Finding the sweet spot to stretch our low back muscles can be difficult if you don’t choose the right exercise for the job. You may do a sustained toe touch in hopes of improving back flexibility. And yes, you’re rounding your back, which technically speaking puts those muscles on a stretch, but the movement of toe touching primarily happens at the hip joints. The back rounding tends to be an offshoot of that, and it is not particularly safe, either.

That’s where the knees-to-chest stretch comes in. Not only does it feel great in most instances, but it’s a wonderful way to restore flexibility in your low back muscles following an afternoon of gardening or housework or after a day at the computer.

But the knees-to-chest stretch is good for more than low back muscle release.

As a range of motion exercise, in other words, a movement that increases your joint flexibility, the knees-to-chest stretch may help reduce stiffness associated with spinal arthritis and/or spinal stenosis.

In fact, range of motion is the most important type of exercise for people who have osteoarthritis in their spines, says Hagit Rajter, physical therapist at the Joint Mobility Center at the Hospital for Special Surgery in New York.

“This type of exercise helps make positive changes in the joint, along with increasing blood supply and assisting nutrients to flow into the area,” according to Rajter.

How to Do the Knees-to-Chest Exercise

For your safety, start doing the knees-to-chest stretch with one leg only. If, after a few days, you’re performing it without pain, it’s likely time to advance to lifting both legs, Rajter tells me.

By the way, if you are unsure whether a double or single legged knees-to-chest stretch is safe given your particular back condition, speak with your healthcare provider before trying the following:

  • Lie on your back with your knees bent and your feet flat on the floor. This is called the supine position.
  • Gently raise one bent knee up enough so you can grasp your lower leg with both hands. Interlace your fingers just under the knee.
  • If you’re doing the two-legged version, bring one leg up and then the other. Because taking both up at the same time takes a lot of abdominal strength, starting with one and then quickly following with the other is likely safer, especially for vulnerable backs.
  • As with the single legged version, if you are taking both up at the same time, interlace your fingers or clasp your wrists between the lower legs, just below the knees.
  • Gently pull your bent knee or knees toward your trunk, using your hands.
  • While you’re pulling, try to relax your legs, pelvis and low back as much as you can. The knees-to-chest better reaches low back muscles when used passively.
  • Hold for a few seconds.
  • Return your leg to the floor.
  • Repeat on the other side.
  • Do the stretch about 10 to 15 times, one or two times per day or as needed.