Muscle Activation Among Supine, Prone and Side Position Exercises With and Without a Swiss Ball

Abstract

PURPOSE: Prone, supine, and side position exercises are employed to enhance core stability, but how these exercises recruit trunk and extremity musculature compared to each other is unclear. The purpose of this study was to compare core muscle activity between supine position exercises (crunch, bent knee sit-up) and prone and side position exercises with or without a swiss ball. Both prone and side positions exercises were performed on the knees, on the toes, and on a swiss ball. METHODS: Eighteen healthy males and females between 23–45 years old served as subjects. Surface electrodes were positioned on the subject’s dominant side over the upper and lower rectus abdominis, external and internal obliques, rectus femoris, latissimus dorsi, and lumbar paraspinals. EMG data were collected from a Noraxon EMG system during five repetitions for 10 different exercises. Each repetition was performed in a slow and controlled manner, taking 3 s to complete followed by 1 s rest. EMG exercise data were normalized by maximum voluntary muscle contractions. Differences in muscle activity were assessed by a one-way repeated measures Analysis of Variance, with Tukey’s post hoc analysis used for pairwise comparisons. RESULTS: Prone position exercises were as effective or more effective compared to the supine position exercises in rectus abdominis recruitment (39-49±9-26%MVIC versus 35-53±13-19%MVIC), oblique recruitment (39-56±8-32%MVIC versus 31-36±11-17%MVIC), and latissimus dorsi recruitment (10-21±10-14%MVIC versus 2-8±1-3%MVIC). Side position exercises were not as effective in recruiting the rectus abdominis (14-26±7-15%MVIC) and internal oblique (17-28±1-12%MVIC), but were effective in recruiting the external oblique (37-62±26-37%MVIC). Lumbar paraspinal activity was low (5-7±2-3%MVIC) in all exercises except side position exercises (18-29±6-16%MVIC). Rectus femoris activity was low in all exercises (6-14±4-7%MVIC) except prone on ball with left hip extension (35±18%MVIC), bent knee sit-up (23±12%MVIC), and prone bridge on toes (20±7%MVIC). CONCLUSIONS: Prone position exercises are good alternatives to supine position exercises for recruiting core musculature. Side position exercises are better for oblique and lumbar paraspinal recruitment compared to rectus abdominis recruitment. Prone and side position exercises can be progressed from on knees to on toes and using a swiss ball.