In this series we will take at the structure of the knee, including muscles, bones and ligaments.
Knee pain is the most common musculoskeletal complaint that brings people to their doctor. Per the American Family Physician Journal, knee pain affects approximately 25% of adults and its prevalence has increased almost 65% over the past 20 years, accounting for nearly 4 million primary care visits annually (Nov 1, 2018 issue).
Anatomy of the Knee and Surrounding Area
The patella is a small bone located in front of the knee, where the femur and tibia meet. It connects the muscles in front of the thigh to the tibia. The patella has several functions: aids with knee extension, allows for smooth movement during knee flexing/extension, and protects the anterior surface of the knee joint. The tibia (shinbone) is the second-largest bone in the body. The tibia’s main function in the leg is to bear weight with the medial (towards the middle or center) aspect of the tibia bearing the majority of the weight load. The fibula is smaller than the tibia and runs beside it. The top end of the fibula is located below the knee joint but is not part of the joint itself. The lower end of the fibula forms the outer part of the ankle joint.
There are 4 major ligaments of the knee. Before we list those, let’s talk about what ligaments are and their functions. Ligaments are a type of connective tissue and are tough, fibrous and slightly elastic. They connect bone to bone and help keep joints together. Ligaments stabilize joints during movement and prevent dislocation by restricting actions outside the normal joint range. The 4 major ligaments of the knee are
- Anterior cruciate ligament (ACL) – The ligament, located in the center of the knee, that controls rotation and forward movement of the tibia.
- Posterior cruciate ligament (PCL) – The ligament, located in the center of the knee, that controls backward movement of the tibia.
- Medial collateral ligament (MCL) – The ligament that gives stability to the inner knee.
- Lateral collateral ligament (LCL) – The ligament that gives stability to the outer knee.
The quadriceps and hamstring muscles provide most of the power and control of the knee joint. The quadriceps main function is to extend, or straighten your knee, and they’re involved in several important tasks of daily living, such as transitioning from sitting to standing and supporting your knees while you’re standing or walking. The function of the hamstrings is to flex your knee, extend the thigh at your hip and rotate your lower leg from side-to-side when your knee is bent.
The Iliotibial band, sometimes referred to as the IT Band, is a thick band of fascia formed at the hip by the fascia of the gluteus maximus, gluteus medius and the tensor fascia latae muscles. This band runs runs asking the outside of your leg from the hip to knee and tibia. The function of the IT band is to extend, abduct* and rotate the hip. The IT Band impacts the knee, therefore we will include it in this series.
Next week in Part 2, we will look at stretching abs strengthening
Next week in Part 2, we will discuss stretching and massage therapy for hamstring, quad and It Band tightness.