Targeting the Hip Abductors to Reduce Falls in Older Veterans Through A Virtual Multimodal Balance Intervention

Falls are multifactorial in origin, with a failure to negotiate environmental hazards, muscle weakness, impaired postural control, and gait and balance deficits among the top contributors. Common between these is impaired lower extremity function, including difficulties during walking, incident slips and trips, or an inability to effectively recover after a loss of balance. The multifactorial origin of falls requires a multimodal approach to effectively reduce risk. The CDC currently includes 17 exercise interventions targeting fall reduction, and most of these programs reportedly decrease fall risk by ~30%. The investigators' MMBI program, developed over the last ten years, is unique in its approach to exercise for fall prevention. It has been developed in older Veterans at high risk for falls, who suffer an average of 16 comorbid health conditions. Further, the target of the hip abductors and multiple planes of movement with functional exercises and progressive lower extremity strengthening is unique to the MMBI program. While some programs have been widely studied, the majority do not have validated benefit to mechanistic outcomes, such as changes in muscle quality or intermuscular adipose tissue. In an on-going systematic review of studies that utilize a live-virtual format for fall prevention, the investigators found only 4 of 16 studies looked at falls at baseline and post-intervention. No studies utilizing the live virtual format followed individuals for a year after intervention to assess the long-term intervention effects. Most falls occur during walking, after incident slips and trips, such that targeted interventions to avoid loss of balance focused on stepping, obstacle negotiation, and walking ability -while also strengthening the muscles critical for balance recovery- are critical to reducing falls. Recent guidelines also suggest that any older adults with impaired gait or balance (slow gait speed or high TUG or FSST time) should be offered tailored exercise focused on balance, gait and strength to prevent future falls. This MMBI program is unique in that it targets not only strengthening but also functional movements in multiple plans to target the hip abductors, improve balance and reduce falls.

This study will address several important knowledge gaps, first by simply assessing the effect of the live virtual Gerofit program on balance and falls. It will also determine whether proven methods of improving balance and hip abductor strength can be safely and effectively translated to novel home delivery for Veterans, using an established standard of care control, and clinically important outcomes of fall rate, muscle strength, and muscle quality via CT scan. This will provide critical information for future fall prevention studies in the VA. In prior studies examining the effects of resistance training on balance, less than 30% of all trials included any resistance training of the hip abductors. Further, the investigators are unaware of any trial that currently targets the hip abductors with a virtual or home-based fall risk reduction intervention in a group that are at increased risk for falls. Understanding mechanistic contributions of the hip abductors to balance and mobility, and finding targeted means to improve their function without the need for center-based exercise opens important new treatment options for older Veterans with mobility limitations at increased fall risk. The investigators will do this through the following Aims.

Aim 1: Determine the 12-week effects of vMMBI vs vGerofit alone on clinical measures of fall risk, physical function, and fear of falling. It is hypothesized greater improvements in fall risk (four-square step test [primary outcome]) following 12 weeks of vMMBI compared to 12 weeks of vGerofit.

Aim 2: Determine the 12-week effects of vMMBI vs vGerofit alone on hip abductor mechanisms of fall prevention, including hip abductor function, hypertrophy, and quality. It is hypothesized that Veterans in the vMMBI group will demonstrate greater improvements in hip abductor (gluteus minimus/medius) function (muscle strength - determined with hand-held dynamometer [primary outcome]) due to the synergistic effects of resistance training combined with balance and mobility exercises, which may enhance muscle hypertrophy of the hip abductors (cross-sectional area) and improve muscle quality (% intramuscular fat by computed tomography).

Clinical Translational Aim: Determine the efficacy of participation in vMMBI+vGerofit vs vGerofit alone as indicated by the incidence of falls and exercise adherence.