Psychophysical considerations in permissible loads

Psychophysics is identified as one of the criteria that has been used with increasing frequency in developing recommendations for permissible loads. A critique of psychophysics is offered, citing both advantages and disadvantages of the method. The relationship between permissible workloads and low-back pain is reviewed. A distinction is made between low-back pain, low-back impairment, low-back disability and low-back compensation. It is suggested that the setting of permissible workloads in industry, regardless of the criteria used, will have little impact on the incidence of low-back pain, but a significant effect upon low-back disability and low-back compensation.