There is plenty of information that you can learn about your ability to move powerfully and efficiently from the straight-leg raise assessment. In this post, we will first run through how to properly set-up and execute the assessment, and then we will go over three common problems that athletes encounter during the test with some options for solving them.

Performing the Straight-Leg Raise

To perform the straight leg raise, lay on your back on a hard, flat surface (do not use a mat) and place your palms/fingers on the floor just beneath the small of your back (the space between your lower back and the floor). You will then raise one leg up until you feel your low back press against your hand – as this means that you have lost control of the pelvis and your range of motion is coming from the wrong place. Ideally, we would like to see the heel of the raised leg just pass or reach the knee of the non-working leg before there is any movement in the low back. That’s it, it is a simple test, but we can infer many things from the results. Let’s take a deeper look.

1.      Contracting The Non-Working Leg

If the opposite (non-working) leg must contract (heel pushing hard into the floor or knee extending/hyper-extending) while performing the straight-leg raise, this is a sign that the abdominals are not doing their job of keeping the pelvis still, and so the hamstring of the non-working leg is doing the work instead. We know this because the abdominals and the hamstrings exert the same action on the pelvis which is to rotate it backward (when two muscles produce the same action on a joint, we call this a “Force Couple”). If you notice this, cue yourself to relax the non-working leg and let your abdominals carry their own weight. This test result would be an example of a Force Couple in which one muscle is “dominant” and the other is “dormant,” thereby causing the dominant muscle to overwork.

2.      The Low-Back Flattens Early

We must remember that there are multiple muscle groups which work on the joints in the body – especially in the case of the pelvis. If you feel the low back flatten against your hand before the heel of the raised leg reaches/passes the knee of the non-working leg, it is a sign that the hamstring muscles on the working leg are generating more stiffness than the hip flexor muscles can counteract, causing the pelvis to tilt backward and the lower spine to flex. In this case the muscles/joints that are generating less stiffness (the spinal erectors/lumbar facets/hip flexors) must be strengthened so that a healthy length-tension relationship between them and the hamstrings involved muscles can be restored.

3.      Low Back Does Not Change – But the Heel of The Raised Leg Does Not Reach the Knees

If the low back remains neutral, but the heel of the raised leg does not reach the knee of the non-working leg, that is a sign that the hamstring muscles are short, and the athlete should work on restoring their flexibility with myofascial release and by training the hamstring in long positions with the low back in a neutral position (slightly curved inward). However, this could also be weakness of the hip flexor muscles. To determine which the problem is, examine the following:

A: If while performing the above, the movement produces a “shaky” leg, or if the hip flexor muscles cramp, it is likely that the hip flexors are weak and cannot support the weight of the limb in question. In this case, try to sit on the edge of a surface with the hips and knees at 90 degrees and the torso tall and the low back flat, and attempt to bring the knee upward toward the head (Seated Hip Flexion Assessment). If the low back rounds during the motion, then you have likely confirmed weakness of the hip flexor muscles. To address this, release the hamstring muscles through massage or foam rolling and immediately afterward, try lifting the knees toward the hips in the standing position. A band can be used for added resistance as shown in the video (BR Hip Flexion), and the hands may support you against a wall or an object for balance. Perform this exercise until you can lift the knee without any movement at the low back.

B: If there is no shakiness or cramping during the test, then while lying supine in the regular test position, instead of performing the straight-leg raise, bring the knee of the working leg toward the chest. If the knee can be brought toward the chest and there is still no low back motion as the knee reaches hip-level, then you can be more certain that the problem is indeed a shortened hamstring.

Parting Thoughts

The above scenarios have some important implications. Short hip flexors can hinder jump and sprint development by diminishing the stretch-shortening cycle of the posterior chain, and lead to dysfunction by increasing the dominance of synergist muscles (think back to our discussion about Force Couples); stiff hamstrings can lead to a more mobile and more flexible lumbar spine resulting in vulnerable lumbar facets/discs during training and performance; and weak abdominals can predispose one to overuse injuries at the groin and hamstring.

There are other things to look for in the test. For example, raising the leg at certain angles may produce a more successful result, or there may even be a lack of space for the leg bone to move in the hip, forcing the pelvis to rotate backward to accommodate the action being tested. In either case, a more thorough evaluation and solution may be required to correct the problem. Typically, however, athletes will encounter one of the three scenarios listed.

Contact me on the website if you have further questions or are interested in being assessed at our facility.

Happy Training!