Reliability of a kinetic and kinematic assessment procedure for kicks in combat sports

Ensuring reliability of measurement instruments in combat sports is crucial for coaches and researchers, promoting their widespread use. This study assessed the reliability of a procedure that measures kinetic and kinematic variables in karate athletes’ roundhouse kicks. Twenty-four male karate athletes participated, performing three kicks initially and three 48 h later. Paired Student’s t-test found no significant differences between tests. Bland–Altman plot revealed few outliers. Strong agreement between test and retest was shown by Pearson correlations, Intraclass Correlation Coefficient (ICC), and Coefficient of Variation (CV) for impact force variables: r = 0.96; ICC = 0.93; CV = 0.12%, impulse: r = 0.95; ICC = 0.93; CV = 1.08%, attack time: r = 0.82; ICC = 0.70; CV = 0.14%, contact time: r = 0.72; ICC = 0.60; CV = 0.18%, return time: r = 0.80; ICC = 0.71; CV = 4.28%, and kick time: r = 0.84; ICC = 0.77; CV = 2.88%. No Smallest Worthwhile Changes (SWC) were observed, and Cronbach’s alpha indicated acceptable internal consistency. In conclusion, the procedure demonstrated reliability in terms of internal and measurement consistency, without random errors.