Question 1

Overview of the quads

Accepted Answer

Your front thigh muscles (quadricep muscles or quads) end in one thick tendon called the quadriceps tendon. Your quadriceps tendon attaches to the top part of your kneecap, but some fibers continue over the kneecap. These fibers help to form your patellar tendon.

Quadriceps tendinopathy (or tendonitis) is an overuse injury, usually caused by activities that work the quadricep muscles intensely, such as deep squatting, jumping, or running.

Question 2

Symptoms of quadriceps tendinopathy

Accepted Answer

Diagnosing quadriceps tendinopathy can be tricky because it can feel similar to other knee conditions, like patellofemoral pain syndrome.

You will feel pain and/or stiffness in the quadriceps tendon, most commonly, in the lower part where it attaches to the upper edge of your kneecap. But you may also feel it in the middle or top parts of the tendon, where it’s attached to the quads. If your pain is more diffuse (spread out) over the kneecap and difficult to pinpoint, it's unlikely to be quadriceps tendinopathy.
Symptoms start slowly and gradually increase as you continue to train and aggravate it. Activities that load the quadricep muscles usually cause pain, e.g., running, walking up or down stairs, squats, or jumping.
You may find that exercise improves your pain initially, only for it to flare up and hurt more several hours later, typically the next day.
Initially, it may only hurt when you do high-load activities such as fast running or jumping. If you continue irritating it, it may eventually be too painful to run.
Low-load activities like swimming, cycling, and walking don't usually cause pain. It usually doesn't hurt at rest, but sitting with your knee bent to 90 degrees or more for extended periods may cause pain.
Quadriceps tendinopathy does not cause swelling or bruising.

Quadriceps tendinopathy should not be confused with patellar tendinopathy. When you have patellar tendinopathy, your pain will be below your kneecap in the patellar tendon.

Question 3

When to see a doctor

Accepted Answer

You should consult your doctor or physical therapist before using the app to ensure you have the correct diagnosis and are ready to start rehab exercises.If you have any concerns about your injury after you've started your rehab, schedule a review with your doctor, particularly if:

You feel a sudden sharp pain in your knee or quadriceps tendon during an activity - this may mean you've strained or torn the tendon, and the app program is not appropriate for tendon tear rehab
You notice bruising or swelling - quadriceps tendinopathy does not cause bruising or swelling
Any part of your leg (thigh, calf, or foot) is swollen, red, hot to touch, or throbs with pain - these signs can indicate a blood clot, and you should have it investigated as soon as possible
You have pain at night that keeps you awake or interrupts your sleep
You feel pins and needles or tingling in your leg - this can indicate an injured nerve, and our rehab plan may not suit you
Your symptoms are getting worse
Your injury is not recovering as expected (see expected recovery times below)

Question 4

Causes of quadriceps tendinopathy

Accepted Answer

Quadriceps tendinopathy is an overuse injury. The overuse can happen during a single hard training session or develop slowly over a more extended period.

Sudden overuse usually occurs during a training session incorporating activities that work your quadricep muscles intensely. Examples include plyometrics (jumping or hopping), heavy and/or deep squats, downhill running, and fast running.

Gradual overload usually happens because you're:

Not allowing enough recovery time between training sessions, or
Doing too many high-intensity training sessions in short succession.

Other causes include:

Fluoroquinolone antibiotics - these medications can cause tendon injuries, including tendinopathy and tears
Inflammatory conditions - conditions like gout, rheumatoid arthritis, and psoriasis also cause tendon pain and can easily be mistaken for tendinopathy

Question 5

Treatment, recovery times & prevention

Accepted Answer

Treatment

Research suggests the most effective intervention is the right combination of rest and exercise tailored to the individual. A well-rounded rehab plan for quadriceps tendinopathy should include:

Relative rest: Cut out aggravating activities and reduce your training program to allow your tendon pain to settle
A slow, progressive strength training plan: Gradually restore the load tolerance of the tendon by targeting the quadricep muscles and tendon
General strength and control exercises: Condition your core and other supporting muscles (glutes, hamstrings, and calf muscles) to help share the load when you run and jump
Mobility and range of movement exercises: Gain and maintain good mobility in all your lower body joints and muscles to reduce the strain on your quadriceps tendon
Movement retraining: Learn how to use your whole kinetic chain (all the interconnected parts of your body) optimally while running and jumping, specifically during the landing phase
The rehab plan in the app includes all of these components. It starts with low-load exercises that help settle your pain, then slowly increases the exercise intensity as your tendon strengthens and heals.

Other treatments you may encounter:

Complete rest: May calm your pain initially, but resting for prolonged periods is not advised as it can cause your tendon to lose more strength
Massage: May help reduce pain, but it does not strengthen your tendon, and vigorous tendon massage can also irritate the tendon and increase your pain
Electrotherapy (like ultrasound): Not recommended by the current research

Recovery time

Most people with quadriceps tendinopathy will take at least 6 months to complete their rehab and return to full sports participation. However, taking 12 months or longer to recover fully is not uncommon.

Staying patient and motivated during this time can be difficult, but rushing your rehab and increasing exercise intensities too quickly can cause setbacks. We’ve included information that will help you monitor your progress and know when to train harder, rest, or ask for help - giving you greater control over your recovery.

Prevention

You may reduce your risk of developing quadriceps tendinopathy if you:

Avoid sudden increases in training intensity or volume
Allow enough recovery time after intense training sessions
Vary your training, i.e., don't push to your limits in every session
Do regular strength training for your calves, core, and legs
Maintain good mobility and flexibility in your lower body joints and muscles

Once you've completed your rehab, switch to the injury prevention plan in the app - it’s been designed with all of these elements in mind.

Question 6

Research References

Accepted Answer

King, D., et al. (2019). "Quadriceps tendinopathy: a review—part 1: epidemiology and diagnosis." Annals of translational medicine 7(4).
King, D., et al. (2019). "Quadriceps tendinopathy: a review, part 2—classification, prognosis, and treatment." Annals of translational medicine 7(4).
Sprague, A., et al. (2019). "Distinguishing quadriceps tendinopathy and patellar tendinopathy: semantics or significant?" Journal of Orthopaedic & Sports Physical Therapy 49(9): 627-630.
Kuwabara, Anne, and Michael Fredericson. "Narrative: review of anterior knee pain differential diagnosis (other than patellofemoral pain)." Current Reviews in Musculoskeletal Medicine 14.3 (2021): 232-238.
Alfredson, Håkan, Lorenzo Masci, and Christoph Spang. "Is There a Relationship Between Quadriceps Tendinopathy and Suprapatellar Plica? An Observational Case Series." International Medical Case Reports Journal 15 (2022): 81.
Mortada, M. A., L. I. Kotb, and Y. A. Amer. "Impact of ultrasonography detected quadriceps calcific tendinopathy on pain and function in patients with primary knee osteoarthritis." Reumatismo 73.2 (2021): 111-116.
In: Brukner P, Clarsen B, Cook J, Cools A, Crossley K, Hutchinson M, McCrory P, Bahr R, Khan K. eds. Brukner & Khan’s Clinical Sports Medicine: Injuries, Volume 1, 5e. McGraw Hill; 2017. Chapter 36 Anterior knee pain

Quadriceps tendinopathy treatment plan