The knee is vital for everyday functions, yet it is often poorly understood. There are many misconceptions about what is ‘good’ or ‘bad’ for knees and exactly what is going on inside the joint.
The knee is identified as a hinge joint, meaning it primarily moves in one direction (ie bending and straightening). It is made up of the femur (thigh bone), tibia (shin bone) and patella (knee cap). These bones are all held in place by a number of ligaments. The ‘joint surfaces’ (parts of the bone that glide on one another) are covered in articular cartilage to absorb shock and reduce friction in the joint. The joint capsule and ligaments serve to provide stability to the knee, whilst allowing it the necessary movement.
The main knee ligaments are summarised below:
- Medial collateral ligament: sits outside the joint capsule and runs between the tibia and femur (inside of the leg) to provide resistance to forces pushing the knee inwards
- Lateral collateral ligament: sits outside the joint capsule and runs between the tibia and femur (outside of the leg) to provide resistance to forces pushing the knee outwards
- Anterior cruciate ligament (ACL): is within the knee joint and runs from the front of the tibia to the back of the femur
- Posterior cruciate ligament (PCL): runs from the front of the femur to the back of the tibia (also within the joint)
- Patellar ligament: sits outside the joint capsule and runs from the patella (kneecap) to the front of the shin
The meniscus is another key structure in the knee joint. It is a fibrocartilaginous disc that sits between the tibia and femur to help absorb shock and improve load-bearing of the knee (twisting and stretching).
Common knee injuries
While we see a lot of pain that is a result of a build-up of accumulated strain, there are also a number of injuries that are caused by sudden trauma. These can include a rugby tackle, poor landing in netball, falling over skiing and even your form during rock climbing.
While accumulative strain injuries are usually the result of tight or weak muscles and stiff joints, traumatic injuries may involve structural damage to the knee joint.
Stay tuned for next weeks blog post, where we will discuss common knee injures, what causes them and most importantly, how to treat them.
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