A kinesiologic electromyography system for the computer-controlled analog and digital recording and processing of muscle action potentials of walking subjects.

A computer-controlled electromyography (EMG) System has been developed for the kinesiologic examination of orthopedic patients. A major objective in the design of the system was its convenient operation in the daily clinical routine. The EMG signals are transduced by specially constructed electrode-preamplifier units and filtered and further amplified in a cable distribution box fixed to the subject's belt or back. The amplified signals are transmitted to the stationary signal conditioning, display, and recording units by an easily tractable trailing cable guided in a ceiling rail. The test gait sequence is performed on a level walkway 14 m in length. A functional partition into periodically recurring gait is achieved either by foot-floor contact sensors or by optional goniometric measurements in the lower extremity. Patient safety is provided by an opto-coupling interface. The EMG signals are displayed on specially constructed large screen oscilloscopes for convenient real-time monitoring by the examiner. An analog recording is carried out by a multi-channel strip chart recorder. The digital recording and processing of the EMG signals and the control of the analog recording unit are implemented by an on-line system. This paper describes the main constructional features of the system and its components, discusses the basic problems involved in the digital recording and processing of EMG signals, and gives an outline of the digital processing mode employed so far in our electromyographical examination of orthopedic patients with various gait disorders.