Why Does My Knee Hurt When I Squat? Common Causes and What to Do
Squatting is a basic movement that we use every day, whether we are sitting on a chair, picking something up from the floor, exercising, or playing sports. But if you experience knee pain when squatting, even a simple movement can become uncomfortable.
Knee pain during a squat can have several possible causes. Sometimes it may be related to muscle weakness, poor movement control, or doing too much activity too quickly. In other cases, it may be associated with conditions affecting the kneecap, tendons, cartilage, or knee joint.
Understanding why your knee hurts when you squat can help you choose the right approach to managing it.
Why Does Squatting Cause Knee Pain?
When you squat, your knee bends while supporting part of your body weight. This increases the demand on the muscles and structures around the knee.
If your knee is irritated, stiff, weak, or unable to tolerate the amount of load being placed on it, pain may occur during the movement.
The location and type of pain can sometimes provide useful clues, although a proper assessment is needed to determine the actual cause.
Common Causes of Knee Pain When Squatting
1. Patellofemoral Pain
Pain around or behind the kneecap is commonly associated with patellofemoral pain.
You may notice discomfort during:
Squats
Stair climbing
Running
Jumping
Getting up from a chair
Sitting for prolonged periods with your knees bent
The way the hip and knee move during activity, along with muscle strength and training load, may contribute to symptoms in some people.
2. Knee Osteoarthritis
Knee osteoarthritis can cause pain and stiffness, particularly during weight-bearing activities.
Squatting requires the knee to bend while supporting body weight, so people with osteoarthritis may find deep squats uncomfortable.
Other symptoms can include:
Stiffness
Swelling
Reduced range of motion
Aching after activity
Difficulty with stairs
Difficulty getting up from a low chair
The presence of knee pain does not automatically mean that you have arthritis. An appropriate assessment is needed.
3. Patellar Tendon Irritation
The patellar tendon is located just below the kneecap and helps transfer force from the thigh muscles to the lower leg.
Repeated jumping, running, or other activities can irritate this tendon. Pain may be felt below the kneecap and can become more noticeable when performing movements that load the knee.
Managing training volume and gradually building strength can be important parts of rehabilitation.
4. Muscle Weakness
The quadriceps, hamstrings, gluteal muscles, and other muscles around the hip and knee contribute to lower-limb movement and stability.
If these muscles are weak or lack endurance, certain activities may become more demanding.
A physiotherapist can assess muscle strength and determine whether strengthening exercises may be appropriate.
5. Previous Knee Injury
A previous injury can sometimes cause ongoing symptoms during activities such as squatting.
For example, a person may experience pain or restricted movement following certain ligament, meniscus, or other knee injuries.
If your knee pain began after twisting, falling, playing sport, or another injury, professional assessment can help identify what may be causing the symptoms.
6. Increasing Exercise Too Quickly
Sometimes knee pain develops after a sudden increase in physical activity.
Examples include:
Starting a new workout programme
Suddenly increasing running distance
Adding heavier weights
Performing more squats than usual
Returning to exercise after a long break
Your muscles and joints may need time to adapt to increased demands. Gradually increasing exercise intensity and volume can help reduce excessive loading.
Does Knee Pain While Squatting Mean You Should Stop Squatting?
Not necessarily.
Whether you should continue squatting depends on the cause and severity of your symptoms.
You may be able to modify the movement by:
Reducing the depth of the squat
Using a chair or support
Performing fewer repetitions
Reducing resistance
Slowing down the movement
Improving your technique
Allowing adequate recovery
If squatting causes significant pain or your symptoms continue to worsen, stop the activity and seek professional guidance.
How Can You Squat More Comfortably?
Good technique is important, but there is no single squat technique that is ideal for everyone.
A physiotherapist or qualified exercise professional can assess how you move and identify factors that may be contributing to your discomfort.
Depending on your individual needs, you may benefit from:
Strengthening the quadriceps
Strengthening the hip muscles
Improving ankle or hip mobility where appropriate
Practising controlled squat movements
Gradually increasing squat depth
Adjusting training volume
The goal is to gradually improve your capacity rather than forcing the knee into a painful movement.
What Exercises May Help?
The appropriate exercises depend on the underlying cause of your knee pain.
A rehabilitation programme may include movements such as:
Sit-to-Stand
Standing up and sitting down from a chair can help develop strength for everyday movements while allowing the depth of the movement to be controlled.
Glute Bridges
Bridges can strengthen the muscles around the hips and may be included as part of a broader lower-limb strengthening programme.
Straight Leg Raises
These can help strengthen the quadriceps while keeping the knee relatively straight.
Step-Ups
Controlled step-ups can help develop strength and movement control needed for activities such as climbing stairs.
These exercises should be adapted according to your symptoms and ability. A physiotherapist can help determine which exercises and progressions are appropriate.
Should You Squat If You Have Knee Arthritis?
People with knee osteoarthritis may still be able to perform modified squatting movements.
The appropriate depth, resistance, repetitions, and frequency depend on the individual's symptoms and physical capacity.
In many cases, exercise is an important part of managing osteoarthritis. Rather than avoiding all knee-bending movements, rehabilitation may focus on gradually improving strength and tolerance.
When Should You See a Physiotherapist?
Consider getting your knee assessed if:
Pain continues for several weeks
Squatting is becoming increasingly difficult
You have recurrent swelling
Your knee feels unstable
Your knee locks or catches
You have reduced knee movement
Pain is affecting exercise or everyday activities
Symptoms started after an injury
A physiotherapist can assess your movement and help determine whether targeted rehabilitation may be appropriate.
When Is Knee Pain More Concerning?
Some symptoms require prompt medical evaluation.
Seek medical attention following a significant injury, especially if you:
Cannot put weight on your leg
Have severe pain
Develop substantial swelling
Notice an obvious deformity
Cannot move your knee normally
Experience significant instability
Persistent locking or repeated episodes of the knee giving way should also be professionally assessed.
Frequently Asked Questions
Why does my knee hurt when I squat but not when I walk?
Squatting places different demands on the knee than walking. It involves deeper knee bending and greater muscle activity, so certain knee problems may become noticeable during squatting but not during ordinary walking.
Are squats bad for your knees?
Squats are not inherently bad for the knees. When appropriately performed and progressed, squatting can be part of a strengthening programme. However, the movement may need to be modified if you have an existing knee problem.
Should I stop squatting if my knee hurts?
If squatting causes significant or worsening pain, it is sensible to stop or modify the movement until you understand what is causing the symptoms. A healthcare professional can advise you on appropriate exercise.
Can weak legs cause knee pain during squats?
Muscle weakness may contribute to difficulty controlling the knee during loaded movements. Strengthening the appropriate muscles can be helpful for some people.
Can physiotherapy help knee pain when squatting?
Physiotherapy can help identify factors contributing to your symptoms and may include strengthening, mobility exercises, movement retraining, and gradual return to activity.
Conclusion
Knee pain when squatting can have several possible causes, including patellofemoral pain, osteoarthritis, tendon irritation, muscle weakness, previous injury, or a sudden increase in activity.
You do not necessarily need to avoid squatting permanently. In many cases, modifying the movement and gradually improving strength and tolerance can help. However, persistent, severe, or worsening knee pain should be assessed rather than repeatedly pushed through.
If squatting, climbing stairs, exercising, or other daily movements are becoming difficult, a physiotherapy assessment can help identify the possible cause and create an appropriate rehabilitation plan.
