Resumen de Within- and Between-Session Reliability of the Isometric Midthigh Pull in Young Female Athletes
Sylvia Moeskops, Jon L. Oliver, Paul J. Read, John B. Cronin, Gregory D. Myer, G. Gregory Haff, Rhodri S. Lloyd
To investigate the within- and between-session reliability of the isometric midthigh pull (IMTP) in pre– and post–peak height velocity (PHV) female athletes. Nineteen pre- and 19 post-PHV athletes performed bilateral IMTPs using a custom-designed isometric testing system. Participants attended 3 separate testing sessions and performed 3 trials within each session. Peak force, relative peak force, force at 30, 50, 90, 100, 150, 200, and 250 ms, rate of force development (RFD) within time-specific bands, time to peak force (TPF), and time to peak RFD were obtained for analysis. Within- and between-session reliability for each variable was calculated from repeated-measures analysis of variance, intraclass correlation coefficients (ICCs), and coefficients of variation (CV) with 95% confidence intervals. Within- and between-session measures of absolute and relative peak force were found to be reliable for both pre-PHV (CV <= 9.4%, ICC >= 0.87) and post-PHV (CV <= 7.3%, ICC >= 0.92), but systematic bias was evident between sessions in the pre-PHV group, from session 1 to 2. Analyses of force at the specific time points revealed CVs between 19–37% and 5–24% for pre-PHV and post-PHV athletes, respectively. Greater variability was evident in TPF, and all RFD-related variables for pre-PHV (CV >= 38%) and post-PHV (CV >= 27%) athletes, respectively. The IMTP appears a reliable and safe method for evaluating peak force in young female athletes. Overall, post-PHV athletes were more reliable than pre-PHV athletes, with pre-PHV athletes needing additional familiarization to minimize the influence of systematic bias.
