Neuromechanisms of Falls in Older Adults With MCI: Targeting Assessment and Training of Reactive Balance Control

Summary

Studies have determined that compared to cognitively intact older adults (CIOA), older adults with mild cognitive impairment (OAwMCI) exhibit more pronounced balance and gait impairments which lead to an increased risk of falls and mobility decline. Such impairments are evident during dual-tasking (i.e., simultaneous performance of cognitive and motor task) and OAwMCI have demonstrated an increased cognitive-motor interference (deteriorated performance of either or both cognitive/motor task). Furthermore, our preliminary laboratory findings indicate that compared to CIOA, OAwMCI in response to large-magnitude treadmill perturbations exhibits poor reactive responses (first line of defense against balance loss) and are unable to modulate their responses as the magnitude of perturbation increases. Despite that conventional exercise methods offer beneficial effects; they comprise of self-initiated task-specific exercises and may not focus on training reactive responses. Additionally, due to the presence of subtle balance and gait deficits, clinical measures used may not be sensitive enough to determine the risk of fall post-training. Furthermore, these training methods incorporate multiple sessions due to which adherence to exercise training is difficult with only a fraction of the older adults benefiting from it. Therefore, it is essential to incorporate a task-specific strategy that promotes factors associated with falling like balance control, muscular responses, coordination of limbs, and cognition through which OAwMCI may acquire maximum benefits to prevent a balance loss. One feasible method, which harnesses technology that can be used to deliver balance disturbances either while standing or walking in a consistent and controlled manner, is via a custom-based motorized treadmill. The scientific rigor from preliminary studies has reported a successful reduction of falls through a single session exposing CIOA to multiple treadmill-induced perturbations during gait and has shown significant improvement in reactive responses. For that reason, this stage 1 pilot study will examine the feasibility, applicability, and tolerability of a combined cognitive, and perturbation training on biomechanical determinants associated with falls and promote physical activity: kinematic variables, muscular responses, and cognitive function.

Description

Eligibility

Age range

55+ years

Sex

All

Healthy volunteers

Yes

Interventions

• Behavioral
  Dual task perturbation training

  Participants will play six cognitive games targeting working memory, executive functioning, visuomotor reactions, and language fluency provided in standing. Following which they will receive 12 slips without performing cognitive task (Single task training) at the highest intensity and 12 slips during standing while performing a cognitive task (dual task). Also, they will then undergo 12 dual task walking trials (at self-selected speed) followed by 12 walking slips.

Location