Instrumented Postural Sway Plugin

ISWAY is an objective, fast, reliable, and sensitive test of balance control which instruments the popular test, CTSIB (Clinical Test of Sensory Integration of Balance). Only one Opal™ inertial sensor is needed to obtain over 40 postural control metrics. It is an elegant solution to expensive, bulky, and immobile force plates. At just a fraction of the cost, ISWAY offers a practical way to measure postural sway during stance. 

By instrumenting the Static Balance Test and designing automatic analysis algorithms, we provide objective and comprehensive assessment that goes well beyond stop-watch measures. The ISWAY test takes only a couple minutes to setup, and 30 seconds to complete.

Sensor Configuration



  • 1 Opal™ Sensor
  • 1 Docking Station
  • 1 Access Point
  • 1 Waist Strap
  • Mobility Lab Software
  • ISWAY Plugin

ISWAY Measurements

The ISWAY test results in 42 primary measures of postural sway, including: sway area, velocity, frequency and jerkiness.

>> Download the full list of measurement

Clinical Test of Sensory Integration of Balance (CTSIB)

Developed by Dr. Shumway-Cook and Dr. Horak (Shumway-Cook, A. and Horak, F.B. Assessing the influence of sensory interaction on balance. Phys. Ther., 66: 15481550, 1986), the CTSIB protocol helps determine which sensory system (visual, somatosensory, or vestibular) a subject relies on to maintain balance. APDM has further bolstered the quality of the test by instrumenting it with our Mobility Lab™ software. Test conditions include:

1) Eyes open, hard surface
2) Eyes closed, hard surface
3) Eyes open, foam surface
4) Eyes closed, foam surface

Measurement Protocol

The subject begins by standing with his/her arms crossed in a comfortable manor, and is looking at the picture on the wall. The test administer will then simply start the test, wait for 30 seconds until the test is completed. Different methods of standing may be used at the guidance of the administer, such as eyes closed, on a foam pad, one-legged, etc (see CTSIB). The administer can make note of the type of stance used within Mobility Lab™ for future reference.

Learn More

For more technical information about the ISWAY plugin, or any other APDM product, please contact us at,

  Phone: 503-446-4055