Abstracts Engineering

Analysis of Head Kinematics in Ice Hockey

by David Pogosian

Ice hockey has been identified as a sport with a high risk for concussions due to it being highly physical. Improvements have been made over the years to improve the protective gear for the players effectively eliminating more severe traumatic brain injuries (TBIs) however mild concussions (mTBI) are still prevalent to this day. One way of predicting these injuries in the recent years is the usage of finite element (FE) analysis to recreate impacts to study the effects of said head kinematics and strain parameters using validated FE models of the brain. In this thesis, video analysis was done on five cases resulting in a concussion and five cases not resulting in concussion from both the Swedish Hockey League (SHL) and the National Hockey League (NHL) to extract the initial velocities and positioning. The average velocity for the injured player and attacking player was 5.12 m/s and 5.08 m/s respectively for the impacts resulting in a concussion. Additionally, the average velocity for the injured player and attacking player was 4.80 m/s and 5.51 respectively for the impacts not resulting in a concussion. The video analysis methodology was also validated using a dataset from a football game and resulted in an average error of 25.4%. The impacts were recreated using the extracted velocities and initial positions in LS-PrePost with the full body FE model THUMS v.4.02 representing a 50th percentile adult male fitted with a helmet previously developed by master thesis students at KTH. The simulations were ran using LS-DYNA. The head kinematics from the head’s center of gravity and brain strain measured called Maximum Principal Strain (MPS) were extracted. Using the MPS values, the 95th percentile was calculated to then determine the likelihood of concussion. The MPS95 ranged from 0.18 to 0.63 for the cases resulting in a likelihood of concussion of 7.48 to 100%. For the cases not resulting in a concussion, the MPS95 values ranged from 0.20 to 0.45 resulting in likelihood of concussion 11.1 to 80.5%. The head kinematics extracted reported similar outcome in terms of risk of suffering concussions. The varying results can be pointed to the drawbacks in the methodology such as the error of the video analysis and the positioning of FE models. Ishockey har fastställts som en sport med höga risker för hjärnskakning på grund av dess fysiska natur. Med åren har förbättringar gjorts på skyddsutrustningen vilket har avlägsnat allvarligare hjärnskador (TBI) från sporten, men dessvärre förekommer mildare hjärnskakningar än idag. På senare år har användning av finita element (FE) metoder använts för att återskapa kollisionerna för att förutspå dessa skador. Detta görs genom att använda validerade FE modeller av hjärnan för att analysera kinematiken samt töjningarna. I detta arbete gjordes en videoanalys av fem fall som resulterade i hjärnskakning samt fem fall där kollisionen inte resulterade i en hjärnskakning från både den Svenska Hockey Ligan (SHL) och "National Hockey League" (NHL). Från videoanalysen togs de initiala…