Age of First Exposure to Soccer Heading and Sensory Reweighting for Upright Stance

Age of First Exposure to Contact Sports Is Not Associated With Worse Later-In-Life Brain Health in a Cohort of Community-Dwelling Older Men

OBJECTIVE

To evaluate whether early age of first exposure to contact sports (AFE-CS) is associated with worse long-term brain health outcomes.

DESIGN

A cross-sectional, survey study of older men with a history of contact sport participation was completed.

SETTING

Tertiary care facility.

PARTICIPANTS

A cohort of community-dwelling older men dichotomized by using AFE-CS (<12 years vs ≥12 years).

INTERVENTIONS

Independent variables included a dichotomized group of AFE-CS (<12 years vs ≥12 years).

MAIN OUTCOME MEASURES

Brain health outcomes measured by depression, anxiety, cognitive difficulties, and neurobehavioral symptoms. Endorsements of general health problems, motor symptoms, and psychiatric history were also collected. Age of first exposure groups was compared using t tests, χ2 tests, and multivariable linear regressions, which included the following covariates: age, number of prior concussions, and total years of contact sport.

RESULTS

Of 69 men aged 70.5 ± 8.0 years, approximately one-third of the sample (34.8%) reported AFE-CS before age 12 years. That group had more years of contact sports (10.8 ± 9.2 years) compared with those with AFE-CS ≥12 (5.6 ± 4.5 years; P = 0.02). No differences were found after univariate testing between AFE-CS groups on all outcomes (P-values >0.05). Multivariable models suggest that AFE-CS is not a predictor of depression or anxiety. Those in the AFE-CS <12 group had fewer cognitive difficulties (P = 0.03) and fewer neurobehavioral symptoms (P = 0.03).

CONCLUSIONS

Those with AFE-CS <12 to contact sports did not have worse long-term brain health outcomes compared with those with AFE-CS ≥12. Individuals with AFE-CS <12 had significantly lower British Columbia Cognitive Complaints Inventory and Neurobehavioral Symptom Inventory scores compared with those with AFE-CS ≥12.

CLINICAL RELEVANCE

The benefits of earlier AFE-CS may outweigh the risks of head strikes and result in comparable long-term brain health outcomes.

Age of first exposure to soccer heading: Associations with cognitive, clinical, and imaging outcomes in the Einstein Soccer Study

Introduction

The objective of this study is to assess the role of age at first exposure (AFE) to soccer heading as a predictor of known adverse associations of recent and longer-term heading with brain microstructure, cognitive, and behavioral features among adult amateur soccer players.

Methods

The sample included 276 active amateur soccer players (196 male and 81 female) aged 18-53 years old. AFE to soccer heading was treated as a binary variable, dichotomized at ≤ 10 years vs. >10 years old, based on a recently promulgated US Soccer policy, which bans heading for athletes ages 10 and under.

Results

We found that soccer players who began heading at age 10 or younger performed better on tests of working memory (p = 0.03) and verbal learning (p = 0.02), while accounting for duration of heading exposure, education, sex, and verbal intelligence. No difference in brain microstructure or behavioral measures was observed between the two exposure groups.

Discussion

The findings indicate that, among adult amateur soccer players, AFE to heading before age 10 compared to later start of heading, is not associated with adverse outcomes, and may be associated with better cognitive performance in young adulthood. Cumulative heading exposure across the lifespan, rather than early life exposure, may drive risk for adverse effects and should be the focus of future longitudinal studies to inform approaches to enhance player safety.

Age of First Exposure to Contact and Collision Sports and Later in Life Brain Health: A Narrative Review

A controversial theory proposes that playing tackle football before the age of 12 causes later in life brain health problems. This theory arose from a small study of 42 retired National Football League (NFL) players, which reported that those who started playing tackle football at a younger age performed worse on selected neuropsychological tests and a word reading test. The authors concluded that these differences were likely due to greater exposure to repetitive neurotrauma during a developmentally sensitive maturational period in their lives. Several subsequent studies of current high school and collegiate contact/collision sports athletes, and former high school, collegiate, and professional tackle football players have not replicated these findings. This narrative review aims to (i) discuss the fundamental concepts, issues, and controversies surrounding existing research on age of first exposure (AFE) to contact/collision sport, and (ii) provide a balanced interpretation, including risk of bias assessment findings, of this body of evidence. Among 21 studies, 11 studies examined former athletes, 8 studies examined current athletes, and 2 studies examined both former and current athletes. Although the literature on whether younger AFE to tackle football is associated with later in life cognitive, neurobehavioral, or mental health problems in former NFL players is mixed, the largest study of retired NFL players (N = 3,506) suggested there was not a significant association between earlier AFE to organized tackle football and worse subjectively experienced cognitive functioning, depression, or anxiety. Furthermore, no published studies of current athletes show a significant association between playing tackle football (or other contact/collision sports) before the age of 12 and cognitive, neurobehavioral, or mental health problems. It is important to note that all studies were judged to be at high overall risk of bias, indicating that more methodologically rigorous research is needed to understand whether there is an association between AFE to contact/collision sports and later in life brain health. The accumulated research to date suggests that earlier AFE to contact/collision sports is not associated with worse cognitive functioning or mental health in (i) current high school athletes, (ii) current collegiate athletes, or (iii) middle-aged men who played high school football. The literature on former NFL players is mixed and does not, at present, clearly support the theory that exposure to tackle football before age 12 is associated with later in life cognitive impairment or mental health problems.

Age of First Exposure to Collision Sports Does Not Affect Patient Reported Outcomes in Women and Men Community Rugby Players

PURPOSE

This study aimed to determine the relationship between age of first exposure (AFE) to repetitive head impacts through contact/collision sports and patient-reported outcomes in community rugby players.

METHODS

We recruited community rugby players older than 18 yr with at least 1 yr of contact rugby participation to complete an online survey. Participants completed the Brief Symptom Inventory-18 (BSI-18), Short-Form Health Survey 12 (SF-12), and Satisfaction with Life Scale (SWLS) via Qualtrics. We used generalized linear models to examine the association between AFE (continuous) and patient-reported outcomes by sex, while controlling for cumulative years contact/collision sport history, age, and concussion history (yes/no). In addition, we used Mann-Whitney U tests to compare patient-reported outcomes between AFE <12 and AFE ≥12.

RESULTS

A total of 1037 rugby players (31.6 ± 11.3 yr (range, 18-74 yr), 59.1% men) participated in this study. Whether analyzed continuously or dichotomously at age 12 yr, younger AFE was not associated with worse patient-reported outcomes for either men or women. Positive concussion history was a significant predictor of worse BSI-18 subscores, SF-12 subscores, and SWLS in women and worse BSI-18 subscores in men. Cumulative contact/collision sport history was a significant predictor of better BSI-18 Depression and SF-12 (Mental Component Summary) subscores in men only. In men and women, older age was a significant predictor of better BSI-18 Depression, Anxiety, and GSI subscores; better SWLS (in men only); and better SF-12 Mental Component Summary, but worse SF-12 (Physical Component Summary).

CONCLUSIONS

Younger AFE to contact/collision sport is not associated with worse patient-reported outcomes in early adult rugby players. Concussion history was predictive of worse patient-reported outcomes.

Age of First Exposure to Football Is Not Associated With Later-in-Life Cognitive or Mental Health Problems

Background: The purpose of this study was to determine if earlier age of first exposure to football is associated with worse brain health in middle-aged and older adult men who played high school football.

Methods: Men from the United States, aged 35 and older, who reported playing high school football, completed a customized, online health survey via the Amazon Mechanical Turk (mTurk) platform. Survey items included physical, psychological, and cognitive symptoms over the past week and over the past year, sports participation history (including age of first exposure to football), medical history, and concussion history. Participants also completed the Patient Health Questionnaire-8 (PHQ-8) and the British Columbia Post-Concussion Symptom Inventory (BC-PSI).

Results: There were 186 men (age M = 51.78, SD = 10.93) who participated in high school football, and 87 (46.8%) reported football participation starting before the age of 12 and 99 (53.2%) reported football participation at or after the age of 12. Those who started playing football at an earlier age reported a greater number of lifetime concussions (M = 1.95, SD = 1.79) compared to those who started playing at age 12 or later (M = 1.28, SD = 1.52; U = 3,257.5, p = 0.003). A similar proportion of men who played football before vs. after the age of 12 reported a lifetime history of being prescribed medications for depression, anxiety, chronic pain, headaches, or memory problems. When comparing men who played football before vs. after the age of 12, the groups did not differ significantly in their ratings of depression, anger, anxiety, headaches, migraines, neck or back pain, chronic pain, concentration problems, or memory problems over the past week or the past year. The two groups did not differ significantly in their ratings of current symptoms of depression (PHQ-8; U = 4,187.0, p = 0.74) or post-concussion-like symptoms (BC-PSI; U = 3,944.0, p = 0.53). Furthermore, there were no statistically significant correlations between the age of first exposure to football, as a continuous variable, and PHQ-8 or BC-PSI scores.

Conclusion: This study adds to a rapidly growing body of literature suggesting that earlier age of first exposure to football is not associated with later-in-life brain health.

Persistent Visual and Vestibular Impairments for Postural Control Following Concussion: A Cross-Sectional Study in University Students

OBJECTIVE

To examine how concussion may impair sensory processing for control of upright stance.

METHODS

Participants were recruited from a single university into 3 groups: 13 participants (8 women, 21 ± 3 years) between 2 weeks and 6 months post-injury who initiated a return-to-play progression (under physician management) by the time of testing (recent concussion group), 12 participants (7 women, 21 ± 1 years) with a history of concussion (concussion history group, > 1 year post-injury), and 26 participants (8 women, 22 ± 3 years) with no concussion history (control group). We assessed sensory reweighting by simultaneously perturbing participants' visual, vestibular, and proprioceptive systems and computed center of mass gain relative to each modality. The visual stimulus was a sinusoidal translation of the visual scene at 0.2 Hz, the vestibular stimulus was ± 1 mA binaural monopolar galvanic vestibular stimulation (GVS) at 0.36 Hz, the proprioceptive stimulus was Achilles' tendon vibration at 0.28 Hz.

RESULTS

The recent concussion (95% confidence interval 0.078-0.115, p = 0.001) and the concussion history (95% confidence interval 0.056-0.094, p = 0.038) groups had higher gains to the vestibular stimulus than the control group (95% confidence interval 0.040-0.066). The recent concussion (95% confidence interval 0.795-1.159, p = 0.002) and the concussion history (95% confidence interval 0.633-1.012, p = 0.018) groups had higher gains to the visual stimulus than the control group (95% confidence interval 0.494-0.752). There were no group differences in gains to the proprioceptive stimulus or in sensory reweighting.

CONCLUSION

Following concussion, participants responded more strongly to visual and vestibular stimuli during upright stance, suggesting they may have abnormal dependence on visual and vestibular feedback. These findings may indicate an area for targeted rehabilitation interventions.