The authors investigated three performance functions, used commonly in computerized gait synthesis and prediction of the magnitude of muscle forces of the locomotor system during gait, by comparing the behaviour of these functions with the behaviour of the metabolic energy expenditure. The performance functions were determined by measuring the moments about the lower limbs joints and the joints angular velocities. The behaviour ofthe performance functions was defined by calculating them for different points in the cadence - stride length domain. It was found that none of the performance functions demonstrated the expected behaviour, i.e., a behaviour similar to that of the metabolic energy consumption.

The authors investigated three performance functions, used commonly in computerized gait synthesis and prediction of the magnitude of muscle forces of the locomotor system during gait, by comparing the behaviour of these functions with the behaviour of the metabolic energy expenditure. The performance functions were determined by measuring the moments about the lower limbs joints and the joints angular velocities. The behaviour ofthe performance functions was defined by calculating them for different points in the cadence - stride length domain. It was found that none of the performance functions demonstrated the expected behaviour, i.e., a behaviour similar to that of the metabolic energy consumption.