Knee Pain When Bending and Squatting? Learn Why


Do you have knee pain while bending, squatting or kneeling? Read on for possible causes and solutions.

Climbing stairs to the office, squatting to tie your shoes, performing lunges at the gym, and kneeling while gardening are just several examples of simple activities that many of us perform daily. What do they have in common? They all require significant stability and mobility of the knee joint. Knee pain when bending your joints can have a substantial negative impact on your quality of life as it limits your ability to comfortably complete everyday tasks.

The Cause of Knee Pain When Bending and Squatting?

Chances are that your knee hurts only when it has to support your bodyweight and feels somewhat normal otherwise. While descending into a squatted position your knee is subject to 6 to 8 times your body weight in pressure.1 If your knee isn’t functioning properly, these tremendous joint forces can cause a pain flare-up or further damage to already injured structures.

Tissue Trauma

Chances are you know whether or not this is you. Sudden injuries are obvious as they are immediately painful and drastically limit knee function. The most common are MCL/ACL tears, meniscus injuries, and bone fractures. If your pain is the result of a fall or collision you should immediately seek expert medical attention for a thorough assessment as diagnostic imaging may be required.

Overuse Injury

If you’re an athlete or work a physically demanding job your knee pain when bending could be the result of overuse. These injuries are typically caused by repeating the exact same movement pattern over and over again without allowing the knees enough to time to recover.

  • Bursitis occurs when a knee bursa gets irritated from repetitive movement or constant direct pressure. The most commonly affected bursae are the prepatellar bursa and pes anserine bursa. Typically pain will increase when bending the knee under pressure and they will be visibly inflamed.
  • Patellar Tendonitis occurs mainly in athletes who participate in jumping sports like basketball. A deep knee bend is typically very uncomfortable, pain may be worse in the morning.
  • Patellofemoral pain syndrome typically occurs in more active individuals. Poor tracking of the knee cap as the knee is bending causes increased friction, which over time causes inflammation and pain.

The back of your knee cap is covered in articular cartilage. This soft viscous tissue allows the knee cap to move freely across the surface of the joint as you bend and straighten your knee. In arthritic knees, some or all of this cartilage has eroded away leading to excessive friction and strain as the kneecap moves. It’s estimated that over 50% of individuals with knee osteoarthritis have some degree of patellofemoral involvement causing pain specifically during movements that require a deep knee bend.2 If you are an older individual and feel that osteoarthritis may be a contributing factor to your pain –  Take a look at our Guide to Severe Knee Arthritis.

What Should I Do About It?

Dumbells on white floor

Quadriceps Strength

A healthy knee joint is a symphony of muscles working in harmony to produce a movement. Unfortunately, sometimes specific muscles attached to your knee joint can become overdeveloped, while others lag behind and are relatively weaker. A weak VMO (vastus medialis oblique) is often the culprit behind disorders such as patellofemoral pain syndrome. Excessively tight lateral (outside) structures on the knee cause the knee cap to track outwards creating abnormal friction and knee pain.3

Research shows that those with stronger knees experience less arthritis pain with normal daily activities.4 Therefore no matter your age, extra leg strength might do you some good!

Ankle Flexibility

Ankle Anatomy

You can think of ankle “dorsiflexion” as your ability to pull your toes up towards your shin as far as possible. Flexible ankles are crucial in many common movements such as squatting, lunging, stair climbing and running. Normal dorsiflexion range of motion is about 20 degrees, less than this and you may begin compensating during movements that require a deep knee bend.5 The most common compensatory movements occur at the feet. Typically with stiff ankles, you may notice that your turn your feet out (pigeon toe) as you walk down stairs and squat down to tie your shoe. Accompanying this is the tendency to collapse inwardly at the arch of your foot. This leads to what is called “knee valgus” or “knock knees”.6 With the knee dumping inwards more pressure is placed on the MCL, ACL, medial meniscus, and medial joint compartment. Over time the extra pressure on the inside of the joint will wear away your cartilage in the area faster causing pain when bending the knee. If you think your ankles are tight there are several things you can to solve or improve the issue.

  1. Stretch! You have two muscles that make up your calf: The Triceps Surae (upper calf) and the Soleus (lower calf). If these muscles get tight they will restrict your ability to move your ankle joint into dorsiflexion.
  2. Wear proper footwear. Modern running shoes have a built-in heel lift which helps make up for any ankle flexibility deficits you may have. Minimalist with less cushioning and support shoes can be great if you have healthy joints, but if your knee is cranky, it’s best to wear something that makes up for any deficits in ankle flexibility you may have.

Weight Loss

More body mass generally means more stress on your knee joint. If you perform activities that require you to regularly get into a deep bend – a reduction in body mass could help ease your knee pain.

Rest & Modification

Person Relaxing in Hammock

Sometimes rest is the best medicine. If your pain has been consistent for a long period of time, it may be worth talking with your employer or coach about a temporary reduction in the number of activities you participate in that regularly irritate your knee. Once you have found some relief, it may be possible to slowly add these activities back in.

What’s Next?


  1. Dahlkvist, N. J., Mayo, P., & Seedhom, B. B. (1982). Forces during squatting and rising from a deep squat. Engineering in medicine, 11(2), 69-76.
  2. Duncan, R. C., Hay, E. M., Saklatvala, J., & Croft, P. R. (2006). Prevalence of radiographic osteoarthritis—it all depends on your point of view. Rheumatology, 45(6), 757-760.
  3. Dixit, Sameer, et al. “Management of patellofemoral pain syndrome.” Am Fam Physician75.2 (2007): 194-20
  4. Fujita, R., Matsui, Y., Harada, A., Takemura, M., Kondo, I., Nemoto, T., & Ota, S. (2014). Relationship between muscle strength and knee pain in knee osteoarthritis patients. Osteoarthritis and Cartilage, 22, S415.
  5. Neely, F. G. (1998). Biomechanical Risk Factors for Exercise-Related Lower Limb Injuries*. Sports Medicine, 26(6), 395–413.doi:10.2165/00007256-199826060-00003
  6. Schoenfeld, B. J. (2010). Squatting kinematics and kinetics and their application to exercise performance. The Journal of Strength & Conditioning Research, 24(12), 3497-3506.

Frequently Asked Questions

Why does my knee hurt when bending or squatting?

Knee pain during bending or squatting may be caused by tissue trauma or by an overuse injury.

What is an overuse injury in the knee?

An overuse injury is an injury caused by the repetition of certain movements over an extended period of time. Examples of overuse injuries in the knee include bursitis, patellar tendonitis, patellofemoral pain syndrome, and patellofemoral arthritis.

How do I treat knee pain caused by overuse?

Strengthening muscles that are weaker compared to other muscles supporting the knee joint can increase knee joint stability and treat pain caused by overuse. Other treatments for overuse injuries include increasing ankle flexibility, rest and activity modification, and weight loss.


By Simon Watts

Simon Watts is a former strength and conditioning coach with an extensive background in orthopedics and athletic therapy. He has a wealth of experience with the rehabilitation of common knee injuries such as osteoarthritis, meniscus tears, ligament injuries, and tendonitis. Simon studied Kinesiology at Dalhousie University, and as a track and field student-athlete was a national champion in the high jump and triple jump. He continues to be actively involved in the track and field community in Nova Scotia as a coach.

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