Types of knee pain from cycling
Anterior Knee PainAs with many active sports, cycling can produce knee pain simple from the continual motion of the knee joint. Many cyclists frequently report knee pain related to repetitive stress or to inflammation. In fact, it is believed that anterior knee pain is the most common reason bicyclists seek physician care. Causes of knee pain include patellofemoral pain syndrome, chondromalacia, quadriceps tendinosis, patellar tendinosis, and, occasionally, prepatellar bursitis.
Patellofemoral pain syndrome, also called retropatellar pain syndrome, refers to anterior knee pain emanating from the patellofemoral joint and supporting soft tissues. Patellofemoral pain syndrome is an early indication of cartilage softening that can progress to frank cartilaginous damage (chondromalacia). Patellofemoral pain syndrome is typically an office diagnosis, while chondromalacia is a surgical or radiologic diagnosis. Because both usually arise from collagen breakdown rather than frank inflammation, they are currently seen as tendinosis rather than tendinitis.
Patellofemoral pain syndrome is related to a combination of factors involving malalignment of the knee extensor mechanism. Patients generally report that anterior knee pain is worse when the knee is loaded (eg, when climbing or descending stairs, during prolonged sitting or squatting). Patellofemoral joint problems frequently differ between cyclists and runners--many cyclists will point to the center of their patella and describe the pain as being directly under the patella, rather than on the medial or lateral side. The pain, sometimes severe, often occurs after cycling, rather than during the ride.
Chondromalacia, characterized by pain or crepitation in the retropatellar area, is described as a grating sensation with anterior patellofemoral discomfort that worsens with climbing, squatting, or prolonged sitting. The condition may be caused by articular cartilage breakdown or chronic synovial inflammation. Excessive patellar shear forces over the femoral condyles and patellar groove with malalignment of the patella contribute to cartilaginous breakdown. Cyclists who have pes planus, overpronation of the foot, or hindfoot valgum may also have a greater degree of patellar malalignment. During cycling, the pain is precipitated by riding up hills or when the rider pushes higher gears with a slow pedal cadence.
Quadriceps tendinosis is characterized by pain at the quadriceps tendon's insertion into the patella. The pain may be located medially or laterally to the suprapatellar area but is more commonly seen on the lateral side in cyclists. Tendinosis may follow an acute traumatic event but is usually caused by repetitive stress, with poor bike fit as a common contributing factor.
Patellar tendinosis can result from irritation of the patellar tendon and is most likely caused by excess angular traction on the tendon when the rider pedals with improperly positioned cleats. Cyclists usually report significant patellar tendon pain related to pedaling and other knee-extension activities. Focal swelling around the patellar tendon with palpable crepitus may be seen.
Prepatellar bursitis, less common in cycling, should be suspected when swelling and tenderness anterior to the patella exist and can arise from acute trauma. Chronic prepatellar bursitis is more common than the acute form and usually results from repeated microtrauma, such as bicycle pedaling.
When evaluating a cyclist who has anterior knee pain, inspect the bicycle fit. The saddle may be too low, too far forward, or both, causing excessive patellofemoral loading throughout the pedal cycle. When the saddle is low, the knee functions in hyperflexion, increasing compression of the patella on the femur.
Improper shoe cleat position or float may force the rider to pedal with poor biomechanics, increasing patellar forces. Float is the motion of the cleat on the body of the pedal and is usually measured in degrees of internal or external angulation (ie, 9° of float means that the foot may rotate 9° inward or outward relative to the pedal body). Cleats with excessive internal or external rotation may cause exaggerated tibial rotation, placing more stress on the anterior knee.
Medial Knee Pain
The normal pedaling motion causes the tibia to internally rotate when the knee is extended. Medial knee pain results when increased stress from improper saddle height, saddle fore-and-aft position, or cleat position (toes pointed too far outward) increases internal tibial rotation. Poor leg flexibility and training errors, such as riding in gears that are too high or excessive hill climbing, increase stress and exacerbate medial knee conditions. Anatomic abnormalities, such as genu varus, overpronation, inherent tibial rotation, and hamstring tightness, may also exacerbate medial knee pain. Medial knee pain often is caused by pes anserine bursitis or mediopatellar plica syndrome.
Pes anserine bursitis is identified by insidious-onset pain over the medial proximal tibial metaphysis approximately 2 to 4 cm below the joint line. Direct trauma or repeated friction over the bursa can lead to inflammation. When the bursa is inflamed, contraction of the hamstring muscles, tibial rotation, and direct pressure over the pes anserine bursa usually produce pain. The popliteal angle should be measured and tightness treated with hamstring-stretching exercises.
Mediopatellar plica syndrome causes pain over the medial retinaculum. A plica is a synovial septum remnant from the embryologic knee. Medial plica occurs in up to 30% of the population. Medial plica may impinge on the femoral condyle during knee flexion, leading to inflammation and swelling. If a normal medial plica is chronically inflamed and turns fibrotic, it may bow-string over the medial femoral condyle during knee flexion and cause irritation and a snapping sensation. The cyclist who has plica symptoms may describe a disabling medial knee pain accompanied by a sensation of medial popping that occurs with each pedaling stroke. Treatment for a symptomatic plica involves adjusting the saddle fit and cleat position to reduce forces on the anterior knee. A local anesthetic may be injected directly into the plica to give temporary relief. Orthopedic referral should be made if symptoms persist longer than 6 months.
Lateral Knee Pain
Anatomic factors and improper bike fit are important considerations when evaluating cyclists who report lateral knee pain.
Iliotibial band syndrome. The ITB is a thick, fibrous band that runs on the outside of the leg from the hip to the knee. ITB syndrome is caused by inflammation of the intra-articular synovium or ITB fascia when the tight ITB repeatedly rubs over the lateral condyle as it moves posteriorly with flexion and anteriorly with extension. Tight, inflexible leg muscles may worsen the condition. Cyclists who have ITB syndrome experience sharp or stabbing lateral knee pain and may report decreased pedaling power because of pain.
The most obvious sources of ITB irritation are anatomic abnormalities and improper bicycle fit. Excess internal tibial rotation, either anatomic or caused by improper cleat position, places significant stress on the distal ITB as it crosses the lateral femoral epicondyle. Varus knee alignment or excess pronation will increase the stretch on the ITB.
Similarly, leg-length discrepancies cause difficulty, because only one leg is correctly fitted to the pedal, producing excessive ITB stretch on the shorter leg. Saddle position can also be a contributing factor. A saddle that is too high results in knee extension greater than 150° that can irritate the distal ITB. Saddles that are too far back cause excessive forward reach for the pedal, also stretching the ITB.
Posterior Knee Pain
Posterior knee complaints in cycling are rare. Most often they are attributed to biceps tendinosis or, less frequently, medial hamstring tendinosis. Cyclists who have biceps tendinosis report insidious onset of point tenderness at the tendinous attachment of the biceps femoris where it inserts on the fibular head.
Saddles that are too high or too far back can stress the biceps tendon. Excessive internal rotation of the cleats will also increase stress. Varus alignment of the knees or leg-length discrepancies may also contribute to posterior knee pain. If the saddle height is set for the longer leg, the shorter leg will be forced to stretch farther with each pedal stroke, increasing posterior knee stress.
Initial management following an overuse injury should follow the PRICEMM acronym (protection, rest, ice, compression, elevation, modalities, and medications) to help control inflammation and allow the tissue to heal. Decreasing inflammation and pain helps increase range of motion, allows early rehabilitation, and speeds return to competition. Once healing and rehabilitative exercise have restored damaged tissues to normal strength, patients will need further training to achieve the supernormal endurance and power required for the demands of sports.
With tendinosis, relative tendon unloading is critical for treatment success. Unloading may be accomplished by correcting anatomic, functional, or equipment related errors.
The authors are not associated with this company and this article should not be read as an endorsement of the kneeVitality procedure. It is for informational purposes only.