The Relative Motion Orthosis

Let’s renew our focus on the Relative Motion Orthosis!

This versatile static orthosis is also known as the “Yoke” orthosis. In essence, it positions one or more digits in relative extension or flexion compared to the adjacent digits at the level of the Metacarpal-Phalangeal (MCP) joint.

In this post, we will give you a brief introduction to the unique orthotic design. From the orthosis’ origins to its most common uses, and the steps for effective orthotic fabrication.

But there’s more! For therapists who want to dive a little deeper, we created a Complete Handout for the Relative Motion Orthosis (free download).

Origins of the Relative Motion Orthosis

The relative motion orthosis (RMO)  first came to our attention as a component of a post-operative rehabilitation protocol for extensor tendon injuries. You will know the protocol as the ICAM or “Immediate Active Controlled Motion” protocol.

The RMO was originally fabricated to be worn with a wrist cock-up orthosis. The idea behind the design was to hold one or two digits in relative extension compared to the adjacent digits. A solution to reduce tension on the repaired extensor tendon.

Common Uses and Conditions

The list of pathologies for which the Relative Motion Orthosis is currently being used has grown significantly. In fact, it is the new “go-to-orthosis” for a wide variety of conditions affecting the hand and digits, such as:

  • Boutonniere deformity (acute and chronic)
  • Sagittal band rupture (acute and chronic)
  • Digital joint stiffness
  • Tendon injury and repair
  • Nerve repair

Aside from the list above the RMO also makes a great exercise aid.

How to Fabricate?

Follow along with this video to fabricate an effective Relative Motion Orthosis in Orficast 6 cm: