Patellar Tendonitis Symptoms: 3 Red Flags You Need to Know

Red Flags for Patellar TendonitisPatellar tendonitis is a deceitful injury. It will trick you into letting it weaken your knees until you’ll eventually need months of rehab.

This article will show you the symptoms of patellar tendonitis and the three red flags that tell you how serious your patellar tendonitis has become.

Keep reading to learn how you can get rid of patellar tendonitis symptoms and stop this injury dead in its tracks.

Patellar Tendonitis Symptoms: Where You Will Feel the Pain

The patellar tendon connects your patella, the kneecap, to the shinbone. You use this tendon every time you straighten your knee. This tendon can withstand very high forces, but in spite of its durability, the patellar tendon can still wear down over time if it’s frequently overstressed.

Where You will Feel Patellar Tendonitis Symptoms

Picture: Where you will feel the pain (it can occur in one or both knees)

With patellar tendonitis, the pain will be located around the patellar tendon. You will feel it on the side of your kneecap, in front of your kneecap, and sometimes even behind the kneecap. Most commonly, the pain is felt in the patellar tendon right below the kneecap.

Some symptoms that don’t happen with patellar tendonitis are pain on the side of the knee, pain behind the knee, swelling of the knee, or inability to fully flex or extend the knee.

Activities That Worsen the Symptoms

You use the patellar tendon every time you extend your knee. All activities that involve this movement can worsen the pain. This includes climbing stairs, squatting, cycling, and walking downhill.

Explosive leg movements, such as jogging, weightlifting, jumping, and sprinting are particularly likely to worsen the pain.

Red Flags for Patellar Tendonitis:
Which Stage of the Injury Are You In?

Research shows that the further you let your patellar tendonitis progress, the more cellular damage will have occurred in your tendon and the weaker it will have become. The weaker the tendon becomes the more of its resilience you’ll lose.

The longer you wait, the weaker your knee becomes.

This means that activities that didn’t cause you pain when you’re in stage 1 of patellar tendonitis are too stressful for your knee when you’re in stage 2 or 3 and will then cause pain.

Additionally, based on what stage you’re in, the injury requires a different healing approach. With that in mind you can understand why it’s very important to know about the symptoms for the individual stages of patellar tendonitis.

Each stage has one red flag symptom that indicates your injury has progressed to this stage.

Here’s an overview of these stages and their red flag symptoms:

Stage 1 Symptoms

  • No symptoms during sports activity
  • Light ache to mild pain after activity
  • Symptoms disappear within a day

Stage 2 Symptoms

  • Light ache during sports activity
  • Mild pain after the activity
  • You’ve had pain some time ago and it went away, but now it’s back

Red flag symptom: Pain lingers for more than two days and keeps coming back after activity.

Stage 3 Symptoms

This is where most people realize that they need to do something about it.

  • Mild pain before sports activity
  • Pain during activity
  • Moderate to strong pain after activity

Red Flag: Pain starts to limit sports performance and there is always some pain throughout the day, even after a lot of rest.

Stage 4 Symptoms

At this stage, the risk of tearing your patellar tendon has become very high. Pain strongly impairs sports performance and everyday activities have become very painful

Please note: this does not replace a thorough examination by your doctor! This list is merely meant to give you an idea of how far your injury has already progressed.

The 2 Types of Healing Requirements

There are two types of healing requirements for patellar tendonitis you need to know if you want to get back to being 100% healthy. They dictate which approach to healing you need to take and depend on which stage of the injury you’re in.

One healing requirement both have in common is that you need to eliminate hidden biomechanical causes for your patellar tendonitis or else it will come back like clockwork [for biomech. risk factors, see for example (Backman, Danielson 2011), (Powers 2010), (Grau et al. 2008), or (Ireland et al. 2003)].

Here is the first set of requirements:

Healing Requirements for Stage 1:

  • Rest until pain is gone
  • Improve biomechanics to reduce load on patellar tendon
    (Patellar tendonitis symptoms will ALWAYS RETURN if you don’t do this!)
  • Reduce training load to prevent return of pain

During the research for my book, I’ve discovered that the only stage in which resting will lead to complete healing is stage #1. In other words, if you have any of the red flag symptoms for stages two through four, resting will not get you back to 100%.

The second set of requirements applies to the chronic stages of patellar tendonitis, when the symptoms have become somewhat constant:

Healing Requirements for Stages 2 – 4:

  • Resting will not heal your tendon completely, you need to…
  • Use specific healing exercises to repair the patellar tendon
    (e.g., safe isometric and eccentric exercises) (Larsson et al. 2012, p. 1643)
  • Improve biomechanics to reduce load on patellar tendon
  • Track your pain levels and modify your training to reduce pain over time
  • Optimize your diet to improve tendon healing through increased collagen formation

Your Next Steps

When I had patellar tendonitis, I waited much too long before doing something about. I made that mistake because I thought patellar tendonitis would go away on its own, but it only became worse.

Academic research shows that chronic patellar tendonitis will not go away on its own. You need to do the right things for the stage of the injury you’re in or else you risk months of rehab and no sports, as well constant pain. (Cook, Purdam 2009, p. 409ff)

I want to prevent this from happening to you, but you need to take action. Here’s your best option.

Here's How You Can Beat Patellar Tendonitis

Most treatments fail and that breaks my heart. I want to help you get back to 100%, so I created an advanced course on patellar tendonitis with some of my best material:
  • Get rid of your pain without ice or painkillers
  • Discover the 5 mistakes that make patellar tendonitis come back
  • Learn why resting doesn't work and what to do instead
Get Free Instant Access

Citations and Further Reading

Backman, Ludvig J.; Danielson, Patrik (2011): Low range of ankle dorsiflexion predisposes for patellar tendinopathy in junior elite basketball players: a 1-year prospective study. In Am J Sports Med 39 (12), pp. 2626–2633. DOI: 10.1177/0363546511420552.

Cook, J. L.; Purdam, C. R. (2009): Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. In British Journal of Sports Medicine 43 (6), pp. 409–416. DOI: 10.1136/bjsm.2008.051193.

Grau, S.; Maiwald, C.; Krauss, I.; Axmann, D.; Janssen, P.; Horstmann, T. (2008): What are causes and treatment strategies for patellar-tendinopathy in female runners? In J Biomech 41 (9), pp. 2042–2046. DOI: 10.1016/j.jbiomech.2008.03.005.

Ireland, Mary Lloyd; Willson, John D.; Ballantyne, Bryon T.; Davis, Irene McClay (2003): Hip strength in females with and without patellofemoral pain. In J Orthop Sports Phys Ther 33 (11), pp. 671–676.

Larsson, Maria E. H.; Käll, Ingela; Nilsson-Helander, Katarina (2012): Treatment of patellar tendinopathy—a systematic review of randomized controlled trials. In Knee Surg Sports Traumatol Arthrosc 20 (8), pp. 1632–1646. DOI: 10.1007/s00167-011-1825-1.

Powers, Christopher M. (2010): The influence of abnormal hip mechanics on knee injury: a biomechanical perspective. In J Orthop Sports Phys Ther 40 (2), pp. 42–51. DOI: 10.2519/jospt.2010.3337.

Photo Credit

Joe Christiansen on Flickr


  1. Kirk freimuth says

    I have been checked out by my knee doctor. I have done xrays and mri and physical therepy. No long term pain relief yet tho

  2. Tyler says

    Hey Martin
    Your pages have been extremely helpful. I have been foam rolling and doung slanted squats like you show and stretching. And I was wandering since you said flute and hip flexor strength is an issue. Is continuing to lift a good idea. Lower body that is. Examples are squats. Deadlift. Leg press. Calf raises. Let me know what you think??? Thanks!

    • Martin Koban says

      Hey Tyler,

      If you do any squatting-type movements slowly (3 second eccentric, 3 second concentric) they will help stimulate collagen synthesis and improve collagen alignment inside the tendon. So that would apply for squats and the leg press.

      You still need to adapt your training volume so that pain goes down from week to week, but generally, heavy slow resistance training works well for tendonitis.

  3. Angela says

    I have been experiencing “zaps” of pain in the area below the kneecap- really the upper area of the tibia below the kneecap. the pain is a burning sensation that lasts about 5 seconds then goes away, usually happens when i am sitting or laying down, only happened once while i was standing. I practice Muay Thai and not sure if it’s related. Doc thought it was a hairline fracture or a “bone bruise” but the Physical therapist in my class says it’s pattelar tendonitis (PT). Doc said it’s not PT bc the pain isnt in my knee but below the knee. Therapist says it is PT bc the tendon attaches at the knee but extends down the leg. He also says i have allignment issues that need to be addressed (knck knees). I’m unsure of what i have or how i should treat it. any help would be appreciated!

    • Martin Koban says

      Hey Angela,

      To rule out mechanical problems with the knee, you have to get an MRI. This will reveal a potential hairline fracture or confirm your suspicion of patellar tendonitis. Without the MRI, you’re just guessing and risk injuring yourself further.

  4. Chris says

    Hi Martin-

    Thank you sharing the information on this website. I’ve had a particularly refractory case of patellar tendonitis for nearly four years. Right now I am undergoing a regimen of physical therapy involving eccentric exercises, similar to those described your site: I sit on the edge of a table, raise the leg of my bad knee with my other knee and lower without assistance. Unfortunately, even 5 to 10 reps really aggravates my knee. Often the pain does not appear until 30-60 minutes later as a the deep, nagging ache that will not subside until the next day. Further activity may cause intense pain lasting 1 or 2 weeks. Once the pain subsides at rest, it is very prone to aggravation for a long time (perhaps a month or two). Its very frustrating because abstaining from activity and exercise also leads to muscle atrophy, which in turn puts more strain on my patellar tendon. Right now, normal activity, such as walking between rooms, can be difficult.

    Last November, my knee was at its best. Although I could not walk very far, normal, but limited activity was tolerable and I could do 3 sets of ten reps of eccentric leg extensions at the gym with 15 pounds. Unfortunately, one day while doing this routine I re-injured my knee, not realizing it until several hours later. Since then its been very volatile. As you can see, progress is difficult to achieve and easy lose.

    Do you have any advice about what I can do while eccentric expertise is not possible?

    Thank you for your time.

    • Martin Koban says

      Hey Chris,

      it sounds like you have some underlying problem that is limiting how well your body can repair the damaged tendon. Have you tried supplementing with hydrolyzed collagen, vitamin c, and fish oil? Have you recently had extensive blood work done to check for mineral and vitamin deficiencies? Do you have other chronic health problems? Do you take NSAIDs like Ibuprofen or statins? Are you a vegan or on a low-protein diet? Do you have bad sleep quality or sleep only very little each night? Do you have auto-immune issues or digestive problems? Are you very stressed?

      These are all areas that can limit the healing capacity of the body and once that’s too limited, exercise will not work. Of course, there may be other problems causing your lack of progress, but often the problem lies with the ones I mentioned.

      If you want, you can email me at martin (at) fix-knee-pain (dot) com and I can give you some more detail about each of these topics.

      – Martin

  5. Joe says

    Hi Martin;

    I am a 44 year old male that has never had knee issues. Over the years I managed to get my weight up to 180 lbs. at 5’7″. Time to change. I started the Beachbody program Insanity and after 60 days I was at a much leaner 148. I started getting relaxed again in my diet and exercise and started losing all I worked for. Never got above 155 lbs. I tried the new program they have out that really pushes you for 30 minutes and 3/4 of the way through I had to quit. I had a lot of aching in my knee joints. There was a lot of jumping and lunges and squats and high impact exercises. I stopped about a month ago but still the ache remains. It’s constant even when I just stand still. There is no pain per se but it feels a hey all the time and stiff. I’m not sure if I should go get a Dr apt or just find some exercises that help my mobility get back to normal. I want to be athletic and be in great shape but I’m not sure where to go from here. Any advice would be helpful! Thank you much!

    • Martin Koban says

      Hello Joe,

      First, congratulations on the weightloss! That’s a great accomplishment that you can be proud of, I think.

      You should definitely get a doctor to check your knee for other types of injuries. Before beginning any rehab program, you have to be sure that you’re addressing the right injury, or else your risk making things worse.

      Once you know it’s patellar tendonitis, you can use slow squats to strengthen your patellar tendon. You take 3 – 5 seconds down and 3 – 5 seconds up with 3 sets of around 10 to 15 repetitions and around 2 to 4 rest days in between training sessions. This allows good collagen synthesis inside the tendon. You should also get the book Beating Patellar Tendonitis on Amazon once you’ve confirmed your suspicion of tendonitis.

      To stay in shape, you can do exercises such as deadlifts (also, single-leg deadlifts) and glute-bridges. Gymnastics and upper body strength training are also great. For aerobic activity, you can go walking or swimming for example. Avoid high impact activities that load your knees, specifically the front of the knees.

      For a tough challenge of strength and resilience, do super-slow squats and push-ups. Try to do 30 seconds on the way down and 30 seconds on the way up. Once that’s easy, do even more. This strengthens the tendons and trains the muscles.

      Let me know how it goes.

      – Martin

  6. John says

    Hi Martin,

    I am a ex-runner turned triathlete about 1 year ago. Since then I have been slowly increasing my biking mileage (10%/week or less); however, about 6 weeks ago I noticed that my right knee began to be tender post exercise (usually after 3+hr sessions). The pain was infrequent and didn’t seem to be consistent until only a few weeks ago as I was only doing 1 of these a week. I recently rested for about 4 days (along with a set of 6 hr flights) and afterwards noticed significantly more pain. After some mild workouts, the pain level has decreased a bit, but still is there. When I evaluate the knee, the kneecap is tender on the bottom interior side and while in use, it feels as if the pain is coming from the upper interior kneecap/quad area.

    Based on what I have been reading, it appears that I may have patellar tendonitis. Any advice?


    • Martin Koban says

      Hey John,

      The fact that your pain has gotten worse after sitting points towards a lot of tension in your quads, and maybe other muscles too. A good starting point is thorough self-massage of the legs, especially the quads. I always recommend using a stick, as that allows for more precise massage and uncovers more problems.

      Next, you can take up daily stretching of the quads, calves, and hamstrings. This article demonstrates some great stretches: – a great summary of the fundamental approach to patellar tendonitis.

      Finally, remember that biking has some inherent limitations that may contribute to the development of knee pain. For example, your hip is always flexed when you’re biking, which can lead to shortening of the hip flexors, including the rectus femoris in the quads. The quad stretches mentioned above will help you solve that imbalance. A second problem with biking is that you’re only training your quads concentrically, that is, you’re always pushing and extending your legs, but never yielding to an external force. Over time, this leads to a strong quad muscle with poor eccentric motor control (poor force absorption). I think poor force absorption is always part of the reason why patellar tendonitis develops … the slow eccentric squats can help you improve that (you don’t necessarily have to do them on a slanted board, if you don’t have one).

  7. Jelani says

    Hi martin

    I’m 16 years old and I have jumpers knee . I have been going through this for 2 year and I feel like I can’t get rid of it. Last summer I spent most of my time trying to heal it but no good. The pain came right back to this one but worse. I literally feel where the tendon is going to tear in half. It only hurt to touch when I really try to get in their. I’ll say the tear is 1/5 of the tendon. I hope you can help me.

    From. Jelani

    • Martin Koban says

      Hey Jelani,

      If there’s already a partial tear, I don’t think you can fix it through exercise. Work with a doctor or an orthopedic surgeon to make sure you don’t make it worse.

      I wish you all the best for your recovery!

  8. Mark says

    Hey Martin

    I’ve been suffering with chronic patellar tendinitis for over a year now. Using your book I was able to eliminate the pain so that I can play sports again. However I still have swelling in my knee that I can’t get rid of hurts if I tap/touch. Do you have an idea of what it could be?


    • Martin Koban says

      Hey Mark,

      Swelling could be caused by any number of issues from arthritis to general inflammation. First, get it checked out by a doctor to rule out mechanical problems with the joint. Once they told you “There’s nothing I can do,” you should know where exactly the swelling is, which can give you a better idea for what you need to do. For example, swelling in the fat pad under the knee can be caused by moving with a knee in hyperextension too often, which can be the result of a tight hip. In other words, look for alignment problems/biomechanical problems associated with swelling in the particular region.

  9. Cindy says

    My daughter is 17 and a level 10 competitive gymnast and has been struggling with jumpers knee since last summer. We have confirmed the diagnosis with an MRI. She sees a D.O. Twice per week for treatments and have been icing at least twice per day. Her practice schedule for gymnastics is 5 hours per day/5 days per week. She has competitions usually every other weekend. She has also been working with a trainer to strengthen the muscles surrounding her knee which has helped. We watched your video on rolling her quad, IT band etc and she is going to start that faithfully tomorrow. I can’t wait to get your next email to see where we can go next. We are just trying to get her through to May which is J.O. Nationals and God willing she does well, hopefully she will be offered a college scholarship. Is there anything else we can do? I have a cold laser but I have been hesitant to use it. I haven’t started the heat therapy yet but plan to sneak that in starting tomorrow. Thank you for all of your excellent information!!!

    • Martin Koban says

      You can support healing through supplementing Vitamin C (2 x 0.5 gram per day), hydrolyzed collagen (2 x 1 tbsp per day), and fish oil (2 gram per day). Legal disclaimer: I’m not a doctor, so check all this with your physician before starting supplementation.

      According to the research I read, cold laser doesn’t help with tendonitis anyways. The supplements are supported by research though.

      In this scenario, you cannot expect significant improvement. You can only hope to manage the symptoms well enough until your daughter has time to focus on rehab 100%.



      • Akash says

        Hlo martin.I am akash from india i have been playing football for last 5 years but 1 year before i got injured and i have patellar tendonites when i do exercises there is pain im my left knee and i dont what to do on which i am help me because i have resting for 6 months and its not recovering

  10. jimmy says

    Hei martin, i have an jumpers knee around 2 years ago. I was reading on the internet that strengthen the muscle around my knee will help.

    So i decide to enroll on a gym member in order to do that, what kind of training on gym are good for jumper’s knee?

    i’ve been doing this 2 exercise:
    – leg press exercise
    – leg extending exercise

    are this exercise helping me, or it’s making it worse??

  11. roberto da lima says

    hey Martin i really found your technique decline board squat to have magical effect on my PT. i suufered this injury 3 years ago and with decline board squat for 12 weeks i got to sport football with no pain.however after a year of enjoying football Pt symptoms appeared again..can do becline board again ? thans for your generous work

  12. Mark says


    I have patellar tendonitis on my right knee. Probably stage 2-3. Rested for 3 months. Pain returned and now i have noticed my left kneeis experiencing the same symptoms. I was wondering if flat feet would cause patellar tendonitis as i have flat feet?

  13. Macey says

    Hi! Iam facing knee pain for almost 3years. I dont have any sports or im not athlete. I normally walk, stand, jump, climb and kicking! What my problem is when i stretch my knee i felt discomfort inside the knee and when i get back my knee i feel nothing happen. Im done in xrays and its normal no fracture. I take vitamin b for 3months and nothing chance. My uric acid test is normal too. Do you have idea what is my condition? Pls reply! God Bless!

Leave a Reply

I'm on a project deadline and unable to answer website comments. To get in touch with me, take one of my advanced courses on knee pain or patellar tendonitis. These courses are invaluable and my gift to you.

Your email address will not be published. Required fields are marked *