Post-Concussion Musculoskeletal Injury Risks

Inclusion Criteria:

Concussed Cohort

* 18-40 years old.
* Self-reported asymptomatic post-concussion following enrollment into the study and monitoring of symptoms by research personnel via daily self-reported symptom questionnaires.
* Recruited within 5 days following being diagnosed with a concussion, and at least 72 hours prior to self-reporting as asymptomatic.
* Access to a functional email address and the internet for completion of patient reported outcomes (PROs) and musculoskeletal injury measures.

Non-Concussed Cohort

* 18-40 years old.
* Active duty Service members and physically active civilians.
* No self-report history of concussion within the previous 5 years.
* No lingering post-concussion signs/symptoms.
* Same gender as the matched concussed participant.
* Within ±5% of the matched concussed participant's height, weight, and body mass index.
* Within ±2 years of age of the matched concussed participant.
* Participant in the same physical activities (work, recreational sports, average type \[no impact, low-impact, high-impact\] and duration of physical activity)

Exclusion Criteria:

* Post-Concussion Cohort AND Healthy Non-Concussed Cohort

  * Unable to read or comprehend the English language.
  * Admitted to the hospital following concussion.
  * Sustained a concussion not related to physical activity participation (e.g., blast-related injury, fall from a ladder, motor vehicle accident).
  * Loss of consciousness longer than 30 minutes.
  * Alteration in consciousness longer than 24 hours.
  * Post-traumatic amnesia lasting longer than 1 day.
  * Glasgow Coma Scale below 13.
  * Abnormal brain imaging findings.
  * Sustained a concussion that took longer than 21 days for the individual to report as asymptomatic.
  * A MSKI within the last 6 months that resulted in altered or missed physical activity for 3 or more consecutive days.
  * History of MSKI surgery.
  * Pregnant females (will be eligible for participation in the study once medically cleared to RTD/A by a qualified and licensed healthcare provider following the end of the pregnancy).
  * Participants will be excluded if they present any known contraindications for electrical stimulation. These contraindications include conditions such as: active deep vein thrombosis/thrombophlebitis, any acute injury with concurrent inflammation, hemorrhagic conditions, impaired circulation, impaired local sensations, presence of infection (osteomyelitis, tuberculosis), malignancy, recently radiated tissue, skin disease/damage and/or at-risk skin.
  * Present with any implanted pacemaker, electronic device, or plastic/cement material