Immediate effects of foot orthoses on gait and balance in boys with Duchenne Muscular Dystrophy: A Pilot Study

Immediate effects of foot orthoses on gait and balance in boys with Duchenne Muscular Dystrophy: A Pilot Study

Melody Tran, SPT

Background

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During my time in the UNC DPT program, I have developed a special interest in evaluating and treating the foot and ankle. In addition to our usual coursework, I have explored opportunities to learn more about custom foot orthotic fabrication. Most notable has been the opportunity to observe and learn alongside Dr. Michael Gross, PT, DPT, FAPTA, who specializes in the fabrication of these products. At the same time, our program has fostered another one of my areas of interest: working with neurologic conditions. Naturally, these experiences have culminated in my active participation in a pilot study looking at the immediate effects of custom orthotics on gait and balance in boys with Duchenne Muscular Dystrophy (DMD).

For my capstone project, Tyler Shelton, SPT and I have collaborated to complete a literature review to identify pertinent studies up until September 2016 on this topic and participate in the completion of the pilot study. Under the guidance of Dr. Vicki Mercer, PT, PhD as our capstone advisor and primary investigator, we have learned about the IRB application and approval process, subject recruitment, and data collection and analysis. As we continue to work and wrap up the report on this, we hope to learn more about processes related to potential journal publication and poster/abstract submission to CSM 2018, should our results reveal significant findings.

Overview

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In a literature search using the following databases: PubMed, CINAHL, and Web of Science, no results were found related to “weak quad* OR decreased quad* strength” in conjunction with heel lifts as an intervention (“insoles OR inserts OR heel lift OR lifts”). No studies were found that were specific to the use of heel lifts as an intervention for boys with DMD. However, a limited number of studies were found that evaluated the effects of heel lifts on stance and gait patterns in different populations than DMD.

Two studies^1,2 analyzed the effects of heel lifts in healthy individuals with limited ankle dorsiflexion (DF) range of motion. During right stance phase, 6mm- and 9mm- heel lifts were shown to increase ankle DF excursion; during left stance phase, the 9mm heel lift increased ankle DF excursion more than the 6mm heel lift, and both more than the shoes-alone control group¹. In a later study, the same authors evaluated the effect of heel lifts on plantarflexor and dorsiflexor activity during gait. From heel-strike to heel-off, both 6mm- and 9mm- heel lifts increased the mean EMG amplitude of the medial gastrocnemius, and the 9mm- heel lift alone increased the amplitude of the tibialis anterior when compared to the shoes-alone control group². These studies led to the conclusion that heel lifts were shown to increase the muscle activity of the medial gastrocnemius and tibialis anterior². Two other studies^3,4 were found that evaluated the effect of heel lifts in healthy individuals. Results suggested a 2cm heel lift elicited a lower degree of energy absorption at heel strike and lesser energy required for push-off during gait³, and a 12mm orthotic heel lift decreased tensile load in the Achilles tendon during shod walking⁴.

Statement of Need

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Overall, the amount of literature that discusses the effects of heel lifts for individuals with short triceps surae musculature and/or weak quadriceps musculature is lacking or non-existent. Heel lifts have been shown to have a place in treatment for individuals with ankle DF ROM limitations and overuse injuries¹, as well as potentially having a protective effect for the triceps surae and rectus femoris musculature³. It would be interesting to see if heel lifts have a role in improving the gait patterns for ambulatory boys with DMD.

Product

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View our final report for our capstone project here: Capstone Report Final

Self-Assessment and Reflection

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This experience has exposed me to a clinical research environment, which has provided me with invaluable insight as I consider pursuing a PhD program in the future. Assessment of our capstone experience has been an ongoing process as we reflect on the status of our project and integrate feedback from our capstone committee members (Dr. Mercer, Dr. Gross, and Cathy Howes, PT, DPT, MS, PCS). At first glance, Tyler and I developed a timeline that allowed ample time for each phase of this project to be completed. However, obstacles that evolved over the past few months related to delayed IRB approval and difficulties with subject recruitment became an important learning experience in the research process, recognizing barriers, and adjusting to variables that affect the course of a study.

A final marker to assess our capstone experience is evaluating our final report by referring to the Call for Poster and Platform Abstracts for the APTA Combined Sections 2018 Meeting. Specifically, we are interested in potentially submitting a poster presentation for the research report, detailed in the CSM Category Definitions.

Acknowledgements

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As this experience nears an end, I would like to express my gratitude for several individuals who have transformed this project into a profound, influential experience that has driven my personal and professional growth. As a friend and colleague, Tyler Shelton has been a source of consistent support, competence, and true teamwork that has allowed us to accomplish our capstone tasks. Dr. Vicki Mercer has played a vital role as our instructor, capstone advisor, and mentor throughout this project as well as through multiple courses throughout the program. Dr. Mike Gross has also undertaken a vital role in mentorship and supporting our learning efforts related to custom orthotic fabrication and advanced orthopedic assessment. Cathy Howes has generously provided her support and pediatric expertise in providing feedback for our experience. Finally, Demi Eckhoff and Dr. Jane Fan, MD have been incredibly helpful references for subject recruitment. Without these individuals, this experience would not have been possible.

References

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1. Johanson MA, Cooksey A, Hillier C, Kobbeman H, Stambaugh A. Heel lifts and the stance phase of gait in subjects with limited ankle dorsiflexion. J Athl Train. 2006;41(2):159-165.
2. Johanson MA, Allen JC, Matsumoto M, Ueda Y, Wilcher KM. Effect of heel lifts on plantarflexor and dorsiflexor activity during gait. Foot Ankle Int. 2010;31(11):1014-1020. doi:10.3113/FAI.2010.1014.
3. Valentini R, Martinelli B, Mezzarobba S, De Michiel A, Toffano M. Optokinetic analysis of gait cycle during walking with 1 cm- and 2 cm-high heel lifts. Foot. 2009;19(1):44-49. doi:10.1016/j.foot.2008.09.002.
4. Wulf M, Wearing SC, Hooper SL, Bartold S, Reed L, Brauner T. The Effect of an In-shoe Orthotic Heel Lift on Loading of the Achilles Tendon During Shod Walking. J Orthop Sport Phys Ther. 2016;46(2):79-86. doi:10.2519/jospt.2016.6030. M, Wearing SC, Hooper SL, Bartold S, Reed L, Brauner T. The Effect of an In-shoe Orthotic Heel Lift on Loading of the Achilles Tendon During Shod Walking. J Orthop Sport Phys Ther. 2016;46(2):79-86. doi:10.2519/jospt.2016.6030.