Tight Hip Flexors and Lower Back Pain: What’s the Connection?

Tight hip flexors are the muscles at the front of your hip feeling stiff or pulling, usually after long periods of sitting. They can contribute to lower back pain, but tightness alone is rarely the whole story. Research suggests strength and endurance around the hips, trunk and back matter more than muscle length, so the best results usually come from building capacity, not just stretching.

Article Summary

Plenty of people with lower back pain have been told their hip flexors are tight, and it’s true that this group of muscles connects directly to the lower spine. But the idea that tight hip flexors pull your pelvis forward and cause back pain is more theory than proven fact. This article explains what the hip flexors are, why they feel tight, how to test them, what the research actually shows about the link to back pain, and what tends to help most.

Key Takeaways

• Tight hip flexors usually come from long periods of sitting, and sometimes from muscles working hard without enough strength behind them.
• The Thomas test is a simple way to check, and the difference between sides tells you more than a single result.
• Research has not found a strong link between hip flexor length and back pain. Strength and endurance show a clearer link.
• Stretching helps some people feel better. Strength work around the hips, trunk and back usually makes the bigger difference.
• Breaking up long periods of sitting is one of the simplest changes you can make.

Table of Contents

• What are the hip flexors?
• What are the symptoms of tight hip flexors?
• How do you test for tight hip flexors?
• Why do hip flexors feel tight?
• Do tight hip flexors cause lower back pain?
• What actually helps tight hip flexors?
• Is there a hip flexor stretch I can try now?
• When should you get it assessed?
• Frequently asked questions

What are the hip flexors?

The hip flexors are a group of muscles at the front of the hip whose main job is to lift your knee towards your chest. They’re working every time you walk, run, climb stairs or get up out of a chair.

The biggest of them, the iliopsoas, attaches to the front of the lumbar spine and runs down to the top of the thigh. Because it connects the spine and the leg, it’s easy to see why it gets blamed when the lower back is sore.

What are the symptoms of tight hip flexors?

People usually describe some combination of:

• A pulling or tight feeling at the front of the hip or top of the thigh
• Stiffness when standing up after sitting for a while
• Discomfort at the front of the hip when taking long strides or running
• Lower back stiffness after sitting, or after standing for long periods
• Finding it hard to stand fully upright straight away after getting out of the car

These symptoms are common and worth paying attention to, but they don’t automatically mean your hip flexors are the reason your back hurts.

How do you test for tight hip flexors?

The simplest check is the Thomas test, the same test most clinics use. It takes about a minute.

1. Sit right on the edge of a firm bed or bench.
2. Hug one knee to your chest and roll back onto the bed, keeping that knee held in.
3. Let the other leg hang down over the edge, completely relaxed.
4. Look at the hanging leg. If the back of the thigh rests flat on the bed, that hip has reasonable length. If the thigh lifts up off the bed, the hip flexors on that side are likely tight.
5. Repeat on the other side.

What matters most is the comparison between sides. A clear difference is more useful information than either result on its own. If the test gives you a pinch at the front of the hip rather than a stretch, stop and get it assessed, because that points to something other than tightness

^{Physio Jordan Baker demonstrating the Thomas test for tight hip flexors}

Why do hip flexors feel tight?

The most common reason is simply time spent sitting. When you sit, your hips are bent and your hip flexors sit in a shortened position for hours at a time. It’s no surprise they feel stiff when you finally stand up.

The other piece, and the one people don’t hear about as often, is that a muscle can feel tight because it’s working hard or lacks strength, not only because it’s short. A hip flexor being asked to do more than it can comfortably handle will often feel tight and guarded. In my experience, a lot of how flexible someone is comes down to genetics, so if your hips have never been particularly bendy, that’s not a failing on your part. It just means the focus should be on what your body can handle, not chasing a range of movement you may never have had.

Do tight hip flexors cause lower back pain?

This is where the common explanation and the research don’t quite line up.

The popular theory goes like this: tight hip flexors tilt your pelvis forward, which increases the arch in your lower back and overloads the joints. It sounds logical, and for some people it may be part of the picture. But when researchers have actually measured it, the link is weak.

A study in the Journal of Orthopaedic and Sports Physical Therapy compared people with and without low back pain across 17 physical measures. Hip flexor length, the size of the lower back curve and pelvic tilt were not associated with back pain. What was associated was muscle endurance and weakness, including the endurance of the back muscles and the strength of the hip flexors and abdominals.

A later systematic review of prospective studies in BMC Musculoskeletal Disorders found something similar. Reduced side bending range, tight hamstrings and actually a flatter lower back curve were linked to developing back pain, which is the opposite of what the “too much arch” theory would predict.

So the honest answer is that tight hip flexors can contribute, but they’re rarely the main driver. Most lower back pain comes back to the same principle as most injuries: the back is being asked to handle more load than it currently has the capacity for. Our article on what’s actually going on with lower back pain goes into that in more detail.

What actually helps tight hip flexors?

The good news is that this gives you a lot more to work with. Instead of trying to stretch your way out of back pain, the focus shifts to things you can build:

• Break up long periods of sitting. Australia’s Physical Activity and Sedentary Behaviour Guidelines recommend minimising prolonged sitting and breaking it up as often as you can. Standing up for a minute or two every half hour or so is a good start.
• Strengthen the glutes. Glute bridges, single leg bridges and step ups build the muscles on the back of the hip that work opposite the hip flexors.
• Strengthen the hip flexors through range. Standing knee marches, slow leg raises and split squats held at the bottom train the hip flexors to be strong in a lengthened position.
• Build trunk and back endurance. Loaded carries and side planks challenge your trunk for longer at a lower intensity, which is what your back needs to hold you up all day.
• Use stretching as one tool. If a hip flexor stretch makes you feel better, keep doing it. It just works best as part of a bigger plan rather than the plan itself.
• Stay active. Walking, running, swimming and the gym are all good for a sore back, as long as the load is matched to where you’re at right now.

In the clinic, we follow the same approach as with most back pain: calm things down first, then build things back up. If you’d like structured help with the strength side, our exercise physiology team can build and supervise a program with you.

A note for Jordan: this is a natural spot for a real, anonymised patient story, for example a desk worker whose back pain improved once the focus moved from stretching to strength (age range, job, timeline, outcome). Nothing has been invented here.

Is there a hip flexor stretch I can try now?

Yes. A kneeling hip flexor stretch is a good place to start:

1. Kneel on one knee with the other foot flat on the floor in front of you, like a lunge.
2. Gently squeeze the glute on the side of the back knee and tuck your tailbone under slightly.
3. Shift your weight forward until you feel a stretch at the front of the hip on the kneeling side. Keep your trunk upright rather than arching your lower back.
4. Hold for 30 to 45 seconds, then swap sides.

It should feel like a comfortable stretch, not pain. Pair it with a glute bridge and you’re working on both sides of the equation.

^{Physio Jordan Baker demonstrating a hip flexor stretch}

When should you get it assessed?

Book in if your back or hip pain has lasted more than a couple of weeks, keeps coming back, wakes you at night, or is getting in the way of work, sleep or exercise. A physio can work out what’s genuinely driving your pain, whether that’s your hips, your back, your training load or a mix.

Seek medical attention urgently if back pain comes with numbness around the groin or buttocks, changes to bladder or bowel control, unexplained weight loss, fever, or weakness in the legs that’s getting worse.

Our physiotherapy team sees lower back and hip pain every week, and the Thomas test is part of a standard hip assessment whether you book in for physio in Blaxland or physio in Glenmore Park.

Frequently asked questions

How do I know if my hip flexors are tight? Common signs are a pulling feeling at the front of the hip, stiffness when you stand up after sitting, and trouble standing fully upright straight away. The Thomas test is a simple way to check, and a physio can confirm what’s going on.

Can tight hip flexors cause lower back pain? They can contribute, but research suggests hip flexor length on its own isn’t strongly linked to back pain. Strength and endurance in the hips, trunk and back tend to matter more.

What is the Thomas test? A quick check for hip flexor tightness. You lie back on the edge of a bed hugging one knee and let the other leg hang. If the hanging thigh lifts off the bed, the hip flexors on that side are likely tight.

Should I stretch or strengthen tight hip flexors? Both can help, but strengthening usually makes the bigger difference. Stretching is a useful extra if it makes you feel better.

What exercises help tight hip flexors? Glute bridges, step ups, standing knee marches, split squats held at the bottom and a kneeling hip flexor stretch are a good mix of strength and mobility.

Is walking good for tight hip flexors? Yes. Walking takes the hip into extension with every step and breaks up time spent sitting, which is the most common reason hip flexors feel tight.

Can tight hip flexors cause abdominal pain? The hip flexors attach deep in the lower abdomen and spine, so a strain can be felt there. Abdominal pain has many other causes though, so new or unexplained abdominal pain should be checked by a GP.

Can I do hip flexor exercises at home? Yes. Bridges, marches, split squats and the kneeling stretch need no equipment. A physio can tailor the mix and the dose to you.

How long does it take to loosen tight hip flexors? Many people feel some relief within a few weeks of regular movement breaks, stretching and strength work. Building real capacity takes longer, typically six to twelve weeks of consistent training.

Is sitting bad for my hip flexors? Sitting isn’t harmful in itself, but long uninterrupted periods can leave your hips and back feeling stiff. Breaking it up regularly makes a noticeable difference.

Author bio block

Jordan Baker is the Owner and Principal Physiotherapist at Physio Local, with clinics in Glenmore Park and Blaxland. Born in Penrith and raised between Glenmore Park and Blaxland, he started his career at the Glenmore Park clinic, took over ownership in 2019 and later opened Blaxland. He has worked as a physiotherapist for more than a decade, with a particular interest in manual therapy, clinical reasoning, running, and strength training. He is registered with the Physiotherapy Board of Australia through Ahpra (registration number PHY0002006351).

“My approach to physiotherapy is to ensure that I listen to and understand each patient sitting in front of me. The one thing I want every patient to feel when they leave is that they were cared for and that we will do our best to help them get what they want and need out of their sessions.”

If your hips or lower back have been bothering you, we’ll test what’s actually going on rather than guessing. Book in at Blaxland or Glenmore Park.