Knee in 6: Anterior cruciate ligament (ACL)

This page reviews the knee's anatomy, common conditions across age groups and activity levels, how clinicians assess it, and general exercise and recovery patterns used in both non-surgical and post-surgical rehabilitation. Patellofemoral pain syndrome describes pain around or behind the kneecap, often related to how the kneecap tracks in its groove during bending movements, and is common among runners and young active individuals.

What is the difference between the meniscus and the ACL? The menisci are C-shaped cartilage cushions that absorb shock between the thigh and shin bones, while the anterior cruciate ligament (ACL) is one of several ligaments that control the knee's stability during rotation and forward sliding of the shin bone.

Many meniscus tears, particularly smaller or degenerative tears in middle-aged and older adults, are managed successfully with exercise-based rehabilitation, while larger or mechanically unstable tears may be considered for surgical repair. Current evidence generally does not support the idea that recreational running increases the risk of knee osteoarthritis, and moderate running is often considered compatible with long-term joint health for most people.