Lower back pain, knee discomfort, getting tired easily when running... More often than not, the root cause of these issues isn't where you'd expect.

In clinical practice, our first step in treating pain is rarely to jump straight into therapy. Instead, we take the time to conduct thorough assessments and tests to pinpoint the real root cause. For many, pain actually stems from overly tight muscles or muscle imbalances—issues that are easily missed without a systematic evaluation.

Today, we'll introduce a simple yet highly practical lower limb assessment: the Modified Thomas Test, along with three targeted stretches based on your results.

Why are tight hip flexors so common?

Modern life keeps us sitting for hours on end—whether we're working, eating, commuting, or relaxing. Spending prolonged periods with our hips bent causes our hip flexor muscles to gradually adapt to this shortened position, becoming increasingly tight.

One of the most common consequences of tight hip flexors is an anterior pelvic tilt—where the pelvis rotates forward, increasing the arch in your lower spine (often referred to as 'swayback'). This is a leading cause of lower back pain and can trigger a chain reaction affecting your knees, hips, and overall gait and athletic performance.

The catch is, most people have no idea their hip flexors are tight. This is exactly where the Modified Thomas Test comes in handy.

Modified Thomas Test | Identify tight muscles in three minutes

Widely used by clinicians, this test is straightforward yet delivers invaluable insights into your muscle health.

How to perform the test:

Sit at the very edge of a bed or a firm, elevated surface. Hug one knee tightly to your chest and slowly lie back, letting your other leg relax and hang down naturally. Once you're lying down, ensure your lower back remains flat against the bed—this is crucial, as an arched back will skew your results.

Once relaxed, observe the position of your hanging leg and check these three indicators:

① Is your thigh flaring outwards?
If your thigh drifts outward, it suggests tightness in your **tensor fasciae latae (TFL)** on the outside of your hip. The TFL connects to the IT band, and tightness here often leads to outer knee pain—a classic culprit behind runner's knee.

② Is the angle of your knee greater than 110 degrees?
If your lower leg can't hang down naturally and stays at an angle wider than 110 degrees, your **quadriceps** (front thigh muscles) are tight, which restricts normal knee mobility.

③ Is your thigh lifted off the bed?
If your thigh remains elevated and cannot rest flat against the bed, your deep **iliopsoas** muscle is tight. The iliopsoas is your primary hip flexor and one of the muscles most prone to shortening from prolonged sitting.

These three muscle groups—the iliopsoas, quadriceps, and TFL—make up your hip flexors. When they tighten up, they pull your pelvis forward, leading to a chronic anterior pelvic tilt. Over time, this posture causes lower back pain, hip discomfort, and compromises your overall lower-body biomechanics.

Found the problem? Here is how to fix it

Assessment is just the first step. To make a real difference, you need to target the specific tight muscles identified in your test with dedicated stretching.

The following three stretches target the three muscle groups assessed in the Modified Thomas Test. Hold each stretch for 20 to 30 seconds and repeat 3 times. You should feel a mild to moderate stretch, never sharp pain.

Stretch 1 | Iliopsoas (Deep Hip Flexor) Stretch

Take a large step back into a low lunge starting position, keeping your front knee bent at about 90 degrees. Next, gently tuck your pelvis under (posterior tilt) while actively reaching your back heel away. If done correctly, you should feel a deep stretch along the front of your hip and lower abdomen.

To deepen the stretch, reach the arm on your trailing side straight up, lengthening the entire side of your body.

Stretch 2 | Quadriceps Stretch

Stand tall, grasp your ankle on the same side, and gently pull your heel toward your glutes until you feel a comfortable stretch along the front of your thigh. Keep your torso upright and avoid arching your lower back or leaning to the side to keep the focus on the target muscles.

If you need help with balance, lightly rest your free hand on a wall or the back of a sturdy chair.

Stretch 3 | TFL (Outer Hip) Stretch

This move is slightly more complex than the first two and takes a bit of patience to master.

Start in the same low lunge position with a big step back. Next, sweep your back foot inward to rotate your hip outward. From there, gently shift your hips out to the side until you feel a stretch along the outer hip. Keep your core engaged throughout to stabilise your torso and prevent swaying.

Finding the right angle for this stretch can be tricky on your first try—let us know how it feels once you give it a go!

Beyond stretching: What else is needed?

Stretching is an essential first step to release tight muscles and restore joint mobility. However, stretching alone isn't enough to permanently resolve hip dysfunction.

Once you've improved your flexibility, you must follow up with strengthening exercises targeting your glutes, hips, and core. This ensures your muscles have the strength and control to support your daily activities and workouts. Without adequate strength, your muscles will quickly tighten up again, leading to a frustrating cycle of recurring tightness.

We'll be sharing targeted strengthening exercises soon, so stay tuned!

A simple test to kickstart your recovery

Physical pain rarely happens out of the blue; it is usually the culmination of long-term postural habits and muscle imbalances.

The Modified Thomas Test takes just three minutes to give you a baseline reading of your hip flexor health. Paired with targeted stretches, it is a highly effective starting point for correcting anterior pelvic tilt and preventing lower back pain.

If you noticed significant tightness during the test, or if you are already dealing with lower back, hip, or leg discomfort, feel free to book a professional assessment with us. We'll help you find the root cause of your pain and design a tailored recovery plan just for you.

To take care of your body, you must first understand it.