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Patellar tendonitis: The comprehensive guide all runners need to read

A runner with a painful knee because of patellar tendonitis. Learn what causes it and how runners can best treat patellar tendonitis.
Kim Van Deventer
Kim Van Deventer
Nov 22, 2023
Learn all you need to know about how patellar tendonitis develops and what you can do to fix it, so you can get back to running sooner.

Patellar tendonitis can be debilitating for runners of all levels. Trying to train while dealing with patellar tendon pain can be extremely frustrating and make keeping fit a struggle.

The good news is that patellar tendonitis is a treatable condition.

All you need is the right advice to get started and a proper rehabilitation plan to follow, and you’ll be able to get back to marking those big races off your calendar again.

The best place to start is to understand the condition.

What is patellar tendonitis?

First, let’s clarify the differences between patellar tendonitis, patellar tendinopathy, and patellar tendinosis.

These names all refer to the same condition - an injury to the patellar tendon. So, to keep things simple, we use these names interchangeably in this article.

Now, what is it?

Patellar tendonitis is an overuse injury of your patellar tendon.

What is the patellar tendon, and what does it do?

The patellar tendon is a strong band of tissue that connects your kneecap (patella) to your shinbone (tibia). It works with other structures in the front of your knee to ensure it moves efficiently, helping you extend your leg when you walk, run, jump, and kick.

Knowing the different parts and how they work together is vital for understanding how and why patellar tendonitis develops.

Let’s look at the anatomy briefly.

Quick overview of the anatomy

The main structures you need to know about in patellar tendonitis are:

The quadriceps muscle
A group of four muscles located at the front of your thigh, above your knee joint
The patella (kneecap)
The small, triangular-shaped bone at the front of your knee joint, between your shin and thigh bones
The quadriceps tendon
The large tendon attaching your front thigh muscles to your kneecap
The patellar tendon
The tendon attaching your kneecap to the front of your tibia (shinbone)
The knee anatomy structures that are affected with patellar tendonitis.

How the front knee structures work together

These structures form part of your knee's built-in "pulley" and "spring" mechanisms that help straighten (extend) it more efficiently.

The knee pulley system

When your quad muscles contract, they pull on the quadriceps tendon, which draws on the kneecap. The kneecap then pulls on the patellar tendon, which pulls on the shinbone and causes your leg to straighten.

The kneecap acts like the pulley, guiding and directing the force from your thigh to your shinbone. The patellar tendon is the rope, and the shinbone is the weight it's lifting.

The patellar tendon forms part of the knee's pulley system and this is affected when you have patellar tendonitis.

Spring mechanism

Like a spring that stores energy when stretched and releases energy when it recoils, your patellar tendon and quadriceps tendons do the same.

They store energy when your knee bends and use it to help power your leg as it straightens to propel you.

The patellar tendon acts like a spring to help propel you forward when you run. When you have patellar tendonitis, this spring-like effect is decreased when you have patellar tendonitis.

This means your patellar tendon works really hard in activities where you require your knee to straighten under high loads, like

  • Walking downhill
  • Doing squat or lunge type exercises
  • Running
  • Plyometrics, where your muscles rapidly or repeatedly stretch and contract, such as jump squats, box jumps, etc.

This may be why patellar tendonitis is one of the most common injuries seen in runners.

How does patellar tendonitis happen?

Patellar tendonitis can develop:

  1. Quickly in one session (sudden overload) if you work too hard or
  2. slowly over time (gradual overload) due to a lack of recovery or rest.

To understand how this overload occurs, you must first understand normal loading.

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Normal patellar tendon loading and stress

The idea of stressing your patellar tendon shouldn’t scare you. Loading and stressing tissues happens every time we exercise. And with this type of loading, it’s normal for tiny micro-injuries to develop in the tissues.

It isn’t harmful because your body is constantly remodeling itself. It carries out breakdown and repair processes in response to these loads. This is necessary for gaining and maintaining healthy, strong muscles, tendons, and bones.

In the case of your patellar tendon, after you exercise, your body automatically begins to repair the tiny micro-injuries that the exercise caused. By removing old, injured tissues and replacing them with new, healthy ones, your tendon becomes stronger and better able to handle more load (stress) in the future.

Patellar tendon overload

Patellar tendon overload happens when you do exercise that is a lot harder than what your tendon is used to or when those tiny injuries don't get a chance to heal fully before you load or stress them again.

For example, if you do too many plyometrics in one session or don’t leave enough recovery time between intense running training sessions. This can lead to accumulated microdamage (getting micro-injuries on micro-injuries) in your patellar tendon, which causes it to become sensitive and lose strength.

Over time you’ll notice pain in your patellar tendon with less strenuous activities. This explains why some things that were once pain-free, such as walking up and down stairs, running, or jumping, may become painful.

Patellar tendonitis can cause pain when walking down stairs.

Symptoms of patellar tendonitis

Pain in the front of the knee is the most common symptom of patellar tendonitis.

But front knee pain is associated with many knee conditions, so we need to be able to tell the difference between them so we can treat it effectively.

According to research, the two defining features of patellar tendonitis are:

  1. Localized pain in the patellar tendon
  2. Pain related to heavy and/or repetitive jumping and landing activities

Localized patellar tendon pain

Unlike runner’s knee (patellofemoral pain syndrome), you’ll most commonly feel patellar tendonitis pain at the lower edge of your kneecap, where the tendon attaches. Less commonly, you’ll feel it along the mid-or lower parts of the tendon where it attaches to the shinbone.

Importantly, your pain will not be "vague" or "spread out" around your knee. You will be able to pinpoint it within your patellar tendon.

When you have patellar tendonitis the pain is localized to the patellar tendon, most commonly where it attaches to the kneecap.

Pain from repetitive jumping and landing

Patellar tendonitis is also called “jumper’s knee” because the pain usually develops or worsens with heavy quads (thigh muscle) work or repetitive jumping and landing activities. Essentially, when your knee pulley and spring-loading mechanisms are pushed to the max.

That’s why it's commonly seen in athletes who jump heavily or repetitively in their sports, such as basketball players, volleyball players, and runners.

Jumping activities like playing basketball are associated with patellar tendonitis.

Patellar tendonitis can also be distinguished by a few other unique characteristics.

Other unique characteristics of patellar tendonitis symptoms

With patellar tendonitis, you will usually have:

A history of "overdoing it," either during one training session or doing more than your usual activity without enough rest (pain coming on gradually)
"Warm-up phenomenon," when the pain seems to ease during exercise, only to feel worse after exercise or the next day

You will not usually have:

Swelling or bruising
Pain with low-load activities like swimming
Pain at rest unless your knee is bent to 90 degrees or more for extended periods (meaning the tendon is on prolonged stretch)

If you can match these traits to your knee pain, there's a chance you have patellar tendonitis. But, it’s always best to get your diagnosis confirmed by your doctor or physical therapist.

Once you have a diagnosis and understand what caused it, you can look at ways to treat it.

What’s the best way to treat patellar tendonitis?

Your patellar tendon likely became injured because it was placed under more load (stress or force) than it could handle. And now that it’s injured, it’s lost some of its strength.

So, for your tendon to heal properly, you must first reduce the load placed on it, so it can start healing. Then slowly build its strength.

Most often, patellar tendonitis responds very well to conservative treatment. This means you won't need surgery or other invasive treatments to fix it.

Conservative treatment involves two main parts:

  1. Offloading: To allow your tendon injury to settle and healing to begin
  2. Strengthening: To gradually build tendon strength while your tendon is healing

Part 1: Offloading your patellar tendon

Your patellar tendon needs enough time to rest, so it can settle, become less irritated, and get a chance to start healing.

Relative rest and pain relief can help you with this.

Relative rest

Relative rest means temporarily offloading your tendon by decreasing your training loads to pain-free levels and avoiding activities that aggravate your pain.

This does not mean stopping all exercise. It simply means finding activities that help you maintain your strength and fitness without causing pain.

Common ways runners keep fit during this phase of rehab include walking and swimming.

Swimming as an option for relative rest for patellar tendonitis.

Although rest is crucial for your recovery, too much rest can cause your patellar tendon to lose more strength, which is not what you want. That’s why finding a balance between rest and exercise is important.

If pain stops you from doing any exercise, pain relief modalities may help you keep active and correct that balance.

Pain relief

You can use pain relief treatments to temporarily help calm your patellar tendon pain and keep you moving. Some of the most common include:

  • Patellar tendon straps
  • Icing
  • Isometric exercises
  • Shockwave therapy

For more information on each of these, our article on patellar tendonitis pain management explains what works best, how to use them properly, and what to avoid.

Isometric exercises can help reduce the pain from patellar tendonitis.

Part 2: Rehabilitation

Once your injury settles and the pain has calmed down a bit, you can begin slowly and steadily strengthening your tendon and help it regain full function for your unique activity needs.

Research shows that the best way to treat patellar tendonitis is with progressive strengthening exercises targeting your patellar tendon and the muscles supporting your knee straightening mechanisms.

Squats are one of the most commonly used exercises for strengthening your patellar tendon.

But simply knowing what exercises to do is not enough. You also need to know how to start safely, when to progress, and how to adapt them for your unique injury and goals.

Jumping in with regular, full range squats can often aggravate your symptoms. If you’d like to learn more, our patellar tendonitis exercises article covers how to choose, start, progress, and adapt your exercises.

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Invasive treatments for patellar tendonitis

Some patellar tendon injuries don’t respond as well as expected to conservative approaches. In these rare cases, you may need to consider more invasive treatments.

Invasive treatments are said to either help relieve pain or promote healing.

Invasive pain relief for patellar tendinopathy

  • High Volume Guided injections: A high volume of normal saline (sterile water) with a small amount of anesthetic injected into the tendon to reduce pain to help you start rehabilitation

Invasive therapy for patellar tendinopathy

  • PRP injections: Your own blood cells are injected into the injured tendon with the aim of speeding up the healing
  • Patellar tendonitis surgery: Surgery removes injured tissues and tissue debris (dead cells)

These treatments cannot heal your tendon on their own. They should be used in combination with a phased rehabilitation program.

Invasive treatment options for patellar tendonitis include injections and surgery.

Patellar tendonitis recovery time

How long does it take to recover from patellar tendonitis?

There’s no one-size-fits-all answer to this question.

Recovery time usually differs among people because everyone’s age, injury severity, health condition, exercise goals, and lifestyles are unique.

Research suggests that it generally takes a minimum of six months to fully recover from patellar tendinopathy, but it can take up to 12 months or more.

Patellar tendonitis rehabilitation takes patience, determination, and motivation to keep you going, but it can be done!

Once you’ve recovered, following a prevention plan can help you stay injury-free.

5 factors that affect recovery time for patellar tendonitis.

Other causes of patellar tendon pain

Sometimes, patellar tendon pain can develop in other ways too. In these cases, different treatment and recovery guidelines may apply. This includes:

  • A direct hit or injury to your patellar tendon
  • Certain medications, such as fluoroquinolone antibiotics
  • Inflammatory conditions, such as gout, rheumatoid arthritis, and psoriasis

If any of these apply to your injury, it’s best to follow your doctor's guidance on treating your patellar tendon.


Patellar tendonitis is a condition that can be extremely painful and can sideline runners for extended periods. This doesn’t need to happen to you.
Begin by understanding your injury and knowing the risk factors. Then get started with the best treatment as soon as possible.

The best way to treat load-related patellar tendonitis is with a progressive rehab plan that allows your injury to settle (with relative rest), then gradually helps your tendon build strength.

Hopefully, this article will help you start your recovery, so you can get back to running sooner than expected. We've also shared tips on how to prevent patellar tendonitis once you're back running in this article.

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Kim Van Deventer
Kim Van Deventer
Kim Van Deventer is a freelance healthcare writer and digital content strategist for healthcare businesses and medical content agencies. She has a BSc in Physiotherapy and worked as a physiotherapist for more than 14 years, specialising in sports injury rehabilitation, chronic pain management, and women's health. Kim combines her clinical experience and digital marketing skills to create relevant and helpful content that improves patients' lives.
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