Staff

Our Knowledgeable Therapists

Mission Statement

To help an individual regain their quality of life by providing the most complete care through comprehensive evaluation, individualized and customized programs, and advanced rehabilitation techniques.

We complete our mission by:

  • Each therapist spends personal time with you completing a thorough initial evaluation and establishing a personalized program specific to your goals.
  • Each therapist maintains higher level knowledge and advanced manual and treatment techniques through continuing education.
  • Each treating therapist is well experienced in a number of areas. Our therapist share our knowledge with each other at monthly meetings and discuss challenging cases that may not be responding to PT.
  • Each treating therapist and staff member cares. We put the patient first.
  • We offer affordable post rehabilitation services to help you maintain you quality of life.

Earl Cox

Earl Cox, PT, MS, OCS, CSCS

Dr. Earl Cox, DPT, MS, OCS, CSCS graduated from Beaver College (now Arcadia University) in 1995 with his Masters of Science in Physical Therapy.  He then pursued and achieved his transitional doctorate of physical therapy from Evidence in Motion. Dr. Cox is the founder and CEO of Superior Physical Therapy & Sports Rehab. He opened his first office in 2001 when he had the vision and goal to become one of the preferred outpatient physical therapy private practices in Frederick County.  Since opening, he and his team have been fortunate enough to a second location in Frederick and one in Purcellville, VA.

Dr. Cox has over 20 years of clinical experience and prides himself on his ability to listen and help solve the root cause of a injury or pathology for patients of any age.  He holds certifications in proficiency for Electrodiagnostic testing (EMG/NCV Studies) and Vestibular rehabilitation. He also earned is Orthopedic Specialist certification from ABPTS and is a Strength and Conditioning Specialist.

Earl has a passion for sports and played lacrosse, soccer and ice hockey at the collegiate level.  His passion for playing sports has helped him with his treatment of athletes at various levels. His abilities have been helping athletes return to their sport as quickly, safely, and most prepared as possible.

Dr. Cox is also very active in the community currently coaching soccer for MVAA and is the former head Coach of both the Middletown and Linganore High School Ice Hockey teams. Prior to having 3 lovely daughters he enjoyed playing hockey for a Men’s National Ice Hockey Team and coaching travel ice hockey.  He now enjoys volunteering at his daughter's schools and attending numerous community events. Dr. Cox's goal is not only to provide the best care in helping individuals reduce pain and improve function, but to be at the forefront of wellness and evidence-based practice in the region.


Brett Halpert

Dr. Brett Halpert, DPT

Brett is a licensed physical therapist who graduated with a Doctorate in Physical Therapy degree from the University of Maryland, School of Medicine. Prior to physical therapy school, Brett received a Bachelor of Science degree in Exercise Science from Frostburg State University, where he ranked number one in his graduating class. Brett has participated in numerous post-graduate courses and is currently studying to become an identified Orthopedic Clinical Specialist through the American Physical Therapy Association. Only about 10% of orthopedic physical therapists throughout the U.S. have this certification. Outside of being a PT, Brett's interests include exercising, hiking, and traveling with his two dogs, a beagle and a yellow-lab/golden retriever mix.

Brett likes the community feel of Spring Ridge/Frederick and gives every patient personalized care. Brett's goal is for everyone one of his patients to not only feel better, but return to their highest level of desired activity.


Janet S. Keller

Janet S. Keller, PT

A graduate of Boston University Sargent College of Health and Rehabilitation, Janet earned her degree in Physical Therapy and obtained Board Certification in Orthopedic Physical Therapy through the APTA from 1994-2004. She has taken numerous continuing education coursework in orthopedic and neurological dysfunctions to enhance her scope of knowledge in giving her patients optimum care and successful outcome. She has devoted time in developing knowledge in various hands on manual therapy techniques. While living in the San Francisco Bay Area, she took advantage of participating in the year-long course "The Austrailian (Maitland) Approach to Manual Physical Therapy".

As a therapist to our local community having over 25 years experience, she has had the privilege of treating a wide array of patient problems in both the in/out patient and home care settings including post op orthopedic, neurological, and musculoskeletal dysfunctions. Janet offers an eclectic approach to improve and maximize her patient’s level of function by utilizing both various manual techniques, tailored individualized exercise programs and education with the emphasis on prevention of future re-injury. She has a strong interest in pain associated with musculoskeletal dysfunction particularly with spinal and shoulder dysfunction teaching her patients the importance of core stabilization strengthening and flexibility to prevent tissue injury.

In her "spare time" she enjoys spending time with family and friends including doing outdoor activities such as sking and hiking with her husband Ron and three active sons Matthew, Sean and Brian.


Marijo Pickett

Marijo Pickett, PTA

Marijo Pickett began her career with Superior PT in 2004 as a tech for Dr. Earl Cox. Over the years working side by side with Dr. Cox MJ had the feeling that becoming a PTA is what she wanted to become in life to help others. From her years in high school volunteering in all the departments in the local hospital to working as a tech at Superior PT she fell in love with the diversity that physical therapy brings from working with a number of different fields such as neurology, sports rehab and cardio patients. From there she attended Frostburg State College where she studied psychology and finished her path to become a PTA at Carrol County College in 2008. After receiving her degree she knew she wanted to come back to Superior PT because their vision for their patients to help them achieve superior health and how they put their patients first.

MJ enjoys all kinds of sports and is involved in the community soccer leagues. At this time she is 3 leagues and enjoys kicking that ball up and down the field and of course scoring a goal or two is always fun. During her free time, she enjoys spending time with her husband who she has been married to since 2009 and two beautiful girls. On a sunny day, you can find them outside hiking new trails while having the latest adventure the outdoor brings but for those warm summer days you will only find them in one spot. Life is better on the water with the Pickets’ and you can find MJ and her husband watching the waves wrestle with the girls as they try jumping over the waves while holding hands or having a contest of who can catch the biggest fish. "My families are always known to be on the water when the summer days come. It truly is my happy place."


Bethany Hershberger

Bethany Hershberger, PTA

Bethany Hershberger is a 2010 graduate from Shepherd University where she obtained a Bachelors in Fitness and Exercise Science. She also graduated from Central Penn College with a degree as a Physical Therapy Assistant.

Bethany was inspired to pursue a career in Physical Therapy while babysitting a child with physical handicaps. She thoroughly enjoyed helping him and wanted to help others as well.

In her spare time, Bethany enjoys spending time with her family, friends, and two dogs, Gus and Bristol. She is a very active member of the Go Team Therapy Dogs where she volunteers most weekends. She is also a huge Steelers fan and can be found watching a game anytime they play.


Gillian Diestel

Gillian Diestel, SPT

Gillian is a Doctor of Physical Therapy student who recently joined the team and has been learning and practicing at both the Thomas Johnson and Spring Ridge clinics. She is currently attending South College, located in Knoxville, TN, and will receive her DPT in June. After graduation, Gillian plans to complete a year long residency through Evidence in Motion along with Dr. Earl Cox as her mentor in order to obtain her Orthopedic Certified Specialty. Gillian is passionate about patient care and believes that great therapy starts with a good patient-therapist relationship in order to build a foundation of trust and respect.

Outside of the clinic, Gillian can be found hiking, swimming, or lounging around the house watching Penn State football with her fiance, Chris, and their dog, Julio. When she isn't studying or traveling back home to Pennsylvania to spend time with her friends and family, Gillian also enjoys exploring downtown Frederick and trying out all of the great food and new places that Frederick has to offer."


Nature Gemmell

Nature Gemmell, Clinical Assistant at Spring Ridge

I am a Senior Exercise Science Major at Towson University. I transferred to Towson from High Point University my sophomore year of college and I will graduate in December of 2017. I'm applying to physical therapy school this July and will hopefully be able to start in 2018! I started working as a tech at Superior Physical Therapy in June of 2017. Before working here, I worked as a tech for a year and a half at a physical therapy clinic in Baltimore, MD. I love helping patients with their exercises and seeing them improve during the course of their therapy. I have been interested in physical therapy since high school and spend a lot of my free time volunteering in different clinics to get as much experience as possible.

When I'm not in the clinic, I love doing anything outdoors. I often go hiking, swimming, or have picnics with my friends and family. I also enjoy spending time with my four younger brothers and all my cousins. I grew up in Middletown, MD and graduated from Middletown High School in 2014. I recently moved back to Frederick now that I am almost done with my undergraduate degree and I'm hoping to stay local during and after physical therapy school because I love the area!