Pain located under or at the front of the kneecap during a squat is a common concern, referred to technically as anterior knee pain. This discomfort often arises when the knee joint is heavily loaded in a flexed position, such as when descending into a squat. The pain signals that the tissues surrounding the patella, or kneecap, are being subjected to stress that exceeds their current capacity. The underlying cause can typically be traced to one of two primary structural conditions affecting the knee.
Common Sources of Anterior Knee Pain
The vast majority of pain felt under the knee when squatting is attributed to either Patellofemoral Pain Syndrome (PFPS) or Patellar Tendinopathy. PFPS involves discomfort originating from the joint where the kneecap meets the thigh bone, often described as a dull ache located behind or around the patella. This condition is frequently linked to patellar maltracking, where the kneecap does not glide smoothly within its groove on the femur during knee flexion. As the knee bends deeply in a squat, the contact forces between the patella and the femur increase significantly, aggravating the irritated joint surfaces.
The other major structural cause is Patellar Tendinopathy, sometimes known as Jumper’s Knee, which causes a more localized, sharp pain just below the kneecap. This condition affects the patellar tendon, the thick cord connecting the kneecap to the shin bone. Pain results from repetitive micro-trauma and overuse that leads to structural changes within the tendon tissue, making it less tolerant of heavy loads. Squatting requires the quadriceps muscle group to generate immense force through the patellar tendon, and the resulting tension is a direct source of pain. Both conditions are fundamentally load-related issues, where the tissues cannot withstand the forces generated by the movement, especially at high degrees of knee bend.
Biomechanical Issues Triggering Discomfort
While the pain originates from the joint or tendon structure, the root cause is frequently traced to specific movement patterns that place uneven stress on the knee during the squat. One common error is knee valgus, the inward collapse of the knees toward the midline of the body during the squat. This inward movement drastically increases strain on the patellofemoral joint by pulling the kneecap out of its proper tracking alignment. Knee valgus often results from weakness in the hip abductor and external rotator muscles, particularly the gluteus medius, which stabilize the femur.
Another factor that increases strain is the excessive forward translation of the knee, where the knees travel too far past the toes, especially in a deeper squat. This shifts a disproportionate amount of the load onto the knee joint, dramatically increasing the compressive forces on the patellofemoral joint. This movement can also be a compensation for limited ankle dorsiflexion mobility, forcing the knee to move farther forward to achieve depth. When the powerful quadriceps muscles overcompensate for inadequate activation from the glutes and hamstrings, the resulting imbalance further contributes to abnormal patellar tracking and elevated stress. Correcting these mechanical errors is a primary strategy for reducing stress on the patella and the patellar tendon.
Immediate Steps for Relief and Modification
When knee pain flares up during or immediately following a squatting session, immediate management should focus on reducing inflammation and temporarily decreasing the load on the affected structures. The initial self-care approach involves the R.I.C.E. principles: Rest from aggravating activities, applying Ice to the painful area, and gentle Elevation if swelling is present. Over-the-counter anti-inflammatory gels or medications can also help manage acute pain and swelling in the short term.
Temporary modifications to your exercise routine are necessary to allow the irritated tissues time to settle. This involves reducing the depth of the squat to a pain-free range, since the forces on the knee increase significantly past 60 to 90 degrees of knee flexion. You should also temporarily decrease the weight being lifted or switch to alternative, pain-free exercises that maintain fitness, such as cycling or using a leg press machine with a limited range of motion. Gentle, focused stretching for tight muscles, such as the quadriceps and hip flexors, may also help restore length and reduce the pull on the patella and its tendon.
Knowing When to Consult a Specialist
While many cases of anterior knee pain resolve with rest and temporary modifications, certain signs indicate the need for a professional medical evaluation. If the pain persists for longer than one to two weeks despite consistent self-care, it is time to seek expert advice. Other concerning symptoms, or “red flags,” include a noticeable swelling or heat around the knee joint that does not subside.
Immediate consultation is warranted if you experience mechanical symptoms such as the knee locking, catching, or giving way unexpectedly, as these may signal a meniscus tear or a more severe patellar instability issue. A healthcare professional, such as a Physical Therapist or an Orthopedist, can perform a comprehensive assessment to accurately diagnose the source of the pain. They can then create a targeted rehabilitation plan that addresses the specific structural and biomechanical factors contributing to the discomfort, often including a detailed movement retraining program.