Stephanie Liddle MPT, ATC

Stephanie is an Idaho Falls native and opened Performance Therapy in 2010.  Her desire is to offer a sports /outpatient clinic where athletes and patients of all ages and levels could return to the level desired in sports /life at a reasonable cost for health care.  Stephanie is an athlete herself competing in local, ½ ironman distance, and Xterra triathlons , mountain bike  and snow bike races, and  ½ marathons.  She has extensive experience in sports with both her physical therapy and Certified Athletic Trainer experience and training.  She was a member of the medical team for the 2002 Salt Lake Olympics working with short track speed and figure skating athletes.  She volunteers on the weekends during the winter for Grand Targhee Ski Patrol assessing snow skiing and boarding injuries.  Stephanie’s passion is to get patients back in their game of life, whatever the sport or activities they desire at the level they desire.

She received her Bachelor of Athletic Training in 1992 from Boise State University working with collegiate football, basketball, track and gymnastic athletes. She received her Master of Physical Therapy in 1995 from Idaho State University. She believes in continuing her education through courses, literature reviews, learning manual techniques, the latest treatment options available in physical therapy,:functional dry needling and treatment of the entire lower or upper extremity chain or spine.  She is committed to help individuals function at the highest level desired.

She is a member of the APTA, NATA, and served on the State Board of Physical Therapy for 10 years from 2002-2013.  She was chairman for 3 of those years served. She was adjunct faculty for Boise State University 1997- 2010.

Stephanie enjoys, competing, mountain biking , triathlon, skiing, hiking and camping with her family.

Shannon Harker, PTA







Shannon grew up in Pocatello. She was a graduate of the Idaho State University’s Physical Therapist Assistant program in 2007. Shannon and her husband Tyson have 4 very active children. Shannon enjoys and spends most of her time supporting, and being involved with her children’s schools and many sporting activities. Shannon has a desire to continue to improve her knowledge, and help her patients get back to their lives and what they enjoy as soon as possible. Shannon loves being a part of the Performance Therapy family, and is thrilled to be serving in the eastern Idaho community.

Heidi Marlow, PTA







Heidi grew up on a dairy farm in Southeast Idaho. As the 2nd oldest of 7 children she learned to work hard and enjoy spending time outdoors. She was active in sports all through high school and knew from a young age that she wanted to go into Physical Therapy. She graduated from the Idaho State University Physical Therapist Assistant Program in 2001 and has been working at Performance Therapy for over 10 years now. Heidi and her husband Ryan are the parents of 5 children and when she’s not busy with her children she spends her free time running, biking, and hiking. She enjoys racing and has participated in many Duathlons, Triathlons, Marathons, Half Marathons and Road Bike Races. One of the highlights of her athletic accomplishments came in 2011 when she was able to run the Boston Marathon.

Heidi enjoys being part of a team that is enthusiastic about pushing themselves and their patients to improve and is dedicated to helping our patients get back to doing the activities that they enjoy.

Molly Ruffner PT, DPT


Molly is a Pennsylvania native who received her Bachelor’s degree from Saint Vincent College and her Doctorate of Physical Therapy from Duquesne University in 2017. Molly’s graduate clinical training included acute care and outpatient orthopedics near Pittsburgh, PA, and acute inpatient rehabilitation at Rancho Los Amigos National Rehabilitation Center in California. Molly then moved to the eastern shore of Maryland to begin her career at an acute inpatient rehabilitation hospital, treating primarily orthopedic and neurologically complex patient populations.

She grew up involved in many sports including swimming, cross country, track, and soccer. She has passion for swimming, and swam competitively at the collegiate level, as well as coached swimming technique clinics and lessons. She continues to enjoy and compete in swimming, triathlons, and cycling. She loves hiking and backpacking with her dog Bob, weight lifting, mountain biking, skiing, gardening and anything fun outdoors. She also loves spending time with her two sisters, family, and partner Austen.

Molly is committed to continuing to learn and develop as a provider and is excited to practice at Performance Therapy and contribute to the Idaho Falls community.

Grace Crook PT, DPT


Grace’s upbringing took place in northern California with her most recent residence in rural South Dakota. In 2020, she completed her Bachelor of Science in Exercise Science at Dakota State University, acquiring a strong background in exercise programming.

Throughout her undergraduate years, Grace worked as a personal trainer, aiding clients of various ages and fitness levels in reaching their goals. This experience solidified her interest in physical therapy, leading her to pursue a Doctorate in Physical Therapy at the University of Mary.
Grace is a certified strength and conditioning specialist (CSCS) and LSVT BIG certified. She enjoys running, working out, spending time with friends and family, and baking.

Looking forward, Grace is excited to begin her career as a physical therapist and serve the people of the Idaho Falls area. Grace is committed to helping individuals of all ages and backgrounds achieve their physical goals.

Joshua Yocum PT, MPT







Joshua is a native of Sugar City. After finishing high school he enlisted in the United States Marine Corps where he spent four years as an Infantry Marine. He earned a Bachelors of Science and Masters Degree in Physical Therapy in 2003 from Husson University in Bangor, ME. He then moved to Virginia where he lived for 17 years before returning to the Intermountain West.

Joshua has 20 years of experience as a Physical Therapist. His post-graduate education includes completing residency work at The Manual Therapy Institute and a Strain CounterStrain residency at McKenzie Crossing Orthopedic Physical Therapy in Springfield Oregon. Joshua believes the key ingredient to effective physical therapy treatment is a hands on approach that identifies and corrects movement impairments in the body contributing to pain and dysfunction.

Joshua has been an endurance athlete from a young age, completing the LoToJa at the age of 14. He has completed two marathons, enjoys competing in Olympic Distance Triathlons and loves spending time in the outdoors hiking, mountain biking and camping.