Assessment of gait parameter in hemiplegic patients by accelerometry

A portable microprocessor-based data acquisition system was used to measure the acceleration of joints during walking in ambulatory subjects and to evaluate temporal and spatial parameters of the gait. The system consists of two triaxial accelerometers and a microdata logger with removable memory. After examination, the recorded data are downloaded to a personal computer to analyze the gait cycle, power spectrum, and attractor of two sites. Experiments were performed on 28 hemiplegic patients of different Brunnstrom stages (Br. stages). The orthogonal accelerations at the head of the fibula were measured when walking at a normal speed. The gait cycle for a subject of a low Br. stage was significantly larger than that for a high Br. stage. The frequency distribution of gait for a low Br. stage subject was significantly smaller than that for a high Br. stage. The attractors of normal subjects and unaffected sites were simple figures with small variance, while those of affected sites were complex forms with large variance. The attractor changes simple form with higher Br. stage. Thus, the authors could estimate the rehabilitation effect from the attractor. This monitor may permit a quantitative evaluation of the recovery of paralyzed patients, both in hospital and at home