Introduction: In the laboratory environment biomechanical characteristics of cricket fast bowlers are assessed using a variety of analysis systems such as retro-reflective motion analysis systems (e.g. VICON). In general these systems allow for detailed and sophisticated analysis of human movement but are limited to the contrived laboratory environment. Previous studies into bowling actions have typically relied upon frame by frame high speed match video analysis or 3 dimensional motion analysis obtained in a laboratory setting. It is generally considered that laboratory analyses provide a more detailed and accurate analysis of bowling actions including "suspect action" but do not provide a "real world" analysis environment. Methodology and Results: Using previously developed wearable technology it is possible to measure arm action at a number of points on the bowling arm. The technology is based on inertial sensors and measures the arms changes in motion hundreds of times a second. These sensors respond to minute changes in inertia in linear and radial directions. These are known as accelerometers and rate gyroscopes, respectively. When combined with absolute positioning technologies such as magnetometers and even GPS (Global Positioning System), laboratory equivalent performance analysis can be obtained.. By comparing the movement of different limb segments it is possible to devolve a detailed picture of arm action.. Case study results from a sub elite bowler show clear differences between throwing and bowling action with elbow abduction and extension being clearly evident signatures in the data Conclusions: The sensors have been shown to be able to classify arm action with comparable accuracy to existing lab based methods. It is hoped that with more complete validation this technology can be used as a training tool to aid in the correction of bowling action to prevent injury, improve performance and correct suspect action.