Goniometers, Potentiometers and Electrogoniometers

 Electrogoniometers have been in development since time the early 1970s. Early devices were bulky potentiometers, sometimes referred to as (potentio-metric goniometers, which were attached to the body segments with rigid bars. Various studies were carried out on normal subjects but they were cumbersome to wear, especially if mul-tiple joints were to be studied. For these reasons the clinical use of such devices was limited. Nicol (1987) described a new flexible electrogoni-ometer which used strain gauge wire. This eliminated the use of rigid bars and made it possible for the elec-trogoniometers to be very light. This breakthrough in relatively cheap and unintrusive joint motion analysis gave rise to a plethora of publications on movement analysis of both normal subjects and patients on a variety of joints. These included studies of the hip and knee motion in pre- and postoperative hip-joint-replacement patients (Rowe et al., 1989), dynamic analysis of wrist circumduction in normal subjects and subjects with wrist disorders  the asessment of subtalar motion (Ball & Johnson, 1993) and active and passive ranges of movement of the ankle and knee motion in children with hemiplegic cerebral palsy (Hazlewood et al., 1994)