Lumbosacral movement in the sit-and-reach and in Cailliet's protective-hamstring stretch

This study analyzed movement characteristics of subjects as they performed two different hamstring stretching activities. The study determined if there were differences in lumbosacral movement as the subjects performed the two stretches. Cailliet contends that his protective hamstring stretch is less apt to be stressful to the structures of the spine than is a more commonly done sit-and-reach stretching activity. No previous biomechanical investigation has tested his contention. Lumbosacral movement was measured with an Ady-Hall lumbar monitor as 40 university students (20 males, 20 females) performed a popular sit-and-reach test and a sit-and-reach test that subscribed to Cailliet's protective hamstring stretch protocol. Lumbosacral movement was almost identical in the two stretching activities. If lumbosacral movement is the only criterion to consider in evaluating the safety of these two stretching activities, it makes little difference which activity is chosen. If moment of inertia were the dependent variable rather than lumbosacral movement, possibly one activity may be less stressful to the structures of the spine than the other.