During baseball pitching, the shoulder is constantly exposed to micro-traumatic stress and shoulder injury can potentially end a career. Recently, an upper limb functional evaluation protocol based on MTx (Xsens Technologies B.V., the Netherlands) was developed by INAIL Prostheses Centre (Italy). The aim of this work was to apply the protocol on baseball pitchers, looking for indications to prevent possible shoulder injuries.
Three baseball pitchers participated in the study. All the pitchers signed informed consent. The scapulo-humeral rhythm (SHR) and the humero-thoracic external rotation (EXT) were evaluated before and after 60 pitches. The same evaluations were repeated 24 hours later. For each subject, the ROM and pattern of SHR and EXT during each session of measurement (S1, S2, S3) were compared to each other.
Subject 1 presented consistent ROM in all the degrees of freedom and movements examined, indicating no particular shoulder alterations due to the pitching. Subject 2 presented alterations occurring between S1 and S2, and an improvement in the SHR after 24 hours. Subject 3 showed an improvement between S2 and S3 but evident compensation strategies were maintained after 24 hours.
Larger population of pitchers are required to confirm the capability of the system to discriminate among different alterations and/or injuries occurring in the players. Moreover, the measurement of the real-time pitching can augment the information about the behavior of the shoulder during training, in terms of performance, repeatability of the movement and injury prevention.