Uninvolved versus target muscle contraction during contract: relax proprioceptive neuromuscular facilitation stretching

Abstract

Objective: The purpose of this study was to compare the acute effect of the contract-relax (CR) stretching technique on knee active range of motion (ROM) using target muscle contraction or an uninvolved muscle contraction.

Design: pre-test post-test control experimental design.

Setting: Clinical research laboratory.

Participants: Sixty healthy men were randomly assigned to one of three groups.

Interventions: The Contract-Relax group (CR) performed a traditional hamstring CR stretch, the Modified Contract-Relax group (MCR) performed hamstring CR stretching using contraction of an uninvolved muscle distant from the target muscle, and the Control group (CG) did not stretch.

Main outcome measures: Active knee extension test was performed before and after the stretching procedure.

Results: Two-way between-within analysis of variance (ANOVA) results showed a significant interaction between group and pre-test to post-test (p < 0.001). Post-hoc examination of individual groups showed no significant change in ROM for the CG (0.8°, p = 0.084), and a significant moderate increase in ROM for both the CR (7.0°, p < 0.001) and MCR (7.0°, p < 0.001) groups.

Conclusions: ROM gain following a CR PNF procedure is the same whether the target stretching muscle is contracted, or an uninvolved muscle is contracted.