Is the psoas a hip flexor in the active straight leg raise?

Hu, Hai, Meijer, Onno G, van Dieën, Jaap H, Hodges, Paul, Bruijn, Sjoerd M, Strijers, Rob L, Nanayakkara, Prabath W B, van Royen, Barend J, Wu, Wen Hua and Xia, Chun (2011) Is the psoas a hip flexor in the active straight leg raise?. European Spine Journal, 20 5: 759-765. doi:10.1007/s00586-010-1508-5

Author Hu, Hai
Meijer, Onno G
van Dieën, Jaap H
Hodges, Paul
Bruijn, Sjoerd M
Strijers, Rob L
Nanayakkara, Prabath W B
van Royen, Barend J
Wu, Wen Hua
Xia, Chun
Title Is the psoas a hip flexor in the active straight leg raise?
Journal name European Spine Journal   Check publisher's open access policy
ISSN 0940-6719
Publication date 2011-05
Year available 2010
Sub-type Article (original research)
DOI 10.1007/s00586-010-1508-5
Volume 20
Issue 5
Start page 759
End page 765
Total pages 7
Place of publication Wien ; New York
Publisher Springer-Verlag
Collection year 2011
Language eng
Abstract Psoas function is a topic of considerable relevance in sports and clinical science. However, the literature on psoas function is not sufficiently consistent. Questions are, amongst others, if during hip flexion the psoas always has the same function as the iliacus, and if the psoas affects the hip more than the lumbar spine. In the present study, 17 healthy women, 20-40 years, performed the active straight leg raise (ASLR), with the right or the left leg ("Side"), and without or with weight added above the ankle ("Condition"). Electromyographic (EMG) activity of psoas and iliacus were recorded with fine-wire electrodes, and of rectus femoris and adductor longus with surface electrodes, all on the right side. Movements of the leg were recorded with active markers and a camera system. During ASLR, the iliacus, rectus femoris, adductor longus and psoas were active ipsilaterally, but psoas was also active contralaterally. All muscles started to contract before movement onset, the iliacus, rectus femoris, and adductor longus largely at the same time, before the psoas. There was no significant difference between the amplitude or time of onset of ipsilateral and contralateral psoas EMG activity, nor was there a significant interaction between Side and Condition for the psoas. Although ipsilateral psoas activity is consistent with the psoas being a hip flexor, contralateral activity is not. The most simplest explanation of the pattern found is that the psoas is bilaterally recruited to stabilize the lumbar spine, probably in the frontal plane. © 2010 The Author(s).
Keyword Active straight leg raise
Fine-wire EMG
Hip flexion
Lumbar spine stability
M. psoas
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Published online 13 July, 2010.

Document type: Journal Article
Sub-type: Article (original research)
Collections: UQ Centre for Clinical Research Publications
Official 2011 Collection
School of Health and Rehabilitation Sciences Publications
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Citation counts: TR Web of Science Citation Count  Cited 9 times in Thomson Reuters Web of Science Article | Citations
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Created: Sat, 12 Feb 2011, 13:14:24 EST by Kathleen Reinhardt on behalf of School of Health & Rehabilitation Sciences