Validity of diagnostic ultrasound as a measure of delayed onset muscle soreness

Study Design: Repeated measures were taken to evaluate delayed onset muscle soreness (DOMS) following eccentric bicep contractions of the nondominant arm at 140% of 1 repetition maximum (RM) while the dominant arm served as c ontrol. Objectives: To explore the usefulness of a noninvasive method to asses dela yed onset muscle soreness. Background: Although many methods have been proposed to assess DOMS, most a re somewhat subjective or require a blood sample. This study compared the a ssessment of DOMS following eccentric exercise using common assessment tech niques with diagnostic ultrasound (US). Methods and Measures: Forty nonimpaired women (18-40 years) used a Cybex is otonic biceps curl machine to eccentrically lower using their nondominant a rm, 140% of their dominant arm 1 RM to induce muscle soreness. Four assessm ent methods, (1) goniometry assessing spontaneous muscle shortening (SMS); (2) subjective muscle soreness ratings (MSRs); (3) serum creatine kinase (C K); and (4) diagnostic US scans of muscle cross-sectional area (CSA), were conducted at 5 different assessment times: (1) pre-eccentric exercise; (2) postexercise; (3) 24 hours postexercise; (4) 48 hours postexercise; and (5) 72 hours postexercise. Results: Significant differences existed across assessment times for 3 of t he 4 assessment techniques, CK, SMS, and MSR. Conclusions: Previously published methodologies used to assess DOMS (CK, SM S, and MSR) were able to provide consistent and expected results relative t o the onset and progression of soreness with a high degree of relatedness ( r = 0.48-0.84). However; it appeared that the ability to assess muscle sore ness by diagnostic US, as evidenced by intramuscular swelling, was limited. Thus, the technique was not sensitive enough to detect any statistically s ignificant changes in muscle CSA.