Sit on floor or mat with knees straight.
Reach toward or beyond toes or bring torso toward legs. Hold position.
The quality of the stretch should be examined for smoothness of spinal curve and the angle of hip (near 90° or more). See Sit and Reach Calculator for scoring reach with feet against sit and reach box.
Feet may be plantar flexed or placed against box, but protocol/norms must be kept consistent for comparisons since ankle position can affect hip flexion performance. Also see Seated Hamstring Stretch. If too great of spinal flexion is detected and greater hamstring flexibility is required, hamstring stretches that do not involve spinal flexion should be prescribed (eg: Lying Single Leg Hamstring Stretch). Other stretches performed by participant should also be modified if spine is found to be hypermobile. Also see concern for too great of flexibility in Stretching and Flexibility.