Soccer Ball Heading Research Articles

Laboratory assessment of a head impact sensor for youth soccer ball heading impacts using an anthropomorphic test device

Recent advances in technology have enabled the development of instrumented equipment, which estimate the head impact kinematics of athletes in vivo. One such headband-mounted impact sensor is the SIM-G (Triax Technologies, Norwalk, CT, USA), which has been previously used to investigate the biomechanics of soccer heading by human subjects. Previous studies have evaluated the accuracy of the SIM-G for pure rotation and pendulum, impulse hammer and drop rig impacts. The current study used a soccer ball heading model to evaluate the accuracy of the SIM-G. A soccer ball was projected at the head of an anthropomorphic test device (ATD) representing a 10-year-old to replicate the heading maneuver at various impact sites, angles and speeds previously identified in youth soccer. Linear regression revealed that the SIM-G sensor overestimated the peak angular velocity and linear acceleration recorded by the ATD headform by approximately 44% and 105%, respectively. Tests in which the ball directly contacted the SIM-G sensor resulted in the largest peak linear accelerations. Glancing impacts were significantly associated with a decrease in percentage error of the SIM-G sensor peak angular velocity data relative to the ATD reference data. While it may not demonstrate accuracy in estimating the magnitudes of head impacts, the SIM-G remains a useful tool to provide estimates of head impact exposure for soccer players.

Blood\u2013brain barrier disruption and ventricular enlargement are the earliest neuropathological changes in rats with repeated sub-concussive impacts over 2\xa0weeks

Repeated sub-concussive impact (e.g. soccer ball heading), a significantly lighter form of mild traumatic brain injury, is increasingly suggested to cumulatively alter brain structure and compromise neurobehavioural function in the long-term. However, the underlying mechanisms whereby repeated long-term sub-concussion induces cerebral structural and neurobehavioural changes are currently unknown. Here, we utilised an established rat model to investigate the effects of repeated sub-concussion on size of lateral ventricles, cerebrovascular blood–brain barrier (BBB) integrity, neuroinflammation, oxidative stress, and biochemical distribution. Following repeated sub-concussion 3 days per week for 2 weeks, the rats showed significantly enlarged lateral ventricles compared with the rats receiving sham-only procedure. The sub-concussive rats also presented significant BBB dysfunction in the cerebral cortex and hippocampal formation, whilst neuromotor function assessed by beamwalk and rotarod tests were comparable to the sham rats. Immunofluorescent and spectroscopic microscopy analyses revealed no significant changes in neuroinflammation, oxidative stress, lipid distribution or protein aggregation, within the hippocampus and cortex. These data collectively indicate that repeated sub-concussion for 2 weeks induce significant ventriculomegaly and BBB disruption, preceding neuromotor deficits.

The Effect of Sub-Concussive Impacts during a Rugby Tackling Drill on Brain Function.

Concussion is known to detrimentally affect brain health. Rugby tackles commonly occur with high collision force between tackler and ball carrier, and low impact head contact is not uncommon. Cognitive deficits following a bout of soccer ball heading has been attributed to the impact and termed sub-concussion. Although soccer ball heading studies provide evidence for acute effects of sub-concussion, it is unknown whether this phenomenon occurs following rugby tackles. This study investigates the acute effects of rugby tackles on brain function and balance in rugby players. Twenty-six volunteers were assigned to either the ball carrier (9), tackler (9) or control (8) group. Controls performed running without the tackle. Outcome measures included corticomotor function using transcranial magnetic brain stimulation (TMS) and balance was assessed by a series of tasks performed on a NeuroCom Balance Master before and immediately after a tackle training drill. Following the tackling bout, the cortical silent period (cSP) increased for the tacklers with no change for ball carrier and control groups, and no differences between groups for balance measures were observed. Lengthening of cSP observed in the tacklers following the bout has been reported in studies of concussion and may indicate long term detrimental effects.

Intracranial Pressure After Soccer Heading

OBJECTIVETo evaluate the effect of soccer heading on intracranial pressure (ICP) in trained athletes.METHODSEight subjects (all male, 21.7±1.7 years) were recruited from the UC San Diego soccer team. ICP and cardiovascular variables were recorded before and after 6 repeats of heading a soccer ball kicked from 35 yards away, into a goal. ICP was estimated non‐invasively from acoustical evoked tympanic membrane displacement (Vm), where a more negative volume displacement is correlated with higher ICP. Mean arterial pressure (MAP), heart rate (HR; Nexfin, Netherlands), and ICP were recorded in three different postures, 15° head up tilt (HUT), 0° supine, −15° head down tilt (HDT), in a randomized order.RESULTSMean Vm at 15° HUT was 37.81±133.21 nL at baseline and −20.82±158.27 nL immediately post soccer heading (P=0.0482, paired t test), analogous to an increased ICP. At 0° supine, mean Vm was −46.19±178.50 nL at baseline and −84.27±183.55 nL after impact (P=0.0321, paired t test). At −15° HDT, mean Vm was −148.48±196.07 nL at baseline and −187.02±186.19 nL immediately post soccer heading (P=0.1176, paired t test). MAP and HR did not significantly change between the baseline and post soccer heading measurements.DISCUSSIONAfter repeated soccer ball heading, ICP significantly increased at 15° HUT and 0° supine, while ICP at −15° HDT, MAP and HR did not significantly change. The relative increase in ICP associated with HDT is comparable to previously described trends. Although the measurement technique currently employed does not provide an absolute ICP baseline, the technique has been established as useful in evaluating relative changes. Under that interpretation, these results reflect what may be an elevated ICP related to soccer heading impacts. Accordingly, the results of this study suggest a potential health risk of participation in head contact sports.Support or Funding InformationNASA (80NSSC19K0020) and Novo Nordic Foundation (NNF16OC0019196)Soccer Heading Increases Intracranial Pressure at Head Up Tilt and Supine PositionsVolume displacement of tympanic membrane (Vm), measured non‐invasively from acoustical evoked tympanic membrane displacement, indicated an increase in intracranial pressure (ICP) after soccer heading at 15° head up tilt (HUT) and 0° supine (n = 8, paired t test, *P < 0.05). No significant increase in ICP at −15° head down tilt (HDT) was observed after soccer heading.Figure 1

Genetic interplay with soccer ball heading.

Mortality from neurodegenerative disease is high among professional soccer players, potentially associated with repeated head impacts during routine gameplay. New data suggest that the apolipoprotein E e4 allele might exacerbate the effects of soccer ball heading on cognition. However, genotyping of athletes to determine their dementia risk remains a distant prospect.

Heads Up on Headers: Effects of Soccer Ball Heading on Brain Function.

Heads Up on Headers: Effects of Soccer Ball Heading on Brain Function.

The Effect of Repeated Soccer Ball Heading on Cortico-spinal Excitability and Inhibition

Postural control has been shown to decline following a bout of soccer ball heading, although mechanisms underling this impairment remain unclear. Repetitive sub-concussive head impacts (RSHI) may disrupt cortico-spinal pathways to trigger these changes, however, no data exists.

Parametric Analysis of the Influence of Elastomeric Foam on the Head Response During Soccer Heading Manoeuvre

Soccer is a unique game that permits the purposeful usage of the head in directing the ball. A lot of studies have coupled heading in soccer with brain trauma injury. This has led to the introduction of various protective headgears for soccer players. Nonetheless, studies have shown that these headgears are only beneficial in head-to-head impact, but none are useful in reducing the risk of sustaining a brain injury due to a soccer heading manoeuvre. The purpose of this study is to evaluate the influence of an elastomeric foam on the head response due to soccer heading manoeuvre by means of the finite element analysis. Validated FE models of soccer ball and human head were used to perform FE analysis of soccer heading. A layer of soft foam was added on the forehead to represent the protective headgear. The foam was defined using hyperfoam material model. A parametric study was conducted to investigate the impact of each material coefficient and foam density on the head response due to soccer ball heading. The results obtained show that an elastomeric foam alone is not able to mitigate the impact caused by soccer heading. Further work on the design of the headgear is needed to look for an optimal impact mitigation strategy.

An Evidence-Based Discussion of Heading the Ball and Concussions in High School Soccer.

Soccer, originally introduced as a safer sport for children and adolescents, has seen a rapid increase in popularity in the United States over the past 3 decades. Recently, concerns have been raised regarding the safety of soccer ball heading (when an athlete attempts to play the ball in the air with his or her head) given the rise in concussion rates, with some calling for a ban on heading among soccer players younger than 14 years. To evaluate trends over time in boys' and girls' soccer concussions, to identify injury mechanisms commonly leading to concussions, to delineate soccer-specific activities during which most concussions occur, to detail heading-related soccer concussion mechanisms, and to compare concussion symptom patterns by injury mechanism. Retrospective analysis of longitudinal surveillance data collected from 2005-2006 through 2013-2014 in a large, nationally representative sample of US high schools. Participants were boys and girls who were high school soccer players. Concussions sustained during high school-sanctioned soccer games and practices. Mechanism and sport-specific activity of concussion. Overall, 627 concussions were sustained during 1,393,753 athlete exposures (AEs) among girls (4.50 concussions per 10,000 AEs), and 442 concussions were sustained during 1,592,238 AEs among boys (2.78 concussions per 10,000 AEs). For boys (68.8%) and girls (51.3%), contact with another player was the most common concussion mechanism. Heading was the most common soccer-specific activity, responsible for 30.6% of boys' concussions and 25.3% of girls' concussions. Contact with another player was the most common mechanism of injury in heading-related concussions among boys (78.1%) and girls (61.9%). There were few differences in concussion symptom patterns by injury mechanism. Although heading is the most common activity associated with concussions, the most frequent mechanism was athlete-athlete contact. Such information is needed to drive evidence-based, targeted prevention efforts to effectively reduce soccer-related concussions. Although banning heading from youth soccer would likely prevent some concussions, reducing athlete-athlete contact across all phases of play would likely be a more effective way to prevent concussions as well as other injuries.

Finite Element Analysis of Soccer Heading

Studies have shown compelling evidence that suggests heading soccer ball might lead to brain trauma. Researchers have attempted to experimentally quantify head acceleration induced by soccer ball heading. A series of linear accelerometers as well as angular accelerometer were used to measure head accelerations. This method however is limited to measuring only head acceleration during the impact. However, it is essential to analyse the acceleration of the brain in addition to the acceleration of the head that takes place during a soccer-heading manoeuvre. Since the motion of the brain is almost impossible to be quantified experimentally, this work focuses on performing finite element (FE) analysis of soccer heading to study the motions of both the head and the brain during the impact. FE model of soccer ball was developed and validated against published experimental data as well as a more detailed model. Moreover, FE model of human head that consists of the skull, facial bones, cerebrospinal fluid (CSF) layer and the brain was also developed and validated against experimental data of blunt impact on human cadaver. Both validated models were assembled to perform the soccer heading simulations. Linear and angular accelerations of the skull and the brain generated are comparable to those of experimental data. However, it has underestimated the angular acceleration due to the absence of neck in the model, but with comparable acceleration profile. Linear and angular accelerations of the brain were found to be almost similar to those of the head, which is contradictory to our initial hypothesis. Further study such as ball impact on instrumented dummy skull is required to corroborate the findings. Nonetheless, the FE models were able to replicate the head accelerations sustained during soccer ball heading satisfactorily. The simulation results show that the models can be employed in finding protective materials that can reduce the accelerations, thus minimising the probability of suffering from long-term brain trauma due to soccer ball heading.

Predicting brain acceleration during heading of soccer ball

There has been a long debate whether purposeful heading could cause harm to the brain. Studies have shown that repetitive heading could lead to degeneration of brain cells, which is similarly found in patients with mild traumatic brain injury. A two-degree of freedom linear mathematical model was developed to study the impact of soccer ball to the brain during ball-to-head impact in soccer. From the model, the acceleration of the brain upon impact can be obtained. The model is a mass-spring-damper system, in which the skull is modelled as a mass and the neck is modelled as a spring-damper system. The brain is a mass with suspension characteristics that are also defined by a spring and a damper. The model was validated by experiment, in which a ball was dropped from different heights onto an instrumented dummy skull. The validation shows that the results obtained from the model are in a good agreement with the brain acceleration measured from the experiment. This findings show that a simple linear mathematical model can be useful in giving a preliminary insight on what human brain endures during a ball-to-head impact.

Selected Abstracts From Other Journals

Objective: To define forces of youth soccer ball heading (headers) and determine whether heading causes retinal hemorrhage. Setting: Regional Children's Hospital, youth soccer camp. Patients: Male and female soccer players, 13 to 16 years old, who regularly head soccer balls. Measurements: Dilated retinal examination, after 2-week header diary, and accelerometer measurement of heading a lofted soccer ball. Results: Twenty-one youth soccer players, averaging 79 headers in the prior 2 weeks, and 3 players who did not submit header diaries lacked retinal hemorrhage. Thirty control subjects also lacked retinal hemorrhage. Seven subjects heading the ball experienced linear cranial accelerations of 3.7±1.3g. Rotational accelerations were negligible. Conclusions: Headers, not associated with globe impact, are unlikely to cause retinal hemorrhage. Correctly executed headers did not cause significant rotational acceleration of the head, but incorrectly executed headers might.

Does Soccer Ball Heading Cause Retinal Bleeding?

To define forces of youth soccer ball heading (headers) and determine whether heading causes retinal hemorrhage. Regional Children's Hospital, youth soccer camp. Male and female soccer players, 13 to 16 years old, who regularly head soccer balls. Dilated retinal examination, after 2-week header diary, and accelerometer measurement of heading a lofted soccer ball. Twenty-one youth soccer players, averaging 79 headers in the prior 2 weeks, and 3 players who did not submit header diaries lacked retinal hemorrhage. Thirty control subjects also lacked retinal hemorrhage. Seven subjects heading the ball experienced linear cranial accelerations of 3.7 +/- 1.3g. Rotational accelerations were negligible. Headers, not associated with globe impact, are unlikely to cause retinal hemorrhage. Correctly executed headers did not cause significant rotational acceleration of the head, but incorrectly executed headers might.