Electrical activity of external oblique and multifidus muscles during the hip flexion-extension exercise performed in the Cadillac with different adjustments of springs and individual positions.

BACKGROUND Despite of the widepread use of Pilates in Physical Therapy, there are few studies that have assessed the muscle electrical activation during Pilates exercises. OBJECTIVE Verify the influence of different spring adjustments and individual positions on the electrical activation of multifidus (MU) and oblique external (OE) muscles during hip flexion-extension (HFE) exercise on the Cadillac. METHODS Eight women practicing Pilates exercises for at least six months performed 10 repetitions of HFE in the following situations: Lower Spring, spring fixed at 30 cm in relation to level which the individuals were positioned. Higher Spring, spring fixed at 90 cm in relation to level which the individuals were positioned. Near Position, distance of 10 cm from the fixed spring. Distant Position, distance of 30 cm from the fixed spring. Kinematic and eletromyographic data (EMG) were collected simultaneously and the MU and OE muscles were monitored. Each movement of HFE was splitted in two phases (extension and flexion). The EMG signal was calculated and normalized using the maximal voluntary contraction (MVC). The Wilcoxon test was used to investigate differences between the situations (p < 0.05). RESULTS MU muscle presented muscle activation values ranging from 10 to 20 % MVC, and the highest muscle activation in the lower spring and in the near position. OE muscles presented muscle activation values ranging from 20 to 45% MVC, and the highest values in the higher spring and in the distant position. CONCLUSION MU and OE muscles presented a distinct electrical activation during different available spring adjustments and individual positions.