This paper describes the practical aspects of the design, construction and use of strain gauged transducers in clinical orthopaedics. The role of force measurement as a procedure for diagnosis and evaluation in orthopaedics is reviewed and the type of useful data this technique can yield is indicated. The procedure for setting up a load measuring programme is then covered in detail. This includes the formulation of a clinically viable procedure which yields meaningful data, design and construction of the transducers, choice of gauges, their associated instrumentation and analysis of data. The strain gauge itself is dealt with in sufficient detail to cover all the measurement situations which may be encountered in the orthopaedic clinic. Practical aspects, such as the source of supply of components, are fully described.