1RM measurement in the standing calf raise: Evaluation of reliability and measurement error

Investigations into the maximum strength capacity of the plantarfl exors have gained interest. An excellent intraclass correlation coeffi  cient (ICC) for the standing calf raise-1RM has been reported. However, research has shown that ICC alone does not suffi  ciently refl ect measurement reliability. The aim of this study was to reassess the reliability of the standing calf raise-1RM. Fifty-six physical education students performed standing calf raises on two occasions. ICC, standard error of measurement (SEM), and minimal detectable change (MDC) were calculated, as well as mean absolute error, mean absolute percentage error, and typical error. A dependent t-test was performed to assess systematic error, and a Bland-Altman plot was created. Low levels of both absolute and relative error were observed. Comparing the diff erent measures, previous criticisms of the ICC and measures calculated from it, such as SEM and MDC, are highlighted. Researchers are advised to report various independent measures to illustrate the accuracy of their procedures.