What Muscles Do You Stretch When Doing the Back-Saver Sit and Reach?

The back-saver sit and reach measures the flexibility of your hamstrings.
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The back-saver sit and reach stretch is a fitness test that measures the flexibility in your legs and hips. It’s used by health professionals to measure and monitor the effectiveness of the workout programs they assign to their clients. Schools may also use the test to detect any possible flexibility issues in their students. The back-saver sit and reach measures each leg independently.


The back-saver sit and reach stretch is similar to the traditional sit and reach test, except that each leg is measured independently. You’ll need a sit and reach flexibility box, which is a box made of metal that features ruler markings of inches and centimeters printed on the top. Take off you shoes and sit on the floor facing the box, with one leg extended with your foot set firmly against the side of the box, and the other leg bent with your foot on the floor. Stack your hands on top of each other with your palms facing down, then slowly bend forward at the waist, sliding your hands over the top of the box as far forward as you can. Repeat the test three times, each time recording your score. Your score is the distance from the end of the box to the point you can reach with the tips of your fingers. Use the ruler printed on the top of the box, and mark down your score in centimeters. Switch legs and repeat the test.


The back-saver sit and reach primarily measures the flexibility of your hamstrings. The hamstrings are a collection of three muscles, including the biceps femoris, semitendinosus and semimembranosus, located at the back of your thighs. They originate at your hip and run down the back of your leg, ending just below your knee joint at the tip of your tibia and fibula bones.

Lower Back

Because you bend forward at the waist, the back-saver sit and reach also measures the flexibility of your extensor muscles at your lower back. These include your erector spinae, which run down the back of your spine, as well as your gluteal muscles, including the gluteus maximus, gluteus minimus and gluteus medius.


Health professionals may monitor hamstring flexibility because hamstrings that are too tight can pull on your pelvis and cause lower back pain. According to ExRx.net, long sedentary hours spent sitting will place the hamstrings in a shortened position, often causing hamstring inflexibility to become an issue. According to D. Scott Davis' 2005 study published in the Journal of Sports and Conditioning Research, the best way to increase flexibility in your hamstring and lower back is to participate in a static stretching routine at least once per day. The hamstring stretch involves sitting with your legs extended and stretching out toward your toes, then holding that stretch for 30 seconds.

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