How Does a CAM Walker Work?

A cam walker is an adjustable orthopedic apparatus that looks like a boot. (The only such trademarked device, called a CAM Walker, is made by Alimed Inc.) “Cam” is an acronym meaning “controlled ankle motion.” As the name indicates, its primary purpose is to prevent or limit ankle and foot movement after a serious sprain, surgery or removal of a cast. Your doctor might also prescribe a cam walker to keep pressure off an ulcerated area on the foot.

Cam walkers offer protection while allowing weight bearing. (Image: ChrisSuperseal/iStock/Getty Images)

Construction Basics

A cam walker consists of a soft, one-piece foam “boot,” which opens entirely down the front. This allows the user to insert the foot and leg with ease. After the foot and leg are in place, the boot is wrapped around the front of the leg and over the top of the foot, and then securely closed with Velcro straps. The boot is attached to two aluminum mechanisms, one on either side of the ankle. These aluminum mechanisms are made of a vertical bar with an adjustable joint mechanism at the base. The joint mechanism is then attached to a hard, plastic form, which serves as the “sole” of the boot. base. The joint mechanism is then attached to a hard, plastic form, which serves as the “sole” of the boot.

Joint Mechanism And Therapeutic Use

The most important feature of the cam walker is the joint mechanism. This mechanism can be adjusted to completely immobilize the ankle. It can also be set by small increments to allow the ankle only a specified range of motion (ROM)--from as little as 2 degrees to a maximum of 45 degrees--which allows therapy to be very gradual and controlled.

The ankle has two natural movements, medically termed dorsiflexion and plantar flexion. Dorsiflexion refers to ankle movement which raises the toes and lowers the heel, while plantar flexion refers to ankle movement which lowers the toes and raises the heel. A cam walker can be set to control both dorsiflexion and plantar flexion, which allows the practitioner maximum control over ankle movement during rehabilitation.

Variations

Cam walkers come in several available styles. Some offer adjustable uprights (the vertical aluminum bars attached to the joints) and the addition of a metal “rocker” to the sole of the plastic form. Boot height may be longer or shorter, depending on how much of the leg must be stabilized. Some allow the tightness of the foam boot to be adjusted by means of an embedded air chamber, which can be pumped or decompressed. Others offer specially constructed joints, which can be adjusted by hand without the use of a tool.

Pros and Cons

Cam walkers allow weight bearing while protecting the injured part of the foot from too much stress. however, they are also removable, which can present a drawback to healing if you don't wear the boot exactly as prescribed.