The effect of stretching intensity on pain sensitivity: A randomized crossover study on healthy adults.

Background: Stretching exercises have effects on local and widespread pain sensitivity. A dose-response relationship may exist between the analgesic effect and the intensity of stretching, such that a higher intensity of stretching may generate a larger reduction in analgesic response, but this remains to be studied. This study aimed to examine the dose-response relationship between stretching intensity and the analgesic effect.

Methods: A randomized, repeated-measures crossover study was performed to examine the effect of stretching to the first point of pain onset and stretching to the point of a sensation of stretching (discomfort). The primary outcome was regional and distant pressure pain thresholds.

Results: Thirty-one participants (n = 24 female) were available for analysis. We observed a 22.2% increase in regional pressure pain thresholds (93.2 kPa, p = 0.001) and a 15.0% increase in distant pressure pain thresholds (50.9 kPa, p = 0.012) following stretching to the point of stretch. We observed a 20.0% increase in regional pressure pain thresholds (90.3 kPa, p = 0.001) and a 15.1% increase in distant pressure pain thresholds (52.1 kPa, p = 0.004) following stretching to the point of pain.

Conclusions: The results showed that local and widespread pain sensitivity decreased following acute stretching, regardless of stretching intensity. No differences in pain sensitivity were found between stretching to the point of stretch or stretching to the first onset of pain. Thus, the results showed no evidence of a dose-response relationship between stretching intensity and the analgesic effect.

Significance: The study showed a significant acute hypoalgesic effect of stretching exercises regardless of stretching intensity. This may have appropriate clinical implications for patients with musculoskeletal and nociplastic pain.