Development of simple evaluation method for power of hip flexor muscles in elementary school children

The purpose of this study was to examine the reliability and validity of the Hip Flexion Test (HFT). HFT is a test to kick away a weight hung on ankle to forward, and it was devised for evaluating hip flexion power easily. The participants were 24 upper grade children in elementary school (Age: 11.60 ± 0.53 years, Height:1.47 ± 0.08 m, Body mass: 38.82 ± 7.72 kg). Time, step frequency, step length, and hip flexion torque during 50m sprint were measured. Furthermore, flying distance of HTF, and jump height of CMJ were also tested. Result for t-test, there was no significant difference between 1st and 2nd measured values of HTF. Furthermore, intraclass correlation coefficient between 1st and 2nd value of HFT was a significant (ICC=0.767). From these results, the reliability of HTF was confirmed. Secondly, to show the validity of HTF, we calculated a correlation coefficient between measured values of HFT and a hip flexion torque during 50 m sprint. There was a significant correlation between them (r=0.573, p<0.01), so it could be found that HFT could evaluate a hip flexion torque during 50m sprint. From this research, the reliability and validity of HFT was proved, and we could find that HTF is effective test to evaluate hip flexion power.