Uninvolved versus target muscle contraction during contract: relax proprioceptive neuromuscular facilitation stretching
One page on PainSci cites Azevedo 2011: Quite a Stretch
PainSci notes on Azevedo 2011:
This well-planned experiment tested whether or not the contraction component of a contract-relax stretch actually makes a difference, and clearly found that it does not. The researchers compared a normal CR stretch of the hamstring to a modified one without any hamstring contraction (instead, some other “uninvolved, distant” muscle was contracted). The effect of both stretches was the same — “a significant moderate increase in range of motion.” In other words, it didn’t matter if the hamstring was contracted or not — with or without a contraction, the result was the same. This strongly undermines the central claim of CR-PNF stretching.
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
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.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- The Problematic Nature of Fibromyalgia Diagnosis in the Community. Srinivasan 2019 ACR Open Rheumatol.
- Fibromyalgia diagnosis and biased assessment: Sex, prevalence and bias. Wolfe 2018 PLoS One.
- Restoring trust in menopause management: menopause hormone therapy is not a panacea, and physical activity remains a critical intervention. Tulloh 2025 Br J Sports Med.
- Common interventional procedures for chronic non-cancer spine pain: a systematic review and network meta-analysis of randomised trials. Wang 2025 BMJ.
- Gabapentinoids and Risk of Hip Fracture. Leung 2024 JAMA Netw Open.