ASSESSMENT OF POSTURE AND MOTION BY MULTICHANNEL PIEZORESISTIVE ACCELEROMETER RECORDINGS

Modern assessment of posture and motion involves the use of wide bandw idth piezoresistive accelerometers. The direct current (DC) component allows for assessment of slow motion and change in position referring to the gravitational axis; the alternating current (AC) component, cal ibrated in g, represents acceleration along the sensitive axis of the device. A method study was designed to evaluate the division in DC and AC components, reliabilities, discrimination between conditions, and detection of types of physical activities. Recordings were made in 26 student participants for eight conditions: sitting, standing, lying su pine, sitting and typing on a PC keyboard, walking, climbing stairs, w alking downstairs, and cycling. This procedure was repeated in reverse d order. A classification of physical activities according to the eigh t conditions (first trial) and based an four parameters, that is DC co mponents trunk, thigh, and lower leg and AC component trunk, was corre ct in almost 100% of patterns, when applied to the second trial.