Runner’s Knee – Patellofemoral Pain Syndrome

There are many common forms of injury that people suffer from in the different disciplines of running. Short distance runners such as sprinters, tend to be more susceptible to hamstring injuries or forms of tendinitis while middle to long distance runners are more susceptible to Achilles tendinopathies, knee pain and pain running down their shins or very occasionally, stress fractures. Other less likely injuries can include IT band syndrome, lower back pain or hip pain.

One of the most common injuries particularly in middle to long distance running is knee pain, known as runner’s knee or in medical terms; Patellofemoral Pain Syndrome (PFPS).

What is PFPS?

It is the most common running injury and is a result of elevated stress between the kneecap (patella) and the thigh bone (femur). Symptoms can include pain that is most often felt along the sides and/or in the front of the knee and in behind the kneecap and may be dull or aching while resting and become sharp when the knee bends or straightens. Pain is worsened when an increased load is placed on the patellofemoral joint with a flexed knee such as running, squatting or climbing stairs. There may also be noticeable swelling around the kneecap, increased stiffness or a grinding or clicking sound known as crepitus.

Why do I suffer from PFPS?

• External factors: It can often be caused by overtraining via increasing your training demands too quickly or drastically increasing the intensity of your training. Poor running technique, sloped terrain particularly downhill running can all increase one’s risk of developing PFPS. Poor footwear while running can also increase the risk.
• Intrinsic variables: Muscular weakness, a lack of flexibility particularly in the quadriceps and hamstrings, lack of joint strength and excessive bodyweight can all be factors.
• Poor strength: Poor strength in muscles and tendons such as the quadriceps (particularly vastus lateralis Oblique) and the different patellar tendons increases the risk of suffering from this condition. Often, if the vastus lateralis muscle is tight and the vastus medialis muscle is weak, there can be an imbalance of forces acting upon the patella as a result of the poor co-ordination and movement of the knee. This can also occur with a stiff IT band.
• Tight hamstrings, poor foot posture or excessive internal rotation at the hips can also increase the load on the patella which can contribute patellofemoral pain.
• Poor hip control and flexibility is another variable. Poor strength across the glutes and hip flexors and poor hip range of motion are closely linked to PFPS. Excessive adduction and internal rotation is common with PFPS.
• Poor footwear while running can also increase the risk of suffering from the condition. If you have a well-worn pair of runners and there’s wear and tear on the medial aspect of the shoe, it could indicate excessive rearfoot eversion which again would cause poor co-ordination at the knee and may cause an imbalance in weight distribution.

How do you treat it and prevent it from happening?

• Primarily strengthen the aforementioned muscles that can affect the knee - the quadriceps, hip flexors and the glutes. Hip and knee extensions and leg abductions should be your best friends while working out. Don’t neglect them. Start small and build your way up.
• Don’t neglect core training, flexibility work and strengthening the calf muscles and tibialis muscles (shins).
• Incorporating isometric exercises to focus on increasing tensile strength of the tendons in the knee and ankles aids in improving joint stability and increases their tolerance to withstand greater loads.
• Good footwear – Wearing a nice cushioned running shoe can add in just taking that a little bit of the load off of the knee while running, especially on harder surfaces.
• Training smart - Mapping out your runs to avoid uneven surfaces and hills until you’re pain begins to decrease. Remember – Don’t overdo it either. It is important you don’t overtrain and flare up the knee and increase the pain.
• If running is too sore, while starting your strength training, exercising on a bike or even in the pool is a great way of reducing the load on the knee joint and can aid in enhancing your performance while reducing the pain.

It is important that you don’t stop exercising as a result of the pain. Looking at ways to better yourself from conditions such as this can be brilliant in optimising your performance. Give it time and put the work in to strengthen yourself and watch your pain begin to subside.

Gavin Smith – Health & Performance Scientist. Final Year UCD Physiotherapist.