Common Injuries and Treatments
The knee is where the bottom end of the thigh bone (femur), the lower leg bones (tibia and fibula) and the kneecap (patella) all come together. The joining of these bones produce 3 joints - tibiofemoral, patellofemoral, and proximal tibiofibular.
- The joint between the thigh (femur) and shin (tibia) - called the tibiofemoral joint - is the main "hinge" joint of the knee. In between the femur and tibia (in the middle of the hinge) are two menisci. These pieces of tough connective tissue act as stabilizers and shock absorbers for the lower extremity.
- The joint between the kneecap and femur (thigh bone) - called the patellofemoral joint - is important for creating a lever for force production for the quadricep (front of the thigh) muscle.
- The joint between the top of the tibia (shin bone) and top of the fibula (outside bone of the lower leg) - called the proximal tibiofibular joint - is important for accommodating rotational forces from the ankle and it limits rotational forces to the knee.
The primary motion at the knee joint is bending (called flexion) and straightening (called extension). There is also a very small amount of rotational movement when the knee fully straightens. But most rotational and side-to-side motions for the leg come from the ankle below and the hip above. This results in the knee being prone for injury because most higher level activities involve some amount of side-to-side and rotational motions. When the hip and ankle have weaknesses or limitations, the knee is often left with excessive stress and injuries occur.