Age-related changes in electromyographic quadriceps activity during stair descent

Hinman, R. S., Cowan, S. M., Crossley, K. M. and Bennell, K. L. (2005) Age-related changes in electromyographic quadriceps activity during stair descent. Journal of Orthopaedic Research, 23 2: 322-326. doi:10.1016/j.orthres.2004.08.004

Author Hinman, R. S.
Cowan, S. M.
Crossley, K. M.
Bennell, K. L.
Title Age-related changes in electromyographic quadriceps activity during stair descent
Journal name Journal of Orthopaedic Research   Check publisher's open access policy
ISSN 0736-0266
Publication date 2005-03
Sub-type Article (original research)
DOI 10.1016/j.orthres.2004.08.004
Volume 23
Issue 2
Start page 322
End page 326
Total pages 5
Place of publication Hoboken, NJ, United States
Publisher John Wiley & Sons
Language eng
Formatted abstract
Purpose: To determine the effects of age on (i) the onset of vastus medialis obliquus (VMO) activity relative to that of vastus lateralis (VL) and (ii) the onset of quadriceps activity in terminal swing relative to heel-strike, during stair descent.

Sixty-six heal thy men and women with no known knee pathology were recruited from the community and the University of Melbourne. Thirty-three older people aged over 50 (mean (SD) 68 (8) years) and 33 younger people aged under 40 (mean (SD) 25 (4) years) participated. Surface electromyography (EMG) was used to record muscle activity during stair descent. Muscle onset was identified from individual EMG traces with a computer algorithm and validated visually.

Results: Both younger and older participants demonstrated a relatively synchronous onset of VMO and VL (i.e. within 10ms of each other) with no differences between the age groups evident (P = 0.262). However older participants activated their quadriceps significantly earlier than the younger group (P < 0.001) even when differences in body mass and speed of stair descent were accounted for.

Conclusion: Age-related changes in quadriceps activity are apparent. The clinical implications of such changes are unknown, but increases in joint loading are possible. Earlier quadriceps activation may compensate for balance and strength impairments in older people during challenging activities.
Keyword Quadriceps
Muscle onset
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Health and Rehabilitation Sciences Publications
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