Patellofemoral pain syndrome (PFPS), commonly referred to as “runner’s knee,” is a prevalent issue among cyclists.
While the exact cause may vary among individuals, it can be frustrating and debilitating for those who experience it.
In this blog post, we will explore one cyclist’s journey to address his left-sided knee pain, discussing the changes he made to his bike setup and how these adjustments affected his cycling experience.
Understanding Patellofemoral Pain Syndrome
PFPS is characterized by pain around the kneecap (patella) and can occur when there is an imbalance or dysfunction in the mechanics of the knee joint. Symptoms typically include pain during or after cycling, tenderness along the inside edge of the patella, and, in some cases, mild swelling.
It’s important to note that the cause of PFPS can vary, making it challenging to pinpoint an exact solution for everyone.
Addressing Bike Setup
Our cyclist recognized the need to make changes to his bike setup to alleviate his knee pain.
We decided to focus on three main adjustments:
- Saddle Height: He raised his saddle by 5 millimeters to reduce knee flexion, aiming for a more extended leg position during cycling.
- Q-factor Adjustment: The cyclist changed his pedal spindle position, removing one washer to slightly narrow his Q-factor (the distance between the pedal attachment points on the cranks). This minor modification aimed to improve overall pedaling efficiency.
- Leg Length Discrepancy: The cyclist discovered that he had a shorter left leg, which could have contributed to his knee pain. To address this issue, he created a custom insole lift using vinyl remnants, a sharpie, and scissors. He placed the lift in his left shoe to compensate for the leg length discrepancy.
Results and Reflection
After making these adjustments, the cyclist noticed a significant improvement in his cycling experience.
Not only did his knee pain decrease, but he also felt an increase in leg strength during his rides. He concluded that addressing saddle height, Q-factor distance, and leg length discrepancy played a crucial role in alleviating his patellofemoral pain.
Other possible knee pain causes and their bike relationship
- Front of the knee pain:
Front of the knee pain is often related to the patellofemoral joint and the patellar tendon. Misalignment in the patella’s movement can lead to inflammation in the cartilage and may eventually cause wear and tear.
This misalignment may result from the knee tracking in an oblique plane away from the crank. Patellar tendon pain can arise due to the seat height being too high or too low, resulting in the quadriceps working too hard and causing micro-inflammation in the tendon.
- Back of the knee pain:
Back of the knee pain is less common and can be attributed to either an overloaded popliteus muscle or aggravated hamstring tendons.
Overextension of the leg from a too-high seat can cause hamstring tendon pain, while excessive foot rotation during pedaling can lead to popliteus muscle pain. Identifying the source of pain can be challenging, as these two issues often present with similar symptoms.
- Lateral (outside) knee pain:
Lateral knee pain, commonly known as ITB pain, stems from the iliotibial band, a large sheet of connective tissue attached to the gluteus maximus and other hip muscles.
ITB pain is typically one-sided and is often caused by pedaling asymmetry, resulting in the ITB becoming overloaded. This overloading can lead to iliotibial band friction syndrome or bursitis.
- Medial (inside) knee pain:
Medial knee pain is frequently caused by inflammation of the pes anserinus, the insertion point of three muscles on the front lower edge of the tibial plateau.
This inflammation often occurs due to the knee “whipping” across the line of the pedal, placing excessive strain on the Sartorius muscle.
Addressing cycling knee pain:
In most cases, knee pain is one-sided and stems from issues with seat height, Q factor (the distance between the pedals), or leg-length differences. To resolve knee pain, it’s essential to establish a symmetrical position on the bike and address the specific factors causing the problem.
This may involve adjusting seat height or Q factor, correcting leg-length differences with shims, or making other subtle modifications to the bike fit.
Conclusion
While the specific cause of patellofemoral pain may vary among individuals, making adjustments to your bike setup can significantly impact your comfort and performance.
If you are experiencing knee pain while cycling, consider evaluating and modifying your bike setup to see if it provides relief. As always, consult with a healthcare professional or bike fit expert for personalized advice tailored to your specific needs.
MD, PhD. Physical Medicine & Rehabilitation Physician from São Paulo - Brazil. Pain Fellowship in University of São Paulo.