Weight-shift activity is measured by small, flat, low-cost pressure sensors placed under the cushion in the seat of the wheelchair. A wireless communications device such as a Blackberry.TM. page processes data received from the pressure sensors and transfers the electronic records to a central database periodically or in near real-time. The information about activity and weight shift exercises is stored at the central database where it may be accessed and viewed by Internet users. Historical records of an individual's activity may be presented to the individual and authorized caregivers through secure web pages. This activity information will encourage the wheelchair user to perform regular weight shift exercises and will allow caregivers to intervene when high-risk periods of inactivity are detected.