Unexpected Findings from a Pilot Study on Vision Training as a Potential Intervention to Reduce Subconcussive Head Impacts during a Collegiate Ice Hockey Season.

Player-to-player contact is the most frequent head impact mechanism in collegiate ice hockey. Training with three-dimensional multiple-object tracking (3D-MOT) could potentially reduce the quantity and severity of head impacts by enhancing player anticipation of these impacts. The purpose of this study was to evaluate the efficacy of 3D-MOT training to reduce the numbers of head impacts sustained by National Collegiate Athletic Association Division III men's and women's ice hockey players. Collegiate men's and women's ice hockey players (N = 33; men = 17, women = 16) were randomly assigned to a 3D-MOT group (n = 17) or a control (C) group (n = 16). Head impacts were monitored during practices and games, and 3D-MOT training occurred twice per week for 12 weeks throughout one regular season. 3D-MOT forwards sustained head impacts with greater mean peak linear acceleration (3D-MOT = 41.33 ± 28.54 g; C = 38.03 ± 24.30 g) and mean peak rotational velocity (3D-MOT = 13.59 ± 8.18 rad.sec-1; C = 12.47 ± 7.69 rad.sec-1) in games, and greater mean peak rotational velocity in practices versus C forwards (3D-MOT = 11.96 ± 6.77 rad.sec-1; C = 10.22 ± 6.95 rad.sec-1). Conversely, 3D-MOT defensemen sustained head impacts with a mean peak rotational velocity less than that of C defensemen (3D-MOT = 11.54 ± 6.76 rad.sec-1; C = 13.65 ± 8.43 rad.sec-1). There was no significant difference for all other parameters analyzed between 3D-MOT and C groups. Player position may play an important role in future interventions to reduce head impacts in collegiate ice hockey.

Head impact exposures in women's collegiate rugby.

Objectives: To describe the incidence, magnitude, and distribution of head impacts and track concussions sustained in a collegiate level women's rugby season. Methods: Data on head impact incidence and magnitude were collected via Smart Impact Monitors (SIM) (Triax Technologies, Inc., Norwalk, CT) within fitted headbands during practices and games of one competitive season. Magnitude data included peak linear acceleration (PLA) and peak rotational velocity (PRV) measurements and were reported as median [IQR]. Results: Players sustained 120 head impacts ≥15 g (18.1 g - 78.9 g) with 1199 total athlete exposures. In eight games, 67 head impacts were recorded with a mean rate of 0.40 ± 0.22 hits per-player per-match, median PLA of 32.2 g, and PRV of 13.5 rad.sec-1. There were 53 head impacts in 47 practices with a mean rate of 0.05 ± 0.04 hits per-player per-practice, median PLA of 29.8 g and PRV of 15.7 rad.sec-1. Four concussions were reported and monitored. Conclusion: The incidence and magnitude of head impacts in collegiate level women's rugby over one season of practices and games were fewer than those reported in other comparable studies. These findings give insight into the impact burden that female collegiate rugby athletes withstand throughout a competitive season.

Head impacts and cognitive performance in men's lacrosse.

OBJECTIVES: The purpose of this investigation was to record head impacts and assess cognitive function throughout a NCAA Division III men's lacrosse season. METHODS: Fifteen NCAA Div III men's lacrosse players (age = 21.1 ± 1.5 years; height = 179 ± 7.00cm; weight = 80.74 ± 8.00kg) wore Smart Impact Monitors (SIM) (Triax Technologies, Inc., Norwalk, CT) within headbands, in 28 practices and 9 home games of one season. The SIM devices communicated with the Triax Technologies SKYi, which confirmed activated SIMs and obtained data of linear acceleration, rotational acceleration, rotational velocity, direction, and location of each head impact. A minimum threshold of 15g of force was set for head impacts to register with the SIMs. The Comprehensive Trail Making Test and Stroop Color and Word Test were administered at preseason, midseason, and postseason to assess cognitive function performance. RESULTS: There was no significant difference found between all measures of frequency and magnitude of head impacts between games and practices. There was also no significant difference for peak linear acceleration of head impacts between different positions and no significant difference between the magnitude of force and the location of impact on the head. There was a significant increase in CTMT performance from preseason to midseason, from midseason to postseason, and preseason to postseason. There was no significant difference in Stroop test performance throughout the season. CONCLUSION: Subconcussive head impacts in men's lacrosse appear to occur at the same magnitude in practices and games, and do not appear to be position dependent, nor head location dependent. Men's lacrosse athletes' cognitive function as measured by the CTMT, can improve, while cognitive function as measured by the Stroop test remained unchanged.