RELIABILITY OF LIFT ALERT((TM)) AS A FEEDBACK DEVICE FOR DETECTING CHANGES IN BODY POSITION

The Lift Alert(TM) is, small battery-operated unit, usually worn on th e back of a worker's collar that is designed to provide a form of biof eedback about changes in trunk position during lifting tasks. The purp ose of this study was to determine how consistent the Lift Alert(TM) w as at each of five different sensitivity settings (A-E) in detecting c hanges in trunk flexion in a given individual during a controlled bend ing maneuver. The subjects were videotaped while performing a series o f trials of bending maneuvers at each of the sensitivity settings acco rding to a specific protocol. The videotapes were then converted onto a computer program where the still images were captured and marked for data analysis. The reliability of the Lift Alert(TM) was determined b y calculating a coefficient of agreement, that is, the percentage of t rials that were within both 10 and 15 degrees for each of the trials a t a given setting for a single individual. The coefficient of agreemen t for all trials at all five settings was 0.76 within 10 degrees and 0 .92 within 15 degrees. The results of this study suggest that the Lift Alert(TM) is a reliable device for detecting changes in trunk flexion during a controlled bending maneuver for a given individual.