Electromyographic Analysis of Conventional and Rubber-Based Band Squats
Date
2011-05
Authors
Palmer, Ty
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Abstract
<b>Purpose:</b>The purpose of this study was to analyze mean I-EMG activity of the vastus lateralis and the hamstrings group during the back squat exercise using three different types of resistances. <b>Subjects:</b> Twenty-two healthy, physically active collegiate males with at least 6 months of resistance training experience using the back squat exercise served as subjects for this study. <b>Measurements:</b> To evaluate maximal strength on the squat exercise, 3 1RMs were required from every subject, one for each resistance condition. The
purpose of this initial testing was to assign an appropriate external load relative to each subject's one-repetition maximum (1RM) for the No Band (NB), Bottom Band (BB), and Top Band (TB) conditions. EMG testing was then conducted using a 2-channel electromyography (EMG) system that analyzed muscle activity from the vastus lateralis and the hamstrings during the squat exercise for each resistance condition. Mean integrated-EMG values were then collected for the 90 and 10% intervals for each phase and expressed as mean arbitrary units. <b>Results:</b> There was a significantly greater 1RM for the BB condition compared to either the TB or NB conditions. Also, there was a significantly greater 1RM for the TB condition compared to the NB condition. For the vastus lateralis, repeated measures ANOVA indicated a significantly lower mean I-EMG output in the eccentric versus concentric contractions. Also, a significantly lower vastus lateralis mean I-EMG output was observed at the 90% interval of displacement compared to the 10% interval of displacement. Post-hoc analysis indicated that at the 90% interval of displacement there was a significantly lower vastus lateralis mean I-EMG output in the NB condition than both the BB and TB conditions. At the 10% interval of displacement for the vastus lateralis, no significant differences among any of the band configurations were observed. For the hamstrings muscle group, repeated measures ANOVA again indicated a significantly lower mean I-EMG output for eccentric versus concentric contractions. A significantly higher mean hamstring I-EMG output was observed at 90% compared to 10% intervals of displacement. Post-hoc analysis indicated for the hamstrings group that at the 90% interval of displacement, no significant differences among band conditions were observed. In contrast, at the 10% interval of displacement there was a significantly higher mean hamstring I-EMG output in the NB condition than the BB condition. <b>Conclusion:</b> These results indicate that during a given repetition of the squat exercise, greater overall muscle activity can be obtained by performing BB or TB squats as opposed to a conventional squat without bands (NB). A greater amount of muscle stimulation per repetition could ultimately enhance greater strength adaptations to occur over time during training.
Description
Keywords
Electromyography, EMG, Bands, Vastus Lateralis, Hamstrings, Squat
Citation
Palmer, T. (2011). <i>Electromyographic analysis of conventional and rubber-based band squats</i> (Unpublished thesis). Texas State University-San Marcos, San Marcos, Texas.