographic Details
Title translated into German:Biomechanische Reaktionen auf wiederholte Dehnungen der menschlichen Hamstrings-Muskeln in vivo
Author:Magnusson, S.P.; Simonsen, E.B.; Aagaard, P.; Kjaer, M.
Published in:The American journal of sports medicine
Published:24 (1996), 5 , S. 622-628, Lit.
Format: Publications (Database SPOLIT)
Publication Type: Journal article
Media type: Print resource
ISSN:0363-5465, 1552-3365
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Identification number:PU199703203424

Author's abstract

To examine stiffness, energy, and passive torque in the dynamic and static phases of a stretch maneuver in the human hamstring muscle in vivo we used a test-retest protocol and a repeated stretches protocol. Resistance to stretch was defined as passive torque (in newton-meters) offered by the hamstring muscle group during passive knee extension as measured using an isokinetic dynamometer with a modified thigh pad. In 13 uninjured subjects, the knee was passively extended to a predetermined final position (0.0875 rad/sec, dynamic phase) where it remained stationary for 90 seconds (static phase). The test-retest protocol included two tests administered 1 hour apart. On a separate occasion, five consecutive static stretches were administered separated by 30 seconds and followed by a sixth stretch 1 hour later. For the test-retest phase, stiffness and energy in the dynamic phase and passive torque in the static phase did not differ and yielded correlations of r=0.91 to 0.99. During the static phase, passive torque declined in both tests (P<0.0001). For the repeated stretches, decreases were observed for energy (P<0.01) and stiffness (P<0.05) in the dynamic phase and for passive torque (P<0.0001) in the static phase. However, the decline in the variables returned to baseline within 1 hour. The data show that the method employed is a useful tool for measuring biomechanical variables during a stretch maneuver. This may provide a more detailed method to examine skeletal muscle flexibility. Verf.-Referat