A few weeks ago we wrote a number of articles on the topic of knee pain. After many requests, I’ve decided to rewrite the patellar tendon article. I’ve also included more on the quadriceps tendon. There is also a number of updated scientific references (for my strength nerds out there) in my attempt to give you the most comprehensive article ever written on this topic. I hope you enjoy.
PATELLAR TENDON ANATOMY 101
First, let’s talk about what a tendon is. A tendon is essentially a fibrous band of tissue that connects muscle to bone. The patellar tendon runs from your kneecap (patella) to the tibial tuberosity (the prominent bony part of your shin bone). Above the kneecap is another band of fibrous tissue, the quad tendon, which attaches to the very large and strong quadriceps muscles. These two tendons work together to absorb and release tremendous power (i.e. squatting, jumping, and running) much like a spring.
Athletes who are involved in sports that include sudden explosive and repetitive movements of the knee can develop pain and tenderness at these tendons. Of the two, patellar tendon pain is usually the more common injury especially in sports such as basketball and volleyball due to the excessive jumping (this is where the term “jumpers knee” was coined). However, patellar and quadriceps tendon pain are both very prevalent in sports such as weightlifting, powerlifting and CrossFit due to the high forces that are sustained during the repetitive strength and ballistic movements.
For example, in 1986 a group of researchers performed a study on a 242lb/110kg powerlifter squatting 550lbs/250kg.12 During this heavy lift, they estimated the loads on the patellar and quadriceps tendons reached 6,000 and 8,000 newtons respectively.12
A newton (N) is an international unit for measuring force. Researchers have estimated that the patellar tendon can withstand forces of upwards of 10,000-15,000 newtons (which is around 13-19x bodyweight for an 176lb/80kg athlete).3,10 Estimating the ultimate strength of the quadriceps tendon however is a little harder. Scientists have found the quad tendon to be around 30-40% thicker than the patellar tendon, therefore it can probably withstand much more force than 15,000 N estimated by at the patellar tendon.11 This means the peak forces sustained while barbell training are almost always going to be below the threshold needed to completely tear these two tendons in half.
Definition of “Tendinopathy”
Historically, patellar and quadriceps tendon injuries have been separated into two distinct categories: tendinitis and tendinosis.2 The “itis” ending of tendinitis refers to an acute injury caused by inflammation. The “osis” ending of tendinosis traditionally means the problem is not caused by inflammation but due to the tendon itself degrading and becoming weak.
However, recent research has challenged the idea that the inflammation commonly seen with tendon pain is a main driver of the injury and pain.13 Furthermore, leading researchers in the field of tendon injuries now believe tendonitis and tendinosis are not mutually exclusive and are actually different parts of the same injury process. Therefore, when we speak about tendon injuries, it is advised to now use the term “tendinopathy” rather than tendonitis and tendinosis.
Where do we feel the pain?
Classically, those with patellar tendinopathy will complain of tenderness and pain at the connection point of the kneecap and patellar tendon (called the inferior pole of the patella). You may even experience pain where the patellar tendon attaches to the tibia (a small bump on the front of your shin called your tibial tuberosity). Usually you won’t have pain directly in the center of your patellar tendon unless you’ve sustained a direct blow to the knee (like hitting your knee into a corner of a desk).
Those with quadriceps tendinopathy will have pain and tenderness at the connection point of the kneecap and the quad tendon (called the superior pole of the patella).
Initially, most people will report feeling a dull ache in the front of their knee after intense workouts. Most people who have this injury will experience pain that gets worse as the load to the knee increases (i.e. the more weight you squat or the deeper you squat, the more your knee hurts). This is called load-related pain (remember this term as it will be an important part of how we fix this injury later).
One of the main factors that differentiates this injury from other forms of knee pain (hyperlink) is that tendinopathies will rarely hurt when completely at rest.20 This is because the load on the tendon is removed when sitting or lying down.
So how do tendon injuries occur?
When I was going through physical therapy school I was taught that tendinopathies occur due to overuse. If this was always true, how is the elite weightlifter able to pull two-a-day training sessions multiple times throughout the week without ever developing pain while a relatively amateur athlete may develop this injury after training for only a few weeks? It all comes down to the individual and their relative training status. Let me explain.
Our body does an amazing job of adapting to the stresses applied to it. Depending on the kind and amount of stress, the cells in our tendons can respond positively or negatively. In response to acceptable training loads our tendons become stronger by increasing their stiffness levels, not necessarily by growing bigger or thicker as muscles do in response to weight training.19 An elite athlete who performs explosive and heavy barbell training every day with minimal rest is able to do so therefore because they have deliberately conditioned their tendons over years of lifting to withstand a very high level of stress.
However, if that same elite athlete took a long break from training and all of a sudden jumped right back into a relatively normal training program (“normal” being relative to what they were used to), they would subject their tendons to a ton of unexpected stress. This is because their tendons would become somewhat deconditioned over the extended break. A similar shock to the body would occur with an athlete who abruptly transitions from from squatting twice a week to every day.
Basically any unexpected loading on the tendon can trigger a reaction and subsequently the tendon can thicken in an attempt to handle the stress of training.14 At this time an athlete may experience pain as well as a small amount of swelling around the tendon. Researchers believe this reactive response is a short-term adaptation and the tendon has the potential to return to normal if the initial training load is significantly reduced or if there is a longer recovery time allowed before the next training day.14
If you have patellar tendon or quad tendon pain that JUST started after a single training session or after a few days of hard days of training in a row, your tendons are probably in a “reactive” state.
If however, someone continues to train past this point of reactivity, the tendon will enter the “disrepair” stage as it continues to thicken in an attempt to heal itself. In fact, researchers have found this exaggerated repair process can cause the patellar tendon to double in thickness (from around 4mm to 8mm) as a protective response.15,16 At this point we also see new blood vessels and nerves growing in the tendon which may play a part in creating more pain.17,18 If proper steps are not taken to address the injury at this time, it will eventually move into the “degenerative” stage.
At this time the small fibers that make up the tendon (collagen matrix) begin to breakdown and die. This final stage of tendinopathy is usually seen in the elderly or in elite athletes who have continued to push through tendon issues for years. At this chronic stage, it is believed that tendons are prone to complete rupture or tearing if subjected to enough load.14 (Something you will see first hand in my 1st short film documentary coming out January 2018).
Expert in the field of tendon research Jill Cook described these three stages of tendinopathy (reactive, disrepair and degenerative) to be on a continuum.13 This means an athlete’s tendon can effectively move between each phase depending on how they treat or fail to treat it.14 For example, an athlete who has a patellar tendinopathy in the “reactive” or “disrepair” stage can return to full health with proper maintenance of training loads/frequency and corrective exercises or physical therapy. However, those who have reached the far end degenerative stage unfortunately have a more uphill battle as there is a smaller chance for a full recovery.
For this reason, if you have been dealing with this injury for many months, I highly recommend going to see a sports physical therapist to manage your healing process rather than trying to fix it on your own with the exercises I discuss below.
HOW DO WE FIX IT?
STEP 1: Finding Your Place on the Continuum
As an athlete competing in the sport of Olympic weightlifting for over a decade, I wholeheartedly understand the drive most of us have to train despite having the aches and pains. Fortunately, I been able to merge my passion for barbell training with my education in physical therapy to help you become as efficient as possible in treating this injury. Contrary to the general advice of your local doctor, not everyone has to completely stop training to fix this problem. It all depends on where you are on the injury continuum we just described.
For example, if you believe you are in the “reactive” stage of tendinopathy you do not need to completely stop training. Your body has experienced an abrupt overload of your tendon tissues and has responded negatively with pain. You need to look into WHY this occurred and make changes in order to decrease your pain.
For most this will mean taking a few days off training to allow your body to recover. You then need to modify your training program the next time you go to the gym as to avoid another flare-up. This means decreasing the amount of reps and how heavy you lift (changing volume and intensity). If you don’t take this step slowly, you’ll risk pushing your body into the next stage on the injury continuum.
If you have been experiencing patellar or quadriceps tendon pain for more than a few weeks, it is likely you’ve entered the next stage of “disrepair.” At this time, I recommend starting corrective exercises and modifying training. A modification in training means decreasing both volume (amount of repetitions) and frequency (days per week) during your workout. Notice I did not include intensity (amount of weight you lift) in this modification.
In my experience, a number of barbell athletes begin to experience this pain in the time leading up to an important weightlifting or powerlifting meet. It is therefore not practical for everyone to completely stop training. For this reason, our goal in treating the injury at this time frame is to maintain a high level of conditioning that allows for continued progress towards the competition platform without over-stressing the tendon and leading to the potential for “degeneration.”
However, if the body does not respond well to this modification in training with the addition of corrective exercises or the pain has been on-going for more than a few months (meaning your injury may now be in the “degenerative” phase) it is highly recommended to cease training and consult with your local sports physical therapist or an orthopedic specialist (MD or DO).
STEP 2: REHABILITATION EXERCISES
Historically, physical therapists have treated tendinopathies at the knee with eccentric exercises.1 One common exercise is a single leg squat on a decline board for 3 sets of 15 reps twice a day. The athlete starts by standing on a decline board (usually on a 25° angle) and performs a slow single leg squat on one leg while maintaining an upright chest. They will then put their free leg down and stand back up with both legs. Placing your body on a decline specially targets the patellar tendon (25-30% more) than when performing this exercise on flat ground.7
Unfortunately, there are two problems with using this exercise. First, there is very limited research to back it up.21 Second, the use of this exercise program may be too aggressive for many. Pain is a normal response to this exercise and using it with an athlete that is continuing to lift may cause excessive irritation and worsen the injury.
In fact, recent research has shown that the type of contraction (eccentric vs normal eccentric & concentric loading) is irrelevant when it comes to driving the healing process with tendonopathies!23 Ultimately it is the amount of load we place on the tendon that drives the injured tissue to return to a normal state.
For this reason, athletes with patellar and quadriceps tendinopathies will likely respond better to heavy slow resistance (HSR) exercises aimed at improving the load-bearing capacity of the healthy portions of the tendon.5,6,21 An HSR program includes a staged progression of isometric and isotonic (normal eccentric & concentric movements with heavy weight) which we will detail next.
So should we never use the decline squat?
I’m glad you asked. We will use the single leg decline squat as a pain-provocation test. Using this test daily allows you to gauge how well your body is responding to the corrective exercises! Let me explain how.
It is normal to have a little pain during the rehab process of tendon injuries. In order to make sure we’re healing as efficiently as possible, we need to make sure we’re placing just the right amount of load on the tendons. By using a pain-provocation test, we can determine how well the tendons are tolerating the exercises (this is called load-tolerance).
Start by performing the single leg decline squat and ranking the amount of pain you have on a scale from 0-10 (0 is no pain and 10 is the worst pain imaginable). That number is your “baseline” score. If your pain has returned to that level within 24 hours of training, the load has been tolerated well and you can continue lifting and possibly increase the training intensity. If the pain is worse, the load-tolerance has been exceeded and you need to modify your training and/or amount of corrective exercises. In many experts’ opinion, pain rated up to a 3/10 is believe to be an acceptable amount during exercise and with the pain-provocation test.21
The most tolerated of all exercises for tendinopathies is an isometric. This is an exercise where the muscle contracts but the joint doesn’t move (i.e. squeezing your quad while standing or laying down). Isometrics have been shown to reduce pain for upwards of 45 minutes after performing.22 They also spark the ability of the quad to kick back on, as it is usually inhibited in strength output due to pain.22 An easy way to perform an isometric on your own is with a wall sit.
Perform a standard wall sit with a moderate bend at your knee. This will usually be around 30-60° as going any lower will usually create pain. Perform 5 repetitions of a 45-second hold. This hold should not create any trembling in your muscles (called a fasciculation). If so, it’s a sign the load is too high and you need to decrease the hold time or the depth of your wall sit.
If you are performing this with enough intensity, you should notice an immediate decrease in the amount of pain noted on your pain-provocation test (the single leg decline squat). If the wall sits are too easy, you can do two things to make it harder. First, you can hold on to a weight. Second, you can move from two feet to one. Ideally we want to push the intensity of these isometrics in order for them to be effective at decreasing pain.
If you are continuing to train through this injury, use these isometrics before your workout as a way to decrease pain and improve neuromuscular control and force generation during your lifting. Make sure to keep an eye on your load-tolerance during this time! I also recommend performing these isometrics two to three times a day with a minute or two rest in between to help maximize recovery.
Addressing other Strength Deficits!
It is common to see strength deficits and coordination issues in how muscles are activated with athletes dealing with tendinopathies. In my experience, many athletes demonstrate underactive or weak glutes. A simple screen to expose this weakness is a single leg bridge test.
Lay on your back with one leg bent and the other straight. Perform a single leg bridge and hold the highest position for 10 seconds. What muscles did you feel working hard after holding this single-leg bridge for 10 seconds?
Our goal with this screen is to identify your “go-to” muscles for hip extension (the movement that drives you out of the bottom of the squat, clean, snatch, etc.). If you felt anything other than your butt muscles (glutes) working hard, you have a coordination and/or strength problem we need to work on. The bridge exercise is great for fixing this problem and can be used directly after your isometrics.
Step 1: Lay on your back with your knees bent as shown.
Step 2: Flatten your back to the ground by bracing your core as if you were about to get punched in the stomach.
Step 3: Squeeze your butt muscles FIRST and THEN lift your hips from the ground. Picking your toes up and driving your heels into the ground can help increase your glute activation. Squeeze your glutes as hard as you can in this bridge position for 5 full seconds before relaxing back to the ground.
Recommended sets/reps: 2 sets of 20 for a 5 second hold. Eventually work your way up to 10 second hold or even 20 seconds.
You can then progress these to a bench with a barbell across your hips (called a hip thruster) and eventually to a single leg version of the movement.
Heavy Slow Resistance Exercises
The Box Squat
The goal with this stage is to increase the amount of load the tendon can handle without creating more pain. The resistance exercises I will detail here should be included as soon as they can be performed with minimal pain (3/10 or less on your pain scale).
Now, if you can squat to full depth with pain already less than a 3/10 by all means continue doing so. However, if extreme pain has limited your ability to squat to full depth limiting your squat descent to a predetermined height will be the next step.
For example, box squats allow you to load the body in a recognizable way while controlling for a few important factors. First, you can control for the amount of depth by setting the box to a predetermined height to limit pain (this will usually be around a parallel depth). Box squats also decrease the total tension placed on the quad and patellar tendons as a powerful turnaround in the bottom of a free squat (which naturally stores and releases energy via the tendons) is not used. By pausing on the box you take away the connection between the eccentric descent and concentric ascent of the squat, which therefore places less overall load on the injured tendons.
Here’s how to perform a proper box squat.
Step 1: Your set up for the box squat should be the exact same as your regular squat. Set your feet in a stable position. Take a breath and brace your core before starting your squat with your hips.
Step 2: While remaining balanced during the descent (barbell tracking over your mid-foot when viewed from the side), sit straight down onto the top of the box. Do not rock back onto the box but instead only pause in the bottom position.
Step 3: Initiate your ascent by driving straight up. If you do this correctly, your knees will not travel forward as your hips rise from the box. Instead they will remain pushed out and in a stable position in alignment with your feet.
How much weight should you use on the squat?
If you can’t perform the full squat without extreme pain, I recommend using 50-70% of your 1RM (of back squat) for the box squat. This may take a few tries before you find the ideal weight for the box squat.
Your tendons (unlike muscles) require heavy loads in order to adapt and heal.23 Research has shown positive changes in muscles (size and strength) with loads anywhere between 30-90% 1RM, where as it takes a much more significant load (>70%) to see the same adaptive changes in tendons.23,24
How fast should you squat?
While the amount of weight on the bar is THE MOST important factor in creating change in our injured tendons, the speed at which we lift is a close second.26 Scientist have recently found that manipulating the speed at which a squat is performed significantly changes the amount of stress and strain placed on the tendons of the knee.
Initially during the healing phase, moving quickly during a squat may elicit more pain. For this reason, performing your strength exercises with a slow descent and ascent is ideal (a key component of HSR training). However, eventually as pain subsides (less than a 3/10) you can start to increase or vary the speed of the lifts.
For example, using a slow descent (~3 seconds) followed by a powerful drive upwards places an increased demand on the tendons that can help promote more healing compared to squatting slow on the way down AND up.25 When you descend in a slow manner, pause and return slow on the way up, the tendons in your knee do not lengthen excessively. However, if you try to accelerate out of a slow descent, the tendons lengthen and shorten quickly (like a spring). This strain placed on a tendon can help promote proper healing and return to a normal state.
How do you know if you’re using the right weight?
When you first start your squat training, work up to 4 sets of 10 repetitions at your 70% 1RM. A small amount of pain (3/10) is acceptable during and after the lift. If your pain is higher than a 3, then the weight was probably too much.
Use the pain-provocation test I described earlier (decline single leg squat) 24-hours after each training session to see if you were using the correct load for your body. If you are using the right amount, your pain will stay the same as the day before or get better. If it is better, increase the weight the next session. If you are using too much weight, your pain will increase 24 hours later and you need to decrease weight during your next session.
There isn’t a set protocol for this progression, so getting with a strength coach and physical therapist that has a background in weightlifting/powerlifting will be key to finding the optimal progression for your body.
The Bulgarian Split Squat
While the box squat is a great exercise, you can easily hide or cover up problems in side-to-side strength/coordination. Consciously or subconsciously, your body often changes the way it moves in the presence of pain. These compensatory movements may be very small and therefore hard for even the most well-trained coach to see with their naked eye. For this reason, using exercises performed mostly on one leg (like a Bulgarian split squat) will expose these asymmetries and ensure you’re loading the injured tendons adequately.
Step 1: Place a lightly loaded barbell on your back or hold a pair of dumbbells at your side. Stand in front of a bench or box.
Step 2: With your back foot resting on the box, perform a small split squat. Try to keep your shin as vertical as possible during this movement. If you’re doing this right you’ll feel the hamstrings and glutes of your forward leg working hard as you descend.
Recommended sets/reps: 3 sets of 6 reps on each leg
Returning to Olympic Lifts
Ballistic lifts like the clean and snatch will be the most aggravating movements to the tendons of the knee and therefore the last to re-incorporate back into your training during the rehab process. If you have returned to squatting heavy without any pain, you can introduce these lifts. Start slow on your progression, especially with the frequency you include them in your training. Having 48-72 hours in between each session is a good rule to start with to allow proper healing.
Here is a simple training progression to use:
Day 1: Olympic Lifting Day
Day 2: Isometric Exercise (Active Rest)
Day 3: Heavy Slow Resistance Day
Day 4: Olympic Lifting Day
Notice how there isn’t a complete rest day. Some athletes will feel worse after a complete day of rest, so making sure to load the tendon with simple isometrics is a good idea.21 At this time continue to use isometric exercises before your Olympic lifts as a warm up. Also use your decline single leg squat to test how well your body is responding to the newly added lifts to make sure your body is tolerating them well and not going backwards.
SHOULD I USE ICE?
While ice has been shown to be beneficial at controlling inflammation and pain in the days following a new injury (the acute phase), there are mixed results and opinions on whether or not it should be used for chronic overuse problems (like most cases of patellar tendinopathy)
I don’t have a problem with using ice to help manage and decrease pain. Just keep in mind that most patellar tendinopathy cases are not inflammatory in nature, it is actually degeneration of the tendon fibers. So ice is a great tool for pain management but it certainly won’t accelerate the healing process.
WHAT ABOUT STRAPS OR BRACES?
The Cho-Pat and DonJoy Cross straps are two of the most common orthotics used for patellar tendon pain.8 They’re simply a thick piece of material that wraps tightly around your patellar tendon, decreasing the strain on the painful tissue. While you can purchase one of these straps at almost any local drugstore, you can save yourself some of that hard earned cash and make your own version with some cheap pre-wrap material.
Step 1: Wrap the pre-wrap 5 or 6 times around your leg, just below the bottom of your patellar tendon.
Step 2: Roll the material up into a thick strap. It should wrap directly across the middle of your tendon.
While some people swear by its use, research has unfortunately been very iffy.9 My thoughts on the patellar straps is that if it decreases pain with activity, you can definitely continue using it. Make sure the strap or tape application wraps around the center of your tendon (this is key for decreasing tension). Just remember, using a strap should only be a supplement to rehab exercises and not the sole method of treatment. The straps are not to be used as a band-aid to mask pain. You still have to address the issue with rehab and relative rest.
SHOULD I USE ANTI-INFLAMMATORY MEDICATIONS?
While I think you should ultimately rely on the judgment of your medical doctor for medication advice, I think it’s necessary we still touch on this question. In many cases by the time most people start to look for help with their patellar or quad tendon pain, their tendinopathy has moved on the continuum to a place where there usually aren’t signs of classical inflammation present.4 For this reason, anti-inflammatory medications (called NSAIDs) are often not very effective.4 Furthermore, covering up your pain with medications may disguise your injury while the strength of the tendon continues to decrease, leading to a further injury (possible tear or rupture) in the future.
Be careful what you put into your body when dealing with pain. We already live in a society that is asphyxiated with unnecessary medications. Don’t assume your knee pain will vanish in thin air by popping a few pills just because a TV ad says it will.
Depending on where your injury lies on the tendinopathy continuum, the process of decreasing pain could take a few days to several weeks or even months. Your progressions for these exercises described will be guided by the amount of pain you experience in the pain-provocation test (single leg decline squat) 24 hours after each session.
No two athletes will respond the same way to the rehab exercises described today. Some will be able to add more weight on session after session. Some will require a more fluctuated load program in order to keep pain at bay. In the end, it is on you the athlete to regulate the weight based on how you feel. Don’t be a tough guy and push through more pain if your knees hurt worse the next day. Listen to your body.
Once you have returned to pain free training, you should continue to perform the isometric, Bulgarian split squats, and coordination re-education exercises (if found to be a weak link) weekly to prevent the tendinopathy from returning. This is because the altered neuromuscular problems that arose in response to pain can often persist even after the pain has resolved.21Also, prior tendinopathy is a good predictor for future tendinopathy issues.
Dealing with patellar and quadriceps tendinopathy can be a very slow and frustrating process. I hope this article was able to help you understand this injury a little more. If you are unable to find relief with your patellar tendon pain after performing these exercises, I recommend going to a medical professional (doctor or physical therapist) to assist in your recovery.
Until next time,
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