Abstract: A golf training device for use in a glove or under the ball of the foot or under the heel, which includes pressure sensors, a visual display which is flexibly connected to the sensors for adjusting the position to suit the wearer, and a controller programmed to provide visual feedback to indicate if the pressure is appropriate or not. For a glove the sensors are located on the palm at the junction with the first three fmgers. There are two or more sensors and for each sensor the controller can display by an appropriately coloured LED that the pressure detected by the sensor is too light, appropriate or too tight. For a shoe the sensors are located under the ball of the foot or the heel and the LEDs indicate whether the weight is appropriately on the ball of the foot or on the heel.

Abstract: For processing data relating to the performance of an apparatus, the data is analyzed using a Kalman Filter. After a first pass of data through the filter, the results are refined by discarding at least one less significant component performance change and/or sensor bias. The Kalman Filter is then re-run using the modified data. As further runs of the Kalman Filter are performed, as required, the input of each successive run is refined by discarding from the preceding run at least one further component performance change and/or sensor bias. For each run, an objective function is evaluated for the amount of unexplained measurement change and/or the amount of component performance change and sensor bias. The run whose results show an acceptable value for the objective function is selected as the best solution. In this way, the tendency of the Kalman Filter to distribute the cause of any sensed performance change over all the possible sources of that change is avoided.