Voluntary Inducement of Triceps Surae Muscle Cramping

Context: Exercise-associated muscle cramping (EAMC) is difficult to induce experimentally. Purpose: T o assess the reliability of a maximum voluntary contraction (MVC) procedure for inducement of a muscle cramp. Participants: Seventy-four healthy and physically active participants (23 ± 8 years of age; 49 males and 25 females); 63 who had previously experienced EAMC. Main Outcome Measure: Each participant’s triceps surae musculature was placed in a shortened and unloaded position. Participants were instructed to maximally contract the triceps surae musculature with the intent to induce a cramp within 60 seconds. Results: Cramping was induced in 31% of participants within 60 seconds, and 97% of participants who experienced cramping during the initial session and who returned for two subsequent testing sessions at one-week intervals reproduced cramping with the procedure. Conclusions: The MVC procedure consistently induced cramping in a subset of 18 cramp-prone participants during multiple testing sessions, which suggests that it may have value as a screening tool for identification of athletes with a predisposition for EAMC.