Strong and healthy hip flexors bring the leg forward easily and powerfully while you run, so if those muscles are tight or weak, you won’t run as efficiently. Instead, you may feel pain in your hips during or after your workout, and tight or weak hip flexors can start a chain reaction of poor mechanics throughout your body that end up manifesting themselves as injuries.

Fortunately, there’s a quick test to determine if your hips are weak or tight. Called the Thomas Test, this simple and effective diagnose weak or tight hips. Because there are five muscles in the hip flexor group — the psoas major, iliacus, rectus femoris, sartorius, and pectineus — the results of the Thomas Test can help determine which specific muscle needs to be strengthened or stretched to support the hip joints in your quest to run pain-free.

How to Do the Thomas Test
Lie face up on the edge of a bed or table so your legs hang off at 90-degree angles. From there, bring both knees toward your chest — keep your back still and flat — then slowly straighten one leg and let it hang off the edge.

A passed Thomas Test, where the back and thigh are flat against the table and the knee hangs off at a 90-degree angle.

If your back and the back thigh of the lowered leg stay flat against the surface while your hanging knee is perpendicular, congratulations! You passed! Happy Hips!

However, if

• your lowered leg remains straight instead of bending at the knee, or
• your lowered knee is bent, but the back of your thigh rises off the surface, or
• your thigh rests on the surface, but your lowered leg hangs slightly out to the side,

then you need to add hip flexor exercises to your workout routine. Each of those symptoms connects to a specific muscle of the hip flexor group, and so being detailed about the results will point you to the right stretch and strengthening solution.

Hip Flexor Stretches and Strength Moves
Hip flexor strengtheners include toe taps, bridges, and clamshells, while hip flexor stretches that alleviate tight hips include specific types of lunges and other quad stretches. Kristopher Ferrera, doctor of physical therapy at Moss Rehab, previously told Runner’s World that even something as easy as rolling out the area with a  ball will work wonders for hip tightness.

Hip imbalances frequently begin when people, including runners, spend too many hours sitting at a desk or in front of a screen. This causes the flexor muscles, which help to bring the knee up toward the torso, to shorten. That’s why, Tom Holland, an exercise physiologist and CEO and founder of TeamHolland LLC, told Runner’s World that “never before has strength-training, stretching, and mobility work been more important for runners.”

Whether it’s a simple new stretch to add to your regular routine or a unique element to add to your workout, our guides have everything you need to alleviate hip tightness and become a more efficient runner.

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