ELECTROMYOGRAPHIC ANALYSIS OF HIP MUSCLE ACTIVATION DURING A SINGLE LIMB SQUAT LATERAL SLIDE EXERCISE.

BACKGROUND

Slider exercises, which may use a gliding disc or "slider", are dynamic exercises used for strengthening. They are proposed to increase challenge as the friction between the body and ground is decreased which increases the demands on muscles of the weight bearing limb.

HYPOTHESIS AND PURPOSE

The purposes of this study were (1) to compare the electromyographic (EMG) activity level of hip muscles of the weight bearing limb while performing a single limb slide squat to that of a standard isometric squat and (2) to investigate the influence of trunk position on hip EMG activity. It was hypothesized that the single limb slide squat would elicit greater hip EMG activity than an isometric squat and trunk position would influence EMG activity.

STUDY DESIGN

Analytic, observational cross-sectional study design.Methods: Twenty healthy male participants (age = 23.7 ± 1.3) volunteered. EMG hip muscle activation of the stance leg was measured during a single limb slide squat and as a comparison, the same leg during a standard double limb isometric squat. Both exercises where performed with a knee flexion angle of 60˚ and the trunk positioned 40˚ (flexed trunk) and 60˚ (upright trunk) relative to the floor. Surface electrodes were used to collect EMG data.

RESULTS

EMG activity of the gluteus maximus, gluteus medius, biceps femoris and rectus femoris was significantly greater with both single limb slide exercises as compared to both squat exercises. EMG activity was greater with the flexed trunk as compared to the upright trunk for the biceps femoris.

CONCLUSION

Slider exercises produced a moderate or high level of activation for all muscles whereas all squat exercises produced a low-level activation.

LEVEL OF EVIDENCE

Level 3 Mechanism-based reasoning intervention study trial.