A comparison between active knee extension test and back-saver sit-and-reach test in assessing hamstring flexibility among healthy schoolchildren in India

Abstract

Objective: This study evaluated the correlation between the active knee extension test and the back-saver sit and reach test among healthy schoolchildren aged 9–13 years in India. Method: Five hundred and two healthy schoolchildren aged between 9–13 years were recruited from selected schools in India, and their hamstring flexibility for the right and the left leg was measured using the back-saver sit and reach test and the active knee extension test. The test protocol for the back-saver sit and reach test was taken from the FITNESSGRAM fitness test (while active knee extension test was performed according to the procedures taken from reliability studies). A Pearson's correlation coefficient was performed to identify the relationship between the two scores. Results: The mean (SD) of the test values were as follows: active knee extension test right leg: 29.09 (± 6.51); left leg: 29.07 (± 6.51). Back-saver sit and reach test right leg: 10.81 (± 1.79); left leg: 10.83 (± 1.70). The two showed a moderate correlation (right leg r=-.439 and left leg r=-.429, P≤.05). The active knee extension test was more sensitive to age increments, showing an overall decrease in the scores with advancing age. Conclusion: The active knee extension test and the back-saver sit and reach test are both tests that measure hamstring flexibility. The active knee extension test was found to be more sensitive to hamstring length changes, and should be used in the assessment of flexibility.