Journal article
An Electromyographic Analysis of Hip Abductor Muscle Activity when Subjects are Carrying Loads in One Or Both Hands
Physical Therapy, Vol.72(3), pp.207-217
1992
DOI: 10.1093/ptj/72.3.207
Abstract
Forces produced at the hip joint as a result of hip abductor muscle contractions while carrying loads reach several times body weight (BW). Physical therapists often advise patients with hip osteoarthritis in ways to minimize these forces as a means of reducing the pain associated with carrying loads. The purpose of this study was to use surface electromyography (EMG) to quantify the relative demands placed on the hip abductors while carrying loads in one hand or in both hands. Thirty asymptomatic college-aged subjects walked while carrying loads of 10% and 20% of BW unilaterally and loads of 10%, 20%, and 40% of BW bilaterally. Signals from footswitches allowed a computer to average the EMG data over the phase of gait when the foot was in complete contact with the ground. All EMG data were normalized to a percentage of the EMG voltage produced during no-load walking (%EMG). Our prime dependent variable was the %EMG averaged over both hip sides of all subjects' multiple walking trials. Our major analysis involved a multifactorial analysis of variance for repeated measures with method of carry (unilateral or bilateral) and load as the two main independent variables. Results demonstrated that both the amount of the load and the method of load carry made a significant difference in regard to the amount of hip abductor EMG produced. Of particular note was the fact that the bilateral 20% of BW condition produced statistically less %EMG (when averaged over both sides) than did the unilateral 20% of BW condition. Persons with hip disease should be aware that hip joint forces may be reduced by the bilateral method of carrying loads.
Details
- Title: Subtitle
- An Electromyographic Analysis of Hip Abductor Muscle Activity when Subjects are Carrying Loads in One Or Both Hands
- Creators
- Donald A. NeumannThomas M. Cook - University of IowaRhonda L. Sholty - Columbia Hospital, Milwaukee, WIDennis C. Sobush - Marquette University
- Resource Type
- Journal article
- Publication Details
- Physical Therapy, Vol.72(3), pp.207-217
- DOI
- 10.1093/ptj/72.3.207
- ISSN
- 0031-9023
- Language
- English
- Date published
- 1992
- Academic Unit
- International Programs; Occupational and Environmental Health; Physical Therapy and Rehabilitation Science
- Record Identifier
- 9983557793402771
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