The purpose of this study was to compare core muscle activity among supine, prone, and side position exercises with and without a Swiss ball. The latissimus dorsi is an upper extremity muscle, but its origin into the thoracolumbar fascia helps provide core stability.
5, 7, 12, 17, 20, 27, 36 While select core and lower extremity muscle activity during prone and side position exercises 8 is known, studies have not examined their effects on recruiting latissimus dorsi muscle activity.
22 To date, prone and side bridge exercises have only been performed with body weight supported on the arms and feet, which are the most difficult positions, but not with weight supported on the knees, which is an easier position. 7 The crunch and side bridge exercises are effective in activating the internal oblique and transversus abdominis, 36 while the side bridge is effective in recruiting the quadratus lumborum. 17 No significant difference in rectus abdominis activity occurs during prone and side bridge exercises, but significantly greater external oblique and lumbar paraspinal activity is seen in the side bridge exercise compared with the prone bridge exercise. 5 Greater rectus abdominis, external oblique, and internal oblique activity occurs in the side bridge exercise compared with the crunch exercise. 1, 5 - 7, 12, 15, 17 - 20, 27, 31 - 34, 36, 38, 39 During the side bridge exercise, greater internal oblique activity occurs using a Swiss ball compared with a stable-surface bench. Several studies examined core muscle recruitment while performing prone and side bridge exercises with and without a Swiss ball. 2Ĭore exercises performed in prone and side positions, with and without a Swiss ball, are increasingly popular in rehabilitation clinics and fitness facilities. 14, 28 Moreover, core muscle strengthening may also help decrease the risk of injuries to the lumbar spine by enhancing spinal stability. Core muscle strengthening can decrease lower extremity injury risk and enhance performance. 2, 3, 21, 23 Although several studies have examined core muscle recruitment during the crunch and bent-knee sit-up exercises, 9, 11, 35, 37 it is not completely understood how core muscle recruitment compares between the supine, prone, and side positions with and without a Swiss ball. The core musculature includes both deep and superficial muscles of the lumbopelvic-hip complex: internal oblique, transversus abdominis, transversospinalis, quadratus lumborum, psoas major and minor, rectus abdominis, external oblique, erector spinae, latissimus dorsi, gluteus maximus and medius, hamstrings, and rectus femoris. Rectus femoris activity was significantly greater in the prone on ball with left hip extension, bent-knee sit-up, or prone bridge (plank) on toes compared with the remaining exercises. Latissimus dorsi activity was significantly greater in the prone on ball with left and right hip extension and prone bridge (plank) on ball and on toes compared with the crunch, bent-knee sit-up, and prone and side bridge (plank) on knees positions. Lumbar paraspinal activity was significantly greater in the 3 side position exercises compared with all remaining exercises. Internal oblique activity was significantly greater in the prone bridge (plank) on ball and prone on ball with left and right hip extension compared with the side crunch on ball and prone and side bridge (plank) on knees positions. External oblique activity was significantly greater in the prone on ball with right hip extension, side crunch on ball, and side bridge (plank) on toes compared with the prone and side bridge (plank) on knees, the crunch, or the bent-knee sit-up positions. Upper and lower rectus abdominis activity was generally significantly greater in the crunch, bent-knee sit-up, and prone position exercises compared with side position exercises.