Meet our Doctors of Physical Therapy

David Ojeda, DPT, OCS

Dr. Ojeda graduated from the University of Southern California with a bachelor's degree in Kinesiology.  While at USC, he was a student-athlete competing on the men's track & field team as a distance runner.  After taking 2 years off to compete, he returned to USC's Physical Therapy graduate program ranked #1 in the country by U.S. News & World Report.

Upon graduating with honors, Dr. Ojeda worked in an orthopedic and sports medicine clinic where he honed his skills and eventually earned the highly-regarded Board Certified Specialty in Orthopedics (OCS).  As an American PT Association Credentialed Clinical Instructor, he has provided years of clinical instruction and mentorship to Doctoral candidates during their physical therapy education.  He is also involved with the California Physical Therapy Association where he has volunteered his time as the Los Angeles District Treasurer and Assembly Representative.  ​

Combining over a decade of clinical experience with a passion for movement science and physical health, Dr. Ojeda provides a patient-centered approach to treatment.  With his extensive educational background, Division I athletic experience, orthopedic specialty, and emphasis on patient care, Dr. David Ojeda possesses a unique perspective on the rehabilitation and sports medicine world.

John Chao, DPT, OCS

Dr. Chao received his Bachelor’s of Science in Kinesiology and a minor in Biology from the University of Texas at Austin.  He then went on to receive his Doctor of Physical Therapy degree from the University of Southern California. 


Immediately upon graduation, Dr. Chao began the year long Orthopedic Clinical Residency program at USC.  During his residency, he was a faculty member teaching at the physical therapy graduate program, attended numerous continuing education courses,  performed patient rounds with Orthopedic surgeons at USC University Hospital, and worked at the USC faculty practice treating patients and participated in their mentorship program.  Dr. Chao then received his Board Certification in Orthopedics Specialty upon completion of his residency. 


Dr. Chao has been working in Santa Monica, California for the past 14 years treating a variety of patients of all ages.  He began a student internship program with the USC Physical Therapy School and serves as the Center Coordinator for Clinical Education.  He has been a clinical instructor to many aspiring physical therapy students.  He has thoroughly enjoyed establishing many wonderful relationships with the referring physicians and patients that he has had the pleasure of working with. 


Dr. Chao enjoys spending time with his family when he is not working in the clinic.  He is also very active working out at the gym, playing golf, tennis, and softball in his spare time.

Jennifer Carr, DPT, OCS

Dr. Carr received her Bachelor’s of Science in Biology with a minor in Psychology from the University of California, San Diego. She then went on to complete her Doctor of Physical Therapy degree from the University of Southern California. She has received her Board Certification Specialty in Orthopedics--a population she relates to having been a competitive gymnast and dancer.  In addition to her specialization in treating orthopedic regions she has done extensive work in a variety of related fields, including TMD (Temporomandibular Joint Dysfunction) and providing ultrasound treatment to nursing mothers who are experiencing pain from clogged milk ducts. Additionally, she also treats the pelvic floor, which can include issues like pelvic pain and incontinence. In addition, she is certified in BFR (Blood Flow Restriction Training), a research-based method of increasing muscular strength.

During her time at USC, Dr. Carr was the student coordinator for a free weekend health and wellness service. She conducted research in exercise physiology and was a volunteer teaching assistant.  She earned the Academic Excellence Award and was recognized for demonstrating a commitment to excellence in the profession of Physical Therapy. She graduated with honors and immediately began her year of Orthopedic Clinical Residency at USC.  During this time, she was a faculty member for the physical therapy graduate program, attended numerous continuing education courses,  performed patient rounds with Orthopedic surgeons at USC University Hospital, and worked at the outpatient orthopedic clinic treating patients while participating in their mentorship program. 

Prior to joining the team at Matrix, Dr. Carr was a senior therapist at an orthopedic and sports medicine clinic in Santa Monica for the past 5 years. In addition to treating a variety of patients, she also provides clinical instruction to doctoral candidates from the physical therapy program at USC. 


In her free time, Dr. Carr enjoys spending time with her husband and two young boys. She also enjoys hiking, running, yoga, and exercising regularly.

Ethan Waldman, DPT, OCS, CSCS

Dr. Waldman received his Doctorate in Physical Therapy (DPT) from the University of Southern California in 2016. After being accepted into USC’s Orthopedic Physical Therapy Program, he continued on to complete his Residency training in 2017 while working at the USC Faculty practice treating the students, faculty, and staff of USC and helping teach the doctoral students in USC’s prestigious physical therapy program. Ethan has worked alongside and learned from many world-class physical therapists and physicians through continuing education courses, and primarily his colleagues, mentors, and professors. 
In 2012, Ethan worked as an intern Strength Coach at UCLA training the Varsity Football, Baseball, and Track and Field teams. While at UCLA, Ethan became a Certified Strength and Conditioning Specialist (CSCS) through the National Strength and Conditioning Association, which is the industry gold-standard certification for performance and fitness training. 


Dr. Waldman became a board-certified specialist in orthopedic physical therapy  in 2019.  This advanced certification makes him a specialist clinician in orthopedic physical therapy. 

While pursuing his Bachelor’s of Science in Health Studies at Bates College in Maine, Ethan competed on the track and field team and became a Division-III All American in the shot put, and a New England Champion in the discus throw. Ethan was the captain of his high school tennis and soccer teams at Alexander Hamilton High School in Los Angeles. 
Ethan is very passionate not only about working with athletes, but with the average person, who may be in pain, or unable to do what they were doing before, and making sure that no stone is left unturned in getting them back to their normal physical function and beyond.

In his free time, Ethan enjoys hanging out with friends and staying active, including going to the gym, running, biking on the beach, and playing recreational sports such as basketball and tennis.

Jessica von den Stemmen, MPT, DPT, OCS

Dr. Jess von den Stemmen offers exceptional patient-centered physical therapy. She was born and raised in Southern California and received her Bachelors of Science at Pepperdine University, graduating in 2010 with honors. She then attended California State University, Northridge and received her Master of Physical Therapy in 2013, again graduating with honors. 


Jess continued to pursue her educational goals and earned her Doctor of Physical Therapy degree from Western University of Health Sciences.  Prior to her experience at Matrix physical therapy, she was a lead therapist working in an outpatient setting for the past 5 years in Westlake Village. She has refined her orthopedic skills via Evidence-Based continuing education courses with emphasis in manual therapy, functional mobilization to improve neuromuscular function and motor control, Kinesio Taping, and clinical reasoning via the Maitland-Australian Approach.  Further, Dr. von den Stemmen has earned the designation of board certified specialist in orthopedics (OCS) making her an expert in orthopedic physical therapy.


In Jess’s free time, she is often found with friends, family, or her pets. She enjoys cooking and learning new recipes, and crafting in her free time. She also stays active by dancing, hiking, and going to the gym, but her favorite hobby is making people laugh.

Kelsey Yankowitz, DPT, OCS, MFDc

Dr. Kelsey Yankowitz is a native of Santa Monica where she grew up and attended high school.  While at Santa Monica High School, she competed on the soccer and softball teams.  After high school, she attended the University of California, Northridge where she earned her Bachelor's degree in Kinesiology.  Then, she attended Temple University and graduated with her doctoral degree in physical therapy.  After graduating, she obtained years of experience in the physical therapy field as a clinician in outpatient orthopedic settings within the Philadelphia region.  After her doctoral studies, Dr. Yankowitz decided to further her knowledge and enhance her clinical skills by completing an advanced Evidence in Motion Orthopedic Residency program. After graduating the residency program, she earned the highly-regarded Orthopedic Certified Specialist (OCS) designation and subsequently became an orthopedic resident mentor. 


In pursuit of becoming an advanced manual therapist, Dr. Yankowitz became a certified Myofascial Decompression (MFDc) practitioner.  Further, she enjoys learning from colleagues, mentors from her orthopedic residency, and other experts in the physical therapy social media world. ​In her free time she enjoys the outdoors, working out, and spending time with her family.

Haley Hawes, DPT

Dr. Hawes graduated with honors from California State University, Northridge (CSUN) with a Bachelor’s of Science in Kinesiology Exercise Science and minor in Business Management. While at CSUN, she was goal keeper and captain of the school’s Division I women’s soccer team, captaining the team that would eventually win the Big West Conference Tournament and go on to the NCAA playoffs in 2012. Additionally, she interned at CSUN’s strength and conditioning program, where she assisted in the training of many of CSUN’s D1 collegiate athletes. During the summer months, she played semi-professional soccer for Santa Clarita Blue Heat. 

Dr. Hawes then went on to obtain her Doctor of Physical Therapy degree from Marymount University. Her clinical experiences include rotations at Georgetown University Hospital, in the treatment of acute and critically ill patients, the Jackson Clinics, as well as Joint Base Andrews where she assessed, treated, and cleared active duty members of The United States Armed Forces. With years of experience working with high-level athletes and an extensive educational background, Dr. Hawes provides evidence-based patient-centered care.


In her free time, Dr. Hawes enjoys hiking with her Siberian Husky puppy, backpacking, mountain biking, snowboarding, camping, traveling, and going to the gym. She has over 10 years of experience coaching soccer players of all ages and continues to train players both on and off the field.

Andrew Cole, DPT

Dr. Cole graduated from University of California, Davis with his bachelor’s degree in Exercise Biology. During his time at UC Davis, Andrew volunteered as a student athletic trainer to a number of the University's NCAA division I teams such as baseball, soccer and women’s lacrosse.


He then went on to attend the University of Southern California where he earned his Doctorate in Physical Therapy (DPT).  Upon graduation, he was accepted into USC’s esteemed Orthopedic Residency Program where he will be teaching doctoral candidates in the physical therapy program, completing research, taking continuing education courses, and honing his clinical skills to work towards becoming a board-certified specialist in orthopedic physical therapy.  Dr. Cole is also certified in blood flow restriction (BFR) training that helps with improving muscle strength and endurance.


In his free time, Andrew likes to spend time staying active in the gym, hiking, playing sports with friends, and cooking. 

Andrew Hammond, DPT, OCS

Dr. Hammond obtained his Bachelors of Science in Kinesiology from Temple University. He then received his Doctor of Physical Therapy degree from the University of Maryland, Baltimore, and subsequently completed the Johns Hopkins Hospital and George Washington University Orthopaedic Residency.


Following residency, Dr. Hammond remained on staff as a full-time therapist at the Johns Hopkins rehabilitation network. He became an advanced board-certified orthopedic clinical specialist the following year, and later became a clinical faculty member of the residency program from which he graduated. His role in the program involved developing and delivering lecture and lab content, instructing during weekend courses, and mentoring residents. During his time at Hopkins, Dr. Hammond also had the opportunity to present QI and research projects at conferences both within and outside the Hopkins network.


Andrew’s clinical/professional interests lie in clinical reasoning, chronic/persistent pain, effective communication, and manual therapy. He is currently pursuing a spine rehabilitation fellowship through Kaiser Permanente.


In his free time, Andrew enjoys spending time with his wife and their dog, exercising, and reading.

Ricki Rosol, DPT, OCS

Dr. Rosol earned her Bachelor’s of Science from Loyola Marymount University in 2008, majoring in Natural Science with an emphasis in Pre-Physical/Occupational Therapy. She went on to earn her Doctor of Physical Therapy degree from the University of Southern California in 2011.

Dr. Rosol was born and raised in Southern California. Her interest in physical therapy began at a young age while a competitive gymnast. After becoming an injured athlete in high school, she began coaching gymnastics and developed a keen interest in optimizing technique and emphasizing proper mechanics to be successful and avoid injury. 

Since graduating from USC, Dr. Rosol has worked in an outpatient orthopedic and sports medicine setting in the West Los Angeles area. She has achieved success in the treatment of orthopedic injuries in patients of all ages. She’s taken numerous manual therapy courses to further hone her skills as an orthopedic manual therapist. In 2016, Dr. Rosol became a board certified Orthopedic Clinical Specialist (OCS). She has become certified in therapeutic taping techniques, instrument assisted soft tissue mobilization techniques, and Blood Flow Restriction Training (BFR) to optimize patient outcomes. Over the years, Dr. Rosol has served as a clinical instructor for several graduate students pursuing their doctorate in physical therapy.  Further, she has served as adjunct faculty at Loyola Marymount University instructing undergraduate Anatomy & Physiology Lab courses.

Outside of physical therapy, Dr. Ricki Rosol enjoys being active outside walking, running, biking along the beach, traveling, boating, and spending time with her friends and family.

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"Dr. David Ojeda has been more than just my therapist, he's my trainer, my doctor, and my coach wrapped up in one!"

Justin N., elite marathoner

"John has enabled me to walk again. Words cannot express how grateful I am for his work. He is simply put, a healer. "

Brittany F.

"I couldn't recommend Matrix more highly. They ... are very scientific and centered around doing work there and on your own that actually makes a very tangible difference."

Noah L.