Exploring The Potential Of In-Shoe Pressure Analysis In Runners

Offering insights on the impact of in-shoe pressure analysis for runners, this author details the treatment of a 21-year-old runner who had been diagnosed with flexor hallucis inflammation or tendinitis, and possible plantar fasciitis on her left heel. In our rapidly changing technological age, keeping pace with top-level athletes requires more than just experience or bravado. It requires results that clinicians can measure in multiple ways.    One way to assess the treatment success of a custom foot orthotic is by using in-shoe pressure analysis. No other technique can give you real-time feedback of the effect that a shoe alone, or in combination with an OTC or custom foot orthotic, can have on an athletes’ foot function.¹ Another way to assess an athlete’s overall lower extremity function is with the use of digital video analysis.² Appreciating an athlete’s symmetry of function at the level of the foot and above can have a huge impact on the success of the foot orthosis you use in the treatment plan.    Detailed information is great but this works best when you implement it in an overall team approach. Having quantified data and discussing this with the athlete, his or her physical therapist and trainer can help everyone achieve the best outcomes possible top-down and bottom-up for that athlete.    A 21-year-old Caucasian female who is a middle distance runner at a major Midwest Division I university presents to the office with her athletic trainer. The patient was recently diagnosed with flexor hallucis inflammation or tendinitis with the possibility of plantar fasciitis on her left heel and chronic low back pain. Her previous treatments for this included topical anti-inflammatories, electrical modalities with physical therapy and other exercises for the last two or three months. Initial treatment consisted of the Graston technique and Active Release Therapy Techniques (ART), and other soft tissue work without any significant results. The patient has no history of the female athlete triad. The patient had orthotics made for her in her high school to address some hip alignment issues. About a year ago, the patient had significant sciatic pain and radiculopathy, and ended up having a discectomy and laminectomy. Her primary nerve issues resolved after the surgery but she continues to have some chronic low back pain.    When the patient started to return to her running program, she had a few flare-ups of her back and it was subsequently determined via X-ray that she had a leg length discrepancy. The right leg is approximately 4 mm longer than the short left leg. Her trainer utilized a lift with her orthotics but she started to develop left heel pain. She ceased all sports activity and she seemed to be doing better initially. However, within two weeks of resuming her program again, her left heel symptoms returned. The patient’s team physician determined a new pair of orthotics might be able to help her. I was contacted by the athletic trainer to evaluate the patient.    After evaluating the patient, I cast her for custom foot orthotics with a digital scanner. The orthotics were milled out that morning so the athlete could have them for her gait analysis appointment later that afternoon.    Using multiple views with digital video, I was able to evaluate the patient both running and walking, barefoot and in her running shoes. I also performed multiple tests with in-shoe pressure for the patient with and without her wearing the custom devices I made for her that day.    I determined that the patient had significant pronation of her right foot. This may have been a compensation for her short left limb. The digital video (see image at above left) showed a significant knee valgus on the right, which correlates with prolonged pronation of the foot on the right side.^2,3    The in-shoe pressure analysis of the patient running with no insoles shows that the patient predominantly lands on the midfoot. Running gait curves show a much higher peak of forefoot curves as well as a higher peak at heel curves on the left side versus the right. These forces are reflected in the graphs (https://s3.amazonaws.com/podiatrytoday/PT0614Online2.pdf ). Note the higher forces on the left versus the right in the force by foot segment. The athlete’s accelerations were faster on the left as well and this is reflected in the contact time by foot segment graphs (below left).    Utilizing a proper orthotic prescription helped to bring symmetry to the force by foot segment forces on the left versus the right and brought symmetry to the contact time by foot segment graphs as well. The final prescription still showed some faster heel lift on the left but with some attention to physical therapy and hip strengthening on the left side, this will likely be eliminated over time.

In Conclusion

When it comes to prescribing custom foot orthotics, there is much more to treating an athlete than just casting his or her feet. No one can really know how a foot orthotic will affect an athlete’s gait, running, walking or how it will perform in a competitive movement without “seeing” how the feet react to the device. In-shoe pressure delivers that insight instantaneously and allows repeated review for modifications in the overall prescription. Digital video can give practitioners insights into weakness of the core and hips that may need significant rehabilitation to achieve the desired outcome, and maintain the desired symmetry in conjunction with the custom foot orthotics.    Dr. Williams is board certified by the American Board of Podiatric Surgery. He is a Past-President and Fellow of the American Academy of Podiatric Sports Medicine. Dr. Williams is the Director of Gait Analysis Studies at Weil Foot & Ankle Institute. References 1. William BE, Yakel JD. Clinical uses of in-shoe pressure analysis in podiatric sports medicine. J Am Podiatr Med Assoc. 2007;97(1):49-58. 2. Atkin K, Herrington L, Alenezi F, Jones P, Jones R. The relationship between 2D knee valgus angle during single leg squat (SLS), single leg landing (SLL), and forward running. Br J Sports Med. 2014;48:563. Available at https://bjsm.bmj.com/content/48/7/563.2.abstract . Accessed May 22, 2014. 3. Kagaya Y, Fujii Y, Nishizono H. Association between hip abductor function, rear-foot dynamic alignment, and dynamic knee valgus during single-leg squats and drop landings. Journal of Sport and Health Science. 8 November 2013. Available at https://www.sciencedirect.com/science/article/pii/S2095254613000768 . Accessed May 22, 2014.