Introduction: Some clinicians advocate stretching to prevent muscle cramps. It is unknown whether static or proprioceptive neuromuscular facilitation (PNF) stretching increases cramp threshold frequency (TFc ), a quantitative measure of cramp susceptibility.
Methods: Fifteen individuals completed this randomized, counterbalanced, cross-over study. We measured passive hallux range of motion (ROM) and then performed 3 minutes of either static stretching, PNF stretching (hold-relax-with agonist contraction), or no stretching. ROM was reassessed and TFc was measured.
Results: PNF stretching increased hallux extension (pre-PNF 81 ± 11°, post-PNF 90 ± 10°; P < 0.05) but not hallux flexion (pre-PNF 40 ± 7°, post-PNF 40 ± 7°; P > 0.05). Static stretching increased hallux extension (pre-static 80 ± 11°, post-static 88 ± 9°; P < 0.05) but not hallux flexion (pre-static 38 ± 9°, post-static 39 ± 8°; P > 0.05). No ROM changes occurred with no stretching (P > 0.05). TFc was unaffected by stretching (no stretching 18 ± 7 Hz, PNF 16 ± 4 Hz, static 16 ± 5 Hz; P = 0.37).
Discussion: Static and PNF stretching increased hallux extension, but neither increased TFc . Acute stretching may not prevent muscle cramping. Muscle Nerve 57: 473-477, 2018.
Keywords: electrical stimulation; flexor hallucis brevis; inhibition; proprioceptive neuromuscular facilitation; range of motion; static stretching; threshold frequency.
© 2017 Wiley Periodicals, Inc.