Patellar tendonitis or more commonly known as Jumper’s Knee is a condition caused due to overuse of the patellar tendon resulting in anterior knee pain. The term was first used in 1973 as a description for insertional tendinopathy noticed in skeletally mature athletes. [01]
The condition is a result of repetitive stress in the extensor mechanism of the knee, which is more prone to occur in activities that involve jumping. Hence, it is also known as Jumper’s Knee.
The condition is usually noticed in athletes involved in repetitive motions such as running, kicking, climbing, and jumping. It is a common cause of knee pain in athletes.
Football does not involve jumping as the main activity but the repetitive stress of the extensor mechanism can also result in this condition. Up to 2.4% of professional football players have been known to suffer from it in a single season. [02]
Tendons are known to transmit the force of the muscle on the skeleton, therefore repeated mechanical forces caused by overuse of the patellar or quadriceps tendon can result in tendinopathy. Middle-aged men are prone to suffer from this condition.
Tendonitis is an inflammatory condition associated with pain at tendinous insertions into the bone. However, certain studies dispute that by stating it more of a degenerative condition. [03]
The condition is characterized by tendinopathy of the attachment of the patellar tendon to the inferior patellar pole and, in rare cases, the attachment of the quadriceps tendon to the superior patellar pole. The most commonly affected region is the posterior proximal fibers of the patellar tendon. [04]
The characteristic symptom of patellar tendonitis is a localized anterior knee pain, which gets worse with activity. Sufferers might feel a sudden pain with swelling just below the kneecap or on the bony bump at the top of the shin. [05]
It is a self-limiting condition and can be treated with self-care techniques. However, chronic tendinopathy can cause weakening of the tendon and eventually lead to a ruptured tendon.
The pain can be intense and result in functional impairment in sports. Physical therapy particularly eccentric exercises have shown success in treating the condition. Immediate relief can be achieved by using RICE principles and anti-inflammatory therapies. [06]
However, anti-inflammatory therapies have shown limited relief as the condition is said to be more degenerative-based than inflammation-based.
Understanding the initial symptoms of the condition can result in proper management and treatment. Usually, individuals wait till they feel a prominent pain to suspect patellar tendinopathy.
Knowing the causes and diagnosing the condition at the initial stages can decrease the healing period.
Jumper’s Knee Brace Review
Here are the best brace for the jumper’s knee –
IPOW Patella Stabilizer Knee Strap
One of the leading brace that provides the best knee support and shock-absorption for the knee joint. A simple looking yet effective brace that helps to reduce the knee pain.
Best fits for – The IPOW patella stabilizer, as the name suggests, best used to stabilize the patella and to absorb the shock diverted towards the patella. It can also be used to treat patellar tendonitis, chondromalacia and as knee strap support for squats, running, basketball, volleyball, hiking, and soccer.
Features – Stay-in-place knee sleeves, 10 to 18 inches in circumference, segmented fix design, fully adjustable strap with double knot design.
Cons – This strap uses velcro to keep it in place which may loosen over the period.
Shop IPOW Knee Strap on Amazon
POWERLIX Knee Compression Sleeve
Made from – Breathable, specialized compression fabrics blend with the high absorption capacity
Best fits for – 360 knee protection and support while running, weightlifting, gym workouts, playing basketball and patellar tendonitis.
Pros – The brace is made from a breathable material that can absorb the sweat and keep the knee dry while workout. Anti-slip design keeps brace in place. Available in 5 different sizes. Elastic in nature to fit snug. 6 months money-back guarantee.
Cons – May become loose after a few week’s uses.
Shop POWRLIX Knee Sleeve on Amazon
UFlex Athletics Knee Compression Sleeve
Made from – High-quality elastic material using 3D knitting technology. Allows 4-way stretch & uses double silicone anti-slip wave.
Best fits for – Everyday activities, sports, running but it can be best used for knee pain relief, sore muscles, knee compression, reduce swelling and inflammation knee, patellar tendonitis, etc.
It can also help in muscular recovery by providing the heating effect and stimulating the blood flow. It is a good choice of knee brace for daily activities like walking, running, performing yoga, dancing, cycling and playing various sports. It is truly a versatile knee brace that can stay in place and snug fits.
Pros – Provides excellent knee compression. Good support while performing knee activities. Comes at a bargain price. Made using excellent material.
Shop Uflex Knee Sleeve on Amazon
Types of Knee Brace
Knee braces are available in different types and they are grouped as per their functions or as per the way it fits around the knee.
Types of knee braces as per the function of brace –
- Prophylactic (pro-fa-lack-tick) Knee Braces
- Functional Knee Braces
- Rehabilitative Knee Braces
- Unloader/Offloader Knee Braces
Types of knee braces as per the way it fits around the knee –
- Knee sleeves
- Wrap-around (Dual-wrap) braces
- Hinged knee braces
- Knee strap
- Closed & open patella brace
Anatomy of Patellar Tendon
The knee’s extensor mechanism includes the patellar ligament, patellar retinaculum, patella, quadriceps tendon, and the quadriceps muscle group.
The patella is a sesamoid bone, which is situated within the quadriceps tendon. The patellar tendon functions as a connection between the tibial tuberosity and the apex of the patella. It connects the kneecap and the shinbone and offers an extension at the knee joint. [07]
As the patellar tendon connects the patella to the tibia, it is also called the patellar ligament. The tendon, which is nearly 2cm wide, functions to help the quadriceps muscle to straighten the leg.
The composition of a healthy tendon is mostly parallel collagen fibers that are closely packed together. The tendon is also composed of elastin, proteoglycans, and inorganic components. The proteoglycan components Decorin and Aggrecan are responsible for holding the collagen together in the tendon.
Blood vessels are known to run parallel to collagen fibers in the tendon. The internal tendon does not have its own nerve supply but nerve endings are situated adjacent to the tendon.
Injuries to the extensor mechanism are quite common and usually include chronic degenerative injuries, acute trauma, and overuse injuries. Patellar injuries can be a result of overuse or acute trauma.
Chronic overload on the patellar tendon by the strain from the quadriceps muscle group can result in microtears and focal degeneration.
The presence of a few inflammatory cells in tendons of chronic patellar tendinopathy has reserved the term patellar tendonitis for acute tendinopathy.
Knee pain diagnosis usually includes a physical examination to determine the presence of inflammation and impairment in the normal motion of the knee. It is important to know what incident caused the pain and if the pain is only limited to activities.
Your medical history plays an important role in evaluating knee pain. A prior injury to the knee can make you prone to tendonitis.
Confirmation of the condition can be achieved by medical imaging such as MRI and X-ray.
Causes
Repetitive Stress
Stress on the tendon could lead to tiny tears, which the body tries to repair. However, repeated stress results in the tears multiplying.
This repeated stress can cause pain as a result of inflammation and weakening of the tendon. The pain is usually not noticed during the initial tear but is more prominent as the tear eventually multiplies.
Tendons are designed to withstand high, repetitive loading, however, on occasions, when the load applied to the tendon is too great for it to withstand the tendon begins to become overloaded with stress.
In the presence of compressive overload, the tendon undergoes a short-term adaptation resulting in it thickening. The effect is to increase the cross-sectional area to reduce the stress.
However, with repetitive stress, the tendons start sustaining small micro tears, which encourage inflammatory chemicals and swelling. This stage can heal quickly if managed appropriately.
A continuous load to the tendon can result in a multiplication of the tears. Gradually, the multiplication of tears can exceed the rate at which the tendons can repair it.
This leads to the damage increasing progressively to cause pain and dysfunction. The resulting condition is termed as tendinopathy or tendinosis.
An extensive study on this condition has resulted in researchers complying with the theory that tendinopathy is a result of cumulative microtrauma that is associated with high tensile and compressive forces.
These forces are common in athletes but can also occur due to repetitive motions in day-to-day lives.
Studies confirm the belief that the cumulative microtrauma exceeds the healing and remodeling ability of the tendon.
Researchers believe that patellar tendonitis is actually a result of tissue disruption, thinning of the tendon, and separated collagen.
The overuse of the tendon is believed to cause cumulative damage to joints and scarring, with the blood supply in the joints being insufficient for healing.
A debate among the cause of the condition has resulted in several theories regarding the use of anti-inflammatory therapies and alternatives such as iontophoresis and extracorporeal shockwave therapy as agents of treatment.
The condition can be a result of several causes that can result in stress on the tendon. Sudden acute trauma to the knee is rarely noticed as the cause of this condition. Usually, it is a result of repetitive stress to the tendon.
Patellar tendonitis is usually seen as a combination of extrinsic factors such as patellar tendon loading and intrinsic factors such as malalignment, muscular tightness, and abnormal patellar laxity.
Physical Activity
Repeated activities involving the knee such as running and jumping are most commonly associated with patellar tendonitis.
Repetitive jumping motions can cause excess strain on the patella tendon and result in tears.
The condition is also noticed in athletes who experience a sudden increase in the intensity or duration of training.
It is important to note that incorrect footwear during physical activity can also result in a stressed patellar tendon.
Tight Leg Muscles
The condition is noticed in individuals with tight quadriceps and hamstring muscles. The tight muscles usually are a sign of poor flexibility and can be remedied with stretching exercises.
The gluteal muscles are responsible for hip extension. Weak hips make the hamstrings work harder to compensate the gluteal muscles.
This results in a situation where the hamstrings become tight as they are being overworked. In a chain of events, tight hamstrings force the quadriceps to work harder to achieve knee extension.
It is important to identify a weak gluteal before trying to remedy tight hamstrings. Glute strengthening exercises can help in solving this problem.
Muscular Imbalance
An uneven pull by a stronger muscle in the leg could pull harder on the patella tendon.
This situation is noticed when some leg muscles are stronger than the others. While exercising, it is important to focus on all leg muscles to avoid this scenario.
Additionally, uneven leg muscle growth, obesity, and shoes without padding are known to cause patellar tendonitis.
Patellar Tendonitis Symptoms
The early stages of patellar tendonitis are characterized by tenderness over the bottom of the patella. The feeling of tenderness is noticed initially after exercise, with the individual experiencing discomfort during squatting and kneeling.
Studies state that the injury is more common in the dominant leg. A gradual increase in pain is noticed as the tears multiply, with the pain now becoming prominent during exercise too.
Most people are able to identify patellar tendonitis once the pain surfaces during rest and during training. It is important to identify the condition as early as possible to manage it effectively.
The initial symptoms of the condition are said to correlate with fluid or edema in the patellar tendon. The condition is actually characterized by degenerative changes in the tendon rather than an inflammatory process.
The pain associated with this condition is usually localized to the anterior knee. The pain appears gradually as the tears in the tendon multiply.
An acute patellar tendonitis is usually a result of an incident, with the symptoms most commonly noticed immediately. Such cases are common in individuals related to sports activities.
However, patellar tendonitis caused by acute trauma is not as common as other knee injuries.
In case of chronic patellar tendonitis, the symptoms appear gradually. The lack of initial symptoms often leads to sufferers straining the knee and resulting in further damage.
The following are the most common symptoms. The symptoms are quite similar to knee bursitis.
Anterior Knee Pain: A sharp throbbing pain can be felt during a workout. Initially, the pain gets better once the activity is stopped however, the pain can become worse if left untreated.
Pain and Stiffness: A sufferer is likely to feel discomfort and pain beneath the kneecap during the night or after waking up in the morning.
Tenderness and Swelling: Tenderness in the anterior knee post activity is known as one of the initial symptoms of patellar tendonitis. Mild swelling and reduced motion are also noticeable symptoms.
Redness: Acute injury-related tendonitis can show signs of discoloration or bruising.
Discomfort: Daily activities could become painful as the tendon is used for extending the knee to straighten the leg during bending down, climbing stairs, and kicking.
The tenderness on touch is a characteristic symptom of patellar tendonitis and is used to differentiate it from Runner’s Knee and Chondromalacia Patella.
It is advisable to consider treatment option after the initial symptoms of patellar tendonitis. Continuing to practice through the initial symptoms could cause further damage to the tendon and increase your recovery time.
Stages of Tendinopathy
The symptoms of pain and tenderness are noticed gradually in the area around the kneecap.
Any additional stress on the kneecap with activities such as kneeling and squatting could make the pain worse.
The damage to the patellar tendon increases with every stage, therefore it is essential to start a treatment plan in the earlier stages to improve the recovery and healing process.
Stage 1
A Stage 1 tendinopathy is associated with pain post an activity. This is a benign stage and does not result in any functional impairment.
Treatment usually includes rest and activity modification.
Stage 2
Anterior knee pain is present during activity and post activity. In this stage, the tissue is attempting a repair and a slight weakness may be felt during activity.
It is important to initiate a treatment plan to prevent tendon deterioration.
Stage 2 tendinopathy can be treated with a physical therapy program aimed to strengthen muscles and tendons. However, a strain on the patellar tendon should be avoided.
Support braces can be worn as a precautionary measure to avoid further injury.
Stage 3
It is usually characterized by degenerative tendinopathy as the injury load gets higher than what can be managed by the tendon’s repairing ability.
Sufferers might feel a prolonged pain during and after activity and find it increasingly difficult to perform tasks.
Rest and activity modification are recommended. Any excess stress on the knee could have a serious impact on balance, therefore it is advised to not put a strain on the knee and start with a comprehensive therapy program tailored for tendonitis.
Stage 4
This is a rare occurrence when a complete tear of a tendon results in a loss of function. A Stage 4 tendinopathy can usually be treated with surgical intervention.
Treatment Overview
A treatment plan for tendinopathy involves implementing measures to offer immediate relief from pain, strengthen the tendon, and prevent recurring tears.
Using a combination of active rest, education, eccentric exercise, progressing the training regime by 10% per week, and activity modifications are known to be effective in tendinopathy treatment.
Immediate Relief
Rest: A short-term option for immediate relief from pain is rest. It is important to let the tendon heal on its own. Therefore, any activity that puts a strain on the knee and causes pain should be avoided.
Physical activities that are related to sports should be continued once the tendon has healed completely.
Ice: Applying an ice pack before and after an activity can help alleviate pain.
Knee Sleeves: A compression sleeve or taping can be worn after an injury to reduce inflammation and pain.
Compression sleeves work by improving circulation, which in turn improves the healing process.
Medications: NSAIDs such as Ibuprofen can be used to get short-term relief from mild to moderate pain.
Stretching Exercises
Stretching exercises for muscles can help improve the recovery time and also act as a preventive mechanism against future injuries.
Calf Stretch: While standing around 18 inches from a wall, place your uninjured knee one step forward. Lean on the wall with both palms flat on the wall. While leaning, bend the injured knee slightly.
A light stretch should be felt in the calf. This position can be repeated regularly.
It is essential to avoid any strain on the knee while performing this exercise.
Quad Stretch: Stand straight and bend the injured leg at the knee. Pull the ankle towards the hip with your hand.
A muscle stretch will be felt when you lean forward. If leaning is difficult due to stability issues, you can take support against a wall.
Leaning should be continued till a slight burning sensation is felt in the upper leg.
Hamstring Stretch: Stand straight and lean forward to touch your toes. Reach as far as you can while keeping the knees locked.
Strengthening Exercises
Strengthening exercises help improve the healing process and offer protection from further injuries.
As weak glutes result in an increased force through the patellar tendon, it is essential to strengthening the glutes to avoid tendonitis.
Strong Glutes
Strong glutes are essential to ensure an even force through the knee. Weak glutes are usually noticed as a cause of all knee ailments. Practicing the below exercise can strengthen the glutes and avoid further injuries.
While lying on your side, keep your hips and knees bent at nearly 90 degrees. Your feet should be together. Start the exercise by lifting the top knee as high as you can and hold the position for a few seconds.
Repeat this pose regularly for benefits. You can also add a heel squeeze to make the glutes stronger. It is imperative to understand your body’s warning signs when performing these exercises. If you notice any pain or discomfort, it is best to stop the exercise immediately.
Eccentric Muscle Training
Eccentric exercises are known to be the best treatment method for patellar tendonitis in athletes as well as non-athletes.
The method is said to be efficient and have no adverse effects and should be considered as the initial physical therapy for tendonitis.
These exercises are known to increase the remodeling process of the collagen fibers in the patellar tendon, with the process resulting in the musculoskeletal unit adapting to protect itself from additional stress.
These eccentric exercises are indicated to result in some level of discomfort, which is normal. However, athletes should resume their activities only after a complete healing is achieved.
Performing these exercises needs the use of a decline board initially and a weights bar at a later stage. It is known to be effective without the equipment too.
While standing straight, perform an eccentric decline squat with or without a slant board. The uninjured leg should extend forward, while the squatting action is performed by the injured leg.
Support in the form of a wall or chair can be used. The movement should be slow without any jerks. The movement can be repeated two to three times a day and the frequency can be increased gradually.
Slight discomfort or a feeling of pain is normal however, a pain in the tendon should be a signal to stop the exercise.
Knee Support
Knee support can be used in conjunction with a rehabilitory program to boost the healing process and prevent further damage.
Different forms of knee support are available depending on the purpose and the stage of the condition.
Knee Strap
This is the simplest form of knee support, which can be worn every day by athletes and non-athletes.
They are unobtrusive and can be worn below any clothing. The strap targets the patellar tendon and keeps the knee joint aligned. Additionally, the strap provides pressure to the tendon to reduce pain and inflammation.
Compression Sleeves
These sleeves can be worn as socks over the knees. They offer a gentle compression and are ideal for Stage 1 and Stage 2 tears as it provides a moderate support.
Patellar Tendonitis Braces
Hinged braces are known to offer relief from anterior knee pain and inflammation. These braces are recommended for individuals requiring an advanced level of support.
The hinges on the braces prevent the knee from hyperextending. Although slightly bulkier than the sleeves and strap, it can be worn during sports and daily activities for support.
It is necessary to use this brace for individuals who have undergone surgery for patellar tendonitis.
Medical Interventions
Surgery: Surgery is usually recommended for Stage 4 tears or when all other treatment options have not been unsuccessful to reduce pain.
Surgical intervention involves longitudinal excision of the involved tendon and restructuring of the residual tendon.
This method has shown promise in some athletes allowing them to resume their activities at their same levels.
A resection of the involved pole of the patella has also been effective in some patients.
If surgery is recommended, a period of rehab will be advised before resuming sports activities.
Injections: Corticosteroid injections are known to offer short-term benefits for patellar tendonitis. However, these injections can result in a weakening of the area.
Repetitive corticosteroid injections can also lead to tendon rupture.
Other Therapies
If the pain associated with patellar tendonitis is not remedied with the above therapies, the following options are usually recommended by a physician. These are mostly non-invasive procedures.
In addition to the following therapies, administering ultrasonographic-guided sclerosing injections into the neovascularized patellar tendon has shown efficiency in minimizing pain and improving function in athletes.
Platelet-Rich Plasma Therapy: The site of the injury is injected with the patient’s own platelet-rich plasma. This therapy aims to accelerate the healing process.
Dry Needling: A needle without a syringe is inserted into the affected area with the help of an arthroscopic camera. The method is used to destroy the degenerative structures that are causing the condition.
Hyperthermia Thermotherapy: Using a heating source and a cooling source results in an increase in the temperature of the patellar tendon. This therapy aims to expose the knee to a high temperature while allowing the surface level tissues to stay cool.
Extracorporeal Shockwave Treatment: The damaged tissues are treated with an electric impulse to the muscle tissue surrounding the patella. The force is usually high enough to destroy damaged or torn soft tissues.
The recovery time for patellar tendonitis can range between a few days and several weeks depending on the severity of the injury, the presence of biomechanical factors, and the overall health of an individual.
The recovery period after a surgical intervention usually lasts for about two months.
The recovery phase is essential for treating patellar tendonitis. You should focus on getting rest, implementing a healthy diet and regular exercise, and following a rehabilitory patellar tendonitis therapy.
Physical activity should be resumed gradually in terms of intensity and duration. Wearing a knee brace during the recovery phase can help accelerate the healing process.
How to Prevent?
Preventing knee injuries due to overuse is difficult as knees are used in our day-to-day lives.
However, understanding the causes and symptoms of tendonitis can help detect the condition at an early stage.
Implementing a preventive mechanism involves knowing the risk factors for patellar tendinopathy.
High body mass index and large abdominal circumference are the known risk factors for this condition. BMI can be calculated by dividing your weight by your height and the answer divided by height again.
A healthy BMI can also protect you from potential medical conditions such as diabetes and heart diseases.
A larger body is associated with a higher force going through the knee during daily activities. Weight loss can be achieved by staying active through household work, exercises, and a healthy nutritional diet.
A large abdominal circumference is also associated with tendonitis. Walking and running are known to help lose tummy fat.
Athletes are prone to suffer from this condition due to incorrect training techniques such as duration and intensity.
A sudden increase in the training time and intensity could put a strain on the tendon and result in tears.
A knee support can be worn as a precautionary measure during sports activities that involve jumping. Knee braces can also be considered if your daily activities involve repetitive use of the knee such as kneeling.
Summary
The theories related to the cause of patellar tendonitis often consider it either inflammation or a degenerative condition.
Researchers are still studying the exact cause and studies are being conducted to understand the most effective treatment.
However, physical therapy is known to be the most effective therapy as of now. Anti-inflammatory therapies such as corticosteroid injections have shown to provide a short-time relief as compared to physical therapy, which has been associated with long-term benefits.
In particular, eccentric exercises have shown good results. Surgery is usually recommended as the last resort.
Athletes are susceptible to suffer from this condition however, overuse of the tendon can also occur during daily lives. Insufficient training preparation, being overweight, and a prior injury is the risk factors for patellar tendonitis.
Understanding what causes mini-traumas might help you start the treatment early than wait for other symptoms to be noticeable.
Mini-traumas are caused when a repetitive action is carried out resulting in stress on the particular area. With regards to the patella tendon, activities that involve jumping on a regular basis can result in an overload of stress to the tendon.
It is also important to note that an acute condition, if not identified and treated properly, can become a chronic condition. Any sign of pain and inflammation during or after activity should not be avoided.
Surgical intervention is recommended as a last resort and is usually considered for athletes who are keen on performing in competitive events.
References:
[01] Garrett Scott Hyman, MD, MPH.Gerard A Malanga, MD. Irfan Alladin, MD. Overview of Jumper’s Knee. Ref: https://emedicine.medscape.com/article/89569-overview
[02] Hägglund M, Zwerver J, Ekstrand J. Epidemiology of patellar tendinopathy in elite male soccer players. doi: 10.1177/0363546511408877
[03] Rees JD, Wilson AM, Wolman RL. Current concepts in the management of tendon disorders. doi: 10.1093/rheumatology/kel046
[04] Patella and Quadriceps Tendinopathy
Information for patients. doi: FACT SHEET – Musculoskeletal Service (NHS)
[05] Duri ZA, Aichroth PM, Wilkins R, Jones J. Patellar tendonitis and anterior knee pain. Ref: https://www.ncbi.nlm.nih.gov/pubmed/10323501
[06] Mark F. Reinking. CURRENT CONCEPTS IN THE TREATMENT OF PATELLAR TENDINOPATHY. Ref: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095939
[07] Loudon J. K. (2016). BIOMECHANICS AND PATHOMECHANICS OF THE PATELLOFEMORAL JOINT. International journal of sports physical therapy, 11(6), 820–830. Ref: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5095937/