Meet the Team
Dr. Eric Dickerson, DC, FRCms
Owner | Director of Clinical Development | Doctor of Chiropractic
As an experienced musculoskeletal provider, Dr. Eric Dickerson DC FRCms integrates functional rehabilitation, physical rehabilitation modalities, and advanced soft tissue techniques, to craft a comprehensive approach to your health. He emphasizes individual needs to help you develop optimal functional movement and reach your goals.
Prior to joining Radius, Dr. Dickerson DC FRCms managed a team of providers in Seattle where he helped patients recover from pain and injuries ranging from plantar fasciitis, frozen shoulder, and rotator cuff tears, to low back pain, hip pain, and rehabilitation of post-surgical conditions. He follows the latest evidence and peer reviewed research to guide the care he and his team deliver. Seattle Met Magazine recognized Dr. Dickerson DC FRCms as a Top Doctor in his category of Sports Chiropractor. With an effective care model and countless patient success stories, in 2017 he moved from Seattle, WA to Grass Valley, CA to deliver high-quality care in the Sierra Nevada foothills.
Dr. Dickerson DC FRCms earned a Bachelor of Science in Kinesiology from Arizona State University and earned the prestigious Academic Excellence award during his chiropractic doctorate program at Palmer College in Iowa. While a member of the Sports Council at Palmer, he minimized injuries in athletes through pre- and post-event treatment. As Vice President of the Palmer Package Club, he excelled in training others in chiropractic techniques, orthopedic and neurological examinations, and rehabilitation/exercise protocols. And, through Palmer, he provided chiropractic care in Salvador, Brazil as a humanitarian aid worker, where he gained an acute awareness of the cultural disparity in healthcare. He graduated from Palmer Magna Cum Laude with a Doctorate of Chiropractic degree. After graduation he co-managed patient care in collaboration with a medical doctor outside of Chicago, IL.
Dr. Dickerson DC FRCms is originally from the Chicago metropolitan area. As an avid enthusiast of healthy and physically active living, you’ll find him anywhere he can get outside and move. He has particular interests in yoga, CrossFit, golf, basketball, volleyball, running, hiking, and mountain biking. Dr. Dickerson DC FRCms is excited about everything California and the Sierra Nevada Foothills have to offer!
Dr. Chris Whalen, DC, FRCms
Musculoskeletal Rehabilitation | Rehab Chiropractor
Dr. Chris Whalen, DC, FRCms is a highly knowledgeable chiropractor and rehabilitation specialist with a proven track record of helping patients achieve their health and fitness goals. With his Doctor of Chiropractic degree from Palmer College of Chiropractic West, Dr. Whalen brings a wealth of expertise to his practice, ensuring that his patients receive the highest quality of care.
Before pursuing a career in chiropractic, Dr. Whalen honed his skills as a personal trainer at 24 Hour Fitness, where he gained a reputation as a coach who could help clients improve their strength and athleticism. He also earned a Bachelor of Science degree in Kinesiology with an emphasis in Exercise Science from Sonoma State University and gained valuable hands-on experience as an intern in a physical therapy office.
At Palmer College of Chiropractic West, Dr. Whalen was a valued member of the Rehab 2 Performance Club and a dedicated teaching assistant for physical therapy and rehabilitation courses. He has also provided treatment to athletes at various athletic competitions, including the first ACA Sports Council event after the pandemic.
With a lifelong passion for physical activity and a commitment to helping others achieve their health goals, Dr. Whalen is dedicated to helping his patients achieve their best possible health. Whether you're recovering from an injury, looking to improve your strength and athleticism, or simply seeking to live a healthier and more active lifestyle, Dr. Whalen has the expertise and experience to help you achieve your goals. He is excited to bring his skills to the small town of Nevada City, where he is eager to help local residents achieve their best possible health.
Dr. Tristan Ginkel, DC, FRCms
Musculoskeletal Rehabilitation | Rehab Chiropractor
Grafton Prewett, DPT
Neuromusculoskeletal Rehabilitation | Physical Therapist
Dr. Grafton Prewett, DPT is a highly skilled Neuromusculoskeletal Rehabilitation Specialist and Doctor of Physical Therapy specializing in concussion recovery and post-traumatic rehabilitation. With extensive experience in motor vehicle accident-related traumatic brain injuries (TBIs), vestibular dysfunction, and whiplash-associated disorders, Dr. Prewett provides targeted treatment plans to help patients regain balance, cognitive function, and mobility after an accident.
Following the California Department of Industrial Relations Medical Treatment Utilization Schedule (MTUS) guidelines, Dr. Prewett employs evidence-based strategies to address post-concussion symptoms such as dizziness, headaches, vertigo, and impaired coordination. His expertise in neuromuscular function and vestibular rehabilitation ensures that patients receive comprehensive care designed to restore their quality of life after a car accident or other head trauma.
Beyond his clinical practice, Dr. Prewett is passionate about staying active and exploring the outdoors. When he's not helping patients regain their stability and confidence, he enjoys building out a van for travel adventures and embracing an active lifestyle.
Whether you’re experiencing persistent concussion symptoms, balance issues, or neck pain from a motor vehicle accident, Dr. Prewett is committed to providing personalized, hands-on care to help you recover safely and effectively. He is proud to serve the Nevada City community and guide patients on their path to long-term healing and mobility.
Ronja Geisser, LMT
Massage Therapist
Ronja Giesser joins Radius with over 12 years of experience. She received her massage training at the acclaimed Hawaiian Islands School of Massage in 2009. She has a special passion for helping people reduce pain and stress in their lives through therapeutic bodywork.
Ronja's work focuses on the treatment and prevention of musculoskeletal dysfunction and pain using myofascial release, trigger point, and neuromuscular techniques as well as Swedish massage, Lomi Lomi, Sports Massage, and Deep Tissue massage.
When she is not helping people relax and return to optimal functioning, you can find her dancing in the air on aerial fabrics or enjoying the great outdoors.
Erin Crow, LMT
Massage Therapist
Erin brings 25 years of massage therapy practice and care to her clients. Her focus is medical massage modalities including Swedish massage, Esalen deep bodywork, myofascial release, prenatal, and elder care. Erin’s therapeutic services encompass therapeutic deep tissue massage, relaxation techniques, and reiki energy work. From athletes to elders, Erin provides effective treatment for acute and chronic physical conditions, rehabilitative injury recovery, and overuse syndromes. Her style is a blend of knowledge, empathy, and experience addressing the human condition.
Serene Renschler
Rehabilitation Specialist
Eric Bachman
Rehabilitation Specialist
Nick Moultrie
Rehabilitation Specialist
Susan Ross
Referral Coordinator
Susie plays an integral role in maintaining Radius' commitment to patient advocacy. As the primary point of contact for our workers' compensation, motor vehicle accident, and personal injury cases, she consistently goes above and beyond for our patients.
Susie's meticulous attention to detail and exceptional communication skills ensure a smooth process for everyone involved. Her dedication is widely recognized and deeply appreciated by both our staff and our patients.
When she’s not assisting patients, you’ll likely find Susie with her animals exploring the great outdoors—hiking, backpacking, and staying active!
Karen Wallack-Eisen
Front Office Coordinator
Natalie Collins
Remote Office Manager
Natalie may not be 'the face' of Radius, but she is the voice of our values. More often than not, she’ll be the first person you hear when you call. With her calming presence and deep understanding of Radius' operations, she ensures every patient receives the care they need.
She takes the time to match each patient with the right provider for their specific injury or condition. Whether you're dealing with low back pain, a shoulder injury, or seeking regular chiropractic adjustments, our diverse team of specialists is here to support your healing journey.
Beyond her role at Radius, Natalie brings expertise in nutrition and food science, along with 13 years of dedicated yoga practice as both a student and instructor.
Juli Bachman
Front Office Coordinator