(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
Figure 1: Core stabilization exercise. (a) Train TrA muscle activation in a prone lying position without spinal and pelvic movements for 10 seconds. Keep respiration normal. You gently draw in the lower anterior abdominal wall below the navel level (abdominal drawing-in maneuver) with supplemented contraction of pelvic floor muscles, control your breathing normally, and have no movement of the spine and pelvis while lying prone on a couch with a small pillow placed beneath your ankles. (b) Train MF activation in an upright sitting position. You raise the contralateral arm while performing the abdominal drawing-in maneuver in a sitting position on a yoga ball. (c) Perform cocontraction of the two muscles in a crooked lying position with both hips at 45 degrees and both knees at 90 degrees. Then, you abduct one leg to 45 degrees of hip abduction and hold it for 10 seconds. (d) Train cocontraction of these muscles in a crooked lying position with both hips at 45 degrees and both knees at 90 degrees. Then, you slide a single leg down until the knee is straight, maintain it for 10-second holds, and then slide it back up to the starting position. (e) Perform cocontraction of the two muscles while raising the buttocks off a couch from a crooked lying position until your shoulders, hips, and knees are straight. You sustain this pose for 10 seconds and then lower the buttocks back down to the couch. (f) Train muscle cocontraction while raising the buttocks off a couch from a crooked lying position with one leg crossed over the supporting leg. You raise the buttocks off the couch until the shoulders, hips, and knees are straight. You sustain this pose for 10 seconds and then lower the buttocks back down to the couch. (g) Perform cocontraction while raising a single leg from a four-point kneeling position and keeping your back in a neutral position. You sustain this pose for 10 seconds and then return the leg to the starting position. (h) Train muscle cocontraction while raising an arm and alternate leg from a four-point kneeling position and keeping your back in a neutral position. You sustain this pose for 10 seconds and then return to the starting position. Black arrows show the contraction direction of core muscles.