Reliability And Criterion-related Validity Of Four Sit And Reach Tests For Measuring Hamstring Flexibility In Male University Students

Objective: to examine and compare the safety,reliability and validity for estimating the hamstring flexibility among the Classical sit and reach test(CSR),the Modified sit and reach test(MSR),the back saver sit and reach test(BS)and the chair sit and reach test(CSRT).Method: The four sit and reach tests,CSR?MSR?MSR and CSRT,the passive straight leg raise(PSLR)and body parameters(height,weight,limb lengths and trunk height)were administered to all 51 sophomores(male,age=19.8±1.11)on the same day.The Perceived Discomfort of performing the sit and reach tests was asked after each form of sit and reach test was administered.The randomly selected 31 participants were retested by four sit and reach tests nine days later.Result: 1)The CSR score were estimated into four levels,A,B,C and D,by gold standard from National Guideline of Student Physical Fitness 2014.The D group showed a statistically worst CSR score,and the CSR score of A group was significantly higher than C group.The height and lower limb length of A group were significantly lower than those from C group(P<0.05),whereas no differences in other body parameters were found among the four CSR groups;2)MBS yielded no significant r with all body parameters(P>0.05),but a Pearson correlation coefficient analysis was significant(p<0.05)for the limbs proportion with BS?CSR and CSRT(r = 0.283 and 0.277 for left and right legs,r = 0.352,and r = 0.316 and 0.285 for left and right legs respectively,P<0.05);3)For all sit and reach tests,reliability was very high(r =0.926–0.987).4)CSRT yielded significant and highest r with the PSLR,which is the criterion measure for hamstring flexibility(r = 0.558 and 0.713 for left and right).BS,CSR and MSR were also yielded significant r with PSLR(r = 0.557 and 0.701 for left and right,r = 0.557 and 0.701 for left and right,and r = 0.476 and 0.620 for left and right respectively).5)The ratings of Perceived Discomfort among the four sit and reach tests were significantly different(P<0.05)from each other.The rating for CSRT was observed the most comfortable test as compared with other tests.Conclusion: 1)MSR successfully overcomes the body parameters bias.CSR,BS and CSRT score do affected by the body parameters,mostly affected by the limbs length.2)MSR yields the worst reliability,and CSRT shows the best reliability.3)CSRT performs the highest criterion-related validity in estimating the hamstring flexibility,and the BS shows the lowest.4)The CSRT test is not only a reliable and test for hamstring flexibility,it is also shows the highest validity for hamstring flexibility in men than other sit and reach tests.