Does continuous passive motion during keyboarding affect hand blood flow and wrist function? A prospective case report

Abstract

The purpose of this prospective case report was to evaluate the use of a keyboard platform device that uses continuous passive motion (CPM) on vascular flow to the hand for clerical employees who perform daily keyboarding tasks. Subjects were two female volunteers, one symptomatic of carpal tunnel syndrome (CTS), who were employed in clerical positions and perform daily keyboarding tasks for most of their workday. Data collection consisted of baseline and follow-up measurements at 6 weeks, including: 1) screening for symptoms based on the Carpal Tunnel Function Disability Form, 2) evaluation using standard physical therapy examination and assessment techniques, including modified Semmes- Weinstein monofilament testing, 3) a typing productivity test, and 4) Doppler ultrasound examination to quantify vascular flow at the wrist. Results revealed that both subjects demonstrated an overall increase in both radial and ulnar blood flow velocity with no decrement in typing productivity. The symptomatic subject also demonstrated an overall improvement of 10 wpm in the typing tests, a decrease in her disability score and symptom severity, and improvement in function. Results suggest that use of CPM as a non-intrusive ergonomic intervention may be used to treat, as well as prevent, carpal tunnel-like symptoms in those who keyboard.