Trunk Muscle Activation in Open Stance and Square Stance Tennis Forehands
Date
2000-01
Authors
Knudson, Duane V.
Blackwell, J.
Journal Title
Journal ISSN
Volume Title
Publisher
Georg Thieme Verlag Stuttgart
Abstract
Electromyography of the trunk muscles were compared between the open and square stance forehand drives of 14 collegiate tennis players. Surface EMG were bilaterally collected from the rectus abdominis (RA), external oblique (EO), and erector spinae (ES) in open and square stance forehand drives. EMG data were transferred by telemetry, 12 bit A.JO converted at 1000 Hz, and stored for analysis. Rectified and smoothed EMG data were normalized (NEMG) to maximal isometric voluntary contractions and mean NEMG were calculated during the forward swing and follow through phases of the- stroke. A 2x2x2x6 factorial ANOVA (Gender, Stance, Phase, Muscle) with repeated measures on Subject showed significant (p < 0.05) effects of Gender, Muscle, Phase, and several interactions. The nonsignificant differences in muscle activation between stances did not support the belief of tennis experts that open stance forehands require greater trunk activation than square stance forehands. Mean NEMG of the ES were significantly (p < 0.05) larger than EO or RA, which was consistent with observations of tennis-specific strength imbalances and increasing incidence of low back injuries in tennis.
Description
Keywords
abdominal, EMG, tennis injuries, square stance forehand drives
Citation
Knudson, D., & Blackwell, J. (2000). Trunk muscle activation in open stance and square stance tennis forehands. International Journal of Sports Medicine, 21, pp. 321-324.
Rights
Rights Holder
© Georg Thieme Verlag Stuttgart New York.