The knee is a hinged joint that can flex and extend, but also allows some rotation. The knee is the biggest weight bearing joint of the body and therefore is at particular risk of injury and a higher risk of osteoarthritis, compared to the upper limb joints. The knee joint consists of a series of ligaments and meniscus to assist in the stability and function of the joint. When an injury occurs, it is important to exclude damage to these structures to ensure the most efficient rehabilitation.
The knee joint is unusual in the fact that it also has a sesmoid, or ‘floating’ bone – the patella. This acts as an attachment for the quadriceps but can have excessive strains and shearing forces applied to it if the quadriceps is dysfunctional.
Common pathologies of the knee include patella-femoral syndrome, osteoarthritis, Osgood Schlatters syndrome, meniscal tears, ligament sprains and tears, fractures and patella tendonitis. All are treated very differently. Gait analysis is a key part of the assessment and treatment to prevent any compensatory mechanisms one may have developed. Reducing pain and inflammatory changes are crucial prior to strengthening as they can inhibit optimal muscle function, especially in the presence of swelling.
Osteoarthritis of the knee
Degeneration of the cartilage of the knee or patella is a common pathology. Osteoarthritis occurs with overuse of the knee and can cause pain, stiffness and weakness. Patients often complain of aching and sometimes, sharp pain at the front, the sides or within the knee joint, which is often directly related to the cartilage change, exercise or sometimes with no cause at all.
Certain factors can increase your likelihood of arthritis such as the following:
- Being female
- Being over 40
- Previous injury or surgery to the knee
- Rheumatoid arthritis (which can lead to secondary arthritis)
As the arthritis or ‘wear and tear’ increases, some notice increased swelling and changes to the look of the knee as the knee is trying to repair itself. Physiotherapy cannot change the structural changes of the cartilage but can teach you how to ease your pain and manage your symptoms. It is important to keep the muscles surrounding the knee as strong and flexible as possible to ensure the longevity of your joints. Ask a physiotherapist which exercises and treatments would benefit you and your symptoms.
Knee pain when running?
Running is a popular sport and is great at increasing the bone density of the lower body as well as improving cardiovascular fitness. However, runners often complain of knee pain. This can be due to a number of factors:
- Inappropriate footwear
- Running ground
- Length of training (for instance, have you trained too quickly)
- Muscle flexibility
- Muscle strength
- Lower leg proprioception
- Core stability/control
- Poor biomechanics of the foot and ankle
Some patients experience a popping or clicking sensation in the knee as well as swelling. Activities such as kneeling, squatting and jogging can be troublesome. It is important that if you experience these symptoms, seek advice from a therapist as soon as possible as the chronicity of any injury makes it harder to treat and will require more treatment sessions than an acute injury.
Seeking advice from a qualified physiotherapist or podiatrist will ensure an appropriate assessment of the foot and lower limb biomechanics and assess the need for orthotics.
Knee pain when cycling?
Cycling is a great form of cardiovascular exercise as well as being a great way to rehabilitate patients from most knee impairments, injuries and surgeries.
What do you do if cycling is causing you pain? If cycling is not new to you, it may be due to overuse or lack of stretching, but this will obviously depend on where your symptoms are.
Often it may relate to tightness in the iliotibial band (ITB). The ITB is a thick fibrous muscle that extends from the outside of the hip to the outside of the knee. As it tightens, it can change the biomechanics around the patella, making it glide, rotate or tilt differently to normal, increasing the stresses on the soft tissue structures of the knee and its cartilage (menisci).
It is always important to ensure saddle height is suitable for the cyclist. When cycling if you can feel your hips rocking forwards and backwards, you need to readjust your saddle height. A seat that is too high will increase forces through the back of the leg and knee. Having a saddle that is too low will increase the forces through the patella and quadriceps. To ensure a good saddle height, extend one leg down to the floor, with the foot in the pedal. The knee will never be completely extend, instead the most it will be able to do so is with 25-30° of flexion.
Other factors such as frame size, handlebar height and foot position can all contribute to poor cycling techniques.