The pain threshold of high-threshold mechanosensitive receptors subsequent to maximal eccentric exercise is a potential marker in the prediction of DOMS associated impairment

Abstract

Background: Delayed-onset muscle soreness (DOMS) refers to dull pain and discomfort in people after participating in exercise, sport or recreational physical activities. The aim of this study was to detect underlying mechanical thresholds in an experimental model of DOMS.

Methods: Randomised study to detect mechanical pain thresholds in a randomised order following experimentally induced DOMS of the non-dominant arm in healthy participants. Main outcome was the detection of the pressure pain threshold (PPT), secondary thresholds included mechanical detection (MDT) and pain thresholds (MPT), pain intensity, pain perceptions and the maximum isometric voluntary force (MIVF).

Results: Twenty volunteers (9 female and 11 male, age 25.2 ± 3.2 years, weight 70.5 ± 10.8 kg, height 177.4 ± 9.4 cm) participated in the study. DOMS reduced the PPT (at baseline 5.9 ± 0.4 kg/cm2) by a maximum of 1.5 ± 1.4 kg/cm2 (-24%) at 48 hours (p < 0.001). This correlated with the decrease in MIVF (r = -0.48, p = 0.033). Whereas subjective pain was an indicator of the early 48 hours, the PPT was still present after 72 hours (r = 0.48, p = 0.036). Other mechanical thresholds altered significantly due to DOMS, but did show no clinically or physiologically remarkable changes.

Conclusions: Functional impairment following DOMS seems related to the increased excitability of high-threshold mechanosensitive nociceptors. The PPT was the most valid mechanical threshold to quantify the extent of dysfunction. Thus PPT rather than pain intensity should be considered a possible marker indicating the athletes' potential risk of injury.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1

A-C display the mechanical thresholds at baseline and 24, 48 and 72 hours after induction of DOMS. Mean change ± SEM of the PPT in kg/cm2 (A), the MDT in mN (B) and the MPT in mN (C). D-F display pain and DOMS-related dysfunction. Mean change ± SEM of pain at rest (A) and during movement (B) in cm VAS and maximum isometric voluntary force (C). Black lines with p-values indicate the post-hoc tests between two times in case that repeated measures ANOVA detected significant effects x time. No between group differences (i.e. sequence of sensory testings) could be observed (refer to the text).

Fig 2

Displays the correlation between the change in PPT (in kg/cm2, with negative numbers indicating an increase in pressure pain) and the change in maximum pain intensity (in cm VAS, A) or MIVF (in N, B).

Fig 3

A-D display the rating of pain perception on the short-form MQP. (A)-(C) shows the mean change ± SEM at baseline and 24, 48 and 72 hours after induction of DOMS of the Total (A), Sensory (B) and Affective (C) Pain Score. D lists the used descriptors ranging from not to strong at the 4 time points. Descriptors at baseline and after 24 hours were connected with lines for a better visualization. Black lines with p-values indicate the post-hoc tests between two times in case that repeated measures ANOVA detected significant effects x time. No between group differences (i.e. sequence of sensory testings) could be observed (refer to the text).