Scientist have been studying baseball mechanics for optimizing the baseball pitch for decades, starting with video analyses of professional player in the 80’s. In the 90’s a lot of studies started focusing on the increase in injuries and the relation between those injuries and pitching. This was driven by the increased demand and financial consequences of professional pitcher. With the rise of computer power and the potential of 3d analyses in the 2000’s, many studies were performed which showed the relationship between rotational velocity of the trunk and the hips and their role in creating throwing velocity. These kind of laboratory measurements are time consuming (and expensive) but are commonly performed nowadays in professional pitching. After many studies, more and more the focus of science shifted towards determining the optimal timing of the kinematic chain, which is the sequence of the segmental rotations through-out the body. Acknowledging that pitching is a full body activity and the body components are related to eachother. An indeed it has been shown that separation time, the timing between the hips and shoulder is a key factor is safe and reliable throwing at velocities.



In addition to the instruction of coaches, the added potential of individualized, near-real time, technical feedback can be described in three aspects that have been neglected before;

First of all, the feedback is individualized, providing progress benchmarks that are customized to each individual’s technique. It has been suggested before that frequent feedback aids performance execution (Wulf et al., 1998b). Furthermore, feedback was found to be most effective when the athlete can self-regulate the intake of that feedback (Chiviacowsky et al., 2012). With PITCHPERFECT, feedback is available every pitch, and a pitcher can look at the feedback at any time he pleases. In a situation without such a device, the frequency of feedback is dependent on the availability of the coach, who most of the time has to take care of 10-20 other players at the same time. Moreover, coaches usually give feedback when something went wrong, even though evidence exist that positive reinforcement is more effective (Mouratidis et al., 2008).

Second, PITCHPERFECT provides feedback on timing between segments. Giving automated feedback about inter-segmental timing introduces feedback to address the serial-order problem. Next to the importance of a full-body approach in teaching pitching, this feedback system has the added value that the sequential rotation of the segments can be quantified and reported, which is very hard to do with the naked eye.

Third, the onset of fatigue and injury can potentially be distilled from the data that are stored during the use of PITCHPERFECT. Apart from the feedback, colleting movement data from players can also serve as an individualized database. The role that these individualised databases can play, and their impact on motor learning, injury prevention, and fatigue, will be major themes in future research.


In recent years a number of single sensor systems have appeared on the market and in science (Makhni et al., 2018), but before PITCHPERFECT only single sensor systems are commercially available, which thus lack the capability to measure inter-segmental timing. At the moment, the commercially available accelerometers in the IMU’s (up to 4000°/s) are not fast enough to keep up with the extreme rotational velocities achieved during pitching (up to 8000°/s). It has been suggested that game pressure, fatigue and the changing tasks during a match can influence performance, and with PITCHPERFECT it becomes possible to accurately collect a whole new set of potentially important data. If large quantities of data will be collected during training and games, rich databases can be developed, detailing different levels of performance and physical characteristics. In all likelihood, this will lead to a better and more encompassing understanding of full-body kinematics and the power-flow for each athlete. In addition, these databases would provide optimized training schedules, assist coaches on the field, empower trainers and medical staff with detailed individualized information, and thus aid each athlete to throw faster while keeping the risk of injury at bay.