Electromyographic Analysis of the Lower Extremity Position during Trunk Exercise in Prone Position

To compare the electromyographic (EMG) activity of local and global muscles in lumborum at various hip positions of lower extremity during lower trunk muscles exercises in prone position. Fifteen healthy adults (10 males and 5 females, means (SD) age; 26.7 (4.3) years) participated in this study. Each subjects performed maximal voluntary isometric contractions (MVIC) of trunk extension, then they performed three exercises for back muscles in the prone position. The activity (%MVIC) of ipsilateral LM were 48.9 (26.8) at EXT, 52.2 (29.1) at EXT-ABD-IR, and 53.8 (26.2) at EXT-ABD-ER. The muscles activity ratio at EXT, EXT-ABDIR, and EXT-ABD-ER were 1.32 (0.67), 1.51 (0.72), 1.40 (0.74) as LM : contralateral IC, 1.53 (0.98), 1.72 (1.06), 1.49 (1.16) as LM : contralateral LT, 1.56 (0.73), 1.55 (0.65), 1.68 (0.79) as LM : ipsilateral IC, and 1.64 (1.05), 1.61 (0.81), 1.85 (1.26) as LM : ipsilateral LT, respectively.