Follow this cycling PT’s approach to preventing and treating Patellofemoral Pain Syndrome When Cycling.
What is Anterior Knee Pain Caused by Patellofemoral Pain Syndrome?
Patellofemoral pain syndrome is a general term describing anterior knee pain related to how the kneecap (patella) interacts with the underlying bone (femur) at the patellofemoral joint. Repetitive stress or overuse causes athletes to complain of pain while running or cycling when they apply pressure (load) through the patellofemoral joint.
In theory, patellofemoral pain syndrome occurs because imbalanced forces on the joint cause improper kneecap tracking when bending and straightening. Basically, if the muscles on the inner side of your knee (VMO) are weak and the tendons, ligaments, and muscles on the outside are tight, your kneecap will track to the side.
Of course, it isn’t as simple as that. Anatomical and biomechanical factors, muscle imbalances, athletes’ training, and equipment play a role. During movement, the patella tracks along the femur in the trochlea groove. When the kneecap tracks incorrectly, it causes inflammation and pain due to irritation. Incorrect tracking is due to overuse, weakness of the VMO, and tightness of the leg and lateral thigh structures.
Think of it as when your brake pad rubs on the rim ever so slightly every time you bend and straighten your knee. Eventually, it wears down.
Brief anatomy of the knee
The knees are stable joints with substantial ligamentous structures. The knee consists of two joints. One is between the femur (the upper leg bone) and the tibia, called the tibiofemoral joint. The other, of particular interest to us, is the patellofemoral joint between the femur and the kneecap. It consists of the patella (kneecap) and the femur.
The patella (knee cap) sits in a shallow trough on top of the femoral condyle called the trochlear groove. It’s this articulation that gives the patellofemoral joint its name.
The patella acts as the fulcrum in a pulley system to improve the quadriceps muscle’s effectiveness. It does this by attaching to the quad muscle via the quadriceps tendon above and the tibia through the patella tendon below.
The iliotibial band attaches to the glutes and hip flexors, travels down the outside (lateral) of the thigh, and inserts into the outside of the knee.
The vastus medialis oblique, or VMO, is one of the four parts that form the quadriceps muscle group. Studies point to the VMO as a primary medial stabilizer of the patella. If your VMO is weak or not firing effectively, the fibers won’t pull the kneecap inward to keep it in the groove. It will track out to the side and potentially cause the pain of PFPS.
Knee Pain Caused by Patellofemoral Pain Syndrome When Cycling
In a recent study of 109 professional cyclists published in the American Journal of Sports Medicine, 58% experienced an overuse injury over the previous year, with 23% of the injuries involving knee pain. The most significant percentage of time lost to training and competition was in cyclists suffering from anterior knee pain.
Patellofemoral pain syndrome (PFPS) is one of the most common athletic overuse injuries. It accounts for approximately 25% of all knee injuries diagnosed in sports medicine clinics, and about 70% occur in adolescents and young athletes aged 16–25 years.
The prevalence seems high for a sport like cycling that doesn’t involve impact or contact. When you consider that you pedal 5,400 times an hour during an average bike ride (at 90 rpm), it’s easier to see that the repetitive nature of cycling could cause problems.
The knee joint moves through the most extensive range and takes the most load when pedaling. However, when we push down on the pedals, we rarely straighten our knees all the way. The final 35 degrees of extension is when the VMO comes into play.
Over time, the VMO becomes weak as the opposing muscles and structures on the outside of the thigh get strong and tight. As the soft tissue outside the patella shortens, it shuts down the VMO, making it more difficult to strengthen. Improper patellar tracking is the result.
Symptoms and Diagnosis of Knee Pain Caused by Patellofemoral Pain Syndrome When Cycling
Often, a cyclist will feel anterior knee pain at the start of the ride that may lessen, only to return later. Pain is also often experienced off the bike while climbing and descending stairs, walking up and down inclines, or squatting.
Ask yourself these questions.
- Does the front of my knee hurt when I push down on the pedals or climb out of the saddle?
- Do I have pain in the front of my knee when I climb up or down stairs or inclines?
- Does my knee hurt in the front when I stand up after sitting with my knees bent for a while (theater-goers sign)?
- When I contract my quadriceps muscle, does my kneecap seem to move out to the side in a J-like pattern (J-sign)?
- Have I been riding harder or increasing my time in the saddle recently?
- Does it hurt when I press into the joint on either side of my kneecap or when I push down on it?
- When I bend and straighten my knee, do I feel crunching under my kneecap?
- Does my knee swell up after cycling?
- Is the muscle on the inside of my quad (VMO) small, or appear to not contract strongly?
If you answered “Yes” to three or more of these questions, Patellofemoral pain syndrome could be the reason, and you need to do something about it before it worsens and takes the fun out of riding.
Patellofemoral pain syndrome can be challenging to diagnose. There are few definitive medical tests, and the condition is mainly theoretical. However, if cycling causes pain in the front of your knee and testing rules out injury or other causes, patellofemoral pain may be the reason.
Don’t think, however, that your complaints aren’t serious since you don’t have a tear or a break. Patellofemoral pain syndrome in cyclists can become a chronic and debilitating condition that worsens unless correctly identified, prevented, and treated.
Causes of Patellofemoral Pain Syndrome in Cyclists
Muscle Imbalance Leads to Improper Patellar Tracking
As a cyclist, it’s hard to believe that you have muscle weakness in your quadriceps, but you must remember. The quads consist of four parts, and the VMO is often underworked when pedaling and becomes ineffective. There are specific exercises that can target the VMO.
When a cyclist’s glutes are weak, it causes the outer quadriceps that are working to work even harder, and this puts more stress on our kneecaps. Weakness of your glutes can lead to increased quadriceps workload and possibly increased kneecap stress.
Strong quadriceps dominate a cyclist’s hamstrings, causing them to become tight and weak. We often neglect the muscles that rotate our hips outward, leading to imbalance. The structures on the outer portion of the thighs, like the iliotibial (ITB) band, get tight and pull the kneecap outward. It can also cause iliotibial band syndrome.
All of these issues contribute to patellofemoral pain syndrome when cycling. Luckily, muscle imbalances are effectively addressed by consistently performing the proper strengthening and stretching movements.
Improper Bike Fit
Improper bike fit is a common extrinsic factor and cause of repetitive overuse injuries in cyclists, and patellofemoral pain is no different. Seat height is a significant factor when identifying the cause of knee pain.
If your saddle is too low, it puts excessive strain on your patellofemoral joint. Adjusting your saddle to the correct height will allow your glutes and calves to fire effectively and decrease tension on the overstretched hamstrings.
The same thing applies if your saddle is positioned too far forward (aft) and if your cleats are too far back. Make sure your cleats have enough float.
An expert bike fit by a certified professional is always a wise idea.
Training and Riding Habits
Cycling knee pain often occurs when we increase our mileage or begin to ride too hard too soon. Riding with a low cadence or doing a lot of climbing when we put a lot of force into the downstroke significantly increases the stress on our kneecaps.
Treatment of Knee Pain Caused by Patellofemoral Pain in Cyclists
Find the Right Float Finding pedals that let your foot rotate the right amount for you is crucial. Every cyclist is different, so your cleat angle should be similar to the natural angle of your heel. When we pedal, there is rotation in our lower legs, and the amount is individual. Too much and too little float is a problem, but most riders are comfortable with a maximum of 4.5 degrees.
Find the proper saddle height There are many ways to find the proper height for your saddle, and a certified expert bike fitter will know. A good rule of thumb is that your saddle height should be about 95-98% of your total leg length (from the bone on the outside of your hip, the greater trochanter, to the bottom of your cleat).
If you’re experiencing symptoms of PFPS, aim to have a 25-degree angle of your knee joint at the bottom of the pedal stroke. Raising the seat height will help distribute the weight load to your hips and thighs, taking some of the stress off your knees and the patellar and quadriceps tendons. Decreasing the range of motion of your knee when pedaling will also help prevent pain.
Stabilize your feet with inserts Without the proper support of the arches, your feet will move within your cycling shoes. Poor stabilization causes your foot to flatten when you push on the pedals, and you can feel the stress on your knee. In addition, it will also harm the float of your pedals. The flimsy insoles in our cycling shoes don’t do the job. Consider replacing them with cycling-specific footbeds.
Refine Your Pedal Stroke When you experience pain in the front of your knee, ask yourself if your cadence has changed. If you’re grinding the pedals or doing a lot of climbing, it will put more stress on the patellofemoral joint. Try to set the pedal cadence to 90-120 revolutions per minute until the pain is under control. Then fall back into a natural cadence, as long as you aren’t mashing the pedals.
Core Strengthening Our core is the foundation for force production when we pedal. If we have weak core muscles, our legs have no basis for support, and our leg strength and performance will suffer.
Every time you put power into the pedals, your body must resist the force. Your core is engaged to keep your pelvis stable to provide a solid power production base. If your core is weak as fatigue sets in, your body will compensate. When cycling, your posture deteriorates, power decreases, and you become prone to overuse injuries like patellofemoral pain syndrome.
Integrate a core strengthening program into your routine.
You can find several Cycling Core Strengthening programs here.
Balance training improves the neuromuscular, ligament, and tendon response when stress is placed on the cyclist’s knee. Add some exercises to challenge your balance off the bike.
Improve Flexibility With Stretching and Foam Rolling
Here are a few exercises and techniques to add to your training routine.
Improve the Strength of the Pedal Power Muscles and VMO
Add these exercises to your program.
Patellofemoral pain syndrome when cycling is a common overuse injury affecting many cyclists’ performance and enjoyment. It doesn’t have to be the thing that keeps you off the bike. Ensure your legs are strong and flexible, your bike fits right, you pedal efficiently, and you avoid riding too hard or too much.
Following these tips to eliminate your pain and keep it away for good.
If all else fails, seek guidance from a healthcare professional. But don’t give up. Patellofemoral pain syndrome when cycling doesn’t have to slow you down!
Has Patellofemoral Pain when cycling ever slowed you down?
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Semi-retired as owner and director of his private Orthopedic Physical Therapy practice after over 20 years, Chris is blessed with the freedom to pursue his passion for virtual cycling and writing. On a continual quest to give back to his bike for all the rewarding experiences and relationships it has provided him, he created a non-profit. Chris is committed to helping others with his bike through its work and the pages of his site.
In the summer of 2022, he rode 3,900 miles from San Francisco to New York to support the charity he founded, TheDIRTDadFund. His “Gain Cave” resides on the North Fork of Long Island, where he lives with his beautiful wife and is proud of his two independent children.
You will read him promoting his passion on the pages of Cycling Weekly, Cycling News, road.cc, Zwift Insider, and Bicycling. Chris is co-host of The Virtual Velo Podcast, too!