Continuing to run with Femoroacetabular Impingement (FAI) is complex and depends on the specific bony abnormality and symptom severity. FAI is a common cause of hip pain in active people, involving a mechanical conflict within the hip joint. This conflict is aggravated by repetitive, high-impact activities like running. While some individuals manage to run with modifications, others find the activity accelerates joint damage. A tailored approach supervised by a medical professional is necessary.
Understanding Femoroacetabular Impingement
Femoroacetabular Impingement occurs when the ball and socket of the hip joint (the femoral head and the acetabulum) do not fit together perfectly due to irregularities in their shape. This mismatch causes the bones to rub or “impinge” against each other, particularly during deep hip movements, leading to friction and pain. Over time, this repetitive friction damages the articular cartilage lining the joint and the labrum, the ring of fibrocartilage that seals the hip socket.
There are three primary anatomical variations of FAI, classified by the location of the extra bone growth, or spur. Cam impingement involves an abnormal shape on the femoral head, which grinds against the socket’s edge. Pincer impingement is characterized by excess bone extending over the rim of the acetabulum, leading to over-coverage. The most common presentation is Mixed impingement, where both deformities are present.
Assessing the Risk: Why Running Exacerbates FAI
Running is a high-impact, repetitive activity that significantly increases the forces transmitted through the hip joint, making it potentially damaging for someone with FAI. During the stance phase, the hip is subjected to compressive and shear forces that can be several times an individual’s body weight. This constant, forceful loading drives the abnormally shaped femoral head or neck against the acetabular rim.
The repetitive microtrauma from this bony abutment directly accelerates damage to the internal structures of the hip. The labrum and the articular cartilage are subjected to increased stress, which can lead to tearing and breakdown of the protective surface. Importantly, this structural damage may not always correlate with immediate pain levels, meaning deterioration can occur even if pain is tolerated. The long-term consequence of this accelerated wear is an increased risk of developing hip osteoarthritis at an earlier age.
Strategies for Activity Modification and Safe Movement
For runners with FAI, activity modification is the first line of defense to reduce symptoms and slow the progression of joint damage. The goal is to minimize movements involving deep hip flexion, adduction, and internal rotation, as these positions promote mechanical conflict within the joint. Reducing the overall volume and frequency of running is a necessary starting point, often alongside decreasing the intensity of each session.
Some runners may benefit from gait analysis to identify and modify running form that exacerbates the impingement. Adjustments might include changing foot strike patterns or reducing stride length to decrease the maximum degree of hip flexion during the swing phase. However, any changes to running mechanics should be guided by a professional to ensure new issues are not created elsewhere. A simple self-assessment tool is the “traffic light” system: green means no pain, yellow means mild pain that warrants slowing down, and red means pain that requires stopping immediately.
When running is too painful or advised against, low-impact cross-training alternatives maintain cardiovascular fitness without damaging bone-on-bone abutment. Swimming, particularly with flutter kicks, is often well-tolerated because it is non-weight-bearing and avoids aggressive hip flexion. Cycling and using an elliptical machine are also suitable options. If cycling, the seat height must be adjusted to prevent the knee from rising significantly above the hip. Deep water running mimics the motion of running without impact, preserving running-specific muscle memory while protecting the joint.
Comprehensive Treatment and Long-Term Management
Non-surgical management of FAI typically begins with a focused program of physical therapy to address soft tissues and movement patterns. The primary goal of rehabilitation is not to change the underlying bony anatomy, but to improve dynamic hip stability and control. This involves strengthening the core muscles, hip abductors, and external rotators to provide better support and control of the femoral head within the socket during activity.
Physical therapy also works on restoring pain-free range of motion, often by focusing on hip extension and avoiding the painful end-range flexion and rotation movements that cause impingement. If symptoms persist after a trial of conservative care, a medical professional may consider a corticosteroid injection into the joint to reduce inflammation and temporarily relieve pain. This injection can also serve a diagnostic purpose, confirming that the pain originates from within the hip joint.
For patients whose pain significantly limits daily life or who have evidence of labral tears or cartilage damage, surgical intervention may be recommended. The procedure, typically a hip arthroscopy, involves minimally invasive techniques to reshape the abnormal bone on the femur (osteoplasty) or the acetabulum (trimming the rim). The surgeon also repairs or debrides any damaged labral tissue to restore the joint’s seal. While surgery aims to reduce symptoms and minimize further damage, it does not guarantee the prevention of future osteoarthritis.