calibration screen is used to select the channels which will be used the user supplies a minimum and maximum level of input to each sensor and the calibration program uses these measurements to adjust the output level of the system such that all output information is presented as a percentage of the sampled minimum and maximum values software programs for implementing the foregoing are wellknown in the art fig3 is an electrical diagram of the biofeedback unit depicted in fig1 a plurality of multiplexers receives electrical signals from the force sensing resistors 13 emg electrodes 7 and the goniometers 12 the outputs 22 23 of the two multiplexers 21a 21b associated with the emg electrodes 7 are input to an operational amplifier 24 which provides a filtered amplified signal 25 representing the level of contraction of a muscle over which the emg electrodes 7 are located the filtered emg signal 25 and the output 26 of the multiplexer 21 associated with the force sensing resistors 13 are input to a first analog to digital a d converter 27 which alternately samples the signals 25 26 at an adjustable rate up to 1000 hz a second a d converter 29 accepts electrical signals 30 from the multiplexers 21 associated with the goniometers 12 sampling the signals 30 at an adjustable rate up to 124 hz a processor 32 accepts the digital signals from the first a d converter 28 and the digital signals from the second a d converter 31 simultaneously displaying a base 10 numerical representation of the digital signals of the selected channel on the liquid crystal display 3 and transmitting the signals via an rs 232 cable 19 to the portable computer the digital signals may also be.