Non-invasive Brain Stimulation and Injury Risk Biomechanics

The overall goal of the project is to determine how repetitive transcranial magnetic stimulation (theta burst stimulation) influences movement among individuals with and without a concussion history. The purpose of this study is prevention via improving injury risk biomechanics to reduce the risk of future musculoskeletal injury.

Participants will complete 2 testing sessions separated by a minimum of 7 days.

During the first testing session, participants will complete single-task serial subtraction, single- and dual-task jump landing, and a theta burst stimulation intervention. The jump landing will be completed before and after theta burst stimulation and under single- and dual-task (serial 7s) conditions. During the second testing session, participants will complete the jump landing before and after theta burst stimulation under single- and dual-task (serial 7s) conditions.

On both testing sessions, the symptom checklist and Tampa Scale of Kinesiophobia 11 (TSK-11) will be administered upon arrival to the lab (after informed consent on day 1), and immediately after repetitive transcranial magnetic stimulation. The Godin Leisure Activity Questionaire will be administered on both days before the jump landing. The NASA Task Load index will be administered on both days immediately after the completion of every cognitive and motor task.

At the end of the second day of testing, the participants will be asked which day the participants believed the participants received the experimental and control conditions of the theta burst stimulation intervention.

This is a single-blinded cross-over design study. The participants will be unaware of when the participants receive the true (experimental) and control (placebo) theta burst stimulation intervention. Experimental (left dorsolateral prefrontal cortex) and control (vertex) conditions will be counterbalanced for the concussion history group. The control group will be matched to their respective concussion history group counterpart's counterbalanced order.

Inclusion criteria

All participants

• self-report to be physically active at least 90 minutes per week
• aged 18-35 years old
• self-report cleared for sports and physical activity

Concussion history group

• self-report experiencing a concussion with the National Institute of Health common data element form

No concussion history group - self-report not experiencing a concussion with the National Institute of Health common data element form

Exclusion criteria

All Participants

• self-report attention deficit disorder and/or attention deficit hyperactivity disorder
• self-report uncorrected vision problems (not included color blindness)
• self-reported history of neurological disease
• self-reported history of seizures/syncope or family history of epilepsy
• self-reported history of frequent severe headaches or migraine.
• self-reported history of respiratory or heart disease.
• self-reported structural brain lesions (e.g., stroke)
• self-reported increased intracranial pressure, such as after infarctions or trauma.
• self-reported currently using antidepressants, neuroleptic medication, medication that lowers seizure threshold, or any other medication that would interfere with testing.
• self-reported currently experiencing a high fever (day of testing; >102.9 degrees)
• self-reported currently undergoing immunosuppressive therapy
• pregnancy
• metal anywhere in the head (except the mouth).
• any electronic implant, such as a cardiac pacemakers, cochlear implant, or deep brain stimulator.
• any implanted medication pump or intracardiac lines.
• self-report not being cleared for sport/physical activity by a medical practitioner (i.e., must be cleared by a medical practitioner to participate if the participant had previous traumatic musculoskeletal injury)
• students working directly in the PI's lab (concussion laboratory, biomechanics laboratory)
• NCAA athletes

Concussion history group

• ≥13 symptom severity on the Sport Concussion Assessment Tool (22 total symptoms are graded on a scale of 0-6. Any symptom with a score >0 [1-6], is summed to get symptom severity).