Improving Active Range of Hip Flexion

Abstract

It is argued that previous studies of active flexibility have not achieved experimental control. An experiment then is described which achieved experimental control by using daily flexibility training over a 7-day period. Forty-two female subjects were randomly assigned to one of six treatment groups or a control group. The six treatment groups received proprioceptive neuromuscular facilitation training for six consecutive days with isometric contraction periods of 0 sec, 3 sec, or 6 sec. Three of the treatment groups followed an active regime (concentric contraction of the agonists) and three a passive regime. All subjects were pretested for active flexibility on Day 1. They were also posttested after training on Day 6, and without training on Day 7. A two factor multivariate analysis of covariance with trend analysis on the period of isometric contraction factor indicated a significant positive linear trend for this factor, approximate F(2, 28) = 7.90, p < .002, together with a significant interaction between this linear trend and the active-passive regime factor, approximate F(2, 28) = 3.81, p < .034. Follow-up tests revealed that this interaction was due to larger gains in active flexibility being associated with longer periods of isometric contraction in the active groups, but not in the passive groups.