Meet the D&D Leadership


Kathy I. Dieringer EdD, LAT, ATC

Kathy is a licensed and certified athletic trainer, who has been in the profession for over thirty five years, and is the original owner/founder of D&D Sports Med. She has extensive experience in the treatment and rehabilitation of high school, collegiate, and professional athletes. Kathy is active in her profession, serving in various leadership positions and earning multiple awards throughout her career. 

Active in the Denton community, Kathy served on the Board of Directors of the Greater Denton Sports Commission. She currently serves as an Ambassador for the Denton Chamber of Commerce and continues to provide athletic training services to numerous athletes in Denton and the surrounding areas. Kathy has also been active in various Olympic organizations as an athletic trainer, including USA Gymnastics and USA Volleyball. As a Wellness Member of USA Gymnastics, Kathy is recognized as a specialist in the treatment of gymnastics injuries. She served as an adjunct faculty member at the University of North Texas, and is currently a contributing faculty member for St. Augustine University and Moravian University. Kathy earned her doctorate in Curriculum and Instruction at the University of North Texas in May 2007. An avid golfer, Kathy is Titleist Performance Institute Certified.

Clinical Lead


Kathy Heimerdinger PT, COMT


Kathy graduated from Texas Woman’s University with a masters degree in physical therapy in 2000. She has worked in outpatient orthopedics in the DFW area since graduating. Kathy is currently pursuing her doctorate of science in physical therapy through Texas Tech University and is working toward certification in orthopedic manual therapy through the International Academy of Orthopedic Medicine. Kathy specializes in orthopedic industrial and sports injuries and in sacroiliac joint disorders. She completed completed her COMT certification of the extremities in 2010. Kathy is also a member of the Double Oak Volunteer Fire Department.

Clinic Managers

Chase sm

Chase Duell PT, DPT


Chase graduated from The University of North Texas with a Bachelor’s degree in Kinesiology in 2016. He then attended UT Southwestern for his Doctorate of Physical Therapy, graduating in 2018. He is dry needling certified through IAOM-US as well as a Certified Strength and Conditioning Specialist (CSCS). Chase is also an active member of the Sports Section of the American Physical Therapy Association. His special interests include sports rehab, concussion management, and helping post-op patients return to their hobbies and prior level of function. Outside of the clinic, Chase enjoys playing sports, traveling, and trying new breweries and restaurants.


Andra Sterzik OT, CHT

Denton Hand Therapy

Andra is a certified hand therapist who graduated with her Master’s in Occupational therapy from Texas Woman’s University in 1997. Since that time, her work throughout the DFW area has included both inpatient and outpatient care, as well as neurological rehabilitation. During her time at D and D Sports Med, she has focused her skills on the treatment of hand and upper extremity post-operative injuries as well as the care of repetitive and degenerative diseases. Her twenty-plus years of outpatient clinical work has focused primarily on hand and burn care. Andra has extensive experience with thermal injuries, wound care, and grafting due to her five years working at a local Level I trauma/burn center. Andra, her husband Chris and her two sons have resided in Corinth for more than a decade, and she has been in the Denton area since 1992.

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Rachel Perkins PT, DPT


Rachel attended Centenary College of Louisiana, where she played volleyball and earned her bachelor's degree with a double major in Biology and Psychology in 2016. She then attended UT Southwestern School of Health Professions, where she graduated with her doctorate of physical therapy in 2018. Rachel is certified in Dry Needling, is currently working towards her strength and conditioning certification (CSCS), and hopes to eventually achieve board certification through the APTA as an orthopedic clinical specialist (OCS).  Rachel is passionate about working with athletes and facilitating return to sport, as well as using exercise to help people of all ages return to their hobbies, and prior level of function. Outside of the clinic she enjoys running with her dog Jaxson, playing volleyball, and trying new restaurants with her friends.