Behaviour modification based on audible electromyographic (EMG) biofeedback signals was used to discourage the awkward hand postures and the exertion of excessive force with the fingers, which are suspected of causing carpal tunnel syndrome (CTS). The null hypothesis was that participation in such a biofeedback programme has no effect on CTS symptoms. Before and during an 8-week study, data were collected from two groups of five female assembly line workers each. The biofeedback group received training and input, while the control group did not. Test results indicated that the null hypothesis could not be rejected.