General and advanced orthopedic injury, sports injury, spinal disorders, hand therapy, work and personal injury, rheumatic disease, podiatric disorders, neurological disorders, oncology related illness

Locust Valley Location
  • Address:146 Birch Hill Road
    Locust Valley, NY 11560
  • Phone: 1-516-759-9717
  • Email: cs@soundsidept.com
Jericho Location:
  • Address:200 Robbins Ln, Suite D2
    Jericho, NY 11753
  • Phone: 1-516-723-4020
  • Email: cs@soundsidept.com
Contact Jericho: 1-516-723-4020

Meet Your Therapist


James Kalenderian, PT
President, SoundSide Physical Therapy

Graduated from the University at Buffalo in 1999
Degrees in Physical Therapy and Sport & Exercise Physiology

When I became a physical therapist my goal was to provide outstanding one-on-one care.  Not satisfied with the quality of care that was available, I decided to venture out on my own.  I began small, visiting homes of my patients to provide the excellent one-on-one service that I believe in.  The overwhelming response I received from my home care services led me to open my first clinic in September 2001.

It has been a pleasure being part of the local community which has enabled us to relocate my practice nine years later to a much larger state-of-the-art medical complex located in the heart of Locust Valley.  The goal of my outpatient orthopedic facility is to continue the intense one-on-one attention while offering the best environment for rehabilitation.  I have invested in new state-of-the-art equipment, including the Biodex un-weighting system and a line of Quantum & Sci-Fit exercise equipment. 

As always, my primary goal when treating patients is to provide quality one-on-one physical therapy allowing our patients to progress with rehab in the most timely and efficient manner possible.  SoundSide stands for quality care with a personal touch.

Dr. Adam Johnnidis, DPT, CAFS

Adam graduated in 2012 with a doctorate in physical therapy from Long Island University,  Brooklyn. After becoming a licensed physical therapist Adam chose to start his career as a traveling P.T., gaining immense professional and life experience while working all over the country from Wyoming to Washington DC. After 2 years of traveling he settled in Hawaii for 2.5 years, working primarily with orthopedic and sports patients. After his time in Hawaii Adam returned to his home on Long Island as he always intended, to be closer to his family and provide excellent care to the community in which he grew up in. He has since became a provider of the unique Graston technique, which is an instrument assisted soft tissue mobilization. This technique helps the treatment of scar tissue and fascial restrictions during rehabilitation, allowing for faster rehab and proven success in restoring range of motion, eliminating pain, and restoring normal function. Dr. Johnnidis is now the Director of SoundSide Physical Therapy's new facility in Jericho. Here he provides quality, personalized P.T. in combination with the Graston Technique and our new sports-specific turf training area. 

Mark C. Willenbacher, PTA

Mark graduated from James Madison University with a Bachelors in Exercise Science in 2010. He then went on to complete his certification for Physical Therapist Assistant in 2016 from Nassau Community College. Mark has been with Soundside Physical Therapy since 2010 working as PT Aide and personal trainer. 

Outside of Soundside Physical Therapy, Mark has worked as a highly regarded personal trainer within the community for all ages. His experience and background in exercise training for all ages makes him an important asset to Soundside. 

Mark grew up in Bayville and has many ties to the community. He is a proud Alumni of Locust Valley High School and still bleeds Falcon Pride. He spent 4 years coaching boys lacrosse for the Oak Neck Athletic Council from 2010-2014, having been a member himself during his childhood. Mark's compassion and dedication to give back to his community make him a valuable member of the Soundside Team.