The Time Course of Musculotendinous Stiffness Responses Following Different Durations of Passive Stretching

Ryan, Eric D. MS
Beck, Travis W. PhD
Herda, Trent J. MS
Hull, Holly R. PhD
Hartman, Michael J. PhD
Costa, Pablo B. MS
Defreitas, Jason M. BS
Stout, Jeffery R. PhD
Cramer, Joel T. PhD

¹Graduate Assistant, Biophysics Laboratory, Department of Health and Exercise Science, University of Oklahoma, Norman, OK.
²Assistant Professor, Biophysics Laboratory, Department of Health and Exercise Science, University of Oklahoma, Norman, OK.
³Post-Doctoral Research Fellow, New York Obesity Research Center, College of Physicians and Surgeons Body Composition, Columbia University, New York, NY.
⁴Assistant Professor, Human Performance Laboratory, Department of Exercise Science and Health Promotion, Florida Atlantic University, Davie, FL.
⁵Assistant Professor, Metabolism and Body Composition Laboratory, Department of Health and Exercise Science, University of Oklahoma, Norman, OK. This study was approved by the University of Oklahoma Institutional Review Board for Human Subjects. Address correspondence to Dr Joel T. Cramer, Biophysics Laboratory, Department of Health and Exercise Science, University of Oklahoma, 1401 Asp Ave, HHC Room 12, Norman, OK 73019-6081. E-mail: [email protected]

Journal of Orthopaedic & Sports Physical Therapy 38(10):p 632-639, October 2008.

• STUDY DESIGN:

Repeated-measures experimental design.

• OBJECTIVE:

To examine the acute effects of different durations of passive stretching on the time course of musculotendinous stiffness (MTS) responses in the plantar flexor muscles.

• BACKGROUND:

Stretching is often implemented prior to exercise or athletic competition, with the intent to reduce the risk of injury via decreases in MTS.

• METHODS AND MEASURES:

Twelve subjects (mean ± SD age, 24 ± 3 years; stature, 169 ± 12 cm; mass, 71 ± 17 kg) participated in 4 randomly ordered experimental trials: control with no stretching, and 2 minutes (2_min), 4 minutes (4_min), and 8 minutes (8_min) of passive stretching. The passive-stretching trials involved progressive repetitions of 30-second passive stretches, while the control trial involved 15 minutes of resting. MTS assessments were conducted before (prestretching), immediately after (poststretching), and at 10, 20, and 30 minutes poststretching on a Biodex System 3 isokinetic dynamometer.

• RESULTS:

MTS decreased (P < .05) immediately after all stretching conditions (2_min, 4_min, and 8_min). However, MTS for the 2_min condition returned to baseline within 10 minutes, whereas MTS after the 4_min and 8_min passive-stretching conditions returned to baseline within 20 minutes.

• CONCLUSIONS:

Practical durations of passive stretching resulted in significant decreases in MTS; however, these changes return to baseline levels within 10 to 20 minutes.

• LEVEL OF EVIDENCE:

Level 5. J Orthop Sports Phys Ther 2008;38(10):632-639. doi:10.2519/ jospt.2008.2843