Gammon M. Earhart, Ph.D., P.T.

Physical Therapy

Neurosciences Program

  • 314-286-1407

  • 314-286-1478

  • 314-286-1410

  • 4444 Forest Park Blvd., Campus Box 8502, Room B115



  • gait, balance, Parkinson disease, motor control, movement, neurodegeneration, neuroimaging, neurorehabilitation

  • Movement and Neurodegenerative Disease

Research Abstract:

We employ kinematic, kinetic, electromyographic, videooculographic and neuroimaging techniques to study the neural control of movement. Our work focuses primarily on individuals with movement disorders, with a particular emphasis on Parkinson disease (PD). Major lines of research in the laboratory focus on:
1) Mechanisms underlying gait impairments, such as difficulty turning and freezing, experienced by individuals with PD
2) Adaptive control of locomotion in response to novel stimuli and training paradigms
3) Effects of exercise interventions, such as dance and treadmill training, on body and brain function in PD
4) Effectiveness and side effects of deep brain stimulation to treat movement disorders
5) Natural history of disease progression in PD
6) Use of mobile health approaches to enhance physical activity and wellness in PD.

Mentorship and Commitment to Diversity Statement:


M is for mutual.  Mentoring is a two-way exchange where both parties benefit from working together.  It is obvious to most that mentees learn from mentors, but it is equally important to acknowledge how much mentees teach mentors.  I am grateful for the lessons I have learned from my mentors AND my mentees.

E is for expectations.  Mentoring works best when everyone knows the ground rules.  I work collaboratively with mentees to establish clear expectations at the outset.  Once expectations are in place, speaking up when they are and are not being met is critical to a successful relationship.  

N is for non-judgmental.  Good mentors realize and appreciate that you may not want to end up like them.  They take it in stride.  I will support you in achieving your goals even if they are not the goals I would choose.

T is for trust.  It can take a long time to build trust and only seconds to destroy it.  Good mentors and good mentees are trustworthy and forthright.  I encourage frequent, open, honest, and transparent communication to ensure that trust is built and maintained.

O is for originality.  We all come to the table with different backgrounds, experiences and perspectives.  The originality that we each bring is vital to the strength and vibrancy of our team.  I seek to recognize originality and encourage its expression and incorporation into our work.

R is for respect.  Mentoring relationships are collaborations, not hierarchies.  Mentor and mentee alike must demonstrate respect for one another.  I like to use the platinum rule, treating others as they want to be treated.  

I is for individual.  One size fits all mentoring is not a good fit.  Good mentors tailor their mentoring to meet the needs of each mentee.  I use individual development plans (IDPs) as a way to help mentees formalize goals and outline the steps needed to achieve said goals.  These IDPs serve as living documents that are revisited and revised throughout training.  

N is for network.  Good mentors encourage mentees to surround themselves with a mentoring team and build a professional network.  I gladly sing the praises of deserving mentees and help them connect with others who can provide support, guidance and future employment.  

G is for giving.  Mentoring is all about giving of one’s self.  Good mentors are available, accessible, and make it clear that mentoring is a priority.  They derive great satisfaction from seeing their mentees succeed.  Good mentors also keep on giving over the years as suits the needs and desires of the mentee.  I am happy to provide letters of recommendation, send words of congratulations on that big promotion,  occasionally fawn over pictures of pets/loved ones, or just remember your special day with a simple happy birthday.


I grew up in a working class family.  Neither of my parents graduated from college and they worked hard to make sure that I was able to do so.  I am forever grateful for their love and support, and consider myself blessed.  Without my parents, who were my first mentors, and a host of other caring and dedicated mentors along the way, I cannot say where I would be today.  As such, I recognize how critical it is to have people who believe in you and are invested in your success.  I understand what a difference one person can make in another person’s life trajectory.  I also appreciate that being that person who makes a difference hinges upon being a person who appreciates differences.

I want to be someone who makes a difference.  To do that, I acknowledge, explore and value differences of all sorts.  I acknowledge that the experiences of my colleagues of color, my students who are members of the LGBTQIA community and my family members with different abilities are not the same as my own.  I recognize that I am privileged.  I have become comfortable with being uncomfortable as I explore differences, educating myself through something as simple as actively listening to someone’s story or as involved as completing a certificate program regarding diversity in the workplace.  I know I have a lot to learn and that this will be a lifelong journey.  Along the way, I strive to make every person feel that they are valued by recognizing the importance and impact of what makes each of them unique and ensuring that their voices are heard.

As Associate Dean for Physical Therapy, I have the ability and the responsibility to foster diversity, equity and inclusion within the Program in Physical Therapy.  I serve as the Program in Physical Therapy liaison to the Office of Diversity, Equity and Inclusion at the Washington University School of Medicine.  Specific actions I have taken include implementing training for all employees and all students, ensuring that Program members have a basic awareness of cultural diversity, implicit bias and prejudices, as well as tools to address discrimination and foster inclusion.  My own training has included anti-racism workshops, completion of a certificate program on diversity in the workplace, continuing education courses of mentoring diverse trainees, and lots of reading, reflection and discussion.  I am grateful for the things students have taught me, and proud to have worked with students to co-found Physical Therapy Inclusion and Diversity (PT ID).  PT ID brings together students, faculty and staff who work collaboratively to foster diversity, equity and inclusion within the Washington University Program in Physical Therapy, the broader context of the institution, and the community.

Selected Publications:

1. Prateek, G.V., Skog, I., McNeely, M.E., Duncan, R.P., Earhart, G.M., Nehorai, A. (2018) Modeling, detecting, and tracking freezing of gait in Parkinson disease using inertial sensors.  IEEE-TBME, 65(10): 2152-2161.
2. Duncan, R.P., Van Dillen, L.R., Garbutt, J., Earhart, G.M., Perlmutter, J.S.  (2018) Physical therapy and deep brain stimulation in Parkinson disease: protocol for a pilot randomized controlled trial.  Pilot & Feasibility Studies, 4:54. PMC5822622
3. Falvo, M.J., Sirevaag, E.J., Rohrbaugh, J.W., Alexander, T., Earhart, G.M.  (2018) Effects of Parkinson disease and antiparkinson medication on central adaptations to repetitive grasping.  Life Sciences, 200:1-5. PMC5882572
4. Myers, P.S., McNeely, M.E., Pickett, K.A., Duncan, R.P., Earhart, G.M.  (2018) Effects of exercise on gait and motor imagery in people with Parkinson disease and freezing of gait.  Parkinsonism Relat Disord, 53:89-95. PMC6120800
5. Rawson, K.S., Creel, P., Templin, L., Horin, A.P., Duncan, R.P., Earhart, G.M. (2018) Freezing of gait boot camp:  Feasibility, safety, and preliminary efficacy of a community-based group intervention.  Neurodegener Dis Manag, 8(5): 307-314.
6. Harrison, E.C., Horin, A.P., Earhart, G.M. (2018) Internal cueing improves gait more than external cueing in healthy adults and people with Parkinson Disease.  Sci Rep, 8(1): 15525. PMC6195608
7. Rawson, K.S., McNeely, M.E., Duncan, R.P., Pickett, K.A., Perlmutter, J.S., Earhart, G.M.  (2019) Exercise and Parkinson disease: comparing tango, treadmill and stretching. J Neurol Phys Ther, 43(1): 26-32. PMC62944320
8. Salazar, R., Weizenbaum, E., Ellis, T., Earhart, G.M., Ford, M.P., Dibble, L.E., & Cronin-Golomb, A. (2019) Predictors of Self-Perceived Stigma in Parkinson’s Disease, Parkinsonism Relat Disord, 60: 76-80.
9. Horin, A.P., McNeely, M.E., Harrison, E.C., Myers, P.S., Sutter, E.N., Rawson, K.S., Earhart, G.M. (2019) Usability of a daily mHealth application designed to address mobility, speech, and dexterity in Parkinson's disease.  Neurodegen Dis Manag, 9(2): 97-105.
10. Duncan, R.P., Van Dillen, L.R. Garbutt, J.M., Earhart, G.M., Perlmutter, J.S.  (2019) Low Back Pain Related Disability in Parkinson Disease: Impact on Functional Mobility, Physical Activity, and Quality of Life.  Phys Ther, 99(10): 1346-1353.
11. Harrison, E.C., Horin, A.P., Earhart, G.M. (2019) Mental singing reduces gait variability more than music listening for healthy adults and people with Parkinson disease.  J Neurol Phys Ther, 43(4): 204-211. 
12. Harrison, E.C., Horin, A.P., Myers, P.S., Rawson, K.S., Earhart, G.M. (2020) Changes in Parkinsonian gait kinematics with self-generated and externally-generated cues: a comparison of responders and non-responders. Somatosensory & Motor Res, 37(1): 37-44.
13. Myers, P.S., Harrison, E.C., Rawson, K.S., Horin, A.P., Sutter, E.N., McNeely, M.E., Earhart, G.M.  (2019) Yoga improves balance and low back pain, but not anxiety, in people with Parkinson’s disease.  Int J Yoga Ther, online ahead of print.
14. Hsiao, D. Belur, P., Myers, P.S., Earhart, G.M., Rawson, K.S. (2019) The impact of age, surface difficulty, and dual-tasking on postural sway. Arch Gerontol Ger, 87: 103973.
15. Prateek, G.V., Mazzoni, P., Earhart, G.M., Nehorai, A. (2020) Gait cycle validation and segmentation using inertial sensors.  IEEE Trans Biomed Eng, 667((8): 2132-2144 .
16. Myers, P.S., Rawson, K.S., Harrison, E.C., Horin, A.P., Sutter, E.N., McNeely, M.E., Earhart, G.M. (2020) Cross-sectional analysis of backward, forward, and dual task gait kinematics in people with Parkinson disease with and without freezing of gait.  J Appl Biomech, 27: 1-11.
17. Belur, P., Hsiao, D., Myers, P.S., Earhart, G.M., Rawson, K.S. (2020) Dual-task costs of texting while walking forward and backward are greater for older adults than younger adults.  Hum Mov Sci, 71:102619.
18. Rawson, K.S., Cavanaugh, J.T., Colon-Semenza, C., DeAngelis, T., Duncan, R.P., Fulford, D., LaValley, M.P., Mazzoni, P., Nordahl, T., Quintiliani, L.M., Saint-Hilaire, M., Thomas, C.A., Earhart, G.M., Ellis, T.D. (2020) Design of the WHIP-PD study: a phase II, twelve-month, dual-site, randomized controlled trial evaluating the effects of a cognitive-behavioral approach for promoting enhanced walking activity using mobile health technology in people with Parkinson disease. BMC Neurol, 20(1): 146.
19. Holleran, C.L., Bland, M.D., Reisman, D.S., Ellis, T.D., Earhart, G.M., Lang, C.E. (2020) Day-to-day variability of walking performance measures in individuals post-stroke and individual with Parkinson disease.  J Neurol Phys Ther, 44(4): 241-247.
20. Harrison, E.C., Earhart, G.M., Leventhal, D., Quinn, L., Mazzoni, P. (2020) A walking dance to improve gait speed of people with Parkinson disease: A pilot study.  Neurodegen Dis Manag, 10(5): 301-308.
21. Horin, A.P., Harrison, E.C., Rawson, K.S., Earhart, G.M. (2020) People with Parkinson disease with and without freezing of gait respond similarly to external and self-generated cues. Gait & Posture, 82: 161-166.
22. May, D.S., van Dillen, L.R., Earhart, G.M., Rawson, K.S., Perlmutter, J.S., Duncan, R.P. (2020) Effects of STN-DBS and levodopa on balance system performance in people with Parkinson disease: a cross-sectional study.  Brain Sci, 10: 693.
23. Horin, A.P., Harrison, E.C., Rawson, K.S., Earhart, G.M. (2020) Finger tapping as a proxy for gait: Similar effects on movement variability during external and self-generated cueing in people with Parkinson’s disease and healthy older adults. Annals Phys Rehab Med, in press.
24. Abraham, A., Duncan, R.P., Earhart, G.M. (2021) The Role of Mental Imagery in Parkinson Disease Rehabilitation.  Brain Sci, in press.
25. Ellis, T.D., Earhart, G.M. (2021) Digital therapeutics in Parkinson disease: practical applications and future potential. J Park Dis, in press. 
26. Ellis, T.D., Colon-Semenza, C., Thomas, C.A., Saint Hilaire, M.H., Earhart, G.M., Dibble, L.E. (2021) Evidence-based physical therapy and exercise for Parkinson disease.  Semin Neurol, in press.

Last Updated: 3/31/2021 10:54:21 AM

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