Runner’s Knee: What is it? How is it caused? How is it treated?

By Last updated on April 5th, 2020 Last updated on April 5th, 2020 No Comments

Runner’s KneeRunner’s knee is a general term for a number of conditions that cause knee pain and is a common issue among highly-active adults.

Constant physical strain and poor running form induce and exasperate the conditions necessary for the problem to start, and once it’s begun, it can be difficult to combat. Though runner’s knee is most prevalent among highly-active individuals, it is still a concern for less active persons who have suffered some form of knee trauma in the past.

Additionally, runner’s knee can escalate into more severe issues if left unchecked. While there are treatments, most of these solutions only help to reduce the speed at these knee issues escalate. Thankfully, breakthroughs in regenerative health services – such as those offered at Cellaxys – are paving the way for more permanent solutions.

What is runner’s knee?

While runner’s knee is a general term for knee issues related to knee fatigue induced by physical aggravation, there are three conditions most associated with the term – Iliotibial Band Syndrome (ITBS), Patellofemoral Pain Syndrome (PFPS) and Patella Tendonitis.

Iliotibial Band Syndrome (ITBS)

Characterized by pain on the sides of the knee, this is the term used to describe a fatigued or worn-out iliotibial band. The iliotibial band is a thick band of connective tissue which extends from the insides of the bottom of knee, and up to the pelvis and hips.

Repetitive flexion and extension of the knee during running causes the band to rub over the lateral femoral epicondyle (bone directly behind and above the knee) and may lead the area to become inflamed.

Overtime, as protective tissues are worn away, the pain from this inflammation may become more and more severe, to the point of drastic reduction in mobility.

Patellofemoral Pain Syndrome (PFPS)

Characterized by pain on the front of the knee, around and under the kneecap, PFPS is the most common type of runner’s knee and extends far beyond the scope of runners. Hikers, cyclists, basketball players and even people who sit for a living (leaving the knee constantly flexed can fatigue the kneecap), may all experience a type of PFPS, albeit at different levels of severity.

Patellar Tendonitis

Characterized by pain under or behind the knee cap, patellar tendonitis affects the patella tendon which attaches the main shin bone (tibia) to the knee cap (patella). This tendon takes the forces of running, jumping and walking with every step and carries a huge amount force every day. This is often referred to as “jumper knee”. The tendon can become inflamed and painful often with coexisting tears or micro-tears.

What causes runner’s knee?

Though the most common contributing factor to runner’s knee is vigorous physical activity, there are many underlying reasons a person may begin to suffer from this condition.

The knee is made up of a complex network of cartilages, fats, ligaments, tendons, muscles and bones which act together to provide fluid motions when walking. In time, some of these components can be worn down or stressed to the point of fracture or tear.

Doctors haven’t reached a consensus on the range of causes for these erosions or tears, but they agree that repetitive cycles of tightening and relaxing this area along with some forms of inflammation can aggravate these tissues and cause some of the symptoms of runner’s knee. Additionally, trauma to the knee, flat feet, arthritis, and weak thigh muscles have also been linked to problematic knee function.

Whatever the mechanism at work, when the condition begins, nerves start to sense pain in the soft tissues and bones which surround the kneecap. Overtime, the severity of this pain increases and the conditions to induce it become milder. If walking up or down slopes, squatting, or simply resting with the knee bent causes knee pain, then it may be time to examine your knee health or seek out professional advice.

What type of runner’s knee do I have?

Before treatment can occur, it is best to identify the source of your runner’s knee as treatments vary based on the origin of the pain. While the best possible way to diagnose the issue is to see a trained physician, you may want to do a preliminary check on your own. Below are some guidelines which may help you distinguish between the two most common knee issues – ITBS and PFPS.


  • Pain is derived from the side of the knee. While pain can be experienced anywhere in the general vicinity of the knee, the focal point is always on the sides.
  • Pain is not induced when poking the kneecap, but rather the side of the knee, especially right under the knee at either end of the cusp of the cap.
  • Pain is worse when moving down stairs or hills and is noticeably less when moving upwards.
  • Pain doesn’t slowly escalate throughout the day, but initiates sharply at once (although for ITBS, it can do both).
  • Deep knee-bends do not cause sharp pain.
  • No obvious damage to the structural integrity of your general knee area.


  • Pain is derived from under or around the kneecap. While pain can be experienced anywhere in the general vicinity of the knee, the focal point is always on the kneecap.
  • Discomfort is experienced when pushing in the kneecap.
  • Pain is worse when moving up stairs or hills and is noticeably less when moving downwards, though it may be equally painful doing both.
  • Pain escalated slowly, over months and years and gets gradually worse throughout the day.
  • Deep knee-bends cause sharp pain.
  • Pain is worse when sitting and once standing up, takes time to go down.
  • Obvious structural integrity issues such as knock-knees, flat feet, or kneecaps which are at an angle.

Patellar Tendonitis

  • Pain can be both sharp or a “dull toothache” pain at rest.
  • Squatting or jumping can be extremely painful.
  • Swollen at or below the level of the knee cap.
  • Pain is worse with vigorous activity.
  • Stairs can be debilitating from the pain in the front of the knee.

While these self-diagnosing suggestions are not all-encompassing, and while not all types of runner’s knee fall into these categories, looking over these suggestions can help give you a preliminary answer as to which type of runner’s knee you have, or, at the very least, identify where the pain is located. It’s always safer to consult a physician if the pain is persistent or immobilizing.

Can runner’s knee cause permanent damage?

If left unchecked, runner’s knee can lead to more severe issues throughout the rest of a person’s life.

Constant strain on the knee – be it from poor running form, flat feet, a previous trauma, or other factors – can cause erosion in the soft tissues within the knee. Our bodies do not have the mechanisms available to repair and replenish our supply of some of these soft tissues.

As these tissues are worn away, bones can begin to rub together, nerves can be pinched, and muscles can become awkwardly strained. These conditions only worsen overtime and the knee pain they cause can become more and more severe to the point of debilitation.

Without proper treatment and consultation, runner’s knee can cause a number of permanent issues.

How do I stop runners knee?

Runner’s knee (and the issues associated with it) becomes incrementally worse if the proper treatments or modifications aren’t made early on. The earlier a person begins to combat the habits which cause runner’s knee, the more fruitful these efforts will be. In order to “stop” runner’s knee, the first step is to correctly diagnose your specific issue. Below is a simple outline of the steps you should take to discover what specifically is going on.

1. Identify the source of the pain

Is it coming from the front of the knee, sides, or neither? You can use this information to identify the source of your issue and develop a treatment routine specific to the problem. While most knee issues have similar solutions, each condition also has a specific set of treatments which specially target individual problem areas. See the next section for more information.

2. Focus on your movements throughout the day

Which activities or parts of your daily routine seem to cause flare-ups? If a specific activity, be it running, jumping, squatting or resting, seems to especially upset your knees, stop doing it or find a way to do it that causes less strain for the knees. Make sure to avoid these activities for a period of time. Even after your knee seems to feel better, it may not have fully recovered enough to resume your routine. Play it by ear and make sure to focus on what your body is trying to tell you.

3. Develop better habits for preventing flare ups

With the problem area and pain-inducing movements uncovered, either eliminate the specific movement from your routine or consult a professional for developing a better method of approaching that routine. If it is part of your workout, a personal trainer may be able to help you identify problems with your form. If the issue stems from a part of your job, you may want to consider buying a knee brace or shoe insoles. Anti-inflammatory medications may be another avenue to pursue, though these treatments often have unwanted side-effects and become less effective overtime.

How do I recover from runner’s knee?

Many people wonder if it is possible to heal completely from runner’s knee. With the constant strain from movement, runner’s knee can be an especially difficult affliction to recover from. So, how do you heal from runner’s knee? There are several options for runner’s knee treatment and rehabilitation, some of the most common are outlined below.

1. Stretches

Knee pain can originate from tightness in the muscles and tendons connected to the knee. Hips, hamstrings, glutes, quads, and calves all work together to provide movement in the knee and when one is jeopardized, the others are affected. In order to reduce the strain and pain in the knee, you must reduce the tension in all of these areas.

Practice various stretches on the different muscle groups and tendons mentioned above. Make sure to hold them for 30 seconds to a minute for maximum effect. You may also consider buying a foam roller or elastic band to help provide deeper stretches. While stretching won’t eliminate the problem completely, it will provide immediate relief for the occasional flare-up.

2. Massage

Be it self or professional, massage is a great way to improve joint mobility and treat pain and stiffness in the knee. A controlled trial by Atkins and Eichler analyzed the effectiveness of self-massage in treating pain and stiffness and increasing physical function in 40 adults diagnosed with knee osteoarthritis. The study found that participants who gave themselves a 20-minute massage twice a week showed significant improvement in their pain as opposed to control groups.

Performing deep, sliding massage strokes helps to soften and lengthen muscle fibers within the knee. Additionally, using knuckles, forearms and elbows to target specific problem areas can help make this form of treatment more effective. You may also tap the knee area to stimulate circulation and warm soft tissue. Another technique involves pressing the fingers firmly into the soft tissue around the knee and moving the tissue back and forth using short strokes.

3. Strength training

Well-trained supporting muscles can help cushion the force being applied to the knee and thus reduce knee pain that is associated with high-impact activities. While strengthening these groups won’t eliminate the pain outright, it will benefit your knee’s health in the long run. Weak supporting muscles place strain in the knee area and thus wear away at the cushioning cartilages of the knee. As these cartilages wear away, your nerves will become more and more exposed, and thus, your pain will become sharper and sharper. With a strong supporting system of muscles, the knee takes less of the strain and the cartilage remains intact for longer. Focus on working groups such as the glutes (butt muscles), the lumbar spine, and quadriceps (specifically the “VMO”) in order to help support the efforts of your knees.

4. Corticosteroid injections

Cortisone helps to suppress the immune system, reducing inflammation and attendant pain and swelling at the site of an injury. Corticosteroid injections work very quickly as opposed to the other treatments mentioned above. The benefits derived from these injections are short term though, and typically last anywhere from 6 to 12 weeks. Doctors agree that while these injections are valuable for the occasional flare up, long-term use of corticosteroids presents many risks and often give less relief the longer they are used. Cortisone degrades tissues and can ultimately lead to worse pain and irreparable damage. Professional athletes began moving away from these injections with the advent of PRP and stem cell therapies. The general public has now done the same.

5. PRP injections

Platelet Rich Plasma (PRP) has been used as a regenerative medicine since 1987, though it was not until 2000 that research began into its efficacy in treating cartilage defects. Since then, PRP has become a viable option for those suffering from knee pain. Patients typically experience improved knee function for up to 6-18 months, though after that, these results decline. Most patients report that pain and function after the initial 3-month period is much better than before the injections. Typically, clinical studies have shown that a series of 3 injections is required for optimal results.

6. Stem Cell Therapies (autologous or allograft)

A relatively new treatment in the last decade, stem cell therapy helps regenerate cartilage tissue in the knee, thereby improving function and reducing pain. One of the longest lasting and most effective treatments, stem cell therapy can help improve function for an average of 3-7 years after a one-time procedure. Cartilage has little capacity to repair itself. This treatment provides the necessary building blocks for bodies to regenerate this vital tissue using fat-derived, bone-marrow-derived or embryologic-derived stem cells. Both fat and bone marrow are rich sources of stem cells, specifically Mesenchymal Stem Cells. By harvesting, concentrating and activating these stem cells the doctors at CELLAXYS induce a state in which the stem cells can regenerate human tissues.

These treatments will not eliminate the problem outright, but will help speed up the recovery process. Both stem cell therapies and PRP begin the healing process by transplanting the necessary ingredients to begin the healing process. Always remember, it is vital that you personally finish the healing process through exercise and activity. It is always recommended that afflicted people consult a doctor or physical therapist for the best treatments for their specific condition.


Runners knee is a difficult problem to combat. The onset can be slow and gradual or quick and intense. It can be difficult to self-diagnose and self-treat, though it is possible.

With scientific breakthroughs in stem cell and PRP therapies, many of the people afflicted with runner’s knee pain are experiencing a revitalized hope for their condition.

New runner’s knee treatments, specialized runner’s knee exercises and stretches, and tools such as knee braces and tapes are being developed every day.

With these new advancements, runners knee recovery is being made simpler and hope for an ultimate cure is being restored. Hopefully one day, runner’s knee will be a thing of the past.

Dr. Matthew HC Otten

Dr. Matthew HC Otten

Director of Orthopedic & Orthobiologics
Fellowship-trained & Board Certified in Sports medicine
Director Angiography at Harvard Clinical Research Institute
Michigan Stage University Alumni