The Knee Cap

One of the most common causes of pain at the front of the knee is a result of problems at the patellofemoral joint. This is where the kneecap (patella) meets the thigh bone (femur). It plays a crucial role in knee function, acting like a pulley to improve the efficiency of the quadriceps muscles when bending and straightening the knee. The underside of the patella is covered with smooth cartilage, which allows it to glide up and down within a groove on the femur, reducing friction during movement. Proper alignment and efficient movement of this joint is essential for pain-free movement of the knee.

When Things Don't Move Smoothly...

Dysfunction in the patellofemoral joint occurs when the patella does not move smoothly within its groove on the femur. This can lead to stiffness, perceived weakness in the knee and pain. Several factors can contribute to this dysfunction, including:

1. Muscle Weakness: Weak muscles will affect coordinated movement; weak quadriceps  can lead to poor patella tracking. Weak hip muscles can cause the knee to roll inwards, changing the angle of the femoral groove, which will affect the way the patella moves within it.

2. Tight Muscles & Poor Flexibility: Tight muscles can also affect proper function; if the quadriceps are too tight, they will prevent proper gliding through of the patella. Tight hamstrings will put increased strain on the knee joint capsule and change the way the patella then moves. If your hamstrings and calves are tight, preventing you from fully straightening your leg, your patella won't have the opportunity to move through its full range of motion.

3. Poor Patella Alignment & Tracking Issues As seen above, tight or weak muscles can affect the patella position in the groove, affecting the way it tracks. If the tracking is not correct it can cause uneven wear on the joint cartilage causing irritation. There are some other structural variations that can cause alignment issues including a shallow patella groove, poor patella positioning (Patella Alta), or a wide femoral angle (a wider pelvis, causing a more angled femur to reach your knee. This is common in females).

   
   

Injuries and Pain in the Knee Cap and Patellofemoral Joint

Dysfunction in the patellofemoral joint often leads to increased and abnormal loading and resultant irritation of the joint. This is then perceived as pain, and the point that most people contact their chiropractor or doctor.  

1. Patellofemoral Pain Syndrome is a result of overuse and repetitive stress on the patellofemoral joint often without proper aftercare and conditioning of the muscles such as balanced muscle strength and stretching. Activities like running, squatting and jumping increase muscle tension and load to the patellofemoral joint. Over time, if not managed properly, this can cause irritation.

2. Cartilage Injury (aka Chondromalacia Patella) occurs when the cartilage on the underside of the patella softens and wears down, leading to pain and discomfort in the front of the knee. Often caused by excessive stressors and loading on the joint.

3. Osteoarthritis of the patellofemoral joint is very common and it occurs when the cartilage under the patella wears down, leading to pain, stiffness, and difficulty with activities like squatting or climbing stairs. The patella's movement in the groove becomes reduced as there is less cartilage to allow smooth movement. In some cases, you can develop extra bone growth, as the body attempts to stabilise the joint, which further reduces movement in the joint. Head to our blog about osteoarthritis to find out more.

4. Trauma is one most of us have probably experienced! Falling onto a knee cap always seems to take ages to heal. This can cause altered tracking, bruise the cushion structure (bursa) in front of the knee cap, or in rare cases cause cartilage damage. Other uncommon forms of injury include patella fractures and dislocations.

How to look after your Patellofemoral Joint

With muscle tightness and weakness being the two most common reasons for patellofemoral joint dysfunction and irritation here in the clinic, it makes sense that looking after your strength and flexibility is a good place to start for prevention.

• Strengthening your quadriceps, glutes, and core muscles will help support proper patella alignment. Exercises like squats, lunges and shoulder bridges help strengthen the leg muscles. Pilates-style core exercises are useful to help build up your core.

• Loosening and stretching tight muscles: simple hamstring and quadriceps stretches done as part of a daily routine needn't take long! Why not try stretching each leg while you brush your teeth? Or how about a massage? Use a foam roller or kitchen rolling pin to roll up and down the muscles, massaging out tight knotted areas will help to alleviate tension.

• Get your joints checked! Speak to your chiropractor, they will assess the function and movements of the knee and surrounding joints to ensure the joints are moving smoothly for correct muscle control – check out last month's blog about knee function and the importance of knee optimal knee movement.

• Keep moving! Get out of the house or office, even if it's for 10-15 minutes a day, to walk, move and lubricate the knee joints, including the patellofemoral joint. This helps the fluid in the joint provide essential nutrients to keep the cartilage healthy.