Bike Fit and Knee Pain in Road Cyclists
By Morven Ross, SPT
Overview
While cycling is generally considered a low-impact and relatively safe physical activity there is a high risk of overuse injuries. 85% of cyclists report one or more overuse injuries at some point in time with 41.7% of them occurring at the knee 1. The average cyclist will perform 5,400 pedal revolutions per hour and up to 81,000 in one week 2. The current assumption is that overuse knee injuries in cycling are caused by repetitive loading of the knee in suboptimal positions such as those caused by an improper bike fit 3.
Traditionally bike fitting techniques were based upon theoretical models. However, increasing interest in cycling has sparked more scientific research in order to apply evidence-based foundations to these models 1. This Capstone project takes an in-depth look at the scientific literature regarding the impact of bike fit on the knee. The findings were used to develop educational materials that emphasize the importance of bike fit and practical application for the prevention and management of knee pain and injuries in cycling.
Literature Review
I began my review of the literature in our Evidence-Based Practice II class with a specific PICO question: “In adult competitive and recreational cyclists with knee pain is a treatment program focusing on modifying saddle position more effective in reducing knee pain during cycling than no treatment?” I synthesized my findings from this review into a research paper. The saddle position is only one of three components on the bike that can be adjusted to prevent and manage knee pain and injury. These three components are the three interfaces where the rider and the bike make contact; (1) the shoe-cleat-pedal interface, (2) the pelvis-saddle interface and (3) the hands-handlebar interface. For my Capstone project I expanded my research to address all three of these interfaces and their impact on the knee. I compiled my findings into three separate evidence tables for each of the different interfaces; shoe-cleat-pedal interface, pelvis-saddle interface, and hands-handlebar interface.
Final Product
Once I had completed the literature review I wanted to create a final product that would synthesize the information into educational materials that emphasized practical application and benefited the local community. I reached out to TrySports, a local fitness store that specializes in cycling, to identify needs regarding bike fit and knee pain in the cycling community. TrySports and I worked together to establish these needs in order to determine the best method for presenting this information. The final products that we decided upon were a presentation to all of the TrySports staff, a more detailed reference guide for the bike specialists at TrySports, an educational customer handout, and an article for the TrySports’ monthly newsletter.
Due to the differences in knowledge and experience levels between my various audiences I reviewed health literacy guidelines and modules detailing how to create an effective presentation. I incorporated many of these strategies into the development of my materials. I also sought feedback from my adviser, committee members, the UNC triathlon and cycling teams and TrySports staff along the way to further enhance the effectiveness of my materials.
Evaluation and Reflections
Following my presentation to the TrySports staff and the completion of my materials I distributed presentation, customer handout and reference guide feedback forms. Overall, I received positive and beneficial feedback regarding these materials. All of the participants “agreed” or “strongly agreed” that these materials were beneficial. I have compiled a feedback analysis for the presentation and customer handout forms.
Aside from learning a great deal about bike fit and its relationship to knee pain, I experienced many of the other roles and responsibilities of physical therapists. I gained experience working as an educator in my community and had the unique opportunity to form a collaborative relationship with other professionals to help optimize community health and wellness.
As cycling continues to grow in popularity there will continue to be a need for more research and application of bike fitting techniques to reduce the risk of injury from cycling. I hope to expand upon this project and develop it throughout my career, so I appreciate any feedback that you may have regarding my Capstone project.
Special Thanks
I would like to extend a special thanks to all of those individuals that helped me throughout this project. Your guidance and advice have been invaluable in its creation and I greatly appreciate all of the time that you put in to helping me make this project as beneficial as possible. Thank you to my adviser, Mike Gross, and my committee members; Brian Diaz, Thijs van de Kamp and Carla Hill. Thank you to Mike McMorris for helping me brainstorm and develop the initial idea that inspired this Capstone and the extra help along the way. Thank you to TrySports staff for your support and feedback and the UNC triathlon and cycling teams for your valuable contributions.
For those of you that would like to provide additional feedback, please do so using the comments section below. Thank you for visiting my website.
References
- Bini et al. Effects of bicycle saddle height on injury risk and performance. Sports Med. 2011;41(6):463-476.
- Silberman MR, Webner D, Collina S, Shiple BJ. Road bicycle fit. Clinical Journal of Sport Medicine. 2005;15(4):271-276.
- Tamborindeguy AC, Rico Bini R. Does saddle height affect patellofemoral and tibiofemoral forces during bicycling for rehabilitation? Journal of Bodywork & Movement Therapies. 2011;15(2):186-191.
9 Responses to “Bike Fit and Knee Pain in Road Cyclists”
Morven Ross
Michael,
Thank you for your feedback on my project! I enjoyed your story about your inservice. The sport of cycling has grown a lot in the past 20-30 years which, fortunately, for me means there is more research. However, much of the research still needs improved upon as the majority of the studies are cross-sectional with small and limited samples.
I added some of the graphics to the pictures in order to get what I wanted the pictures to illustrate. but I did not have to adjust the ones that you mentioned. I was fortunate to be able to find that picture on the internet. One of the adjustments that I would make in the future to this project is to take the pictures myself. This would assist in illustrating the concepts and add uniformity in the pictures and presentation.
Thanks again for your interest and feedback.
Morven
Michael Tighe
Dear Morven:
Over 20 years ago, I did an in-service (during a student rotation) about iliotibial band syndrome, and particularly its occurrence with bike riding. It was a cut-and-paste handout (literally “cut” with scissors, and “pasted” with glue, at a 24-hour Kinko’s!), and the research I found at that time basically came down to adjusting the seat height to reduce stressors during the last 20 degrees of movement in and out of knee extension.
Your project really illustrates how far we have come since that time!!
I really enjoyed how you broke down the bike mechanics into looking at the three separate interfaces: shoe-cleat-pedal, pelvis-saddle, and hands-handlebars. As clinicians, we sometimes get so focused on looking at a single joint, that we forget just how inter-related all the stressors through the remaining joints are.
Your pictures, in particular, I found very illuminating, especially with the graphics listing the angles of movement and the location of stressors in these positions. I think this was best shown in the three-picture slide with the excessive valgus and varus knee positions on the outsides, and the proper alignment in the middle picture. I’m curious– did you add the graphics and angles on the pictures yourself? It looked so seamless, and instead of being distracting (as too much, or poorly placed, graphics can do), it was very sharp and directive. You almost didn’t need the notes on those slides…the pictures said it all!
Michael
Morven Ross
Carla,
Thank you for your kind feedback. I tried to create materials that pertained to a variety of different audiences, so I am glad to hear that they have been useful for a therapist!
Thanks,
Morven
Morven Ross
Daniel,
Thanks for your feedback and your insight into my project. It seems like you got a really good grasp on the material and hopefully will be able to use some of it in your practice.
The low back, neck and knees are among the most common areas subject to injury and/or pain during cycling. Fortunately, a proper bike fit can help to limit all three of these complaints!
Thanks again for your input Daniel.
Morven
Carla Hill
Excellent work on this project! Your products provide a lot of useful information for the therapist or fitness/retail provider. It provides appropriate background for those not previously knowledgable in bike components or fit consideration and also does an great job of summarizing the most relevant literature for those interested in a more in depth analysis. I hope you get to put this new knowledge into action during your final clinical rotation.
Carla
Daniel Blackmon
As always, great job, Morven. I am very surprised that exercises participating in a “low impact” activity such as cycling would experience such a high incidence of knee pain. Given the high degree of knee flexion, and repetitive motions, it does however make sense that this could be a potential problem. I think the article you put together is very user-friendly and concise, so excellent job with that.
I noticed in the presentation that the lumbar spine can also be put in a less than optimal position. While you were searching for information, did you find that low back pain was also highly prevalent in this population, as well?
Lastly, I really like how you point out that bike fit must be individualized to the individual. I think that is a great example of how we often have to account for what is “right” and “wrong” based on the individual and not just provide sweeping statements about what bike fit is or is not appropriate. Very well done!
Daniel
Morven Ross
CJ and Michelle,
Thank you both for your interest in my Capstone Project and for taking the time to look through the materials.
CJ, as you mentioned, for a cyclist with knee pain it may be more beneficial to have more precise measurements such as using the “knee-flexion method,” but the “heel method” as well as the “trochanteric height method” are other methods that have been used and studied in the literature that may be more practical for establishing saddle height. 1
When adjusting a cyclist’s saddle height using the “heel-method,” the knee must be fully extended when the cyclist is seated on the saddle, the heel is on the pedal (over the center of the pedal or axis) and the crank is in line with the seat tube.1 When using the “trochanteric method” the saddle height is adjusted so that it is at 100% of the trochanteric length (the length measured from the greater trochanter to the floor).1 While these two methods are more practical and are commonly used be cautious for any deviations from normal knee kinematics, cycling mechanics or symptoms of knee pain that may suggest that a more specialized bike fitting is needed. (Reference 1 has pictures of both of these two methods for clarification).
You both asked whether the materials presented in my Capstone would be appropriate for individuals taking or teaching spin classes and my answer is absolutely! I am unfamiliar with any precise literature regarding spin cyclists, however, my guess would be that the pedal revolution rate is even higher per hour than road cyclists as spin classes generally maintain a higher cadence. Consequently, for individuals participating in spin classes on a regular basis this could put them at an increased risk for knee injuries. I would absolutely recommend teaching some of these bike fitting strategies to spin cyclists and teachers. My suggestions would be to recommend the heel or trochanteric method for establishing saddle height for practicality, adjusting the saddle position (forward or backward) so that the knee is over the center of the pedal at the 3 o’clock position of the pedal cycle, and for those that participate regularly purchasing cleats that allow some float or movement at the foot/pedal interface. I do not have a lot of experience with spin classes, but from what I have experienced there are intervals that mix in very high cadences that can cause the foot to move an excessive amount in the toe straps. Often, to counteract this many individuals will try to tighten the toe-straps. Evidence suggests that toe-straps and fixed cleats; as well as too much motion at the foot/pedal interface can actually increase stresses and loads at the knee during cycling.2,3
Michelle, I would love to share this information with you and your spin instructor group, but I will be heading off to Asheville shortly for my last rotation. However, I would be more than happy for you to share my materials with your fellow spin/cycling enthusiasts. Please feel free to contact me with any questions that you may have.
CJ, you hit the nail on the head about having fellow PTs understand this material! Cycling is a commonly used PT intervention for increasing ROM, strengthening and endurance. PTs also commonly suggest cycling as a relatively safe and low load physical activity for patients that want to remain active and build endurance. We, as PTs, are doing our patients a disservice by not adequately assessing their bikes and limiting their risk of future injury.
Thanks again,
Morven
References:
1. Bini et al. Effects of bicycle saddle height on injury risk and performance. Sports Med.2011;41(6):463-476.
2. Boyd TF. Neptune RR. Hull ML. Pedal and knee loads using a multi-degree-of-freedom pedal platform in cycling. J Biomechanics. 1997; 30 (5): 505-511.
3. Wolchok JC. The effect of intersegmental knee moments on patellofemoral contact mechanics in cycling. J Biomechanics. 1998; 31: 677-683.
Michelle Green
Morven, I thoroughly enjoyed this project! Throughout this year, we have been talking about ways Physical Therapists can put themselves out into the community to show how beneficial our skill set is to WELLNESS, not only disease states. I love it!!!!!! I love how you integrated into the community and made your knowledge known to others and set your skill set apart from others. Catherine mentioned it, but I can’t find it in the above information, so I’ll ask again (I apologize if I overlooked it): Does this same information apply to indoor cycling? I am and have been a spin instructor for (don’t laugh) 15 years and lead a group of instructors who teach. I would love to have you share this information with them (but you are far away) or let me share it if it is the same for indoor cycling. Great Job!
Michelle
Catherine Jacobs
Awesome work Morven!! All of your materials are very thorough and well done! While I expect that most people who receive the TrySports newsletter will already know that bikes should “fit”, I have found this is not always common knowledge. Your work will be a great way to raise awareness! I will definitely be saving the Reference Guide for future use. I especially think the “practical application” sections are very useful and understandable. I also thought you did a great job of explaining the background information and then relating how that may affect riding performance. While I know your focus was on knee pain, information about performance may also help encourage competitive cyclist to evaluate their positioning. I have heard before that a quick way to assess your saddle height is to sit with your heel on the peddle and your leg should be almost fully extended. For those who aren’t able to measure out the 25-35 degree and 110-115 degree bends, is that a practical suggestion? If someone is having pain, I appreciate that specific measures are more appropriate.
It’s exciting to hear how many people you have been able to reach and hopefully will continue to reach- staff members, gym members, etc! I would imagine that spin instructors at other gyms or campus rec could also benefit from your work. You may have thought about this already, but I would even be curious if this information could benefit therapists and patients who use stationary cycling therapeutically? Again, great job! I am very impressed with how much information you were able to synthesize and share in a very understandable way!