Obstacle Negotiation in Older People With and Without Vision Impairment

Not Applicable

Recruiting

• Conditions: Low Vision
• Interventions: Other: Obstacle characteristics

• Registration Number: NCT05888441
• Lead Sponsor: Indiana University

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2023-04-14
• Study First Submitted: 2023-05-04
• Study First Submitted QC: 2023-05-25
• Study First Posted: 2023-06-05
• Status Verified: 2024-09
• Last Update Submitted: 2024-09-30
• Last Update Posted: 2024-10-02
• Primary Completion: 2025-12-31
• Study Completion: 2025-12-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 200

Inclusion Criteria

• 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.

Exclusion Criteria

• 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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Low Vision Group	Obstacle characteristics	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.
Control Group	Obstacle characteristics	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.

Primary Outcome Measures

Name	Time	Method
Vertical foot clearance, lead limb	During a single intervention visit (Study Visit 2), up to 2-3 hours in duration.	Distance from lowest point of foot (heel or toe) to top of obstacle
Foot placement variability	During a single intervention visit (Study Visit 2), up to 2-3 hours in duration.	Standard deviation of position of toe to obstacle over 2-4 steps before the obstacle
Obstacle crossing speed	During a single intervention visit (Study Visit 2), up to 2-3 hours in duration.	Speed from lead toe off immediately before the obstacle to trail heel down immediately after the obstacle.
Gaze sequencing	During a single intervention visit (Study Visit 2), up to 2-3 hours in duration.	Sequence of fixations from start of trial to end of trial, normalized to the total duration and divided into 100 equal segments

Trial Locations

Locations (1)

Indiana University; 🇺🇸 Bloomington, Indiana, United States