Perception of Affordances and Obstacle Crossing in People With Parkinson's Disease and Healthy Adults

Affordances and Impairments: A Paradigm for Understanding Obstacle Crossing in Parkinson's Disease

This study aims to explore how young adults, older adults and people with Parkinson's disease (PwP), perceive their abilty to cross obstacles while walking, and how this perception is related to their actual performance of obstacle crossing and disease-related motor and cognitive impairments. The study will explore this percepeption and the actual performance in different walking environments(floor, synthetic grass turf). Understanding how people perceive obstacles may help improve rehabilitation methods and reduce the risk of falls. The study will take place at the Motor Performance Laboratory, University of Haifa, and will include walking tasks, eye-tracking measurements, and motor and cognitive assessments.

Study Overview

• Status: Recruiting
• Conditions: Parkinson's Disease (PD)
• Intervention / Treatment: Other: Assessment of Gait and Visual Exploration

Detailed Description

This study investigates the role of affordance perception - the ability to perceive opportunities for action - during obstacle crossing in people with Parkinson's disease (PwP). Falls are highly prevalent in PwP, often resulting from tripping over obstacles. While previous research has mainly focused on gait impairments, this study uniquely examines the perceptual stage that precedes movement and the association between perception, cognition, and motor performance.

Participants will include 60 PwP and 120 healthy adults (60 older adults and 60 young adults). All participants will perform walking tasks involving obstacle crossing under different environmental conditions (e.g., different obstacle heights and surfaces). Prior to walking, participants will judge whether they can safely cross the obstacle. Eye-tracking glasses will measure visual exploration patterns to assess how participants scan the environment. Additionally, walking variables such as speed and step length, will be recorded using wearable sensors.

The study will explore:

1. Differences in affordance perception between PwP and healthy adults.
2. Associations between motor and cognitive impairments and affordance perception in PwP.
3. How affordance perception relates to gait performance during obstacle crossing.

Results from this study may help to develop new intervention strategies aimed at improving safe walking and obstacle negotiation in PwP.

• Study Type: Observational
• Enrollment (Estimated): 180

Contacts and Locations

• Study Contact: Name: Galit Yogev Seligmann, PhD; Phone Number: +972-53-5315761; Email: galit.yogev@gmail.com
• Study Contact Backup: Name: Michal Kafri, PhD; Phone Number: +972-58-6862261; Email: kafri.michal@gmail.com

Study Locations

• Israel
  • Haifa, Israel, 3103301
    • Recruiting
    • University of Haifa, Motor Performance Laboratory
    • Contact: Galit Yogev Seligmann, PhD; Phone Number: +972-53-5315761; Email: galit.yogev@gmail.com
    • Contact: Michal Kafri, PhD; Phone Number: +972-58-6862261; Email: kafri.michal@gmail.com
    • Principal Investigator: Galit Yogev Seligmann, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

The study population will include three groups: (1) people with Parkinson's disease (PwP), aged 60-80 years, diagnosed by a physician and able to walk independently outdoors; (2) healthy older adults aged 60-80 years without neurological or orthopedic conditions affecting gait; and (3) healthy young adults aged 20-30 years without neurological or orthopedic conditions affecting gait.

Participants will be recruited from the community, from clinical settings (for PwP), and through university-based recruitment systems (for young healthy adults).

Description

Inclusion Criteria:

• Participants aged 20 to 80 years.
• Ability to walk independently outdoors without assistive devices.
• For Parkinson's Disease (PD) group: Diagnosis of PD confirmed by medical records.
• For healthy control groups: No neurological or orthopedic conditions affecting gait.

Exclusion Criteria:

• Feezing of gait (for PD group only), based on a score greater than 0 on the Freezing of Gait Questionnaire.
• Severe visual impairment that cannot be corrected with glasses or lenses.
• Cognitive impairment, defined as a score below 18 on the telephone-based Mini-Mental State Examination (MMSE).
• Any orthopedic condition, pain, or other medical condition that may affect walking, based on self-report.

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Parkinson's Disease; Participants diagnosed with Parkinson's disease (PwP), aged 60-80 years, able to walk independently outdoors.	Other: Assessment of Gait and Visual Exploration; Participants will perform walking tasks involving obstacle crossing while their gait and visual exploration patterns are recorded using wearable sensors and eye-tracking glasses. This is a non-invasive observational study with no therapeutic intervention.
Healthy Older Adults; Healthy adults aged 60-80 years, without neurological or orthopedic conditions affecting gait.	Other: Assessment of Gait and Visual Exploration; Participants will perform walking tasks involving obstacle crossing while their gait and visual exploration patterns are recorded using wearable sensors and eye-tracking glasses. This is a non-invasive observational study with no therapeutic intervention.
Healthy Young Adults; Healthy adults aged 20-30 years, without neurological or orthopedic conditions affecting gait.	Other: Assessment of Gait and Visual Exploration; Participants will perform walking tasks involving obstacle crossing while their gait and visual exploration patterns are recorded using wearable sensors and eye-tracking glasses. This is a non-invasive observational study with no therapeutic intervention.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Affordance Perception Accuracy	Accuracy of participants' perception of their ability to cross obstacles of varying height and surface conditions. Participants will judge whether they can safely cross an obstacle prior to walking.	During single laboratory session (about 3 hours)
Affordances measured by gaze behavior	Eye movement patterns during obstacle approach and crossing. Gaze behavior will be recorded using wearable eye-tracking glasses (Tobii Pro Glasses 3) to assess visual exploration of the walking environment and obstacle. Measures will include fixation(on obstacle) duration (milisecondes).	During a single laboratory session (approximately 3 hours)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS)	Disease severity will be assessed using the MDS-UPDRS (Motor Examination). This standardized clinical assessment measures motor symptoms in people with Parkinson's disease, including tremor, rigidity, bradykinesia, and postural stability. Higher scores indicate greater motor impairment.	During a single laboratory session (approximately 3 hours)
Walking Speed	Walking speed during obstacle crossing tasks, measured using wearable sensors (APDM Mobility Lab). Walking speed will be calculated in meters per second based on time and distance walked during the trials.	During a single laboratory session (approximately 3 hours)
Step Length	Step length during obstacle crossing tasks, measured using wearable sensors (APDM Mobility Lab). Step length will be calculated in meters for each leg during walking trials, as an indicator of gait characteristics and stability.	During a single laboratory session (approximately 3 hours)
Levodopa Equivalent Daily Dose (LEDD)	The total daily dose of antiparkinsonian medications will be calculated for participants with Parkinson's disease using the standardized Levodopa Equivalent Daily Dose (LEDD) formula. Higher values indicate greater medication use.	During a single laboratory session (approximately 3 hours)
Cognitive Performance - Stroop Test (NeuroTrax Cognitive Battery)	Cognitive function will be assessed using the computerized NeuroTrax Cognitive Battery. Specifically, performance on the Stroop test will be used to evaluate executive function, focusing on response inhibition and attention control. The Stroop test provides accuracy and reaction time scores, with higher scores reflecting better performance.	During a single laboratory session (approximately 3 hours)

Collaborators and Investigators

• Sponsor: University of Haifa
• Collaborators: University of Haifa, Israel
• Investigators: Principal Investigator: Galit Yogev Seligmann, PhD, University of Haifa

Study record dates

Study Major Dates

• Study Start (Actual): April 24, 2025
• Primary Completion (Estimated): April 24, 2028
• Study Completion (Estimated): June 24, 2028

Study Registration Dates

• First Submitted: April 10, 2025
• First Submitted That Met QC Criteria: April 10, 2025
• First Posted (Actual): April 17, 2025

Study Record Updates

• Last Update Posted (Actual): July 22, 2025
• Last Update Submitted That Met QC Criteria: July 17, 2025
• Last Verified: April 1, 2025

More Information

Terms related to this study

• Keywords: Balance; Gait; Parkinson's Disease; Motor Control; Fall Risk; Affordances; Obstacle Crossing; Visual Exploration; Gaze Behavior
• Additional Relevant MeSH Terms: Synucleinopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurodegenerative Diseases; Movement Disorders; Parkinsonian Disorders; Basal Ganglia Diseases; Parkinson Disease
• Other Study ID Numbers: 1561/25

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared. Data collected in this study will only be used by the study investigators for research purposes, in accordance with the approved study protocol and ethical guidelines.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No