A difference in the length of your legs can throw your spine out of alignment, tilting your pelvis and placing more pressure on one leg. This will likely cause lower back pain. Having one leg shorter than the other is called short leg syndrome. If the cause is hereditary and one leg is physically shorter than the other, a heel lift in your shoe will help correct the imbalance, but exercises to stretch out the muscles that have became tight due to walking with unequal legs will address the back pain.
TFL Stretching Exercise
Short-leg syndrome causes your pelvis to shift out of position, which causes muscles of the hip and thighs to get shorter and tight. These include the iliopsoas, adductors, TFL and piriformis. To lengthen the tensor fascia latae (TFL) muscle along the IT band, lie on your stomach and squeeze your legs together. Rest your head on your arms. Then, bend your knees and bring your heels toward your buttocks until you feel a stretch in the front and side of your thigh.
Adductor Stretching Exercise
The adductor muscles are in your inner thighs. These muscles contract to bring your legs together. To stretch the adductors, bring your hips outward away from each other. You can do this by lying on the floor with your buttocks against a wall. Place your legs straight up against the wall, together, and relax your arms next to you. Slowly slide your legs down the wall as you open them as wide as you can without causing pain. Do not let your lower back arch off the floor as you do this. Keep your abs squeezed. Gravity will pull slowly down on your legs to stretch your adductors.
Iliopsoas Stretching Exercise
Tension in the psoas or ilicus muscles of the hips, commonly together called the iliopsoas, may cause lower back pain and shorten the range of motion of the hips. To stretch the psoas muscle, kneel on your shorter leg with the knee of your longer leg in front. Place your hands on your front knee with your arms straight. Align the knee on the floor with your hip. Then push your hips forward and bend your front knee over your toes until you feel a stretch in the front of your back thigh. This stretches the psoas muscle of your shorter leg.