Chronic Flexibility Gains: Effect of Isometric Contraction Duration during Proprioceptive Neuromuscular Facilitation Stretching Techniques

TLDR

The study aimed to evaluate how 5‑second versus 10‑second isometric contractions during proprioceptive neuromuscular facilitation stretching affect hip flexibility gains. Forty‑three young women were randomized to 5‑second or 10‑second isometric contraction groups or a control group, and hip flexibility was measured at baseline, 3 weeks, and 6 weeks. Results showed that both 5‑second and 10‑second contractions improved hip flexibility compared with control, and the 10‑second contraction produced the greatest gains at 3 and 6 weeks.

Abstract

Abstract The aim of this study was to assess the effect of two isometric contraction durations during proprioceptive neuromuscular facilitation stretching on gains inflexion at the hip. Forty-three women (M age = 20.0 years, SD =1.3) were assigned to one of three groups: 5-s isometric contraction (5-IC), 10-IC, and control. Flexibility was assessed at baseline and Weeks 3 and 6. Analysis of covariance, controlling for pretest differences, showed a significant interaction, F(2, 33) = 44.1, p <. 001. Flexibility was significantly lower in the control group relative to the 5-IC and 10-IC groups and in the 5-IC group relative to the 10-IC group at 3 and 6 weeks (3 weeks = 101.2 ± 1.4°, 114.3 ± 1.5°, 120.5 ± 1.3°; 6 weeks = 103.0 ± 1.4°, 126.1 ± 1.6°, 133.3 ± 1.4° for control, 5-IC and 10-IC groups, respectively). A longer contraction time led to greater increases inflexibility.