Veterans with old brain injuries may face hidden balance risks

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Enrollment Criteria for Participant with TBI (TBI+ group) Inclusion criteria * Age 50-75. People of this age normally do not exhibit substantial balance or cognitive impairments, so observing a clear deficit between groups will provide compelling evidence of a TBI-related effect. This "younger old" age group will also help to avoid other comorbid health conditions of older age that would increase variability (uncertainty) in the data set. * Prior history of moderate closed-head TBI at least 10 years prior to study enrollment. Single or multiple TBIs are acceptable. All participants who self-report a prior TBI will complete a standardized interview called the Ohio State University TBI Identification Method (OSU TBI-ID) to characterize and confirm the occurrence of a prior moderate TBI. Moderate TBI will be defined as any of the following: * loss of consciousness from 30 minutes to 24 hours * and/or alteration of consciousness/mental state for greater than 24 hours * and/or post-traumatic amnesia for \>1 to \<7 days * and/or abnormal structural imaging confirmed by medical records * Affirmative response to the question: "At the present time, do you consider yourself to be fully recovered from the TBI?" * Score on the Activities Specific Balance Confidence Scale of 90 or higher (out of 100 possible points), which indicates absence of self-reported balance/mobility deficits. * Score of 19 or higher on the telephone version of the Montreal Cognitive Assessment, which indicates absence of major cognitive impairment. * living in the community and able to travel to the research site Exclusion Criteria: Enrollment Criteria for Participant with TBI (TBI+ group) Exclusion criteria * Neurological injury or disease other than prior history of moderate TBI * Current clinically significant post-traumatic stress disorder (PCL score \>30) * severe arthritis, such as awaiting joint replacement, that would interfere with participation balance/mobility tasks * Current substance abuse * Current uncontrolled major depressive episode, history of severe psychiatric illness unrelated to TBI (e.g., bipolar 1 or schizophrenia). * severe obesity (body mass index \> 35) * unstable cardiovascular disease (for example, recent angina or uncontrolled high blood pressure) * lung disease requiring use of supplemental oxygen * renal disease requiring dialysis * serious uncontrolled diabetes * terminal illness * myocardial infarction or major heart surgery in the previous year * cancer treatment in the past year, except for nonmelanoma skin cancers and cancers having an excellent prognosis (e.g., early stage breast or prostate cancer) * uncontrolled hypertension at rest (systolic \> 180 mmHg and/or diastolic \> 100 mmHg) * bone fracture in the previous year * hip joint replacement or metal implants that would preclude accurate assessment of lean mass or hip bone mineral density * Use of any pharmacologic agents (within past 180-days) that are known to influence BMD, including anti-resorptive or bone anabolic therapies, any compounded or over-the-counter androgenic hormone or androgen precursor, clomiphene, aromatase inhibitors, anti-estrogen or estrogen treatment, or growth hormone? * Chronic use of systemic glucocorticoids \>7.5 mg/d prednisone equivalent (e.g., hydrocortisone 30 mg, methylprednisolone 6 mg, or dexamethasone 1.2 mg) * current participation in physical therapy for lower extremity function * current enrollment in a clinical trial that might jeopardize safety or scientific integrity of either trial * unable to communicate sufficiently with study personnel, and/or non-English speaking * other medical conditions other that would adversely affect balance, cognition, or oculomotor function. * clinical judgment of investigative team regarding safety or non-compliance.