Soccer Heading Research Articles

Self-reported head injury symptoms exacerbated in those with previous concussions following an acute bout of purposeful soccer heading

ABSTRACTRates of concussion in soccer are high, especially in female players. The primary aim of this study was to examine differences in self-reported concussion-related symptoms (CRS), balance (BESS), and neurocognitive performance (ImPACT) following an acute bout of soccer heading in a group of female collegiate players with and without a history of concussion. Eighty-seven players with 0 to 3+ previous concussions participated. The measurement variables were assessed before and after heading sessions; including one linear and one rotational bout. Players with concussion histories reported more CRS than their non-concussed teammates both before and after the heading sessions. Balance and neurocognitive scores were generally unaffected. This finding should heighten our awareness to carefully monitor soccer players who have experienced concussions and be aware that they may develop concussion-like symptoms, especially after acute bouts of heading either during practice or in matches. The long-term implications of this finding remain unknown.

In Vivo Protocol of Controlled Subconcussive Head Impacts for the Validation of Field Study Data.

Subconcussive hits pose a threat to neuronal health as they have shown to induce neuronal structural damage and functional impairment without causing outward symptomology and appear to be a key contributor to an irreversible neurodegenerative disease, chronic traumatic encephalopathy (CTE). In addition, athletes can incur more than 1,000 of these hits per season. The subconcussive soccer heading model (SSHM) is a relevant, reproducible, and leading method of isolating and examining the effects of these subconcussive head impacts. By controlling variables such as ball traveling speed, the frequency of impacts, interval, ball placement to the head, as well as by measuring head impact magnitude, the SSHM provides the scientific community with a superior avenue of investigating the acute subconcussive effects on neuronal health. In this paper, we demonstrate the utility of SSHM in studying a time-course expression of neurofilament-light polypeptide (NF-L) in plasma in a repeated measures fashion. NF-L is an axonal injury marker that has previously been shown to be elevated in boxers and football players following subconcussive head trauma. Thirty-four adult aged soccer players were recruited and randomly assigned to either a soccer heading (n = 18) or kicking (n = 16) group. The heading group executed 10 headers with soccer balls projected at a velocity of 25 mph over 10 min. The kicking group followed the same protocol with 10 kicks. Plasma samples were obtained before and at 0 h, 2 h, and 24 h after heading/kicking and assessed for NF-L expressions. The heading group showed a gradual increase in plasma NF-L expression and peaked at 24 h after the heading protocol, whereas the kicking group remained consistent across the time points. These results confirmed the NF-L data from clinical field studies, encouraging the use of SSHM to validate clinical subconcussion data.

No Evidence of Association Between Soccer Heading and Cognitive Performance in Professional Soccer Players: Cross-Sectional Results.

Although the scientific community has focused on the effects of concussions in contact sports, the role of subconcussive impacts, as it can occur during soccer heading, has recently gained attention, considering that it may represent an additional mechanism of cumulative brain injury. The aim of this study is to investigate the effects of soccer heading on cognitive functioning in active professional soccer players. Male soccer players (n = 44), from two soccer teams that play in the Brazilian A Series Championship, and non-athletes (n = 47), comparable in age and education, were submitted to cognitive assessment, consisting of computerized and conventional neuropsychological testing (Neupsilin battery). In the computerized cognitive assessment, soccer players performed better than controls on reaction time measures in general motor coordination, executive functioning and memory tests, and on accuracy measures in executive functioning tests. There were no significant differences between groups on the Neupsilin battery. A comparison between two sub-groups of soccer players, based on the self-reported number of headings, did not show significant differences on tests performance. No significant correlations were found between an estimate of exposure to heading during professional soccer career and cognitive performance. Our data demonstrate no evidence of cognitive impairment in soccer players, compared to non-athletes, and no association between heading exposure and performance on neuropsychological tests. Longitudinal investigations, including neuroimaging assessment, will help to clarify whether soccer heading may be associated with brain injury and cognitive dysfunction.

Head impact magnitudes that occur from purposeful soccer heading depend on the game scenario and head impact location

PurposeThis study quantified the linear and angular kinematics that result from purposeful heading during youth soccer games, and the influence of game scenario and head impact location on these magnitudes. MethodThis observational study recruited thirty-six female soccer players (13.4 ± 0.9 years old) from three elite youth soccer teams (U13, U14, U15) and followed for an entire soccer season. Players wore wireless sensors during each game to quantify head impact magnitudes. A total of 60 regular season games (20 games per team) were video recorded, and purposeful heading events were categorized by game scenario (e.g. throw in), and head impact location (e.g. front of head). ResultsGame scenario had a statistically significant effect on the linear head acceleration, and rotational head velocity, that resulted from purposeful headers. Rotational velocity from purposeful headers varied significantly between head impact locations, with impacts to the top of the head (improper technique) resulting in larger peak rotational velocities than impacts to the front of the head (proper technique); this was also the case for the linear acceleration for punts. ConclusionOur findings suggest that the magnitude for both linear and angular head impact kinematics depend on the game scenario and head impact location. Headers performed with the top of the head (improper technique) result in larger rotational velocities compared to the front of the head (proper technique). Accordingly, youth players should be educated on how to execute proper heading technique to reduce head impact accelerations.

A pilot study of diffusion tensor imaging metrics and cognitive performance pre and post repetitive, intentional sub-concussive heading in soccer practice

Background Although soccer players routinely head the ball in practice and games, recent research has suggested that cumulative effects of repetitive heading may cause sub-concussive injury with accompanying effects on brain and behavior. The current study aimed to prospectively investigate the effects of repetitive, intentional heading in soccer practice on brain structure and cognitive function, using a within-subjects design. Methods Participants included 10 soccer players (mean age 20.09 years ± 2.88) who were examined immediately pre- and post-heading practice. An accelerometer was used to measure the force of the impact during soccer heading. Magnetic resonance imaging data were acquired on a 3 T GE Scanner with diffusion tensor imaging. Diffusion tensor imaging analyses were completed using functional magnetic resonance imaging of the brain software library’s Tract-Based Spatial Statistics to examine changes in both fractional anisotropy and mean diffusivity due to heading the soccer ball. Behavioral measures were also completed pre- and post-soccer heading and included the Sport Concussion Assessment Tool and three short-computerized executive function tasks; R studio was used to compare behavioral data within subjects. Results Accelerometer data revealed that none of the heading impacts were >10 g. At this level of impact, there were no significant pre–post heading differences in either fractional anisotropy or mean diffusivity. Additionally, aside from minimal practice effects, there were no significant differences in Sport Concussion Assessment Tool scores and no significant differences in the performance of the three executive function tasks pre–post heading. Conclusions The results provide initial evidence that repetitive heading in soccer practice, at a g force of 10, does not cause changes in brain structure or executive function. Future research should investigate heading in the context of games and with a greater sample size that would allow for sex-based comparisons.

Postural Control Deficits After Repetitive Soccer Heading.

To determine the acute effects of repetitive soccer heading on postural control. Prospective study; participants were divided into 2 groups: a soccer heading group and a control group. Biomechanics laboratory. One hundred sixty participants, including youth (age = 13.0 ± 0.8 years), high school (age = 17.2 ± 1.0 years), and collegiate (age = 20.2 ± 1.3 years) male and female soccer players, participated in this study. Participants in the soccer heading group performed 12 soccer headers (initial velocity = 11.2 m/s). Postural control testing was performed both before (PRE) and immediately after (POST) the purposeful soccer headers. Control participants performed postural control testing PRE and POST a 15-minute wait period. During postural control testing, participants were asked to stand on the MobileMat (Tekscan Inc, Boston, Massachusetts) for two 2-minute intervals with their hands on their hips and their feet together with one eyes-open and one eyes-closed trial. Using the center-of-pressure data, 95% area, sway velocity, and ApEn were calculated. Multilevel linear models were used to analyze the effects of age, sex, group, condition, and concussion history simultaneously. Participants in the soccer heading group had significantly higher sway velocity POST than participants in the control group after controlling for age, sex, concussion history, condition, and PRE (t = -3.002; P = 0.003; 95% confidence interval, -0.482 to -0.100). There were no significant differences from PRE to POST for 95% area, M/L ApEn, and A/P ApEn. Repetitive soccer heading does not affect most postural control measures, even among youth athletes. However, sway velocity increased after heading relative to control participants independent of age, sex, and concussion history.

Greater exposure to repetitive subconcussive head impacts is associated with vestibular dysfunction and balance impairments during walking

Exposure to repetitive subconcussive head impacts (RSHI), specifically soccer heading, is associated with white matter microstructural changes and cognitive performance impairments. However, the effect of soccer heading exposure on vestibular processing and balance control during walking has not been studied. Galvanic vestibular stimulation (GVS) is a tool that can be used to probe the vestibular system during standing and walking. The purpose of this study was to investigate the association of soccer heading with subclinical balance deficits during walking. Twenty adult amateur soccer players (10 males and 10 females, 22.3 ± 4.5 years, 170.5 ± 9.8 cm, 70.0 ± 10.5 kg) walked along a foam walkway with the eyes closed under 2 conditions: with GVS (∼40 trials) and without GVS (∼40 trials). Outcome measures included mediolateral center-of-mass (COM), center-of-pressure (COP) separation, foot placement, mediolateral ankle modulation, hip adduction, and ankle push off. For each balance mechanism, a GVS response was calculated (GVS, mean [without GVS]). In addition, participants completed a questionnaire, reporting soccer heading exposure over the past year. A linear regression model was used to determine if vestibular processing and balance during walking were related to RSHI exposure. Both foot placement (R2 = 0.324, p = 0.009) and hip adduction (R2 = 0.183, p = 0.50) were predicted by RSHI; whereby, greater exposure to RSHI was associated with greater foot placement and hip adduction responses. However, COM-COP separation (R2 < 0.001, p = 0.927), ankle modulation (R2 = 0.037, p = 0.417), and push off (R2 < 0.001, p = 0.968) were not related to RSHI exposure. Individuals who were exposed to greater RSHI were more perturbed by vestibular stimulation during walking, suggesting that there may be vestibular dysfunction and balance impairments with frequent heading; specifically, individuals with greater exposure to RSHI responded with larger foot placement and hip adduction responses to GVS.

History of undiagnosed concussion is associated with concussion-like symptoms following subconcussive head impacts

Objective Immediate removal from activity after sport-related concussion is associated with less time missed from sport, a shorter symptomatic period, and better outcomes on acute clinical measures than delayed removal from activity. However, the effects of undiagnosed concussion on clinical outcomes have not been studied. In the case of an undiagnosed concussion, when the athlete is not removed from play, he/she may undergo subsequent repetitive head impacts. Subsequent head impacts may prevent complete recovery and make the athlete more sensitive to even mild mechanical head impact. The purpose of this study was to determine if soccer players with a history of undiagnosed concussion are more likely to report concussion-like symptoms following typical soccer heading than those without a history of undiagnosed concussion. Methods Thirty-one adult amateur soccer players (17 males and 14 females, 22.3 ± 4.5 years, 171.0 ± 9.2 cm, 71.9 ± 11.4 kg) completed a self-reported concussion/sport history questionnaire as part of a larger study aimed to identify behavioral and biomarkers of subconcussion. Participants were asked to report diagnosed and undiagnosed concussions. Undiagnosed concussions consisted of unreported and unrecognized concussions. Participants also indicated concussion-like symptoms typically experienced after soccer heading. A χ2 analysis was used to determine if a history of undiagnosed concussion was associated with prolonged concussion-like symptoms following subconcussive head impacts. Results Individuals with a history of undiagnosed concussion were more likely to report concussion-like symptoms following soccer heading (χ2 = 5.114, p = 0.024; Likelihood Ratio = 4.693, p = 0.030). Conclusions The results of this study suggest that individuals who experience unreported or unrecognized concussions may be more likely to experience concussion-like symptoms following repetitive subconcussive head impacts and highlight the importance for athletes in immediately reporting concussion signs and symptoms. We speculate that these individuals may not fully recover and may remain sensitive to mild mechanical head impact even years following their concussion.

Quanterix’ Test Links Soccer Headers with Concussions

Quanterix’ Test Links Soccer Headers with Concussions

Association of Acute Increase in Plasma Neurofilament Light with Repetitive Subconcussive Head Impacts: A Pilot Randomized Control Trial.

The purpose of the study was to examine an association of repetitive subconcussive head impacts with changes in plasma neurofilament light (NF-L) levels following 10 bouts of controlled soccer heading. In this randomized control trial, 37 healthy adult soccer players were randomly assigned into either a heading (n = 19) or kicking-control group (n = 18). The heading group executed 10 headers with soccer balls projected at a velocity of 25 mph over 10 min. Plasma samples were obtained at pre-heading baseline, 0 h, 2 h, and 24 h post-heading. The kicking-control group followed the same protocol with 10 kicks. Plasma NF-L was measured using ultrasensitive single-molecule array technology. Data from 34 subjects were eligible for analysis (heading n = 18 and kicking n = 16). Ten subconcussive head impacts induced a gradual increase in plasma NF-L expression for the heading group (β = 0.0297, standard error [SE] = 0.01, p = 0.0049), whereas there was no significant time effect for the kicking-control group. A follow-up analysis revealed that a significant difference appeared at 24 h post-heading (3.68 ± 0.30 pg/mL) compared with pre-heading (3.12 ± 0.29 pg/mL, p = 0.0013; Cohen's d = 1.898). At the 24 h post-heading time-point, the plasma NF-L level for the heading group was significantly higher than that of the kicking-control group with an estimated mean difference of 0.66 pg/mL (SE = 0.22, p = 0.0025). The data suggest that the increased level of plasma NF-L was driven by repetitive subconcussive head impacts and required longer than 2 h after the head impacts for the increase to be detected. Plasma NF-L levels may serve as an objective marker to monitor acute axonal burden from subconcussive head impacts.

The number of purposeful headers female youth soccer players experience during games depends on player age but not player position

ABSTRACTPurpose: The aim of this study was to describe the frequency and characteristics of purposeful soccer heading in youth players based on age, position, and head impact location.Methods: Game video was recorded for three female youth teams [under-13 (U13), under-14 (U14), and under-15 (U15)] for an entire season. Purposeful headers were categorized for these three teams and their opposition.Results: The median number of headers experienced during games was one, and the minimum number of headers was zero. The maximum number of headers performed during a game by a U13 player was eight, and nine for U14 and U15 players. There were statistically significant differences in the number of headers performed in the different age groups (p < 0.05), but no significant differences between player position (p > 0.05). There was no significant association between head impact location and game scenario (p > 0.05).Conclusions: Our study shows that youth players frequently head the ball during games. This information may guide data-driven approaches regarding heading restrictions in youth soccer.

Heading in soccer increases serum neurofilament light protein and SCAT3 symptom metrics

ObjectivesTo determine the effect of heading a soccer ball on serum neurofilament light (NF-L) protein, plasma tau protein and symptom metrics including total number of symptoms reported and symptom severity...

MRI-defined White Matter Microstructural Alteration Associated with Soccer Heading Is More Extensive in Women than Men.

Purpose To examine the role of sex in abnormal white matter microstructure after soccer heading as identified by using the diffusion-tensor imaging (DTI) metric fractional anisotropy (FA). Materials and Methods In this prospective cross-sectional study, 98 individuals who were enrolled in a larger prospective study of amateur soccer players (from 2013 to 2016) were matched 1:1 for age and history of soccer heading in the prior 12 months. Among the subjects, 49 men (mean age, 25.7 years; range, 18-50 years) and 49 women (mean age, 25.8 years; range, 18-50 years) with median total soccer headings per year of 487 and 469, respectively, underwent 3.0-T DTI. Images were registered to the Johns Hopkins University template. A voxelwise linear regression was fitted for FA with terms for the number of headings during the previous 12 months and its interaction with sex after controlling for the following potential confounders: age, years of education, number of lifetime concussions, and handedness. In the resulting statistical maps, P < .01 indicated a statistically significant difference, with a threshold cluster size larger than 100 mm3. Results Among men, three regions were identified in which greater heading exposure was associated with lower FA; eight such regions were identified among women (>100 contiguous voxels, P < .01). In seven of the eight regions identified in women, the association between heading and FA was stronger in women than in men. There was no significant difference of heading with FA between the sexes for any region in which heading was associated with FA among men (P > .01, <100 contiguous voxels). Conclusion With similar exposure to heading, women exhibit more widespread evidence of microstructural white matter alteration than do men, suggesting preliminary support for a biologic divergence of brain response to repetitive trauma. © RSNA, 2018 Online supplemental material is available for this article.

Head Impact Kinematics Estimation With Network of Inertial Measurement Units.

Wearable sensors embedded with inertial measurement units have become commonplace for the measurement of head impact biomechanics, but individual systems often suffer from a lack of measurement fidelity. While some researchers have focused on developing highly accurate, single sensor systems, we have taken a parallel approach in investigating optimal estimation techniques with multiple noisy sensors. In this work, we present a sensor network methodology that utilizes multiple skin patch sensors arranged on the head and combines their data to obtain a more accurate estimate than any individual sensor in the network. Our methodology visually localizes subject-specific sensor transformations, and based on rigid body assumptions, applies estimation algorithms to obtain a minimum mean squared error estimate. During mild soccer headers, individual skin patch sensors had over 100% error in peak angular velocity magnitude, angular acceleration magnitude, and linear acceleration magnitude. However, when properly networked using our visual localization and estimation methodology, we obtained kinematic estimates with median errors below 20%. While we demonstrate this methodology with skin patch sensors in mild soccer head impacts, the formulation can be generally applied to any dynamic scenario, such as measurement of cadaver head impact dynamics using arbitrarily placed sensors.

Brain Motion, Deformation, and Potential Injury During Soccer Heading

Brain Motion, Deformation, and Potential Injury During Soccer Heading

Brain Motion, Deformation, and Potential Injury During Soccer Heading

Brain Motion, Deformation, and Potential Injury During Soccer Heading

Heading Frequency Is More Strongly Related to Cognitive Performance Than Unintentional Head Impacts in Amateur Soccer Players.

Compared to heading, unintentional head impacts (e.g., elbow to head, head to head, head to goalpost) in soccer are more strongly related to risk of moderate to very severe Central Nervous System (CNS) symptoms. But, most head impacts associated with CNS symptoms that occur in soccer are mild and are more strongly related to heading. We tested for a differential relation of heading and unintentional head impacts with neuropsychological (NP) test performance. Active adult amateur soccer players were recruited in New York City and the surrounding areas for this repeated measures longitudinal study of individuals who were enrolled if they had 5+ years of soccer play and were active playing soccer 6+ months/year. All participants completed a baseline validated questionnaire ("HeadCount-2w"), reporting 2-week recall of soccer activity, heading and unintentional head impacts. In addition, participants also completed NP tests of verbal learning, verbal memory, psychomotor speed, attention, and working memory. Most participants also completed one or more identical follow-up protocols (i.e., HeadCount-2w and NP tests) at 3- to 6-month intervals over a 2-year period. Repeated measures General Estimating Equations (GEE) linear models were used to determine if variation in NP tests at each visit was related to variation in either heading or unintentional head impacts in the 2-week period before testing. 308 players (78% male) completed 741 HeadCount-2w. Mean (median) heading/2-weeks was 50 (17) for men and 26 (7) for women. Heading was significantly associated with poorer performance on psychomotor speed (p < 0.001) and attention (p = 0.02) tasks and was borderline significant with poorer performance on the working memory (p = 0.06) task. Unintentional head impacts were not significantly associated with any NP test. Results did not differ after excluding 22 HeadCount-2w with reported concussive or borderline concussive symptoms. Poorer NP test performance was consistently related to frequent heading during soccer practice and competition in the 2 weeks before testing. In contrast, unintentional head impacts incurred during soccer were not related to cognitive performance.

Sex and age differences in head acceleration during purposeful soccer heading

ABSTRACTDifferences in head–neck segment mass, purposeful heading technique, and cervical strength and stiffness may contribute to differences in head accelerations across sex and age. The purpose of this study was to compare head acceleration across sex and age (youth [12–14 years old], high school and collegiate) during purposeful soccer heading. One-hundred soccer players (42 male, 58 female, 17.1 ± 3.5 years, 168.5 ± 20.3 cm, 61.5 ± 13.7 kg) completed 12 controlled soccer headers at an initial ball velocity of 11.2 m/s. Linear and rotational accelerations were measured using a triaxial accelerometer and gyroscope and were transformed to the head centre-of-mass. A MANOVA revealed a significant multivariate main effect for sex (Pillai’s Trace = .165, F(2,91) = 11.868, p < .001), but not for age (Pillai’s Trace = .033, F(4,182) = 0.646, p = .630). Peak linear and rotational accelerations were higher in females (40.9 ± 13.3 g; 3279 ± 1065 rad/s2) than males (27.6 ± 8.5 g, 2219 ± 823 rad/s2). These data suggest that under controlled soccer heading conditions, females may be exposed to higher head accelerations than males.

Head and neck size and neck strength predict linear and rotational acceleration during purposeful soccer heading

There is increasing societal concern about the long-term effects of repeated impacts from soccer heading, but there is little information about ways to reduce head impact severity. The purpose of this study was to identify factors that contribute to head acceleration during soccer heading. One-hundred soccer players completed 12 controlled soccer headers. Peak linear (PLA) and rotational (PRA) accelerations were measured using a triaxial accelerometer and gyroscope. Head acceleration contributing factors were grouped into 3 categories: size (head mass, neck girth), strength (sternocleidomastoid, upper trapezius) and technique [kinematics (trunk, head-to-trunk range-of-motion), sternocleidomastoid and upper trapezius activity]. Multiple regression analyses indicated size variables explained 22.1% of the variance in PLA and 23.3% of the variance in PRA; strength variables explained 13.3% of the variance in PLA and 17.2% of the variance in PRA; technique variables did not significantly predict PLA or PRA. These findings suggest that head and neck size and neck strength predict PLA and PRA. Anthropometric and neck strength measurements should be considered when determining an athlete’s readiness to begin soccer heading.

Feasibility of virtual reality-based balance rehabilitation in adults with spinocerebellar ataxia: a prospective observational study

Objective: To test the effects of a virtual reality (VR) balance rehabilitation program in patients diagnosed with SCAs.Materials and methods: A prospective observational study was carried out with a cohort of 28 patients diagnosed with SCAs, including eight females and 20 males, 15–70 years of age (mean, 41.5 ± 16.9 years). Patients were submitted to otorhinolaryngological assessment to exclude any kind of middle ear impairments that may hinder exam results, and vestibular evaluation to verify the existence of vestibular disorders, kind and site of the lesion. The Dizziness Handicap Inventory (DHI), Berg Balance Scale (BBS), and 36-item Short-form Health Survey (SF-36) questionnaires were applied before and after VR rehabilitation. The criterion for significance in before versus after VR training comparisons was p < .05.Results: Regarding to baseline, the participants showed significant improvements posttraining in their DHI and BBS scores. These improvements were accompanied by improvements in perceived quality of life (QoL) as measured by the SF-36. There were significant improvements in balance and gait, fall frequency, and patients’ self-confidence.Conclusions: Showed consistent improvement postrehabilitation in their ability to play VR games (i.e. Soccer Heading, Tightrope, Table Tilt, and Ski Slalom). VR rehabilitation may be an effective SCA therapy. The breadth of improvements evidenced here should promote physical and psychological recovery, while fostering a better QoL.