D+R Balance uses hardware technology within the iPhone to assess postural sway (posturography) and rotation on Fukuda step testing.
Postural sway, or posturography, can be recorded by attaching the iPhone to a subject whilst performing a Standard Romberg or Tandem Romberg test. Subject movement is recorded in three planes and data used to generate the volume of an ellipsoid (mean and SD deviations are also presented). The iPhone may be attached to a subject at the waist, arm or on the lower limb. The application has been used to assess improvement in vestibular function, this study was awarded an Innovation Prize by the Chartered Society of Physiotherapists.
The application can also assess the extent of rotation on Fukuda, or Unterberger test. The device is held by the subject and the extent of rotation is presented on the iPhone screen.