The Effect Of Playing Surface And Temperature On Concussion Risk In High School Women's Lacrosse

PURPOSE: Environmental factors such as playing surface have been associated with injury risk. Temperature can affect the compliance of playing surfaces; however, how playing surface and temperature influence concussion risk in girls’ high school lacrosse (GLAX) is unknown. This study examined if playing surface and geographic temperature is associated with GLAX concussion incidence. METHODS: Concussions and athlete exposures (AEs) were obtained using a national injury surveillance system (NATION). Variables included temperature category, surface type (turf vs grass), and mechanism of injury (MOI). States were categorized as cold or warm based on annual mean temperature < or > 55oF, respectively. Florida was excluded due to its headgear mandate. Incidence rates (IR) were defined as the number of concussions per 1000 AEs. 95%CIs were calculated for incidence rate ratios (IRR) using Poisson regression with values excluding 1.00 being significant. RESULTS: No significant differences were observed by surface type (IRR: 1.046, 95%CI: 0.837 to 1.308) or temperature (IRR: 1.220, 95%CI: 0.985 to 1.510; See Table 1). Cold on grass play had higher concussion rates compared to warm on grass (IRR: 1.532, 95%CI: 1.046 to 2.247) but not when cold and warm states were compared on turf (IRR: 1.113, 95%CI: 0.859 to 1.441). When considering MOI, concussion risk was higher for the player vs surface MOI for cold on grass compared to cold on turf (IRR: 2.389, 95%CI: 1.208 to 4.730) as well as in cold on grass compared to warm on grass (IRR: 3.375, 95%CI: 1.111 to 10.254). No significant differences observed for any other MOIs. DISCUSSION: Temperature and playing surface type may interact to influence concussion risk in GLAX. Specifically, game play in colder states on grass surfaces may increase concussion risk, particularly when falling to the ground. These findings may help inform stakeholders regarding player safety when considering changes to an organization’s playing surface. Table 1: - Concussion Incidence by Surface, Temperature, and Mechanism of Injury N AE IR 95% CI Grass 109 144143 0.756 0.627 - 0.912 Field Turf 265 366890 0.722 0.640 - 0.815 Cold States 246 312561 0.787 0.695 - 0.892 Warm States 128 198290 0.646 0.543 - 0.768 Cold States on Grass 65 70757 0.919 0.720 - 1.171 Cold States on Field Turf 181 241986 0.748 0.647 - 0.865 Warm States on Grass 44 73386 0.600 0.446 - 0.806 Warm States on Field Turf 84 124904 0.673 0.543 - 0.833 Cold States on Grass* 14 70757 0.198 0.117 - 0.334 Cold States on Field Turf* 20 241986 0.083 0.053 - 0.128 Warm States on Grass* 4 73386 0.055 0.020 - 0.145 Warm States on Field Turf* 9 124904 0.072 0.037 - 0.138