Practice Area(s)
Physical Therapy
Knee Pain
Accepting New Patients?
From the Doctor (Sponsored)

Reflex clinic in Portland specializes in clinically-proven, non-surgical treatment of osteoarthritis and chronic knee pain.

At Reflex we focus our practice on treating osteoarthritis of the knee. Everything we do is designed to relieve your pain, bring you more mobility, and help you to get back to life.

Our entire team believes in patient-centric care. This means you come first. We are devoted to providing you with meticulous care and an ongoing and informed relationship with your doctor.

Are you suffering from any of the following symptoms?

  • Your knees ache while being active, but improve when you rest.
  • Your knees are stiff when trying to stand up or get out of bed.
  • You have a limited range of motion in your knees.
  • Your knees crack or pop.
  • You injured your knee in the past and it bothers you from time to time.


If you answered ‘yes’ to any of the above symptoms you may be a good candidate for treatment at Reflex. Or take the quiz on our website.

No referral is necessary to come in for your initial knee consultation. You can call Reflex directly at (503) 719-6783 to set up your initial evaluation or fill out an Appointment Request Form on our website.


The Reflex treatment plan varies by individual, but can include any number of the following options:

Hyaluronic Acid (HA) Injections: Joint Fluid Therapy, also known as viscosupplementation, relieves knee pain and increases joint mobility by helping to replace the Hyaluronic Acid (HA) in your knee joint. HA is a naturally occurring polymer found in every tissue of our body. For joints, HA supports healthy lubrication and shock absorption. Depending on the severity of the Osteoarthritis, treatment results can last anywhere from two months to a year and can be repeated without adverse side effects.

Off-loading Knee Braces: The off-loading brace is designed to realign the leg back into proper position as well as lessen the pressure being placed on a worn-down area of the knee joint; resulting in immediate knee pain relief when being active, and stopping additional wear and tear on the joint.

Health Supplementation: Many people with osteoarthritis and knee pain use supplements in their diet to ease their pain. Clinical research has shown that these nutrients are safe and can effectively reduce inflammation, help relieve pain, promote joint comfort and improve knee function. It is important to note that proper dietary supplementation is essential and necessary to maximize your well-balanced diet, exercise, and hydration efforts.

Physical Therapy: Our on-site Physical Therapy (PT) program is focused on increasing knee stability and function with various strengthening and corrective exercises – the foundation of your recovery. Our physical therapy program has incorporated research-proven treatments, with a focus on knee health. We want to help you become stronger, healthier, and equip you with new skills to achieve your optimal mobility.

Bionicare: Reflex is the only clinic in Oregon and Washington that offers the BioniCare Knee System. This unique electrical stimulation treatment is a non-drug, non-invasive option for osteoarthritis (OA) of the knee.

Click here to view PDF Brochure with more information about the BioniCare system. 

What causes osteoarthritis (OA) of the knee?

Although researchers are not completely certain what causes OA of the knee, some likely contributors are:

  • Advancing age: Risk factor most strongly correlated with osteoarthritis as more than 80% of individuals over the age of 75 years are affected
  • Wear and tear on the knee over many years
  • Previous injury: Risk of knee OA most closely related to previous knee injury in athletes (ACL or Meniscus Injury), as opposed to simple participation in soccer, baseball, football, tennis etc.
  • Excessive weight: The evidence linking body mass index (BMI) to severe OA shows a strong association in the knee. An increase in 1 unit of BMI at baseline was associated with a 10.5% increased risk of TKA and at year 5 the increased risk is 8.6%. The risk is greatest at baseline when the patients were in middle age suggesting that this is the most important time to target weight reduction.
  • Genetics: It may “run in the family.” Twin pair and family risk studies have indicated that the heritable component of osteoarthritis may be 50% to 65%.
  • Gender: Women are more likely than men to have OA of the knee. Although women have a lower prevalence than men before age 50, there is a marked increase in prevalence among women after age 50.


Who we are: Reflex opened in 2011 after extensive research and planning by doctors Russ Riggs and Greg Carroll. The idea for Reflex came when Dr. Riggs began experiencing knee pain which began to limit his hiking, and discovered that a novel treatment, viscosupplementation, was available for treatment of knee arthritis. Dr. Carroll also developed a personal interest as he watched his mother’s health deteriorate due to osteoarthritis (OA). Reflex’s focus is a non-surgical approach to treating knee OA. As Dr. Carroll notes, “Patients are often told that surgery is their only option, despite several effective non-surgical treatments being available. Several patients want to explore non-surgical treatments before undergoing an operation as monumental as total joint replacement.” Dr. Carroll and Dr. Riggs are both passionate about quality, and insist that all treatments offered at Reflex be backed by evidenced-based research.