# Development of an Eco-Friendly Head Impact Protection Device
## 1 Introduction  
Soccer, ice hockey and American football are among the most popular sports in the world and where the contact between players is more prone. This fact raises several concerns, especially regarding head injuries. Traumatic brain injuries (TBIs) have been a worrisome issue in the sports world, not just because of the injury itself, but also due to the increasing number of players (including the ones at young ages) and the awareness about long term effects such as chronic traumatic encephalopathy (CTE). A concussion is one of the most common resulting scenarios for worrying parents, coaches, players, physicians, etc. Tables 1 and 2 present a small summary of studies and results about concussion having in consideration different sport levels, gender and institutions. The results are measured in concussions per 1000 Athletic Exposures (AEs, defined as one athlete participating in one practise or a game where he/she is exposed to the possibility of athletic injury). Regarding young athletes, there is a higher incidence despite the small risk factors (less exposure and fewer cumulative concussions) [3, 17]. Indeed, high school players may be at greater risk given their lack of experience to avoid unnecessary contacts [2]. Another important factor in the concussion mechanism is the location of the head impact. Some studies concluded that specific head regions are more prone to injuries, as indicated in Table 3.  
Regarding gender influence, female incidence is higher [7, 8, 14, 17, 18, 19, 20], excepting lacrosse, where concussion was predominant for male players [8, 14, 16, 18, 21]. Direct contact (impacts) affected 72% of men and a much lower 41% of women [22]. \begin{table}
\begin{tabular}{l l l} \hline \hline
**Sport** & **Statistic** & **Reference** \\ \hline
**Football** & High school: 0.48/1000 AEs and reported 1.03/1000 AEs. & [2, 3] \\  & College: estimated 0.52/1000 AEs and reported 0.81/1000 AEs. & [4, 5] \\  & NFL: estimated 4.51/1000 AEs. & [6] \\  & Multisport: from 0.33 to 0.64/1000 AEs. & [7, 8] \\ \hline
**Rugby** & Nonprofessional players (male): 7.97/1000 player hours. & [9] \\  & 14\% per 20 hours season (professional athletes. & [10] \\  & Annual Rugby concussions between 4\% and 14\% (junior players) and & [11] \\  & between 3\% and 23\% (seniors). & \\ \hline
**Ice** & Junior hockey: from 21.52/1000 AEs in. College: 1.55/1000 AEs. & [12, 13] \\
**Hockey** & Female hockey: 0.91/1000 AEs. & [14] \\ \hline
**Lacrosse** & College (male players) 1.08/1000 AEs and 0.52/1000 AEs (female). & [15, 16] \\  & Concussion rates: 8.6\% (male) and 9.4\% (female). & \\ \hline
**Soccer** & Concussion: 0.13/1000 AEs in junior female players to 0.41/1000 AEs in & [7, 14] \\  & Sniors. & Male incidence: 0.17 (junior) to 0.49/1000 AEs (senior level). & [17, 18] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Concussion rates in different sports [1]. \begin{table}
\begin{tabular}{l l l l} \hline \hline  & **Percentage** & **Injuries** & **Injury Rate per** & **95\%** \\  & **All Injuries** & **1000 Athletic** & **Confidence** \\  & **(\%)** & **Exposures** & **Interval** \\ \hline
**Men’s baseball** & 2.5 & 0.07 & 0.06, 0.08 \\ \hline
**Men’s basketball** & 3.2 & 0.16 & 0.14, 0.17 \\
**Women’s basketball** & 4.7 & 0.22 & 0.20, 0.17 \\ \hline
**Women’s field hockey** & 3.9 & 0.18 & 0.15, 0.21 \\ \hline
**Men’s football** & 6.0 & 0.37 & 0.36, 0.38 \\ \hline
**Women’s gymnastics** & 2.3 & 0.16 & 0.12, 0.20 \\ \hline
**Men’s ice hockey** & 7.9 & 0.41 & 0.37, 0.44 \\
**Women’s ice hockey** & 18.3 & 0.91 & 0.71, 1.11 \\ \hline
**Men’s lacrosse** & 5.6 & 0.25 & 0.23, 0.29 \\
**Women’s lacrosse** & 6.3 & 0.25 & 0.22, 0.29 \\ \hline
**Men’s soccer** & 3.9 & 0.28 & 0.25, 0.3 \\
**Women’s soccer** & 5.3 & 0.41 & 0.38, 0.44 \\ \hline
**Women’s softball** & 4.3 & 0.14 & 0.12, 0.16 \\ \hline
**Men’s wrestling** & 3.3 & 0.25 & 0.22, 0.27 \\ \hline
**Men’s spring football** & 5.6 & 0.54 & 0.5, 0.58 \\ \hline
**Total concussions** & 5.0 & 0.28 & 0.27, 0.28 \\ \hline \hline \end{tabular}
\end{table}