Patellofemoral syndrome (PFS) is one of the most common causes of knee pain in active patients and stems from problems with the kneecap (patella) as it moves over the front of the knee. PFS causes pain in the front of one or both knees, especially after either exercising or sitting for prolonged periods. Some patients will experience minor swelling and the feeling that their knee “catches” or gives way.
What causes it?
PFS is usually an overuse syndrome caused by doing “too much, too soon.” It typically involves inflammation of the underside of the kneecap or the tissues that surround the kneecap called the synovium. These structures tend to become inflamed secondary to improper tracking of the kneecap. Factors that can lead to this include decreased strength or flexibility of the upper leg (quadriceps) or hip muscles, poor alignment of the leg bones, or a combination of factors. The latest research supports that the majority of patellofemoral conditions are due to insufficient quadriceps strength and endurance.
How is it treated?
The first step is to reduce the pain and swelling (if present). Frequent use of ice (about 15 to 20 minutes at a time), especially after exercise or when the knee is sore, can ease pain. Anti-inflammatory medications (such as ibuprofen or naproxen) can help reduce pain and inflammation (swelling). Once pain eases, you can begin a stretching and strengthening program guided by your physical therapist to further decrease symptoms and the risk of recurrence.
What are the best exercises?
One of the best exercises for treating patellofemoral syndrome and for developing sufficient quadriceps strength and endurance is single leg biking on an upright stationary bike. It is a non-impact exercise that recruits the quadriceps, hamstring and hip flexor muscles. The goal that we set for our patients is 10 minutes of continuous single leg biking with emphasis on speed (minimum of 90 RPMs) vs. resistance. The emphasis on speed actually places less stress on the patellofemoral joint and should not create pain in the knee.
Other strengthening exercises include double/single leg squats, step-downs, and walking lunges. All of the aforementioned exercises are deemed ‘closed-chain’ exercises and should be performed in the pain-tolerated range. Exercises or activities should not exceed the person’s pain or tissue tolerance, which I will discuss later. In some instances where the pain is more acute and intense it may be more suitable to perform exercises in an unloaded or ‘open-chain’ position e.g. straight leg raises.
With any of these exercises we like to emphasize low load, high reps (50 repetitions) tissue toughening for reasons previously discussed in the August 2002 article of the month.
Can I exercise through the pain?
You can train if you have PFS, but you may find that symptoms tend to come and go depending on your activity level. Keep in mind, however, that the more you train through pain, the longer your knees will hurt. A good rule of thumb is to stay within what we call your ‘tissue tolerance’. This means that on a pain scale of 0 to 10, you should not push through a pain level greater than 3 out of 10. At this guideline you can still achieve the benefits of the particular exercise without compromising the healing process. When you are ready to resume or advance your activity, do it slowly and remember listen to your body!
If you think you may have this condition or have any questions regarding it then please feel free to contact us at 831 462-1212 or see your doctor to get referred to physical therapy for further evaluation.