link 4 as the tissue being treated is lengthened the plantar fascia tissue 11 the achilles tendon 12 the calf musculature 13 the popliteal fossa 14 the hamstring muscle group 15 and the lower back muscles and sinew 16 begin to lengthen as the user pulls the extremity to the second position 17 the user then reads the extremity flexibility number 2 in the passive stretching position 17 a shorter distance between the extremity support 3 and the handheld tissue stretching device 1 corresponds directly to lengthening the tissue of the posterior lower extremity plantar fascia tissue 11 the achilles tendon 12 the calf musculature 13 the popliteal fossa 14 the hamstring muscle group 15 and the lower back 16 an extremity flexibility number 2 is displayed to the user any time the extremity is engaged with the extremity support 3 the user may adjust treatment based on the extremity flexibility number 2 the user may disengage the release mechanism 6 from the retractor gear 23 to extend 20 the extremity support 3 away from the handheld tissue stretching device 1 and allow the user to lower the extremity to the support surface the stretchscore extremity flexibility number 2 can be obtained in numerous ways one embodiment for determining the stretchscore measures the distance between the handheld tissue stretching device 1 and user 39 s extremity when the extremity is engaged with an extremity support 3 a pliable inelastic link 4 is used to connect the extremity support 3 to the handheld tissue stretching device 1 the handheld tissue stretching.