Disclaimer: Knee pain is complex but rarely harmful. However, the following section is meant for educational purposes only and not to diagnose any conditions. You should always consult a medical professional before attempting any treatments when experiencing pain.
Our goal is to simplify your understanding of why your knee hurts. There are a few common causes of painful knees and two main categories that a painful knee may fall into - knee pain due to trauma/injury or non-traumatic knee pain.
The menisci (plural) are wedge-shaped, semicircular cartilage disks inside the knee that help distribute weight and cushion the joint.
Meniscal injuries typically occur with twisting of the knee or bending it to an extreme range of motion. Meniscal tears typically cause acute pain, swelling, and sometimes locking or catching sensations.
Non-traumatic meniscal tears, common in people over 40, tend to have a chronic history with mild swelling and pain along the joint line (the little gap of the knee on both sides of the knee cap).
Non-operative treatment focuses on controlling swelling, managing pain, restoring knee range of motion, and maintaining quadriceps strength with non-weight-bearing exercises.
Patients should avoid activities like squatting, pivoting, and running until pain and other impairments are resolved.
The ACL (anterior cruciate ligament) is crucial for knee stability, and injury to it can cause the knee to give way during sports or buckle during daily activities.
Most ACL injuries occur from non-contact pivot movements (knee twisting on a planted foot).
Non-surgical treatments aim to restore joint mobility, strengthen the quadriceps, improve endurance, train agility, use protective bracing, and modify activities. This approach is often successful for sedentary individuals or those willing to adjust their sports activities.
Following ACL reconstruction (ACLR), rehabilitation must balance time-based and criterion-based progressions (achieving strength and range of motion milestones before progressing to the next rehab phase). Rehabilitation focuses on immediate weight-bearing, full passive knee extension (straightening of the knee), quadriceps strengthening, and emphasizing the importance of respecting the biological tissue healing timeframes.
Return to sport after an ACL surgery, if all rehab milestones are achieved, should be no earlier than 9-12 months post-surgery to ensure proper healing and strength of the reconstructed ACL ligament.
Iliotibial Band Syndrome (ITBS)
ITBS is a common cause of pain on the side of the knee in athletes like runners and cyclists due to repetitive bending and extending of the knee.
The iliotibial band (ITB), extending from the hip muscles to the knee, can lead to pain as it moves over the bony structures on the outside of the knee during activity.
This condition is usually related to changes in activity levels or prolonged aerobic exercises. The pain often worsens with running on uneven surfaces, hills, or with longer strides. Diagnosis involves a physical examination and specific tests, which help identify pain and restriction in the iliotibial band area.
The primary treatment for ITBS is nonoperative, involving rest from the triggering activity, ice application for acute pain, and physical therapy focused on ITB stretching and strengthening. Non-steroidal anti-inflammatories, corticosteroid injections, and modifications in footwear and technique can also help. Most patients recover within 6 to 8 weeks, but if symptoms persist beyond six months, surgical options may be considered.
Biceps Femoris (Lateral Hamstring) Tendinopathy
The biceps femoris is the strongest hamstring. It extends from the sitting bone (ischial tuberosity) to the side of the knee and is responsible for bending it.
The portion of the biceps femoris tendon that attaches to the outside of the knee may become aggravated due to repetitive stress with activity and start hurting.
Biceps femoris tendinopathy is typically seen in athletes such as soccer and tennis players.
In many patients, this condition responds to conservative management such as physical therapy, ice, rest, and anti-inflammatory medications. Surgical management should be considered only when conservative management fails.
Baker's cysts
A Baker's cyst is a bump that forms behind your knee and can cause pain. It happens when extra fluid from your knee joint pushes out, creating a lump. This can be due to knee problems like arthritis or injuries. The lump can press on other parts of your leg or sometimes leak, causing more pain. You can usually feel this cyst as a soft bump behind your knee.
Tendonopathy and muscle complex pain
Three main muscle groups can cause pain behind the knee: the hamstrings, gastrocnemius (calf muscle), and popliteus. Hamstring injuries are common in sports involving sprinting and can cause aching pain in the inner part of the knee. The gastrocnemius can be injured during activities that involve bending the knee or calf raises. At the same time, the popliteus can be strained from overuse or direct injury. Treatments for these injuries include rest, ice, physical therapy, and sometimes surgery, with stretching and warm-ups beneficial for prevention.
"Pes anserinus" refers to the combined tendons of three muscles (sartorius, gracilis, and semitendinosus) that attach to the inner part of the upper tibia (one of the two lower leg bones), just below the knee. These tendons help bend the knee, rotate the tibia inward, and stabilize the knee against twisting and sideways forces.
Pes anserine bursal inflammation often occurs due to knee disorders like osteoarthritis. It is worsened by activities such as climbing stairs. Issues with the medial knee joint, such as damage to the meniscus or MCL ligament, can trigger the inflammation. Diagnosing this inflammation can be challenging because imaging tests like ultrasound and MRI may not show any abnormalities, even with apparent symptoms.
Initial treatment for pes anserine bursitis includes rest, ice, and short-term use of anti-inflammatory medications. Rest involves reducing or avoiding activities that worsen the symptoms. Physical therapy is essential, focusing on stretching and strengthening muscles such as the adductors, abductors, quadriceps, and hamstrings and improving the last 30 degrees of knee extension.
Quadriceps Tendinopathy
Quadriceps tendinopathy is a common cause of front knee pain, above the knee cap. It's often found alongside patellar tendinosis, collectively known as Jumper's knee. It is commonly seen in athletes due to high stress and repetitive loading on the knee, with a high prevalence in sports like volleyball and basketball. This condition is also seen in non-athletes with higher body mass indexes (BMI).
Quadriceps tendinopathy is initially managed non-operatively with rest, ice, proper warm-up, and physical therapy. If these initial treatments fail, injections may help. Surgery is considered for advanced cases or when non-operative treatments are exhausted.
Patellofemoral Pain
Patellofemoral pain (PFP) is a common condition affecting the front of the knee, especially in young and physically active individuals, though it can affect people of all ages. It typically presents as a gradual onset of poorly defined pain in the front of the knee, which worsens with activities that increase pressure on the knee joint, such as squatting, climbing stairs, and sitting with a bent knee. Activities like running and jumping can also aggravate PFP, making it a challenging condition to treat due to its varied causes.
Recognizing the specific causes of PFP is crucial for creating an effective rehabilitation plan, using a combination of symptom assessments, movement coordination, muscle strength, flexibility tests, and evaluating joint motion.
Studies have shown that weakness in the quadriceps muscles is a key issue for patients with PFP. While hip weakness is not always present in all cases, it's important to assess and treat any identified weakness in the hip, quadriceps, hamstrings, and other lower extremity muscles. Additionally, reduced flexibility in these muscles, which cross the knee joint, should be evaluated and treated as it can impact knee biomechanics and contribute to PFP.
Patellar Tendinopathy
Patellar tendinopathy is a common knee condition characterized by pain at the bottom of the kneecap, often seen in athletes, playing volleyball and basketball. It frequently results from overuse and leads to symptoms that worsen with increased knee activity but typically cease once the activity stops. Diagnosing patellar tendinopathy requires ruling out other causes of knee pain, like bursitis or fat pad irritation.
Treatment for patellar tendinopathy typically begins with non-surgical methods, especially physical therapy that focuses on progressively loading the patellar tendon. Effective non-invasive treatments include taping, bracing, shockwave therapy, and laser therapy, while more invasive options like dry needling and platelet-rich plasma injections are considered for persistent cases. Progressive loading, particularly eccentric training, has been shown to significantly improve symptoms. Programs often start with isometric exercises and progress to heavy slow resistance training and eccentric squats over a 12-week period. Improvement may take six months or more, so it's important to have patience when dealing with this condition.
To be able to tell with more certainty what is causing your knee pain, we recommend an assessment from a licensed medical professional or book a call with one of our licensed Doctors of Physical Therapy.
