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Today I’m going to cover a basic but very important exercise referred to as the straight leg raise exercise. I am going to show you how to do this properly without causing unnecessary and uncomfortable strain in your lower back.

I consider this an active straight leg raise since you will consciously use your breath, core strength, posture, shoulders, hip flexors, and quadriceps as you raise your leg.

You will need two pieces of equipment:

  • Pillow (optional depending on your comfort level).
  • Small support for your waist.

You might need a second pillow for additional support (I will explain this later).

Straight Leg Raise Exercise Benefits

The straight leg raise exercise benefits and strengthens muscles in your quadriceps and your hip flexors. If you keep everything engaged and tight as I describe in the video and in the step-by-step instructions, then your hip flexors will not pull on your back and potentially cause discomfort.

straight leg raise exercise melioguide physical therapy

Straight Leg Raise Exercise in Physical Therapy

The straight leg exercise is often used in Physical Therapy to help patients improve the strength of their lower extremities.

Over the past 34 years as a Physical Therapist (Physiotherapist), I have often prescribed the straight leg raise exercise to patients recovering from a variety of surgeries or traumas to their body.  It is a popular exercise that can be done before you are able to place full weight on a joint or limb. The straight leg raise is a cornerstone exercise in rehabilitation for knee replacements or many surgeries involving the lower leg, foot and ankle.

As the name implies, the straight leg raise exercise does not require you to bend the knee joint. This is encouraged when an individual has advanced arthritis in their knee(s).   The straight leg raise exercise strengthens the muscles of the upper thigh, the quadriceps, without placing any stress on the knee joint.

How to Avoid Back Pain During the Straight Leg Raise

Although the straight leg raise exercise is kind to the knee, it can be hard on the low back.  The reason back pain can occur is because the hip flexor muscles work along with the quadricep muscles to raise the leg up.  Engaging the hip flexors without counteracting some of its effects can lead to back pain. Let me explain why this happens.

The quadricep muscles attach from the front of the pelvis and upper thigh to below the knee. This is illustrated in the image to the right.

If you only had to engage your quadricep muscles to raise your leg, you would not have to worry about compromising your low back.

However, the act of doing a straight leg raise exercise also involves a powerful hip flexor muscle, known as your iliopsoas.

The psoas part of the hip flexor muscle originates from the front of the spine, and it joins the iliacus before attaching onto the upper thigh. The psoas major and psoas minor as well as the iliacus muscles can be seen near the top of the image to the right.

The pull from psoas at it’s spinal attachment points (caused by raising the leg) can cause you to arch your lumbar spine area. This back arch, in turn, can lead to back pain. You must counter the back arch by engaging your deep abdominals. Activating your deep abdominal muscles will counter the strain on the lower (or lumbar) spine and reduce the chance of back pain.

[Image attribution. Henry Vandyke Carter [Public domain]]

straight leg raise exercise • quadriceps + psoas

How to Do the Straight Leg Raise Exercise

Follow these steps to do the straight leg raise exercise properly.


It is important that you set yourself up correctly to do the straight leg raise exercise. Do the following before you start the exercise:

  • Always go down onto your shoulder before you roll over. If it’s comfortable for you to use a pillow, then, by all means, I recommend that you do so.
  • I encourage you to use a little support in the small of your back whether it is a pillow or some other support. The size and thickness of that support should be the same the depth of your hand when it is placed flat on the floor.
  • Slide the support out to one side and after you have verified that the support is the correct size, bring that back in a position to support your lower back.
  • When you use the muscles of your legs, you should also engage your abdominals. This keeps your low back safe.
  • Like all of the exercises that I work through with you online, I want you to think about your posture and alignment. This very important!
  • If you are comfortable without a pillow, then, by all means, do the exercise that way. This approach will give you an extra stretch through your neck.
  • Use a little roll just at the base of your skull if you feel you need support through your neck . That should fill in that cavity or space behind your neck.

Step by Step Instructions

Follow these step-by-step instructions:

  • Make sure that you tuck your shoulders down and orient your palms to the sky.
  • Keep your knees well bent while you support your low back.
  • Slide out the leg your going raise.
  • This is a nice opportunity to stretch your toes before we begin the rest of the exercise. (You can never get enough toe stretches!)
  • Keep your toes pointed towards your nose and raise your leg.
  • Lift your leg no higher than the opposite thigh.
  • Pause.
  • Bring the leg down in a controlled manner (do not drop!)
  • Pay special attention to your breathing through the movement and make a point of not holding your breath.

Here are the steps you should follow to control your breathing.

  • Take a full breath in.
  • Exhale and tighten your lower tummy as you raise your leg.

Here is a breathing tip. As you exhale, gently blow through pursed lips to help you tighten your pelvic floor.

Please refer to the Exercise Safety Tips in Exercise for Better Bones to learn more about supportive breathing while exercising.

You might want to start with a shorter leg lift, raise (or elevation) or use an assist depending on:

  • How strong that you are when you do the straight leg raise exercise.
  • If you wear a support boot on your ankle because you are recovering from a recent surgery or fracture.

Exercise Recommendations for Osteoporosis

Exercise is an essential ingredient to bone health. If you have osteoporosis, therapeutic exercise needs to be part of your osteoporosis treatment program.

But what exercises should you do and which ones should you avoid? What exercises build bone and which ones reduce your chance of a fracture? Is Yoga good for your bones? Who should you trust when it comes to exercises for osteoporosis?

A great resource on exercise and osteoporosis is my free, seven day email course called Exercise Recommendations for Osteoporosis. After you provide your email address, you will receive seven consecutive online educational videos on bone health — one lesson each day. You can look at the videos at anytime and as often as you like.

I cover important topics related to osteoporosis exercise including:

  • Can exercise reverse osteoporosis?
  • Stop the stoop — how to avoid kyphosis and rounded shoulders.
  • Key components of an osteoporosis exercise program.
  • Key principles of bone building.
  • Exercises you should avoid if you have osteoporosis.
  • Yoga and osteoporosis — should you practice yoga if you have osteoporosis?
  • Core strength and osteoporosis — why is core strength important if you have osteoporosis?

Enter your email address and I will start you on this free course. I do not SPAM or share your email address (or any information) with third parties. You can unsubscribe from my mail list at any time.

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Straight Leg Raise Exercise With External Rotation

If your Physical Therapist gave you ten straight leg raises to do, five should be done in the position that I just demonstrated and five should be done with your leg slightly externally rotated.

Follow these instructions to do a straight leg raise with external rotation:

  • Roll out the whole leg about 30 degrees.
  • Follow the detailed step-by-step instructions above.

Straight Leg Raise Exercise With Extra Support

If you are following the instructions and still have a hard time keeping your back down and engaged, use another pillow for support. The higher the pillow, the more assistance you’re going to get.

  • Rest your thigh all the way down to your heel on the pillow. This extra support will take away the hardest part of the lift for the abdominal.
  • Follow the detailed step-by-step instructions above.

Follow these instructions and you will not cause any undue stress on your back (1).


That is how I like to see you do the straight leg raise exercise. This approach will yield all the benefit of the straight leg raise without creating any stress in your low back.


  1. McGill, Stuart. Low back Disorders, Evidence-based Prevention and Rehabilitation. p. 240.

Osteoporosis Exercise Plan

Visit my Osteoporosis Exercise Plan page for more information on this topic.