Does Startle Explain the Exaggerated First Response to a Transient Perturbation?

Siegmund, Gunter P.1,2; Blouin, Jean-Sébastien2,3; Inglis, J. Timothy2,3,4

Exercise & Sport Sciences Reviews: April 2008 - Volume 36 - Issue 2 - pp 76-82
doi: 10.1097/JES.0b013e318168f1ce

Here we review recent experimental evidence suggesting that exaggerated muscle response to an unfamiliar transient perturbation consists of combined postural and startle responses. Summation of these two independent responses explains the experimental data and suggests that habituation consists of the extinction of the startle response leaving only the postural response.

Recent evidence suggests that combined postural and startle responses produce the exaggerated first response to unfamiliar transient perturbations.

1MEA Forensic Engineers & Scientists, Richmond; and 2School of Human Kinetics, University of British Columbia; 3Brain Research Centre; and 4International Collaboration of Repair Discoveries (ICORD), Vancouver, British Columbia, Canada

Address for correspondence: Gunter P. Siegmund, Ph.D., PEng, MEA Forensic Engineers & Scientists, 11-11151 Horseshoe Way, Richmond, British Columbia, Canada V7A 4S5 (E-mail:

Accepted for publication: September 13, 2007.

Associate Editor: Roger M. Enoka, Ph.D.

©2008 The American College of Sports Medicine