Knee Pain in the Cyclist

An overview of common diagnoses in cycling

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Knee pain is the most common injury of the lower extremity of cyclists. There are a multitude of factors that can contribute to knee pain, which can make it difficult to isolate the problem. Bike fit, biomechanical/muscular insufficiency or imbalance, recent changes in equipment, intensity and duration changes in training can all lead to injury if not properly progressed or addressed. Often knee pain in cycling is due to an “overuse injury” or an injury caused by repetitive microtrauma to an area. Acute injuries like dislocations, ligamentous ruptures, and fractures, typically only occur following a crash. Listed below are the most common cycling overuse injury diagnoses grouped by the location of the pain. The “anterior” is the front of the knee, “medial” and “lateral” refer to the inside and the outside of the knee respectively, and finally “posterior” is the back of the knee.

Anterior knee pain

Anterior knee pain is the most common reported knee pain in cycling.The anterior knee consists of the quadriceps, patella (knee cap), quadriceps tendon, and patellar ligament. These structures require a balance of forces to stay happy. With misalignment and repetitive inflammation/trauma, irritation and pain can begin to occur.

• Patellofemoral Pain Syndrome (PFPS) typically occurs due to biomechanical or muscular imbalances and/or improper bike fit. As the knee extends and flexes, the patella travels in a groove on the femur and tibia. The underside of the knee cap is covered with cartilage to create a smooth surface and increase congruency between it and the tibia/femur. Improper tracking can cause it to rub repetitively creating inflammation, pain, and degeneration of the cartilage over time. If pain is present when riding, it will typically occur when a cyclist has a greater load on the pedals like when climbing a hill or pushing a higher gear with a slow pedal cadence.

• Patellar Tendonosis/ Tendonitis: The patellar tendon attaches the patella to the tibia (shin bone). Improper cleat position tends to be one of the primary causes of patellar tendonosis as it changes the line of force of the patellar tendon through the pedal stroke. Patellar tendonosis will typically present with tenderness to the touch or with resisted knee extension. Localized swelling will also commonly occur in the area. Once inflamed, activities that caused loading of the patellar tendon (squats, jumping, or even stairs) can also be painful.

• Quadriceps Tendonosis: Quadriceps tendonosis differs from patellar tendonosis as the pain most commonly presents directly above the patella instead of below. Quad tendonosis typically occurs following an acute event like a crash or a squat that was too heavy, but can sometimes be caused by overuse. Typically an improper bike fit is to blame in cycling with a saddle that is either too high/low or too far forward/backward. An improper saddle position may place an excessive load on the quads limiting recruitment from the gluteal musculature to assist during the pedal stroke.

Medial knee pain

While less common than anterior knee pain, medial knee pain in cycling is still prevalent and can be very painful. The medial knee consists of the hip adductors, pes anserine bursa, and some ligamentous tissue that provides stability and reduces lateral and rotational forces to help guide the knee through its motion.

• Pes Anserine Bursitis typically presents with pain along the top of the inside of the shin approximately 2-4 cm below the joint as well as tenderness in the adductor musculature which is located on the inside of the thigh. The pes anserine bursa is a fluid filled sac that prevents the adductors (inner thigh muscles) from rubbing on the bone and fraying. When the adductors are placed under repeated stress from excessive or repetitive load, it places pressure on the bursa, causing irritation, inflammation, and pain. Pes anserine bursitis is typically caused by muscular imbalance or tightness. Hamstring tightness and adductor weakness tends to be the most common cause of this injury in cyclists.

• Mediopatellar Plica Syndrome: Plica is a synovial septum remnant from the embryologic knee (tissue left over from when you were a fetus). In some of the population, this septum can become impinged in the knee leading to pain, swelling and inflammation. If the medial plica is consistently stressed due to improper loading (as can happen when riding with improper bike fit) the plica may turn fibrotic and can roll over the bony aspect on the inside of the knee causing further irritation and a muscle snapping sensation.

Lateral knee pain

Lateral knee pain, or pain in the outside of the knee, most commonly occurs with medial and anterior knee pain from improper bike fit or anatomical imbalances causing excessive loading on soft tissue structures. The lateral knee consists of the iliotibial band, gluteal musculature, and some ligamentous tissue which provides stability in the knee and prevents medial and rotational forces.

• Iliotibial Band Syndrome: One of the primary structures on the outside of the leg is the iliotibial band (ITB). The ITB is a taught fibrous band running along the outside of your leg crossing the hip and knee. The ITB’s main job is to provide stability in the knee through the contraction of its muscle attachments. ITB syndrome is the inflammation of the intra-articular synovium, otherwise known as fascia, that occurs when a tight ITB repeatedly rubs over the lateral condyle (bony point of the femur) as it moves forward and backward with knee flexion and extension. An anatomical abnormality like knee valgus (knock knees) during the pedal stroke increases the tension on the ITB. Tightness or weakness in the originating musculature can also create tension or laxity respectively and increase irritation of the ITB. Saddle height may also play a role in ITB compression due to excessive knee flexion with peddling. Cyclists typically report ITB syndrome as a stabbing lateral knee pain that can decrease power production. ITB pain typically is less painful when not riding, however if irritated enough can give symptoms when walking, squatting, or performing stairs.

Posterior knee pain

Posterior knee pain is the least common ailment observed in cyclists. Posterior knee pain typically occurs when in a rider with a saddle height that is too high or far back. This can begin to stress the hamstrings, or more specifically, the bicep femoris tendon, as we over extend the knee at the bottom of the pedal stroke. Other anatomical imbalances like leg length discrepancies or knee varus (bowed knees) can also create tension in this area.

Injury prevention and correction

In the end, improper bike fit is the most common cause of pain and discomfort on the bike. When fitting yourself, always start with small adjustments. Your body is used to your cycling position and big adjustments may begin to create irritation in new areas. Anatomical abnormalities and muscular weakness, tightness, or imbalances can be observed with a musculoskeletal screen that you can perform on yourself with some guidance from a trained professional.

Please contact us with any questions or if you are looking to receive further guidance on rehabilitating your injury or with proper bike fit. Set up a free 10 minute consultation to see if Telehealth PT is right for you!

References:

Iliotibial band syndrome in cyclists: James C, Holmes, MD, Anderw L. Pruitt, Edh, Nina J. Whalen, ANPC

Knee Pain and Bicycling : CPT Chad Asplund, MD; COL Patrick St Pierre, MD

Kinematics of cycling in relation to anterior knee pain and patellar tendinitis: Martin P. Baily, Frederick J. Maillardet, Neil Messenger