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

ObjectiveThe 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.Designpre-test post-test control experimental design.SettingClinical research laboratory.ParticipantsSixty healthy men were randomly assigned to one of three groups.InterventionsThe 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 MeasuresActive knee extension test was performed before and after the stretching procedure.ResultsTwo-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.ConclusionsROM gain following a CR PNF procedure is the same whether the target stretching muscle is contracted, or an uninvolved muscle is contracted.