Test-Retest And Minimal Detectable Change In The Assessment Of Muscle Strength And Muscle Power In Upper And Lower Extremity Exercises In 9-To 14-Year-Old Children

The prescription of maximal dynamic strength training in both adults and children is based on the evaluation of maximum strength, usually by one-repetition maximum tests (1RM). This study examined the test-retest reliability and the minimal detectable change (MDC) of the maximal force test and muscle power test. Forty-eight children (9-14 years old) completed two test-retest sessions that involved a one-repetition maximum (1RM) test and a muscle power test for leg extension (LE) and seated bench press (SBP). The MDC values of the 1RM test in the LE and SBP tests ranged from 7.35 to 11.34 kg and 6.84 to 7.92 kg, respectively. The MDC values of the muscle power test in the LE and SBP ranged from 30.32 to 63.20 Watt and 22.65 to 29.53 Watt, respectively. In children 9 to 14 years old, the increase of maximum strength along the growth curve was different in each muscle group studied. The repeatability of the 1RM test of the SBP was excellent (ICC 0.974) and was better than that of the LE (ICC, 0.954). The MDC of the 1RM test evaluation was 19.56% in the LE and 12.93% in the SBP.