Understanding concussion and protection

  Understanding Concussion and Protection   As helmet technology moves forward, concussion remains an issue, so the question we must ask is whether this is despite improvements to helmets, or because of them? Could the lifestyle of a work rider contribute to the risk of sustaining concussion in a fall, or could a change in lifestyle protect against the risk? Can a poor state of mental health increase the risk of concussion, or is mental health affected by repeated concussion? These are just some of the questions being asked by scientists, doctors and engineers in ongoing research to protect riders.  A concussion is a brain injury that occurs when a blow to the head causes the brain to spin rapidly in the opposite direction from where the head was struck and is the most common type of “closed brain injury”, where the skull is not split. Those suffering from concussion may have symptoms such as headache, sensitivity to light, tinnitus, dizziness, sleepiness, confusion and behavioural changes, although many of these symptoms can also be caused by other injuries sustained in a fall and unrelated to brain injury. A specific diagnosis is vital to securing the necessary treatment and correct aid to recovery.  Our natural protection comes from cerebrospinal fluid (CSF), which cushions the brain within the skull and serves as a shock absorber for the central nervous system. CSF is often thought of as existing only between the brain and the skull, but the brain has a much more complicated structure and CSF also fills a system of cavities at the centre of the brain, known as ventricles, as well as the space surrounding the brain and spinal cord.  The transfer of energy when a rider’s head hits the ground causes rapid acceleration and deceleration, which briefly deform the brain. Because of this deformation, the volume of the brain decreases while the volume of the rigid skull remains unchanged. CSF flows into the skull from the spinal cord and fills the empty spaces created by the brain deformation, flowing back with acceleration and forward with deceleration, to prevent the brain impacting against the skull.  Research on turf impact has shown that concussion can occur without any associated helmet damage. The soft surface of the turf distorts and collapses, instead of the helmet, and the energy from the impact is transferred to the head. Currently, equestrian helmets are designed and tested to protect the head from impact with hard surfaces, but concussion most commonly occurs after being thrown from a horse onto a soft surface such as turf.  To improve performance for concussive injury, helmet technology needs to be rethought. Several research projects have risen to this challenge, with help from the sporting communities most at risk. A key player in this research is the NFL and in 2016 pledged $100 million, to become one of the largest funders of concussion research in the United States. Its "Play Smart, Play Safe" initiative aimed to spend $60 million to create a safer helmet as a means of reducing concussion, joining with global sports organisations such as the NHL and World Rugby.  Another major research group is HEADS, an Innovation Training Network funded under the European Commission’s Marie Sklodowska-Curie Programme, structured around 13 individual research projects focusing on the three main topics of accident reconstruction and simulation, head model refinement, and helmet certification improvements. This involves six partners, three industry and three academic, across five countries, who are already involved in working towards new helmet standards: Lead Partner, University College Dublin, Ireland; KU Leuven, Belgium; KTH-Stockholm, Sweden; AGV, Italy; Lazer Sport, Belgium; and Charles Owen, Britain.  Charles Owen is widely recognised as one of the leading manufacturers of riding helmets and the company was chosen in 2015 as one of five first-round winners of the $60 million Head Health Challenge presented by the NFL, to develop new advanced materials for helmets.  Professor Roy Burek of Cardiff University is the Managing Director of Charles Owen, and one of the supervisors of the HEADS project. He explains, “the length of time the impact lasts in contact with the surface is becoming an important factor. For example, impact lasts five milliseconds on steel, but 25-30 milliseconds on softer surfaces. We are seeing concussions at much lower force levels which can only be explained by taking the time into account.  “There are a huge number of blood vessels in the brain, which are stronger and stiffer than neurons (brain cells), so when you are distorting the brain you are straining neurons through a matrix of blood vessels. In CTE (Chronic Traumatic Encephalopathy) studies, the damage is focused around the blood vessels due to the much, much higher local strains.  “The neurons have viscoelastic properties and if you stretch them over a short space of time they stiffen and resist stretching, but if you continue to pull, they start to stretch. It is the amount of stretch that causes the body to react. This is why we are particularly interested in the time interval of impact.”  Burek suggests that helmet development in the past, by not looking at the surface or impact time, may have failed in protecting the milder forms of brain injury that we are only starting to understand their importance. “Slowing the rate of energy transfer rate down is the normal thing we do, but at some point rather than protecting the brain we could actually be causing injury. Are we finding a ground and helmet combination that is making the impact last so long we’re causing injury?” he wonders.  “There is another area we need to consider in how the helmet works with the ground. Historically, helmet design has just focused on the exterior surface. However when the helmet hits the ground it comes to an abrupt stop as there’s not much momentum due to its lightness. On the outside the helmet sticks to the ground, while the head slides within the helmet, which means we have two active surfaces. So now we have to design the inside of the helmet, which is very revolutionary.  “We want the inner surface to allow the skull to slide and move, similar to the scalp. Out of KTH in Stockholm a new technology has developed called MIPS, with a plastic shield on the inside of the helmet, designed to slide from side-to-side, attenuating tangential forces when we impact the ground at speed. The technology mimics the body’s own brain protection. In most equestrian accidents the scalp alone is sufficient protection, but as the speed of riding increases, there is some benefit in having a second biofidelic scalp.”  Burek group has also studied data from helmets involved in equestrian falls. “Helmets from the racing and eventing community have been examined with financial help from BETA. All the helmets were from those who have had a head injury. We found 35% of helmets had not permanently absorbed any energy from the fall, which then suggested are we designing helmets for more extreme accidents than are commonly happening? How do we deal with this, do we say riders rarely get kicked in the head so we don’t need helmets as protective, but instead we want a helmet to be much more absorbing at the lower end of the fall spectrum? As a society should we allow adult athletes to decide on their level of protection? Is it about keeping you alive, or reducing concussion? That’s a big debate.”  The Irish Horseracing Regulatory Board’s Senior Medical Officer, Dr Adrian McGoldrick, is in no doubt that current riding helmets have radically reduced the rates of concussion within the horseracing industry. He has collected figures from falls in competitive races, as well as making his own observations as a General Practitioner based on the Curragh and regularly tending those involved in falls at exercise.  "The researchers in this field are doing a fantastic job and modern helmets have dramatically reduced the level of concussion I'm seeing by 95%,” he says. "There is still a lack of knowledge regarding head injury and the long-term damage to health. It would be wonderful if research could lead to a set of biomarkers that we could use as a gold standard to regulate when a rider could return to the saddle after a concussion. That's something we don't have."  Another major study is being conducted at the New York Institute of Technology (NYIT), which earlier this summer received $15,000 from the New York Thoroughbred Horsemen’s Association (NYTHA). “We take jockey health and safety very seriously,” NYTHA President Joe Appelbaum says. “We are thrilled to be able to help further research in the vital area of head trauma and concussion, so that we will be better able to protect our riders going forward.”  Three-times Eclipse Award winning jockey Ramón Dominguez was forced into retirement in 2013 due to head injuries sustained in a fall and is now a key figure in connecting the racing community with researchers. “I’m in regular contact with the New York Institute of Technology and the work they are doing there is very important for me and other jockeys,” he says. “I am connecting with the racing industry and getting the funding, and the racing industry really does care and sees this as one of the main priorities. Protecting against any risk of head injury is recognised as very important and the racing industry is very proactive in this.”  Dominguez is also working with researchers from other sports who share a common concern in concussion. “Through the Jockeys Guild I met Professor Jeff Crandall, Chair of the NFL Head, Neck, and Spine Engineering Subcommittee and an engineer at the University of Virginia, working on helmets. The NFL had done research where the ideal subjects were jockeys. He agreed most definitely that we are at an age now, when it comes to brain protection, that we would, and should, be benefiting from each other’s work in this field. We need to collaborate with other sports while taking advantage of each other’s research.  “We have a real need to develop a helmet that protects against the force of impact. Jockeys worldwide are riding with helmets that are a lot more expensive than those previously used, but we are still seeing the same, or increased, number of concussions. So, for me, protecting the head with the right helmet is what every jockey wants, as well as other athletes at risk from head injury, and we all want something better.”  Leading the NYIT study on concussion and helmet safety is Dr Milan Toma, whose research is currently one of two NYIT initiatives aimed at elevating visibility for jockey concussions. Dr Hallie Zwibel, Director of NYIT Centre for Sports Medicine, recently partnered with the Jockeys Guild to develop "return to ride" rules that will provide instruction on when injured jockeys can safely return to racing. National protocols do not currently exist in North American horseracing.  "Dr Zwibel, Ramon Dominguez and I got together and we introduced my computational assessment of brain injuries to the Aqueduct Racetrack in New York,” reveals Dr Toma. “They were impressed and decided to contribute $15,000 donation to our research study. While much of the discussion regarding helmet safety has been focused on other sports, I am happy to lend my expertise to help deliver much-needed awareness for horseracing. The headform used in this study represents a leap in head injury modelling by both the complexity and inclusion of the effect of the CSF on potential brain injury.  “First, we need to understand the injury mechanism to reach any conclusion that could lead to adjustments in the current helmet designs. Therefore, we are currently running simulations that show us the events occurring inside the skull when the head hits the ground while wearing helmets for jockeys. Once we can see what's happening inside the head, then we can suggest potential solutions after we confirm their efficacy.  “The study is currently ongoing and it's too soon to publish any new results,” Dr Toma stresses. “However, within a year we should have better understanding of the injury mechanism that governs the resulting damage to the brain when exposed to conditions typical for horseracing accidents.”  Improving helmet design to protect against concussion is just one focus of research, however. Prof Burek reminds us of other key elements currently being examined. Significantly for work riders and jockeys, dehydration can increase the risk of sustaining concussion in a fall.  “Many factors can help us prevent over-reaction to an impact to the head and one of them is hydration. It’s known to reduce concussive events,” reveals Burek. “Another is diet. The body has many neuro protective mechanisms and we need to enable them. For example, if there is sulphur in the diet, such as broccoli, cabbage and garlic, with exercise it produces the protective chemical the brain releases when it feels under threat.  “We are also seeing depression as a factor in increasing the likelihood of sustaining concussion. Depression seems to activate the brain in the same way that prior impacts activate the brain to become unwell. Depression could cause worse symptoms from hitting your head than if you are happy and healthy.”  Of course, not every fall results in a head injury and, indeed, not every head injury results in concussion. “Quite a number of things can be going on inside following an impact, so it should be stressed that people need to identify what type of injury they have,” warns Burek. “An impact may not always result in a mild traumatic injury to the brain. Impacts to the ear canal can create vertigo and dizziness, a totally different mechanism, but can be mistaken for concussion. There can be damage to muscles that control the eyes, which causes disorientation because the eyes are not moving together and the brain receives confused messages. A neck injury can create symptoms of pain and headaches, but has nothing to do with the brain. Hormones can be disrupted, and the sexual drive or menstrual cycle affected. If the growth hormone produced by the pituitary gland, is reduced, as we see in head injury studies, it can lead to depression and suicide attempts. It is important that we identify, sight, ear, hormone, neck or brain? There are specialist exercises to help recovery.”  Dr McGoldrick provides clear advice for all trainers. "To reduce serious injury, a trainer should provide staff with the best available helmet and vest. Riding staff should all be wearing a level 2 safety vest of the standard EN 13158:2009 and 2018 or equivalent. The helmets should conform to the PAS 015:2011 VG01 01 2012 standard required by EU law."  Simply wearing a helmet is not enough, however. Care must be taken that the helmet fits properly and the straps are tight and secure. As Dr Toma points out, “When the head hits the ground the brain first collides against the skull at the point of impact and then rebounds, causing injury on the opposite side. When the helmet isn't tight enough the head similarly rebounds inside the helmet and subsequently increases the number of times that the brain hits the skull in the point of impact and rebounds. You see a lot of loose helmet straps on professional athletes in all sports. A helmet that is too loose may shift position as you ride and hit the ground, and thus reduce the helmet’s protective potential.”  Ultimately, trainers have a duty of care to ensure staff are supplied with correctly fitting safety wear, but individuals can aid their well-being by following a healthy diet and avoiding dehydration. As Prof Burek suggests, “As a jockey, if you are going to be the best then you need a plan to protect yourself, because falls are inevitable. Exercise riders also need to start out with a plan to protect themselves for the future.  “The key message is that someone’s working on it and the protection of riders is part of a whole research community. Equestrianism is up there at the top of scientific research and is not being ignored.”       RECOGNISING CONCUSSION   A rider does not need to lose consciousness to suffer concussion. Watch for, in the days following the fall:  Confusion, inability to remember things that happened before and/or after the injury  Slow to answer questions or follow directions  Easily distracted  Not performing duties as well as expected  A blank stare/glassy eyed  Headache  Dizziness  Loss of vision, seeing double or blurred, seeing stars or flashing lights  Ringing in the ears  Sleepiness  Stomach ache, stomach pain, nausea, vomiting  Poor coordination or balance, unsteady on feet  Slurred speech  Poor concentration  Strange or inappropriate emotions (i.e. laughing, crying, getting angry easily)  Feeling generally unwell

By Lissa Oliver

Understanding Concussion and Protection

As helmet technology moves forward, concussion remains an issue, so the question we must ask is whether this is despite improvements to helmets, or because of them? Could the lifestyle of a work rider contribute to the risk of sustaining concussion in a fall, or could a change in lifestyle protect against the risk? Can a poor state of mental health increase the risk of concussion, or is mental health affected by repeated concussion? These are just some of the questions being asked by scientists, doctors and engineers in ongoing research to protect riders.

A concussion is a brain injury that occurs when a blow to the head causes the brain to spin rapidly in the opposite direction from where the head was struck and is the most common type of “closed brain injury”, where the skull is not split. Those suffering from concussion may have symptoms such as headache, sensitivity to light, tinnitus, dizziness, sleepiness, confusion and behavioural changes, although many of these symptoms can also be caused by other injuries sustained in a fall and unrelated to brain injury. A specific diagnosis is vital to securing the necessary treatment and correct aid to recovery.

Our natural protection comes from cerebrospinal fluid (CSF), which cushions the brain within the skull and serves as a shock absorber for the central nervous system. CSF is often thought of as existing only between the brain and the skull, but the brain has a much more complicated structure and CSF also fills a system of cavities at the centre of the brain, known as ventricles, as well as the space surrounding the brain and spinal cord.

The transfer of energy when a rider’s head hits the ground causes rapid acceleration and deceleration, which briefly deform the brain. Because of this deformation, the volume of the brain decreases while the volume of the rigid skull remains unchanged. CSF flows into the skull from the spinal cord and fills the empty spaces created by the brain deformation, flowing back with acceleration and forward with deceleration, to prevent the brain impacting against the skull.

Research on turf impact has shown that concussion can occur without any associated helmet damage. The soft surface of the turf distorts and collapses, instead of the helmet, and the energy from the impact is transferred to the head. Currently, equestrian helmets are designed and tested to protect the head from impact with hard surfaces, but concussion most commonly occurs after being thrown from a horse onto a soft surface such as turf.

To improve performance for concussive injury, helmet technology needs to be rethought. Several research projects have risen to this challenge, with help from the sporting communities most at risk. A key player in this research is the NFL and in 2016 pledged $100 million, to become one of the largest funders of concussion research in the United States. Its "Play Smart, Play Safe" initiative aimed to spend $60 million to create a safer helmet as a means of reducing concussion, joining with global sports organisations such as the NHL and World Rugby.

Another major research group is HEADS, an Innovation Training Network funded under the European Commission’s Marie Sklodowska-Curie Programme, structured around 13 individual research projects focusing on the three main topics of accident reconstruction and simulation, head model refinement, and helmet certification improvements. This involves six partners, three industry and three academic, across five countries, who are already involved in working towards new helmet standards: Lead Partner, University College Dublin, Ireland; KU Leuven, Belgium; KTH-Stockholm, Sweden; AGV, Italy; Lazer Sport, Belgium; and Charles Owen, Britain.

Charles Owen is widely recognised as one of the leading manufacturers of riding helmets and the company was chosen in 2015 as one of five first-round winners of the $60 million Head Health Challenge presented by the NFL, to develop new advanced materials for helmets.

Professor Roy Burek

Professor Roy Burek of Cardiff University is the Managing Director of Charles Owen, and one of the supervisors of the HEADS project. He explains, “the length of time the impact lasts in contact with the surface is becoming an important factor. For example, impact lasts five milliseconds on steel, but 25-30 milliseconds on softer surfaces. We are seeing concussions at much lower force levels which can only be explained by taking the time into account.

“There are a huge number of blood vessels in the brain, which are stronger and stiffer than neurons (brain cells), so when you are distorting the brain you are straining neurons through a matrix of blood vessels. In CTE (Chronic Traumatic Encephalopathy) studies, the damage is focused around the blood vessels due to the much, much higher local strains.

“The neurons have viscoelastic properties and if you stretch them over a short space of time they stiffen and resist stretching, but if you continue to pull, they start to stretch. It is the amount of stretch that causes the body to react. This is why we are particularly interested in the time interval of impact.”

Burek suggests that helmet development in the past, by not looking at the surface or impact time, may have failed in protecting the milder forms of brain injury that we are only starting to understand their importance.  “Slowing the rate of energy transfer rate down is the normal thing we do, but at some point rather than protecting the brain we could actually be causing injury. Are we finding a ground and helmet combination that is making the impact last so long we’re causing injury?” he wonders.


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