Obstacle Negotiation in Older People With and Without Vision Impairment

NCT05888441 | Recruiting

• 1 other identifier: 16447
• Study Type: interventional
• Target: 200
• Locations: 1 country
• Sites: 1

Brief Summary

Falls are common among people with vision impairment and can lead to devastating health consequences. Understanding the functions of vision and how the visual characteristics of obstacles in the walking path impact the gait of people with vision impairment is necessary to create strategies to prevent falls in this population. The purpose of this study is to determine how adults with vision impairment change their gait behavior when stepping over obstacles that vary in height and contrast to the ground. We will then determine the mechanisms of gaze behavior that correlate to the gait behavior.

Conditions

Low Vision

Outcome Measures

Primary Outcomes (4)

• Vertical foot clearance, lead limb

  Distance from lowest point of foot (heel or toe) to top of obstacle

  During a single intervention visit (Study Visit 2), up to 2-3 hours in duration.

• Foot placement variability

  Standard deviation of position of toe to obstacle over 2-4 steps before the obstacle

  During a single intervention visit (Study Visit 2), up to 2-3 hours in duration.

• Obstacle crossing speed

  Speed from lead toe off immediately before the obstacle to trail heel down immediately after the obstacle.

  During a single intervention visit (Study Visit 2), up to 2-3 hours in duration.

• Gaze sequencing

  Sequence of fixations from start of trial to end of trial, normalized to the total duration and divided into 100 equal segments

  During a single intervention visit (Study Visit 2), up to 2-3 hours in duration.

Study Arms (2)

Low Vision Group

EXPERIMENTAL

At a single study visit, the group of low vision participants will be asked to perform a series of short walking trials. During each trial they will walk at a self-selected speed along a walkway (6 meters in length) that may or may not contain an obstacle to step over. The trials will be randomly varied with regard to an obstacle's presence, height, and contrast from the walkway surface. Repeated trials of each condition variation will be performed during the visit.

Other: Obstacle characteristics

Control Group

ACTIVE COMPARATOR

At a single study visit, the group of age-matched participants without low vision will be asked to perform a series of short walking trials. During each trial they will walk at a self-selected speed along a walkway (6 meters in length) that may or may not contain an obstacle to step over. The trials will be randomly varied with regard to an obstacle's presence, height, and contrast from the walkway surface. Repeated trials of each condition variation will be performed during the visit.

Other: Obstacle characteristics

Interventions

Obstacle characteristics OTHER

In the walking trials, when an obstacle is present, the obstacle height and obstacle contrast level will be varied across the trial repetitions. Each participant will be exposed to obstacles of two heights: the first will be 1 centimeter in height, and the second will be approximately 20% of the subject's leg length (ranging in physical height between 15 - 22 centimeters to cover a range of leg lengths in the population). Obstacles (of both heights) will also be painted such that their measured luminance (or contrast) level against the floor luminance is varied. High contrast obstacles will have ≥80% Michelson contrast and low contrast obstacles will have ≤30% Michelson contrast.

Control Group; Low Vision Group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18 or over
• Able to walk independently
• Either have normal vision, or impaired vision.
• Impaired vision is defined as binocular visual acuity of 20/25 or worse with or without a central scotoma; and/or binocular visual field that is restricted to an average of 100 degrees in diameter or less
• Control subjects will have visual acuity of 20/40 or better.

You may not qualify if:

• Not cleared by a medical provider for moderate physical activity
• Self-report or have a history of: vestibular disorder or deafness
• Medical history of any condition that affects the ability to walk for up to 2 hours with breaks, such as feeling dizzy or faint, chest pain, palpitations, pain or numbness in the legs, shortness of breath,
• Cognitive limitations either by self-report or a score on the Mini Mental State Exam below 24 (out of 30)
• Walking or gait abnormalities, such as those caused from an injury, surgery, severe arthritis, or neurological condition such as Parkinson's disease
• Unable to walk without any walking aids such as a walker, cane, guide dog, or oxygen tank.
• Does not speak English

Sponsors & Collaborators

• Indiana University: lead

Study Sites (1)

Indiana University

Bloomington, Indiana, 47405, United States

RECRUITING

MeSH Terms

Conditions

Vision, Low

Condition Hierarchy (Ancestors)

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

Central Study Contacts

Kierstyn A Napier-Dovorany, OD

CONTACT

8128554426; knapier@iu.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: May 4, 2023
• First Posted: June 5, 2023
• Study Start: April 14, 2023
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028
• Last Updated: November 13, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)