GYKO-Based L-Test Reliability in Parkinson's Disease

NCT07327346 | Active Not Recruiting

• 1 other identifier: HKU/PH/2
• Study Type: observational
• Target: 25
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to investigate the interrater and test-retest reliability of GYKO-based postural sway measurements collected during the L-Test and Timed Up and Go (TUG) test in individuals with Parkinson's disease (Hoehn \& Yahr stages 1-3). Two independent raters will perform GYKO-based assessments of the L-Test and TUG with a 20-minute interval. Participants will return one week later to repeat the same procedures for test-retest reliability. Concurrent validity will be examined using the Berg Balance Scale.

Conditions

Parkinson Disease

Keywords

parkinson disease; balance; postural sway; interrater reliability; test-retest reliabilit; validity

Outcome Measures

Primary Outcomes (2)

• Interrater Reliability of GYKO-Based Postural Sway Parameters

  Interrater reliability of postural sway will be evaluated using a composite set of parameters derived from GYKO inertial sensor data collected during the Timed Up and Go (TUG) and L-Test procedures. Measurements will be obtained independently by two raters on the same day. The composite postural sway outcome includes ellipsoid area, displacement-related parameters in the mediolateral and anteroposterior directions, and velocity-related parameters. Although individual variables are expressed in different units, all parameters collectively represent a single postural control construct. Interrater reliability will be assessed using the intraclass correlation coefficient (ICC 2,1) with 95% confidence intervals.

  Day 1

• Test-Retest Reliability of GYKO-Based Postural Sway Parameters

  Test-retest reliability of postural sway will be assessed using a composite set of parameters derived from GYKO inertial sensor data collected during the Timed Up and Go (TUG) and L-Test procedures. Participants will be re-evaluated after a 1-week interval. The composite postural sway outcome includes ellipsoid area, mediolateral and anteroposterior displacement parameters, and velocity-related parameters, representing a single postural control construct. Test-retest reliability will be analyzed using the intraclass correlation coefficient (ICC 3,1) with 95% confidence intervals. Paired t-tests will be used to examine differences between test and retest measurements.

  1 week

Secondary Outcomes (3)

• Validity of GYKO Postural Sway Parameters with Functional Mobility (TUG and L-Test)

  Day 1

• Relationship Between Postural Sway and Balance Performance (Berg Balance Scale)

  Day 1

• L test and TUG Completion Time

  1 week

Study Arms (1)

Parkinson's disease group

Parkinson's disease patients with stage 1-3 hoehn yahr

Other: GYKO-Based Postural Sway Assessment

Interventions

GYKO-Based Postural Sway Assessment OTHER

This procedure involves obtaining postural sway parameters using the GYKO inertial measurement device during the Time Up and Go (TUG) test and L-Test. No therapeutic intervention is applied. Time Up and Go Test: Timed Up and Go (TUG) is a standardized functional mobility test used to assess dynamic balance and gait performance. Participants are instructed to stand up from a standard-height chair, walk 3 meters, turn around, walk back to the chair, and sit down. The total time to complete the task (in seconds) is recorded. Higher times indicate reduced mobility. L Test: Time (in seconds) to complete the L-Test of Functional Mobility. The test requires participants to stand up from a chair, walk 3 m, execute a 90° turn, walk another 7 m, perform a 180° turn, and return along the same path (total walking distance ≈ 20 m). The task ends when the participant sits back down. The total time to complete the task (in seconds) is recorded. Higher times indicate reduced mobility.

Parkinson's disease group

Eligibility Criteria

• Age: 50 Years - 85 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Individuals aged 50-85 years with idiopathic Parkinson's disease (Hoehn \& Yahr stages 1-3) who can walk independently and participate in TUG, L-Test, and GYKO assessments.

You may qualify if:

• Diagnosis of idiopathic Parkinson's disease
• Hoehn \& Yahr stage 1-3
• Ability to walk independently with or without an assistive device
• Ability to follow verbal instructions
• Age 50-85

You may not qualify if:

• Other neurological, vestibular, or musculoskeletal disorders affecting balance
• Deep brain stimulation (DBS) implant
• Severe visual or auditory impairment

Sponsors & Collaborators

• Hasan Kalyoncu University: lead

Study Sites (1)

Hasan Kalyoncu University

Gaziantep, Şahinbey, 27000, Turkey (Türkiye)

Location

Related Publications (2)

• Haas B, Clarke E, Elver L, Gowman E, Mortimer E, Byrd E. The reliability and validity of the L-test in people with Parkinson's disease. Physiotherapy. 2019 Mar;105(1):84-89. doi: 10.1016/j.physio.2017.11.218. Epub 2017 Dec 5.

  PMID: 29395266 BACKGROUND

• Zampieri C, Salarian A, Carlson-Kuhta P, Aminian K, Nutt JG, Horak FB. The instrumented timed up and go test: potential outcome measure for disease modifying therapies in Parkinson's disease. J Neurol Neurosurg Psychiatry. 2010 Feb;81(2):171-6. doi: 10.1136/jnnp.2009.173740. Epub 2009 Sep 2.

  PMID: 19726406 BACKGROUND

MeSH Terms

Conditions

Parkinson Disease

Condition Hierarchy (Ancestors)

Parkinsonian Disorders; Basal Ganglia Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Movement Disorders; Synucleinopathies; Neurodegenerative Diseases

Study Officials

• Büşra Akıncı, MSc

  Hasan Kalyonuc University

  STUDY CHAIR

• Günseli Usgu, Assoc. Prof.

  Hasan Kalyoncu University

  STUDY DIRECTOR

• Saadet Nur Çörekçioğlu, P.T.

  Hasan Kalyoncu University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MSc

Study Record Dates

• First Submitted: December 8, 2025
• First Posted: January 8, 2026
• Study Start: December 1, 2025
• Primary Completion: April 1, 2026
• Study Completion: May 1, 2026
• Last Updated: January 21, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)