Cycling Mechanics and Orthotics
ORTHOTICS | CYCLING
Edward S. Glaser
DPM and David C. Fleming
A cyclist can spin their wheels 5,000 to 7,000 times per hour. That’s around 24,000 revolutions on a four-hour ride. With this amount of repetition, proper cycling biomechanics is crucial for injury maintenance and performance. Proper fit and mechanics can greatly influence the rider and their injury potential. Custom orthotics are a powerful piece of the puzzle when attempting to improve any of these factors.
MASS Posture Theory
Mass Posture custom foot orthotics have been found to reduce pain1, improve gait economy2, provide postural stability3, and improve pressure distribution across the plantar aspect of the foot to restore first ray load-bearing 4. Proprioception and biomechanics of bipedal locomotion can be improved with the use of full contact custom orthotics—such as MASS Posture based foot orthotics. These same benefits can be applied to cycling, especially with respect to full foot stability for efficient pedaling and lower extremity alignment. Orthotics have also been recommended for cycling to decrease pain, injury, and improve performance5 6 7. Many professional riders use orthotics for these reasons. Custom Orthotics can play a significant role in improving biomechanics and neurosensory input.
Why?
The goal of cycling is to deliver as much force as you can
‘ ‘ The contact point between the delivery of the body’s force to the bike is at the pedal/shoe interface. JJ
efficiently and effectively from the body to the pedal to turn the rear wheel. To do this, your body must work together with the bike to deliver power to the pedals and with as few “energy leaks” as possible.
The body does everything it can to produce a consistent and efficient force to the pedals. Poor bike fit as well as body imbalances can drastically affect this.
The contact point between the delivery of the body’s force to the bike is at the pedal/shoe interface. Everything the body does amounts to force produced on this area. If you look at a true cycling shoe, it is very stiff and flat. If there is a flat overpronated foot, it remains in a flat, overpronated position in this shoe without support. An overpronated foot is by definition unlocked (open-packed) and not very stiff. Energy can easily be lost at this link in the chain if force is delivered through
an unlocked, too-flexible foot. Due to compensations for poor biomechanics, tissues can be overstretched or stressed, which create injury and pain. A fully supportive and corrective orthotic in the shoe creates a better supinated posture that translates into more rigidity and greater transfer of power.
Common Question: ‘‘But the only contact point with the pedal is the ball of the foot (forefoot)?”
A chain is only as strong as its weakest link. Energy has to be delivered h orn the legs, core, and upper body down through the foot and ankle to the pedal. If the foot is overpronated, a significant share of that energy will go into flattening the tarsus, which creates a large “mush” factor that results in inefficient pedal power. Some of the energy also goes to creating abnormal tissue stresses as the flattened tarsus attempts to achieve stability and transfer force. Additionally, leg muscles, such as the posterior tibialis, must spend extra energy trying to stabilize tarsal posture.
In addition to the biomechanical benefits, a major contribution of full contact orthotics is proprioceptive feedback. The contact with the foot allows for more efficient and effective
“If you allow one or more planes of the foot to escape correction, the overpronation will occur in those planes."
feedback to position and force production. It also allows the body to better correct imbalances or weak output.
Another reason a full foot, triplanar foot correction is important over a wedge or no correction is that it affects the whole foot as a cylinder or machine in all three planes. Meaning that if you correct the posture of the foot with the MASS Theory orthotic, you affect the rearfoot, midfoot, AND the forefoot! If you allow one or more planes of the foot to escape correction, the overpronation will occur in those planes. The foot is a three-dimensional structure and requires threedimensional support to achieve postural correction.
Good biomechanics in the legs and trunk can also be affected by foot position in a cycling shoe. By creating supination at the foot, you can correct for tibial and femoral internal rotation, knee valgus, hip varus, and pelvic anterior rotations in all three planes rather than just the frontal or sagittal planes. This will help align the body to produce more force as well as treat for injuries such as PFPS, ITB Issues, Piriformis or SIJ Pain, and more. By adding a MASS orthotic, you externally rotate the tibia, which abducts the knee and allows for better patellar tracking, which externally rotates the femur and allows for decreased tension with the ITB and hip muscles,
which posteriorly rotates the pelvis and relieves pressure at the SIJ, L-Spine, and Hip muscles.
The following information should be taken into consideration as best practices when maximizing custom orthotics for cycling:
Design Considerations—Most cycling shoes are pretty constrictive. We recommend a narrow shell, shallow heel cup, and a 2mm top cover for a MASS Posture Orthotic. If there is room, a 3mm top cover can be used. Pull out the shoe manufacturer’s insert and see how thick it is. If it is really thick, you can use a 3mm. If it is average or thin, use the 2mm top cover. Considerations need to be taken into account for cyclists with special needs, such as triathaletes with wet feet, and foot odor prevention.
Break In—Follow the normal break-in protocol. The cyclist may continue to bike, just not in the orthotic until after the normal break-in period. Then, gradually build up the time with the cycling orthotic on the bike. Instruct them to try a one-hour ride and realistically build up from there. Do not compete or do a long ride right away in them.
Some riders or fitters have also been known to add external wedges underneath the cleat or in the shoe—look for these as they will also have a conflicting influence on your MASS orthotic.
Bike Fit
The bike fit is the most important fundamental aspects of any cyclist who wants to treat injury, prevent future problems, and improve performance. The primary focus in a good bike fit is the rider, not just the bike. Fit and positioning should revolve around the strengths and weaknesses of the rider, not just a generic formula.
However, a bike fit is not black and white. It is both an art and a science. There are several great bike fitters out there, especially medical bike fitters. Bike fits range from basic to complex, depending on your individual needs.
A good orthotic can change a bike fit, and it should. Best practice is to re-do the bike fit after they get their new orthotics. However, when that is not possible, consider raising the saddle a few millimeters to make up for the orthotic correction. Usually, around 2-3mm is sufficient. Cleat position usually does not need to be changed, and rarely does the saddle fore/aft. Re-check the pelvis and upper extremity for any significant changes.
Pedal Stroke
Pedal Stroke is another significant factor when treating the cyclist. While the orthotics are part of the bike fit and they address biomechanical factors, Pedal Stroke is a major part of using those biomechanics properly.
The pedal stroke is the circle in which your foot produces force to the pedal to turn the crank to power the wheel—in other words, how well your foot is pushing on the pedal during a full circle. This is one of the most powerful tools you can learn when trying to be a better cyclist—no matter what type of bike you ride. It will allow for a significant increase in your strength, endurance, and speed.
Despite how important it is to learn, it can be rather confusing trying to master the technique. Some bad habits are formed when learning it, and sometimes people need help from an expert to make sure they are getting it.
“Stroke Thoughts” = Cleat, Circle, Smooth
Try to keep it simple. In golf, when you step up to hit the ball, you are allowed only 2-3 “Swing Thoughts.” Any more and you mess up your technique by thinking too hard. Remember the “Stroke Thoughts” above, and the rest should correct itself. If you think too much about more toeing, heeling, or scraping the poop off of your shoe, that is what you will be doing. So, think about your “cleat” moving in a nice “smooth circle” and that’s what you will be doing!
References:
1. Trotter, L el al. 2008. The Short-term Effectiveness of FullContact Custom-made Foot Orthoses and Prefabricated Shoe Inserts on Tower-Extremity Musculoskeletal Pain. J Am Podiatr Med Assoc 98(5): 357-363, 2008.
2. Trotter, T el al. 2008. Changes in Gait Economy Between Full-Contact Custom Made Foot Orthoses and Prefabricated Inserts in Patients with Musculoskeletal Pain. J Am Podiatr Med Assoc 98(6): 429-435.
3. Cobb, S el al. 2006. The Effect of 6 Weeks of Custom-molded Foot Orthosis Intervention on Postural Stability in Participants With 7 Degrees of Forefoot Varus. Clin J Sport Med. 16: 316-322.
4. Hodgson, B el al. 2006. The Effect of 2 Different CustomMolded Corrective Orthotics on Plantar Surface. J of Sport Rehab. 15:33-44.
5. Wanich, T el al. 2007. Cycling Injuries of the Lower Extremity. J Am Acad Orthop Surg. December 2007, vol. 15 no. 12: 748-756.
6. Zinn, L. 2004. Block 8: Orthotics. Zinn’s Cycling Primer: Maintenance Tips and Skill Building for Cyclists, pp. 25-27.
7. Baker, A. 1998. Other Treatment Options: Orthotics. Bicycle Medicine. Chapter 3, pp. 168-169.
Dr. Edward S. Glaser DPMstudied mechanical engineering at SUNY Stonybrook, and went on to receive his doctorate in podiatric medicine at the New York College of Podiatric Medicine. This is not a common pathway for a podiatrist, but it turned out to be just the right exposure for a future foot bio mechanist. Dr Glaser defied the odds and developed his own successful practice over thirteen years. Yet he chose to walk away from that success in order to be the first to challenge over thirty years of orthopedic conventions with his revolutionary MASS Posture Theory. With the founding of Sole Supports in 1992, Dr. Glaser made his life’s mission a reality: ‘We make people better ’. MASS Posture Theory is a unique look at managing foot biomechanics from an engineering perspective, an all axis model of foot biomechanics, based on the individuals ’ idealized gait. Dr Glaser has earned a substantial following at home and abroad for re-visioning and re-engineering the way practitioners can significantly correct poor biomechanics in the foot and lower extremity. He was recently granted the honor of participating in the Federation of International Podiatrists ’ tri-annual panel in Montreal and ACFAOM's 2016 Annual Clinical Conference on Theories and Custom Foot Orthoses (Debate).
David Fleming was born in Miami, FT. He received the B.S. degree in Biomedical sciences from the University of South Florida. He joined the research service at the James A. Haley Veterans Medical Center concentrating in endocrine and cardiovascular systems. Later on, he held the position of assistant administration and compliance officer for the same service. He then studied podiatric medicine at the Ohio College of Podiatric Medicine. Since 2014 he has been with Sole Supports Inc., where he has published three papers relating to MASS Posture.
