Spinal Mobility, Rigidity, and Kinesiophobia in PD and TMD

September 30, 2026 updated by: İsmail KARA, Mustafa Kemal University

A Comparative Study of Spinal Mobility, Axial Rigidity, and Kinesiophobia Between Parkinson's Disease Patients With and Without Temporomandibular Disorders

Axial rigidity and loss of spinal mobility commonly observed in Parkinson's disease (PD) lead to postural deformities and substantial reductions in trunk flexibility. This condition can impair the biomechanics of the craniocervical and lumbopelvic kinetic chain, potentially exerting a negative impact on temporomandibular joint (TMJ) functions. In this context, the planned study aims to determine whether differences exist in spinal mobility, axial rigidity, and kinesiophobia levels between individuals with PD with and without Temporomandibular Disorders (TMD), and to investigate whether a biomechanical relationship exists between TMD and spinal mobility, axial rigidity, and kinesiophobia levels in this population.

The study will be conducted face-to-face at the Neurology Outpatient Clinic of Hatay Mustafa Kemal University Research and Training Hospital. Individuals aged 40-75 years, diagnosed with PD, staged between 1.5 and 4 according to the Hoehn and Yahr Scale, with a Mini-Mental State Examination score of 24 or higher (MMSE ≥ 24), and in the "ON" state during the evaluation will be included. Individuals with a history of cervical, lumbar, maxillofacial, or TMJ surgery that could directly affect spinal mobility and posture; acute orthopedic or rheumatologic disorders that would preclude testing (e.g., advanced Ankylosing Spondylitis); comorbid neurological conditions (e.g., stroke, multiple sclerosis); complete edentulism or severe disruption of oral anatomy; active toothache; pregnancy or suspected pregnancy; and severe psychiatric disorders will be excluded. Written informed consent will be obtained from all participants, and the study will be conducted on a voluntary basis. All data will remain confidential and be utilized solely for scientific purposes.

In this cross-sectional study, evaluations will be carried out in a single session for each participant. Following the recording of demographic and clinical characteristics, the presence of TMD will be assessed using the Fonseca Anamnestic Index, jaw range of motion with a millimeter ruler, and spinal mobility using the modified-modified Schober test, tragus-to-wall distance, intermalleolar distance, and occiput-to-wall distance measurements. Axial rigidity will be evaluated using item 3.3 (Rigidity) of the Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS), posture will be assessed using MDS-UPDRS item 3.13 (Posture) alongside craniovertebral angle measurement, and kinesiophobia will be assessed via the Tampa Scale for Kinesiophobia.

The resulting findings are expected to contribute to understanding the impact of spinal mobility, axial rigidity, and kinesiophobia on the temporomandibular system in PD, offering valuable clinical guidance for assessment, physiotherapy, and multidisciplinary neurological rehabilitation pathways.

Study Overview

Status

Recruiting

Conditions

Study Type

Observational

Enrollment (Estimated)

60

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

35 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

The study population consists of individuals aged 40-75 years diagnosed with Parkinson's disease (Modified Hoehn & Yahr stages 1.5-4) who are admitted to the Neurology Outpatient Clinic of Hatay Mustafa Kemal University Research and Training Hospital.

Description

Inclusion Criteria:

  • Diagnosed with Parkinson's disease
  • Modified Hoehn & Yahr stages 1.5 to 4
  • Mini-Mental State Examination (MMSE) score ≥ 24
  • Evaluated during the medication "ON" state

Exclusion Criteria:

  • History of cervical, lumbar, maxillofacial, or temporomandibular joint surgery -Acute orthopedic or severe rheumatologic disease (e.g., advanced ankylosing spondylitis)
  • Additional comorbid neurological disorders (e.g., stroke, multiple sclerosis)
  • Complete edentulism or severe disruption of oral anatomy
  • Ongoing acute dental pain
  • Pregnancy or suspected pregnancy
  • Severe psychiatric disorders

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: OTHER
  • Time Perspectives: CROSS_SECTIONAL

Cohorts and Interventions

Group / Cohort
Parkinson's Disease with TMD
Parkinson's Disease without TMD

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Spinal Mobility
Time Frame: Baseline (measured once during a single evaluation session)

Assessed through Modified-Modified Schober Test (cm), Tragus-to-Wall Distance (cm), Occiput-to-Wall Distance (cm), and Intermalleolar Distance (cm)
Baseline (measured once during a single evaluation session)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Axial Rigidity
Time Frame: Baseline (single evaluation session)

Assessed using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III, item 3.3 (Rigidity). Scores range from 0 (normal) to 4 (severe)
Baseline (single evaluation session)
Kinesiophobia Level
Time Frame: Baseline (single evaluation session)

Evaluated using the Tampa Scale for Kinesiophobia (TSK; 17 items, 4-point Likert scale, total score range: 17-68, where higher scores indicate greater fear of movement)
Baseline (single evaluation session)
Postural Alignment and Forward Head Posture
Time Frame: Baseline (single evaluation session)

Assessed via MDS-UPDRS item 3.13 (Posture, score 0-4) and Craniovertebral Angle measurement using a goniometer (degrees)
Baseline (single evaluation session)
Temporomandibular Joint Range of Motion
Time Frame: Baseline (single evaluation session)

Maximum mouth opening, protrusion, retrusion, and bilateral lateral excursion measured in millimeters using a millimeter ruler.
Baseline (single evaluation session)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Mustafa Kemal University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 23, 2026

Primary Completion (Estimated)

December 23, 2026

Study Completion (Estimated)

December 30, 2026

Study Registration Dates

First Submitted

September 23, 2026

First Submitted That Met QC Criteria

September 23, 2026

First Posted (Actual)

September 30, 2026

Study Record Updates

Last Update Posted (Actual)

October 5, 2026

Last Update Submitted That Met QC Criteria

September 30, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • HMKU-PD-TMD-45

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared in order to protect participant confidentiality and privacy in accordance with ethical committee regulations. De-identified study data may be made available from the corresponding author upon reasonable academic request.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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