Impact of Early Specialization on Ice Hockey Goaltender Hip Kinematics

The purpose of this cross-sectional study was to compare hip kinematics between early specialized (ES) and not early specialized (NES) ice hockey goaltenders. This study included 13 ES and 13 NES goaltenders. Kinematics were quantified during common goaltender tasks (i.e., butterfly drops, power and butterfly slides) on a custom slide board using Theia3D markerless technology. The maximum and minimum hip flexion, adduction, and internal rotation angles were determined. The concurrent hip angles in the two other planes at these maximum and minimum positions were also extracted (e.g., adduction and internal rotation at maximum flexion). For discrete data, groups were compared using independent t-tests or Mann-Whitney U tests (α = 0.05), dependent on normality. Statistical parametric mapping was used to compare the groups' hip angles over time. The ES goaltenders moved with increased hip internal rotation and abduction at lower hip flexion angles but with less internal rotation and abduction at higher flexion. Neither of the groups reached the expected extreme ranges of flexion, adduction, or internal rotation typically associated with the mechanical bony impingement of FAIS. The ES goaltenders may minimize large magnitudes of combined flexion and internal rotation or abduction as a pain avoidance mechanism in hips with FAIS or labral tears, or they developed advantageous hip control strategies to avoid abnormal hip contact mechanics that contribute to the development of these pathologies. This study also suggests that hip joint loading throughout internal rotation and abduction may be influential in goaltenders' increased risk of intra-articular hip injuries.