The knee joint is actually two separate joints, the weight-bearing tibiofemoral joint between the tibia (shin bone) and the femur (thigh bone), and the patellofemoral joint where the patella (knee cap) slides up and down a groove in the femur as we bend and straighten our knee. The purpose of the patellofemoral joint is to give our quadriceps more leverage when straightening the knee making them more efficient. In fact muscles that move the knee are some of the strongest in our body.

Whilst in reality the anatomy is a little more complicated, functionally the knee can be considered a simple hinge joint, i.e. it bends and straightens, but has a little bit of give into rotation, and as such the tissues and structures around the joint including ligaments, muscles, and cartilage are designed to handle stress when it is applied in this way.

Almost without exception injuries to the knee occur due to excessive lateral and rotational stresses. These stresses can occur with one sudden forceful event causing ligament injuries (e.g. anterior cruciate or medial collateral) or tears to cartilage structures such as the medial or lateral meniscus. Careful assessment of the severity of these injuries is important as not uncommonly surgery is required for satisfactory outcomes.

Other injuries such as patellofemoral pain syndrome, patella tendinitis or ITB friction syndrome (‘runner’s knee’) most result from smaller but repetitive lateral and rotational stresses over a longer period time ultimately leading to irritation of tissues and pain.

Due to the design and anatomy of the knee as described above effective treatment focuses on decreasing / eliminating any excessive lateral and rotational stresses that exist thus facilitating ‘straight-line’ mechanics of the knee. Identifying and treating underlying factors that drive these stresses underpins the treatment process.

Poor muscle control of the pelvis / hip region when in single limb support often manifests as a Trendelenburg sign and/or inward rotation of the knee, and is corrected with specific exercises to improve ‘brain to muscle’ activation and strength of the gluteal musculature.

Subtle changes to foot shape and structure (something we refer to as skeletal drivers) such as external tibial torsion, forefoot / rearfoot varus, and Hallux limitus tend to drive excessive pronation of the foot resulting in excessive rotation of the shin bone and therefore knee. Gait analysis performed by an experienced Podiatrist is required identify these issues and to determine whether a combination of orthotic devices or running shoe advice are needed.

A comprehensive rehabilitation programme should also include strengthening exercises for all lower limb musculature (performed within a framework of sound lower limb alignment), core stability training, proprioceptive exercises, and sport / function specific exercises.