Correlation Between Visual Analog Scale and Pressure Algometry Measures in Assessing Skeletal Muscle Soreness

Abstract

Muscle soreness following strenuous exercise is a common finding and has been studied extensively in relation to eccentric exercise-induced skeletal muscle injury. In the exercise science field muscle soreness is most commonly measured using a visual analog scale (VAS) in which a subject reports their degree of soreness on a 10cm horizontal line. However, the measurement of muscle soreness using pressure algometry is common in clinical practice, and suggested to be a more precise measurement tool. PURPOSE: To determine the correlation between muscle soreness ratings using a 10cm VAS and pressure algometry readings in resistance trained men before and following 100 eccentric repetitions in the bench press exercise. METHODS: 21 resistance trained men (age: 24±6 years, height: 177±6 cm, weight: 88±21 kg, body fat: 12±9 %, 1-RMbench press: 102±16 kg, mean±SD) performed 10 sets of 10 eccentric repetitions in the bench press exercise at 70% of their 1 -RM using a Smith machine. Muscle soreness was assessed pre-exercise, immediately (0), 24 and 48 hours post-exercise using both a 10cm VAS (recorded following 2 repetitions of the barbell bench press using a standard 20kg bar) and pressure algometry via a force dial (Wagner Instruments; Greenwich, CT) at selected anatomical sites (pectoralis major, anterior deltoid, triceps lateral head, triceps long head). For each site, both the onset of pain and the tolerance of pain were recorded. Pairwise correlations for all measurements were made and an alpha level of < 0.05 was accepted as statistically significant. RESULTS: Subjects reported increased muscle soreness following exercise, as evidenced by a time main effect using the VAS data (pre: 0.95±0.22, 0 post: 4.06±0.45, 24 post: 6.40±0.40, 48 post: 5.83±0.53, mean±SEM, p <0.0001). Statistically significant correlations were noted between the VAS data and the pressure algometry measures for the chest onset of pain (r = −0.287, p = 0.008) and tolerance (r = −0.254, p = 0.0196), the deltoid tolerance (r = −0.255, p = 0.019), and the triceps long head tolerance (r = −0.228, p = 0.037). CONCLUSIONS: These data indicate that in resistance trained men, pressure algometry measures of muscle soreness are correlated to VAS measures in a site specific manner. However, while statistical significance was noted between the VAS data and these selected sites, the correlations are weak. Furthermore, although all muscles measured are recruited during the bench press exercise, the degree of soreness is not uniform across muscle groups, possibly due to differences in muscle recruitment.