Parkinson DiseaseNCT07327346
GYKO-Based L-Test Reliability in Parkinson's Disease
An observational study of Parkinson Disease, run by Hasan Kalyoncu University at 1 site in Turkey (Türkiye).
Trial 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). Read more about this study
- Who is it for?
- Ages 50 to 85 years
- Conditions the study is for
- Parkinson Disease
- What is being tested?
- GYKO-Based Postural Sway Assessment
- How many people
- 25 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Dec 2025to 1 May 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 to 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
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.
Who may be able to join
- 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
Who cannot join
- Other neurological, vestibular, or musculoskeletal disorders affecting balance
- Deep brain stimulation (DBS) implant
- Severe visual or auditory impairment
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Hasan Kalyoncu University
Gaziantep, Şahinbey, 27000
About this study
Official title: Test-Retest and Interrater Reliability and Validity of Postural Sway Parameters Measured With GYKO During the L Test in Individuals With Parkinson's Disease
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.
Read the detailed description
This study aims to investigate the test-retest and interrater reliability, as well as the concurrent validity, of GYKO-based postural sway measurements obtained during the L-Test and the Timed Up and Go (TUG) test in individuals with Parkinson's disease. Participants diagnosed with idiopathic Parkinson's disease (Hoehn \& Yahr stages 1-3) will be evaluated using the GYKO inertial measurement unit, which provides quantitative postural sway parameters including ellipse area, mean length, mediolateral and anteroposterior mean length, mediolateral and anteroposterior mean distance, and velocity.
Two independent raters will perform GYKO-based assessments of the L-Test and TUG on the same day, with a 20-minute interval between raters, to determine interrater reliability. Participants will return one week later to repeat the same procedures, allowing assessment of test-retest reliability.
To examine concurrent validity, participants' functional balance will also be assessed using the Berg Balance Scale, and correlations between GYKO variables and clinical mobility tests (L-Test and TUG) will be analyzed.
- Conditions
- Parkinson Disease
- Being tested
- GYKO-Based Postural Sway Assessment
- Keywords
- parkinson disease, balance, postural sway, interrater reliability, test-retest reliabilit, validity
- Medical subject headings
- Parkinson Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
GYKO-Based Postural Sway AssessmentOther
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.
| Study group | Role | What they receive |
|---|---|---|
| Parkinson's disease group | Parkinson's disease patients with stage 1-3 hoehn yahr Receives: Other: GYKO-Based Postural Sway Assessment |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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.
Measured: 1 week
Secondary outcomes (3)
Validity of GYKO Postural Sway Parameters with Functional Mobility (TUG and L-Test)
Concurrent validity will be examined by analyzing the relationship between the composite GYKO-based postural sway parameters obtained during the Timed Up and Go (TUG) and L-Test procedures and functional mobility performance.
Pearson correlation coefficients will be used to assess the associations between postural sway composite outcomes and TUG and L-Test completion times.
Measured: Day 1
Relationship Between Postural Sway and Balance Performance (Berg Balance Scale)
Balance performance will be assessed using the Berg Balance Scale at baseline. The relationship between Berg Balance Scale scores and the composite GYKO-based postural sway parameters obtained during the Timed Up and Go (TUG) and L-Test procedures will be analyzed using Pearson correlation coefficients.
Measured: Day 1
L test and TUG Completion Time
Functional mobility will be assessed using the Timed Up and Go (TUG) test and the L-Test. The TUG requires participants to stand up from a chair, walk 3 meters, turn, return, and sit down.
The L-Test is a modified version of the TUG and consists of standing up from a chair, walking 3 meters, performing a 90° turn, walking an additional 7 meters, performing a 180° turn, and returning along the same path (total walking distance approximately 20 meters).
The time required to complete each test will be recorded in seconds.
Measured: 1 week
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Jan 2026
- Study start1 Dec 2025
- Primary completion1 Apr 2026 (estimated)
- Study completion1 May 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Parkinson DiseaseStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 25 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hasan Kalyoncu University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Büşra Akıncı, Hasan Kalyoncu University
- Investigators
- Büşra Akıncı, MSc, Study chair, Hasan Kalyonuc UniversityGünseli Usgu, Assoc. Prof., Study director, Hasan Kalyoncu UniversitySaadet Nur Çörekçioğlu, P.T., Principal investigator, Hasan Kalyoncu University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07327346
- Sponsor's protocol ID
- HKU/PH/2
- Status last verified
- Jan 2026
- First submitted
- 8 Dec 2025
- Last updated
- 21 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
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.
PubMed 29395266Zampieri 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.
PubMed 19726406
Study at a glance
From the registry record, last updated by the sponsor on 21 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Test-Retest and Interrater Reliability and Validity of Postural Sway Parameters Measured With GYKO During the L Test in Individuals With Parkinson's Disease
- ClinicalTrials.gov ID
- NCT07327346
- Acronym / sponsor ID
- HKU/PH/2
- Conditions
- Parkinson Disease
- Keywords
- parkinson disease, balance, postural sway, interrater reliability, test-retest reliabilit, validity
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 25 participants (estimated)
- Lead sponsor
- Hasan Kalyoncu UniversityUniversity, hospital or other
- Study start
- 1 Dec 2025 (actual)
- Primary completion
- 1 Apr 2026 (estimated)
- Study completion
- 1 May 2026 (estimated)
- First posted
- 8 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
This study aims to investigate the test-retest and interrater reliability, as well as the concurrent validity, of GYKO-based postural sway measurements obtained during the L-Test and the Timed Up and Go (TUG) test in individuals with Parkinson's disease. Participants diagnosed with idiopathic Parkinson's disease (Hoehn \& Yahr stages 1-3) will be evaluated using the GYKO inertial measurement unit, which provides quantitative postural sway parameters including ellipse area, mean length, mediolateral and anteroposterior mean length, mediolateral and anteroposterior mean distance, and velocity.
Two independent raters will perform GYKO-based assessments of the L-Test and TUG on the same day, with a 20-minute interval between raters, to determine interrater reliability. Participants will return one week later to repeat the same procedures, allowing assessment of test-retest reliability.
To examine concurrent validity, participants' functional balance will also be assessed using the Berg Balance Scale, and correlations between GYKO variables and clinical mobility tests (L-Test and TUG) will be analyzed.
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Parkinson's disease group | – | Other: GYKO-Based Postural Sway AssessmentParkinson's disease patients with stage 1-3 hoehn yahr |
Who may qualify
- Ages
- 50 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- 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.
Key inclusion criteria (5 listed)
- 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
Key exclusion criteria (3 listed)
- Other neurological, vestibular, or musculoskeletal disorders affecting balance
- Deep brain stimulation (DBS) implant
- Severe visual or auditory impairment
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| GYKO-Based Postural Sway AssessmentThis 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. | Other | Parkinson's disease group |
Primary outcome
Interrater Reliability of GYKO-Based Postural Sway Parameters
Time frame: Day 1
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.
Test-Retest Reliability of GYKO-Based Postural Sway Parameters
Time frame: 1 week
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.
3 secondary outcomes
Validity of GYKO Postural Sway Parameters with Functional Mobility (TUG and L-Test)
Time frame: Day 1
Relationship Between Postural Sway and Balance Performance (Berg Balance Scale)
Time frame: Day 1
L test and TUG Completion Time
Time frame: 1 week
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Jan 2026.
- Background: PubMed 29395266Haas 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.
- Background: PubMed 19726406Zampieri 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.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Büşra Akıncı, MSc study chair
Hasan Kalyonuc University
Günseli Usgu, Assoc. Prof. study director
Hasan Kalyoncu University
Saadet Nur Çörekçioğlu, P.T. principal investigator
Hasan Kalyoncu University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Parkinson Disease, run by Hasan Kalyoncu University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 21 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Interrater Reliability of GYKO-Based Postural Sway Parameters (time frame: Day 1). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07327346, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Jan 2026.