The effect of the direction of gaze on the kinematics of the squat exercise.

The purpose of this study was to determine whether the direction of gaze influences the kinematics of the squat exercise. Ten men experienced in the squat exercise performed a total of 30 repetitions of the squat in the form of 2 sets of 5 repetitions under 3 different conditions. Conditions varied with respect to the direction of the subjects' gaze as they performed the exercise. Condition D entailed gazing downward at the intersection of the facing wall and the floor throughout the exercise. Condition S required subjects to gaze straight ahead at their own reflection (eyes) in the mirror on the wall directly in front of them. Condition U involved gazing upward at the intersection of the facing wall and the ceiling throughout the exercise. Dependent variables included the linear displacement of the bar and hip, linear velocity of the bar, and the angular displacement/position and velocity of the head, trunk, hip, and knee. The mean data were subjected to a repeated measures analysis of variance, and, where appropriate, pairwise comparisons using Tukey's Studentized Range Test. The results revealed overall similarity in movement kinematics when performing the squat exercise using the 3 different gaze directions. In particular, the upward and straight gaze conditions were not differentiated by the analysis. Conversely, the downward gaze was shown to increase the extent of hip flexion (F[2, 9] = 4.82, p < .05), especially relative to the upward gaze, and possibly trunk flexion as well (F[2, 9] = 3.02, p = .07). In terms of the practical application, because excessive hip and trunk flexion in the squat are contraindicated, cautioning athletes against allowing the head or direction of gaze to drop below a neutral position appears to be warranted.