Physiological Effects of Soccer Heading

Study Overview
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Brief Summary
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There is growing concern for the resulting neurological and physiological outcomes from repeated head impacts in sports that do not manifest into traditional concussion symptoms. Specifically, there is evidence of immediate physiological deficits following controlled soccer heading. This study will compare the physiological changes of adolescents completing a set of soccer headers to those randomized to a set of soccer kicks to evaluate the effect of repetitive head impacts.

Detailed Description
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There is limited data relating head impact biomechanics to neurological outcomes in humans. Concussion occurs from rotational loading of the head giving rise to diffuse stresses and strains in the brain tissue leading to autonomic and physiological dysfunction. Repeated head loading is common in contact sports and an integral part of soccer. It is unknown whether the same biomechanical forces from lower severity head impacts such as typical soccer heading cause temporary physiological deficits as well. Advancement of objective physiological function assessment devices allow measurement of neurological effects in the absence of diagnosed concussion. Recent soccer heading studies have evaluated neurophysiological changes pre- and post-repetitive heading. These studies have found conflicting results for the effect on neurocognitive performance immediately following a bout of heading, but consistent changes were observed in measures of vestibular balance, ocular function, and neurochemical biomarkers. Soccer heading biomechanics studies showed that females experienced higher severity head loading, and in equivalent sports such as soccer and basketball, females have higher concussion rates. This study will compare the physiological changes of male and female adolescents completing one of two soccer heading paradigms to those randomized to kicking to evaluate the effect of repetitive head impacts. This study will relate biomechanical measures of head loading with physiological function changes associated with repeated head impacts, and compare sex-differences in biomechanical measures and physiological changes.

Official Title
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Effect of Repetitive Soccer Heading on Biomechanics and Physiological Measures

Conditions
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Repeated Head Impacts

Intervention / Treatment
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* Other: Soccer Kicking
* Other: Soccer Heading (Frontal)
* Other: Soccer Heading (Oblique)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males or females ages 13 to 18. Actively participating on a competitive soccer team. At least 1 year of soccer heading experience. Parental/guardian permission (informed consent) and child assent. Exclusion Criteria: Subject sustained a concussion or spinal injury within the past 6 months or still has active symptoms from a previous injury. Inability to exercise because of lower-extremity orthopedic injury or significant vestibular or visual dysfunction. Currently taking medications that can affect autonomic function. Plays exclusively the goalkeeper position and does not regularly head the ball. Parental/guardian permission (informed consent) not obtainable or not provided. Parents/guardians or subjects who, in the opinion of the Investigator, may be non-compliant with study schedules or procedures. Subject has fixed orthodontia on upper teeth. Cannot understand English.

Ages Eligible for Study
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Minimum Age: 13 Years
Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: Kicking<br>Subjects will complete a suite of clinical and neurophysiological assessments at 3 timepoints (Pre, 0-hour post, and 16-72 hour post soccer kicking intervention). | Other: Soccer Kicking<br>* Subjects assigned to the soccer kicking arm will complete 10 soccer kicks in 10 minutes.<br>|
| Experimental: Soccer Heading (Frontal)<br>Subjects will complete a suite of clinical and neurophysiological assessments at 3 timepoints (Pre, 0-hour post, and 16-72 hour post soccer heading intervention). | Other: Soccer Heading (Frontal)<br>* Subjects assigned to the soccer heading (frontal) arm will complete 10 frontal soccer headers (ball headed directly back to launch direction) in 10 minutes. Soccer balls will be projected at 10-17.5 m/s from approximately 10-15 m with a JUGS ball launcher.<br>|
| Experimental: Soccer Heading (Oblique)<br>Subjects will complete a suite of clinical and neurophysiological assessments at 3 timepoints (Pre, 0-hour post, and 16-72 hour post soccer heading intervention). | Other: Soccer Heading (Oblique)<br>* Subjects assigned to the soccer heading (oblique) arm will complete 10 oblique soccer headers (ball headed 90° to the right from ball launch direction) in 10 minutes. Soccer balls will be projected at 10-17.5 m/s from approximately 10-15 m with a JUGS ball launcher.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Clinical Concussion Exam immediately post intervention | A standard concussion physical exam includes smooth pursuits, horizontal and vertical saccades, horizontal and vertical gaze stability, visual motion sensitivity, convergence and divergence, and tandem walk. | Pre-intervention to 0 hours post intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Head linear acceleration | Linear acceleration (g) of the head will be measured during soccer heading via an instrumented mouthguard equipped with a 3-axis accelerometer. | During Intervention | 
| Head angular velocity | Angular velocity (radians/second) of the head will be measured during soccer heading via an instrumented mouthguard equipped with a 3-axis gyroscope. | During Intervention | 
| Change in Clinical Concussion Exam at up to 72 hours post intervention | A standard concussion physical exam includes smooth pursuits, horizontal and vertical saccades, horizontal and vertical gaze stability, visual motion sensitivity, convergence and divergence, and tandem walk. | Pre-intervention to between 16 and 72 hours post intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Soccer Heading