High-intensity eccentric contractions induce performance decrements and delayed onset muscle soreness. The purpose of this investigation was to study the 21.4(3.3) years, mean(s.d.) height 160.0(5.0)cm, mean(s.d.) weight 59.8(7.9)kg) volunteered to perform an eccentric exercise regimen designed to produce DOMS in the elbow flexor goup (primarily biceps brachii and brachialis). The nonexercised arm was used as a control. Measures of perceived muscle soreness, tenderness, isometric strength, arm circumference and range of relaxed elbow extension were taken on the 'treatment' and 'control' arm immediately before and immediately after exercise, and at 24-h intervals for the next 11 days.To ensure repeatability of goniometric, myometric and circumference measures, both arms of each subject were marked at the proximal and distal musculotendinous (MT) junctions and at the midbelly of the biceps.Br J Sp Med 1992; 26(4) 267