VANDERBILT UNIVERSITY
Minimizing the Risks of Head Trauma in Modern Day
American Football
Focus on limiting causes of subdural brain hemorrhaging
BME 272
Group #3
Doug Browne, Jeff Markle, Tyler Severance
Advisor: Dr. Jonathan Forbes
11/11/2010
Abstract
As a result of this design process, the group hopes to:

Study the effects of angular acceleration in football emulated collisions

Improve existing helmet design, or create a new model to reduce the angular acceleration
from collisions

Develop a system to determine when a helmet has lost the functionality and can no longer
safely protect athletes from angular acceleration
(3.1) Introduction
Since the inception of the game in 1869, American football has enjoyed ever increasing
popularity until becoming the pinnacle of sporting entertainment which it achieved in the 21st
century. However, as the sport continues to grow, more and more athletes are exposing
themselves to the inherent risks of the game. One of these, subdural hemorrhages (SDH), poses
a significant risk to athletes of any level and serves as the focus of this design and application
process. It has been theorized, but only loosely proven, that subdural hemorrhages, and thus,
concussions and other similar injuries, are the result of angular acceleration due to violent head
collisions (Forbes). In fact, based on research performed from 1945 to 1994, subdural
hemorrhages have accounted for the majority of football related deaths. To be more precise, it
was determined that at least 352 of the 684 fatalities during this timeframe were the result of
SDH (Cantu).
This significance of head injuries has dictated the policy of equipment design for several
decades. Helmet use has been mandatory for approximately 70 years and facemasks have been
required for almost 60. As these new equipment models were required, it slowly began to
change the manner in which the game was played. New technique, such as leading a tackle with
the crown of the helmet, by athletes yielded a significant increase in helmet leading tackles
(Cantu). Thus, the incidence of fatalities as a result of brain injuries peaked from 1965 to 1969.
This led to the initiation of the National Operating Committee on Standards for Athletic
Equipment (NOCSAE). By 1973, the NOCSAE had created a new set of rules and regulations
on how to play the game safely, and by 1980, similar standards had been passed down to
collegiate and high school level football as well. Additionally, the NOCSAE began
implementing new standards of helmet regulation which further improved the safety of football
players.
Despite the initial indications that helmet related injuries were decreasing, this trend soon
plateaued around 1994, and began to steadily increase once again. Additionally, the cause of a
significant majority (94%) of fatalities was directly linked to the incidence of subdural
hemorrhages (Boden). Modern testing and the improvement in helmet assessment now allow for
a much better investigation as to the precise levels of translational and rotational accelerations
and the values of these collisions, even at the high school level, overlap with the minimum
threshold to induce subdural hemorrhages (SDHs). Because translational acceleration has been
studied thoroughly over the past decade with minimal success, it is reasoned to believe that a
much greater cause of injury due to SDH is the rotational acceleration from violent collisions.
This study hopes to investigate this claim, engineer helmets that more appropriately address this
concern, and finally propose a new system to the NOCSAE to properly test and measure this
concept as it relates to regulating helmets in American Football.
(3.2) History and Context
To date, the group has done a thorough job researching the background of the NFL,
NCAA, and high school football regulating bodies. Specifically, the NOCSAE is the
organization responsible for enforcing all rules regarding helmet standards. As a starting point,
used helmets from local teams can be used in rotational acceleration simulations to calculate
actual values and determine the likelihood of them resulting in subdural hemorrhages. After a
baseline has been established, it will be possible to try new types of materials and to incorporate
different designs (such as shortening the lever arm) to attempt to reduce the angular acceleration.
Eventually, it will be possible to create an easily replicated test that can be used by teams to
determine when helmets actually need to be replaced.
This project has a wide scope of applicability in that it can be applied to all three levels of
competitive football. The potential market includes countless colleges, high schools,
professional teams, and even Canadian and Arena football leagues. The practicality of this study
cannot be underestimated as the severe nature of head injuries will always be an issue of
concern.
3.3. Team
Our design team is composed of three Vanderbilt University undergraduate engineering
students. Tyler Severance is a Biomedical Engineering student who will serves as group leader,
communicator, and biomechanics and physics specialist. Doug Browne is a Mechanical
Engineering student who will act as the team’s design engineer and materials and mechanics
specialist. Jeff Markle is a Biomedical Engineering Student with a background in Computer
Science. He will serve the group as task focuser, technology specialist, and statistical analyst.
This team features a strong mix of skills that are all extremely relevant to the biological and
physical study of subdural hemorrhaging as well as the design and construction of a helmet. The
team members are also all accountable for their own work and dedicated to this specific task.
The team reports to three outside sources, Dr. Paul King a Biomedical Engineering professor, Dr.
Joel Barnett a professor of Mechanical Engineering, and Dr. Jonathan Forbes who is a
neurologist at Vanderbilt Hospital. Dr. Forbes is the project adviser and will oversee the group
over the course of the grant.
(3.4.) Work Plan and Outcome
We hope to learn about the risks of subdural brain hemorrhaging and concussions in
American football. Also, we wish to understand the causes of these injuries and why they occur
more frequently in high school than in the National Football League. Ultimately, this project has
a twofold goal, firstly, to design a new football helmet to drastically reduce the events that cause
subdural brain hemorrhaging and concussions, and secondly to develop a system to assess the
degradation of quality of helmets used in lower level football programs. The major processes we
will follow include a research period to determine the causes of these injuries and how they can
be reduced, a research-based brainstorming session to generate design ideas, a design proposal, a
design period to implement our proposed design, a testing period, and finally a marketing and an
application period. Throughout this design project we hope to firstly understand the causes and
effects of subdural brain hemorrhaging and concussions occurring in football. Then, at the
conclusion of the grant period we hope to have successfully created an easily accessible and
affordable helmet to reduce these risks that can be marketed to football programs of all levels.
(3.5) Evaluation and sustainability plan
In this project, we are attacking two different problems with subdural hemorrhaging in
American football. The two problems are the helmet itself and the process for which used
helmets are tested to make sure they meet standards before they are redistributed and reused. As
a design team we will feel like the project is a success if that by the end of April we have
designed a football helmet that decreases rotational acceleration of a player’s head when hit to
below the threshold where subdural hemorrhages can take place. We will be looking for
innovative ways to decrease the rotational acceleration that a player’s head will undergo such
that subdural hemorrhages will decrease in likelihood at all levels of American football. The next
part of this project will be considered a success if we formulate a plan to make the testing of used
helmets more efficient and more accurate. We will look into the current processes used by
different helmet manufacturers and see if these processes can be improve and standardized such
that an industry-wide standard can be set. We will consider this part of the project a success if we
find a way to significantly improve on the current testing process or if we come up with an all
new process that is more efficient, cost effective and accurate.
Budget Proposal
Expense
Justification
Cost
Travel to Denver
If we make sufficient progress, me may be
able to attend a conference in April
Testing Equipment
To measure acceleration to see if new helmet
designs decrease rotational acceleration
400
Used Helmets
4-5 helmets to modify and experiment with
design
200
Total
Timeline:
Date
October
28
Proposed Activities
Submit NCIIA Grant Proposal
November
3
4
10
11
16
18
Week of 22
Research Begins
Update Website
Submit Progress Report #1
Submit Progress Report #2
Updated NCIIA Grant Proposal
Submit Progress Report #3
Electronic References due
Oral Report #1
December
7
9
18
Research Continues
IWB Conflict Map Due on Web
Submit Progress Report #4
Submit Progress Report #5
CHRISTMAS BREAK
January
14
Research Continues
Update Website
2000
2600
20
28
Submit Progress Report #6
Oral Report #2
February
1
4
6
10
16
25
Begin Design Process
Brainstorm Sessions
Relate ideas to possible designs
Submit Progress Report #7
Update Website
Oral Report #3
Submit Progress Report #8
March
1
5
14
18
Design Continues
Update Web
SPRING BREAK
Oral Report #4
Submit Progress Report #9
April
1
12
18
21
28
Testing and Modifications
Submit Progress Report #10
Submit Progress Report #11
Oral Report #5
Submit Progress Report #12
Prepare final presentation/poster
May
~1
Poster Presentation
Future
Marketing and Application
References
1. Forbes, Jonathan. Biomechanics of Subdural Hemorrhage in American Football.
Department of Neurological Surgery, Vanderbilt University Medical Center. Nashville,
TN. 2010
2. Cantu RC, Mueller FO: Brain injury-related fatalities in American football, 1945-1999.
Neurosurgery 52(4): 846-852; discussion 852-853, 2003.
3. Boden BP, Tacchetti RL, Cantu RC, Knowles SB, Mueller FO: Catastrophic head injuries
in high school and college football players. Am J Sports Med 35(7):1075-81, 2007.