The goal of this clinical trial is to examine the feasibility, utility, and efficacy of a smartphone-based assessment battery and remotely administered virtual Neuromuscular/Dual-Task (vNDT) intervention among healthy U.S. military service members and physically active young adults with a recent concussion.

Aim 1. Determine the baseline neuromuscular/dual-task performance characteristics among a sample of active-duty military service members compared to physically active young adult civilians.

The investigators hypothesize that active-duty military service members will have similar baseline gait and dual-task abilities as civilians, demonstrating translation potential between populations.

The investigators also hypothesize that baseline gait and dual-task abilities will be influenced by history of prior mTBI injuries among military Service Members.

Aim 2. Examine the efficacy of a smartphone-based vNDTT intervention to reduce musculoskeletal injury and improve neuromuscular/dual-task performance after a recent mTBI.

The investigators hypothesize that those randomized to the intervention within three weeks of mTBI will have a lower risk of MSK injury in the 3-month period following mTBI, relative to standard-of-care.

The investigators also hypothesize that those randomized to the intervention within three weeks of mTBI will have better post-intervention gait and dual-task performance than those assigned to standard-of-care, despite similar baseline performance.

Inclusion Criteria:

• 18-40 years of age at the time of enrollment
• Mild TBI or concussion diagnosis by a physician
• Confirmed MTBI diagnosis via VA/DOD guidelines at time of enrollment
• Participation in regular physical activity prior to injury (confirmed via the Global Physical Activity Questionnaire [GPAQ]) (Cleland et al., 2014; Keating et al., 2019)
• Access to a smartphone for app download

Exclusion Criteria:

• Moderate or severe TBI
• Pre-injury neurological disorder
• Abnormal brain imaging findings (if performed as a part of routine care)
• Previous TBI (mild/moderate/severe) <12 months prior to enrollment other than the current injury for which they are being seen

Unidentified/blinded IPD data may be made available upon reasonable request.

The study PI, Co-Is, and the biostatistician will not know group assignments until after the primary analyses are complete.