The femur is the thighbone — the single large bone that runs from your hip socket down to your knee, forming the structural core of your entire lower limb.
What your femur connects and why it matters for pain above and below the knee
Your femur sits at the center of your lower body's mechanical system. At the top, its rounded head fits into the hip socket to form the hip joint, allowing you to move your leg in nearly every direction. At the bottom, it meets the tibia and kneecap to form the knee joint. The muscles that power your hip — including the glutes, hip flexors, and adductors — all attach along the femur's shaft, and the quadriceps and hamstrings cross from the femur down to the lower leg. This means that how your femur is angled and how it rotates during walking, running, or squatting influences stress at both the hip and the knee. Changes in femoral alignment — often driven by muscle imbalances — are a common underlying contributor to knee pain, hip pain, and iliotibial (IT) band problems.
How Sword Health can help
If you're managing hip or knee pain, a physical therapist can assess how your femur is moving within the joint system and identify what's driving the problem. Sword makes that assessment and a targeted plan available from home, with clinical oversight throughout your recovery.
About the author
Carolina Moreira
Medical Director of Clinical Development at Sword Health
