Archives of Physical Medicine and Rehabilitation, 07/01/2014 Clinical Article
Penney T, et al. – The objective of this study is to determine the activation of the gluteus medius in chronic non–specific low back pain compared to controls and to determine the association between clinical rating of Single Leg Stance (SLS) with CLBP and gluteus medius weakness. Individuals with CLBP had weaker gluteus medius than control subjects without back pain. Even though there was no significant difference in onset time of the gluteus medius when moving to unipedal stance between the groups, the CLBP group had greater gluteus medius activation, a key finding was that a positive SLS test did not distinguish CLBP group from controls nor was it a sign of gluteus medius weakness.
Methods
- Cohort–Control Comparison.
- Academic research laboratory.
- Convenience sample of people with CLBP (>12 weeks) recruited by local physiotherapists (n=21) and age and gender matched controls (n=22).
- Subjects diagnosed with specific pain diagnoses were excluded.
- Back pain using the Visual Analogue Scale (mm); Back–related disability using the Oswestry Back Disability Index (%); Strength of gluteus medius measured using hand dynamometer (N/kg); Single Leg Stance Test; Gluteus medius onset and activation using electromyography during unipedal stance on a force plate.
Results
- The CLBP group exhibited significant weakness in gluteus medius compared to controls (right, p=0.04; left, p=0.002).
- They also had more pain (CLBP mean 20.50mm, (95%CI :13.11mm –27.9mm); Control mean 1.77mm,( 95%CI: –0.21mm–3.75mm)) and back–related disability (CLBP mean 18.52%, (95%CI:14.46%–22.59%); Control mean 0.68%, (95%CI: –0.41%–1.77%)) and reported being less physically active.
- Weakness was accompanied by increased gluteus medius activation during unipedal stance (R=0.50, p=0.001) but no difference in muscle onset times.
- Although greater gluteus medius weakness was associated with greater pain and disability, there was no difference in muscle strength between those scoring positive and negative on the SLS test (right F=0.002, p=0.96; left F=0.1.75, p=0.19).
Arch Phys Med Rehabil. 2014 Jun 30. pii: S0003-9993(14)00440-7. doi: 10.1016/j.apmr.2014.06.009. [Epub ahead of print]
Determining the Activation of Gluteus Medius and the Validity of the Single Leg Stance Test in Chronic Non-specific Low Back Pain.
Penney T
Abstract
OBJECTIVE:
To determine the activation of the gluteus medius in chronic non-specific low back pain compared to controls and to determine the association between clinical rating of Single Leg Stance (SLS) with CLBP and gluteus medius weakness.
DESIGN:
Cohort-Control Comparison SETTING: Academic research laboratory PARTICIPANTS: Convenience sample of people with CLBP (>12 weeks) recruited by local physiotherapists (n=21) and age and gender matched controls (n=22). Subjects diagnosed with specific pain diagnoses were excluded.
INTERVENTIONS:
Not applicable.
MAIN OUTCOME MEASURES:
Back pain using the Visual Analogue Scale (mm); Back-related disability using the Oswestry Back Disability Index (%); Strength of gluteus medius measured using hand dynamometer (N/kg); Single Leg Stance Test; Gluteus medius onset and activation using electromyography during unipedal stance on a force plate.
RESULTS:
The CLBP group exhibited significant weakness in gluteus medius compared to controls (right, p=0.04; left, p=0.002). They also had more pain (CLBP mean 20.50mm, (95%CI :13.11mm -27.9mm); Control mean 1.77mm,( 95%CI: -0.21mm-3.75mm)) and back-related disability (CLBP mean 18.52%, (95%CI:14.46%-22.59%); Control mean 0.68%, (95%CI: -0.41%-1.77%)) and reported being less physically active. Weakness was accompanied by increased gluteus medius activation during unipedal stance (R=0.50, p=0.001) but no difference in muscle onset times. Although greater gluteus medius weakness was associated with greater pain and disability, there was no difference in muscle strength between those scoring positive and negative on the SLS test (right F=0.002, p=0.96; left F=0.1.75, p=0.19).
CONCLUSION:
Individuals with CLBP had weaker gluteus medius than control subjects without back pain. Even though there was no significant difference in onset time of the gluteus medius when moving to unipedal stance between the groups, the CLBP group had greater gluteus medius activation. A key finding was that a positive SLS test did not distinguish CLBP group from controls nor was it a sign of gluteus medius weakness.
Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.