NCT05888441 · Indiana University
Obstacle Negotiation in Older People With and Without Vision Impairment
What this study is about
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.
View original scientific description
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.
Interventions
OTHER
Obstacle characteristics
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.
Primary outcome measures
Vertical foot clearance, lead limb
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 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
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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
Where
- Bloomington, Indiana
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Nov 13, 2025 · Source of record for eligibility and locations