The Sensorimotor Locus of Balance Control in Elderly Gait

NCT03341728 | Completed Results

• 2 other identifiers: 15-2267R56AG054797-01A1
• Study Type: interventional
• Target: 14
• Locations: 1 country
• Sites: 1

Brief Summary

The aging population is at an exceptionally high risk of debilitating falls, contributing significantly to reduced independence and quality of life. It remains extremely challenging to screen for falls risk, and programs designed to mitigate falls risk have only modestly influenced the sizeable portion of the aging population experiencing one or more falls annually. Balance control in standing and walking depends on integrating reliable sensory feedback and on planning and executing appropriate motor responses. Walking balance control is especially dynamic, requiring active and coordinated adjustments in posture (i.e., trunk stabilization) and foot placement from step to step. Accordingly, using a custom, immersive virtual environment, the investigators have shown that sensory (i.e., optical flow) perturbations, especially when applied during walking, elicit strong and persistent motor responses to preserve balance. Exciting pilot data suggest that these motor responses are remarkably more prevalent in old age, presumably governed by an increased reliance on vision for balance control. Additional pilot data suggest that prolonged exposure to these perturbations may effectively condition successful balance control strategies. Founded on these recent discoveries, and leveraging the increase reliance on vision for balance control in old age, the investigators stand at the forefront of a potentially transformative new approach for more effectively identifying and mitigating age-related falls risk. The investigator's overarching hypothesis is that optical flow perturbations, particularly when applied during walking, can effectively identify balance deficits due to aging and falls history and can subsequently condition the neuromechanics of successful balance control via training.

Conditions

Ambulation Difficulty; Gait, Unsteady; Fall; Position Sense Disorders

Outcome Measures

Primary Outcomes (3)

• Change in Postural Sway After 10 Min of Walking

  Magnitude of side-to-side postural sway

  Baseline, 10 minutes

• Change in Kinematic Variability After 10 Min of Walking

  Magnitude of step-to-step corrections in step width measured in cm

  Baseline, 10 minutes

• Change in Foot Placement Targeting Accuracy After 10 Min of Walking

  Accuracy of performing foot placement targeting task. i.e., distance between heel marker at initial contact and target line (measured using three-dimensional motion capture during walking).

  Baseline, 10 minutes

Secondary Outcomes (3)

• Change in Cognitive-motor Interference Accuracy After 10 Min of Walking

  Baseline, 10 minutes

• Change in Cognitive-motor Interference Response Time After 10 Min of Walking

  Baseline, 10 minutes

• Change in Margin of Stability Variability After 10 Min of Walking

  Baseline, 10 minutes

Study Arms (2)

Intervention, then Control

EXPERIMENTAL

Older adults will walk during exposure to optical flow perturbations

Behavioral: Optical flow perturbations; Behavioral: Normal walking

Control, then Intervention

EXPERIMENTAL

Older adults will walk normally (without optical flow perturbations)

Behavioral: Optical flow perturbations; Behavioral: Normal walking

Interventions

Optical flow perturbations BEHAVIORAL

Continuous mediolateral (i.e., side-to-side) 20-minute perturbations of optical flow that elicit the visual perception of lateral imbalance via virtual reality during treadmill walking.

Control, then Intervention; Intervention, then Control

Normal walking BEHAVIORAL

Usual treadmill walking without optical flow perturbations

Control, then Intervention; Intervention, then Control

Eligibility Criteria

• Age: 65 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

• Be able to walk without an assistive aid (i.e., walker, cane)
• Have the full capacity to provide informed consent
• OLDER NON-FALLERS
• Age 65+ years
• No history of falls\* in the prior 12 months
• OLDER ADULTS WITH A HISTORY OF FALLS
• Age 65+ years
• History of one or more falls\* in the prior 12 months
• For the purposes of this study, falls counted towards the self-reported total will be defined as per the Kellogg International Work Group - a fall is "unintentionally coming to the ground or some lower level and other than as a consequence of sustaining a violent blow, loss of consciousness, sudden onset of paralysis as in stroke or an epileptic seizure"

You may not qualify if:

• Current lower extremity injury or fracture
• Taking medication that causes dizziness
• Have a leg prosthesis
• Prisoners
• Individuals clearly lacking the capacity to provide informed consent

Sponsors & Collaborators

• University of North Carolina, Chapel Hill: lead
• National Institute on Aging (NIA): collaborator

Study Sites (1)

Applied Biomechanics Laboratory

Chapel Hill, North Carolina, 27514, United States

Location

Related Publications (5)

• Franz JR, Francis CA, Allen MS, O'Connor SM, Thelen DG. Advanced age brings a greater reliance on visual feedback to maintain balance during walking. Hum Mov Sci. 2015 Apr;40:381-92. doi: 10.1016/j.humov.2015.01.012. Epub 2015 Feb 14.

  PMID: 25687664 RESULT

• Francis CA, Franz JR, O'Connor SM, Thelen DG. Gait variability in healthy old adults is more affected by a visual perturbation than by a cognitive or narrow step placement demand. Gait Posture. 2015 Sep;42(3):380-5. doi: 10.1016/j.gaitpost.2015.07.006. Epub 2015 Jul 17.

  PMID: 26233581 RESULT

• Thompson JD, Franz JR. Do kinematic metrics of walking balance adapt to perturbed optical flow? Hum Mov Sci. 2017 Aug;54:34-40. doi: 10.1016/j.humov.2017.03.004. Epub 2017 Apr 2.

  PMID: 28371662 RESULT

• Stokes HE, Thompson JD, Franz JR. The Neuromuscular Origins of Kinematic Variability during Perturbed Walking. Sci Rep. 2017 Apr 11;7(1):808. doi: 10.1038/s41598-017-00942-x.

  PMID: 28400615 RESULT

• Richards JT, Selgrade BP, Qiao M, Plummer P, Wikstrom EA, Franz JR. Time-dependent tuning of balance control and aftereffects following optical flow perturbation training in older adults. J Neuroeng Rehabil. 2019 Jul 1;16(1):81. doi: 10.1186/s12984-019-0555-3.

  PMID: 31262319 DERIVED

Related Links

• Applied Biomechanics Laboratory

MeSH Terms

Conditions

Mobility Limitation; Gait Disorders, Neurologic; Somatosensory Disorders

Condition Hierarchy (Ancestors)

Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Neurologic Manifestations; Nervous System Diseases; Sensation Disorders

Results Point of Contact

• Title: Jason R Franz, PhD
• Organization: University of North Caroilina at Chapel Hill

jrfranz@email.unc.edu

919-966-6119

Study Officials

• Jason Franz, PhD

  Unviersity of North Carolina at Chapel Hill

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: No Masking
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: In two 20 min sessions, on different days in a randomized cross-over design, older adults will walk with ("treatment" session) and without ("control" session) prolonged exposure to optical flow perturbations.

Study Record Dates

• First Submitted: October 31, 2017
• First Posted: November 14, 2017
• Study Start: October 30, 2017
• Primary Completion: July 25, 2018
• Study Completion: July 25, 2018
• Last Updated: July 5, 2019
• Results First Posted: July 5, 2019

Record last verified: 2019-02

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)