Pes PlanusNCT07125781
Central Sensitization and Nociplastic Pain in Pes Planus
An observational study of Pes Planus and Flatfoot, run by Bozok University at 1 site in Turkey (Türkiye).
Trial summary
Background: Pes planus, commonly known as flatfoot, is a condition characterized by the collapse of the medial longitudinal arch of the foot. While some individuals remain asymptomatic, many experience foot or leg pain, walking difficulties, and functional limitations. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Pes Planus, Flatfoot, Central Sensitization
- How many people
- 214 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 27 Nov 2024to 31 May 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
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 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Adults aged 18-65 years, including individuals with clinically diagnosed pes planus and age- and sex-matched healthy volunteers without lower extremity pain. Participants were recruited from physical medicine and rehabilitation clinics at Etlik Zübeyde Hanım Gynecology and Pediatrics Training and Research Hospital, Ankara Etlik City Hospital, and Yozgat City Hospital.
Who may be able to join
- Age between 18 and 65 years.
- For pes planus group: clinically diagnosed pes planus confirmed by physical medicine and rehabilitation specialists, with persistent lower extremity pain for at least 6 months.
- For control group: age- and sex-matched healthy volunteers without current or past foot or leg pain.
- Willingness to complete all self-report questionnaires.
- Provided written and verbal informed consent.
Who cannot join
- History of diabetes mellitus, hypothyroidism, malignancy, vasculitis, neuropathies, or lumbar radiculopathy.
- History of lower limb surgery or trauma.
- Recent local injection or extracorporeal shockwave therapy.
- Any rheumatologic disease affecting pain perception (e.g., rheumatoid arthritis, ankylosing spondylitis).
- Severe psychiatric disorder or cognitive impairment interfering with questionnaire completion.
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Yozgat Bozok University Faculty of Medicine, Department of Physical Medicine and Rehabilitation
Yozgat, Yozgat, 66100
About this study
Official title: Prevalence of Central Sensitization and Nociplastic Pain in Individuals Diagnosed With Pes Planus: A Multicenter Cross-Sectional Study
Background:
Pes planus, commonly known as flatfoot, is a condition characterized by the collapse of the medial longitudinal arch of the foot. While some individuals remain asymptomatic, many experience foot or leg pain, walking difficulties, and functional limitations. In some cases, symptoms persist despite adequate conventional treatment. This suggests that central pain mechanisms, such as central sensitization and nociplastic pain, may contribute to ongoing symptoms. These mechanisms involve changes in the central nervous system that amplify pain perception and can occur even in the absence of active tissue damage. Understanding these mechanisms in pes planus may help guide more targeted and effective treatment strategies.
Read more
Purpose:
The aim of this multicenter cross-sectional study was to determine the prevalence of central sensitization and nociplastic pain in individuals with clinically diagnosed pes planus and to compare the findings with age- and sex-matched healthy controls.
Methods:
Between November 2024 and May 2025, a total of 107 patients with pes planus and 107 healthy controls were recruited from three medical centers. Participants completed validated Turkish versions of the Visual Analog Scale for pain intensity, the Foot Function Index for functional limitation, the Pain-DETECT questionnaire for nociplastic pain symptoms, the Central Sensitization Inventory for central sensitization, the Hospital Anxiety and Depression Scale for psychological distress, and the Short Form-12 for quality of life. Data were analyzed using comparative statistical tests and multiple linear regression models to identify factors associated with nociplastic pain and central sensitization in the pes planus group.
Read the detailed description
Pes planus, also referred to as flatfoot, is a common musculoskeletal condition characterized by the flattening or collapse of the medial longitudinal arch of the foot. It affects a considerable portion of the adult population and may be associated with foot pain, functional impairment, and reduced quality of life. In many patients, pain symptoms persist despite adequate structural correction and conventional treatments such as footwear modifications, orthotic support, exercise, or anti-inflammatory medications. This persistence suggests that central mechanisms of pain processing may be involved.
Central sensitization is a phenomenon in which the central nervous system exhibits heightened responsiveness to sensory input, resulting in amplified pain perception even in the absence of ongoing tissue injury. Nociplastic pain is a relatively new classification describing pain arising from altered central nociceptive processing without clear evidence of tissue damage or nerve injury. Both mechanisms are increasingly recognized in chronic musculoskeletal disorders, yet they have been underexplored in individuals with pes planus.
This multicenter cross-sectional study was designed to investigate the prevalence of central sensitization and nociplastic pain in adults with clinically diagnosed pes planus and to compare these findings with healthy controls matched for age and sex. Participants were recruited from three medical centers between November 2024 and May 2025. Inclusion criteria required adults aged 18 to 65 years with lower extremity pain lasting at least six months and a diagnosis of pes planus confirmed by a physical medicine and rehabilitation specialist. Healthy controls had no history of foot or leg pain or relevant musculoskeletal disorders.
All participants completed standardized and validated assessment tools, including the Visual Analog Scale for pain intensity, the Foot Function Index for foot-related disability, the Pain-DETECT questionnaire for nociplastic pain features, the Central Sensitization Inventory for signs of central sensitization, the Hospital Anxiety and Depression Scale for psychological distress, and the Short Form-12 for quality of life. Demographic and clinical information was also recorded.
Statistical analyses compared results between the pes planus and control groups and examined correlations among pain severity, functional impairment, central sensitization, nociplastic pain, and psychological measures. Multiple linear regression models were used to identify independent predictors of nociplastic pain and central sensitization in the pes planus group.
The findings of this study are intended to improve understanding of the complex pain mechanisms associated with pes planus and to highlight the potential need for multidisciplinary management approaches that address central pain processes and psychological factors alongside conventional biomechanical interventions.
- Conditions
- Pes Planus, Flatfoot, Central Sensitization, Nociplastic Pain
- Keywords
- Pes Planus, Flatfoot, Central Sensitization Inventory, Nociplastic Pain, Pain-DETECT Questionnaire, Foot Function Index, Chronic Foot Pain, Biopsychosocial Pain Mechanisms
- Medical subject headings
- Flatfoot, Nociplastic Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| the patient group | Adults aged 18 to 65 years with a clinical diagnosis of pes planus confirmed by a physical medicine and rehabilitation specialist, experiencing lower extremity pain for at least six months. Participants completed validated questionnaires to assess pain intensity, foot function, nociplastic pain features, central sensitization, psychological status, and quality of life. No therapeutic intervention was administered as part of the study. | |
| The control group | Age- and sex-matched healthy volunteers with no current or past foot or leg pain. Participants had no history of pes planus, lower limb surgery, trauma, or rheumatologic, neurologic, endocrine, or vascular disorders that could influence pain perception. No interventions were applied; they completed the same validated questionnaires as the pes planus group for comparison purposes. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pain-DETECT questionnaire
The Pain-DETECT questionnaire consists of 9 items with a total score range of 1-38. Scores ≤12 indicate that neuropathic or nociplastic pain components are unlikely, 13-18 indicate uncertainty, and ≥19 indicate probable nociplastic or neuropathic pain. The validated Turkish version, developed by Alkan et al. (2013), demonstrated a sensitivity of 90% and specificity of 67.5% for the ≤12 cutoff, with a negative predictive value of 87%.
Measured: Baseline
Central Sensitization Inventory
The Central Sensitization Inventory contains 25 items scored 0-4 (0 = never, 4 = always). Total scores ≥40 indicate the presence of central sensitization, with severity categories as follows: 0-29 subclinical, 30-39 mild, 40-49 moderate, 50-59 severe, ≥60 very severe. The validated Turkish version, developed by Keleş et al. (2021), reported 81% sensitivity and 75% specificity for the ≥40 cutoff, with excellent internal consistency (Cronbach's alpha = 0.92) and test-retest reliability (intraclass correlation coefficient = 0.93).
Measured: Baseline
Secondary outcomes (4)
Visual Analog Scale
The Visual Analog Scale is a 10 cm horizontal line anchored with "0 = no pain" and "10 = very severe pain." Participants mark their pain severity at rest and during activity for each foot. Higher scores indicate greater pain intensity.
Measured: Baseline
Foot Function Index
The Foot Function Index consists of 23 items across three subscales: pain (9 items), disability (9 items), and activity limitation (5 items). Each item is scored using a 10 cm visual analog scale reflecting the previous week's foot condition. Higher scores indicate greater impairment. The Turkish version was adapted and validated by Yalıman et al., with cultural and linguistic modifications for plantar fasciitis patients.
Measured: Baseline
Hospital Anxiety and Depression Scale
The Hospital Anxiety and Depression Scale contains 14 items, split evenly into anxiety and depression subscales, each scored 0-21. Interpretation: 0-7 = normal, 8-10 = mild, 11-14 = moderate, 15-21 = severe. The validated Turkish version was developed by Aydemir et al. (1997).
Measured: Baseline
Short Form-12 Health Survey (SF-12)
The Short Form-12 assesses physical and mental components of health-related quality of life across eight domains. Higher scores indicate better quality of life. The validated Turkish version was established in 2022 by Soylu and Kütük.
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Aug 2025
- Study start27 Nov 2024
- Primary completion31 May 2025
- Study completion31 May 2025
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 Pes PlanusStudies 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
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 214 participants (actual)
Sponsor and investigators
- Lead sponsor
- Bozok University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Gulseren Demir Karakilic, Bozok University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07125781
- Sponsor's protocol ID
- 2024/30
- Status last verified
- Aug 2025
- First submitted
- 10 Aug 2025
- Last updated
- 15 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Individual participant data that underlie the results reported in the article (after deidentification) will be made available upon reasonable request to the corresponding author after publication. Data will be shared with researchers who provide a methodologically sound proposal for use in achieving the aims stated in their proposal. Requests should be directed to gulserendmr58@hotmail.com. Data will be available for 12 months following article publication.
Publications
Alkan H, Ardic F, Erdogan C, Sahin F, Sarsan A, Findikoglu G. Turkish version of the painDETECT questionnaire in the assessment of neuropathic pain: a validity and reliability study. Pain Med. 2013 Dec;14(12):1933-43. doi: 10.1111/pme.12222. Epub 2013 Aug 7.
PubMed 23924395Buldys K, Gornicki T, Kalka D, Szuster E, Biernikiewicz M, Markuszewski L, Sobieszczanska M. What Do We Know about Nociplastic Pain? Healthcare (Basel). 2023 Jun 17;11(12):1794. doi: 10.3390/healthcare11121794.
PubMed 37372912
Study at a glance
From the registry record, last updated by the sponsor on 15 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prevalence of Central Sensitization and Nociplastic Pain in Individuals Diagnosed With Pes Planus: A Multicenter Cross-Sectional Study
- ClinicalTrials.gov ID
- NCT07125781
- Acronym / sponsor ID
- 2024/30
- Conditions
- Pes Planus, Flatfoot, Central Sensitization, Nociplastic Pain
- Keywords
- Pes Planus, Flatfoot, Central Sensitization Inventory, Nociplastic Pain, Pain-DETECT Questionnaire, Foot Function Index, Chronic Foot Pain, Biopsychosocial Pain Mechanisms
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 214 participants (actual)
- Lead sponsor
- Bozok UniversityUniversity, hospital or other
- Study start
- 27 Nov 2024 (actual)
- Primary completion
- 31 May 2025 (actual)
- Study completion
- 31 May 2025 (actual)
- First posted
- 15 Aug 2025 (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.
Background:
Pes planus, commonly known as flatfoot, is a condition characterized by the collapse of the medial longitudinal arch of the foot. While some individuals remain asymptomatic, many experience foot or leg pain, walking difficulties, and functional limitations. In some cases, symptoms persist despite adequate conventional treatment. This suggests that central pain mechanisms, such as central sensitization and nociplastic pain, may contribute to ongoing symptoms. These mechanisms involve changes in the central nervous system that amplify pain perception and can occur even in the absence of active tissue damage. Understanding these mechanisms in pes planus may help guide more targeted and effective treatment strategies.
Purpose:
The aim of this multicenter cross-sectional study was to determine the prevalence of central sensitization and nociplastic pain in individuals with clinically diagnosed pes planus and to compare the findings with age- and sex-matched healthy controls.
Methods:
Between November 2024 and May 2025, a total of 107 patients with pes planus and 107 healthy controls were recruited from three medical centers. Participants completed validated Turkish versions of the Visual Analog Scale for pain intensity, the Foot Function Index for functional limitation, the Pain-DETECT questionnaire for nociplastic pain symptoms, the Central Sensitization Inventory for central sensitization, the Hospital Anxiety and Depression Scale for psychological distress, and the Short Form-12 for quality of life. Data were analyzed using comparative statistical tests and multiple linear regression models to identify factors associated with nociplastic pain and central sensitization in the pes planus group.
Detailed description
Pes planus, also referred to as flatfoot, is a common musculoskeletal condition characterized by the flattening or collapse of the medial longitudinal arch of the foot. It affects a considerable portion of the adult population and may be associated with foot pain, functional impairment, and reduced quality of life. In many patients, pain symptoms persist despite adequate structural correction and conventional treatments such as footwear modifications, orthotic support, exercise, or anti-inflammatory medications. This persistence suggests that central mechanisms of pain processing may be involved.
Central sensitization is a phenomenon in which the central nervous system exhibits heightened responsiveness to sensory input, resulting in amplified pain perception even in the absence of ongoing tissue injury. Nociplastic pain is a relatively new classification describing pain arising from altered central nociceptive processing without clear evidence of tissue damage or nerve injury. Both mechanisms are increasingly recognized in chronic musculoskeletal disorders, yet they have been underexplored in individuals with pes planus.
This multicenter cross-sectional study was designed to investigate the prevalence of central sensitization and nociplastic pain in adults with clinically diagnosed pes planus and to compare these findings with healthy controls matched for age and sex. Participants were recruited from three medical centers between November 2024 and May 2025. Inclusion criteria required adults aged 18 to 65 years with lower extremity pain lasting at least six months and a diagnosis of pes planus confirmed by a physical medicine and rehabilitation specialist. Healthy controls had no history of foot or leg pain or relevant musculoskeletal disorders.
All participants completed standardized and validated assessment tools, including the Visual Analog Scale for pain intensity, the Foot Function Index for foot-related disability, the Pain-DETECT questionnaire for nociplastic pain features, the Central Sensitization Inventory for signs of central sensitization, the Hospital Anxiety and Depression Scale for psychological distress, and the Short Form-12 for quality of life. Demographic and clinical information was also recorded.
Statistical analyses compared results between the pes planus and control groups and examined correlations among pain severity, functional impairment, central sensitization, nociplastic pain, and psychological measures. Multiple linear regression models were used to identify independent predictors of nociplastic pain and central sensitization in the pes planus group.
The findings of this study are intended to improve understanding of the complex pain mechanisms associated with pes planus and to highlight the potential need for multidisciplinary management approaches that address central pain processes and psychological factors alongside conventional biomechanical interventions.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| the patient group | – | –Adults aged 18 to 65 years with a clinical diagnosis of pes planus confirmed by a physical medicine and rehabilitation specialist, experiencing lower extremity pain for at least six months. Participants completed validated questionnaires to assess pain intensity, foot function, nociplastic pain features, central sensitization, psychological status, and quality of life. No therapeutic intervention was administered as part of the study. |
| The control group | – | –Age- and sex-matched healthy volunteers with no current or past foot or leg pain. Participants had no history of pes planus, lower limb surgery, trauma, or rheumatologic, neurologic, endocrine, or vascular disorders that could influence pain perception. No interventions were applied; they completed the same validated questionnaires as the pes planus group for comparison purposes. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Adults aged 18-65 years, including individuals with clinically diagnosed pes planus and age- and sex-matched healthy volunteers without lower extremity pain. Participants were recruited from physical medicine and rehabilitation clinics at Etlik Zübeyde Hanım Gynecology and Pediatrics Training and Research Hospital, Ankara Etlik City Hospital, and Yozgat City Hospital.
Key inclusion criteria (5 listed)
- Age between 18 and 65 years.
- For pes planus group: clinically diagnosed pes planus confirmed by physical medicine and rehabilitation specialists, with persistent lower extremity pain for at least 6 months.
- For control group: age- and sex-matched healthy volunteers without current or past foot or leg pain.
- Willingness to complete all self-report questionnaires.
- Provided written and verbal informed consent.
Key exclusion criteria (5 listed)
- History of diabetes mellitus, hypothyroidism, malignancy, vasculitis, neuropathies, or lumbar radiculopathy.
- History of lower limb surgery or trauma.
- Recent local injection or extracorporeal shockwave therapy.
- Any rheumatologic disease affecting pain perception (e.g., rheumatoid arthritis, ankylosing spondylitis).
- Severe psychiatric disorder or cognitive impairment interfering with questionnaire completion.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Pain-DETECT questionnaire
Time frame: Baseline
The Pain-DETECT questionnaire consists of 9 items with a total score range of 1-38. Scores ≤12 indicate that neuropathic or nociplastic pain components are unlikely, 13-18 indicate uncertainty, and ≥19 indicate probable nociplastic or neuropathic pain. The validated Turkish version, developed by Alkan et al. (2013), demonstrated a sensitivity of 90% and specificity of 67.5% for the ≤12 cutoff, with a negative predictive value of 87%.
Central Sensitization Inventory
Time frame: Baseline
The Central Sensitization Inventory contains 25 items scored 0-4 (0 = never, 4 = always). Total scores ≥40 indicate the presence of central sensitization, with severity categories as follows: 0-29 subclinical, 30-39 mild, 40-49 moderate, 50-59 severe, ≥60 very severe. The validated Turkish version, developed by Keleş et al. (2021), reported 81% sensitivity and 75% specificity for the ≥40 cutoff, with excellent internal consistency (Cronbach's alpha = 0.92) and test-retest reliability (intraclass correlation coefficient = 0.93).
4 secondary outcomes
Visual Analog Scale
Time frame: Baseline
Foot Function Index
Time frame: Baseline
Hospital Anxiety and Depression Scale
Time frame: Baseline
Short Form-12 Health Survey (SF-12)
Time frame: Baseline
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Aug 2025.
- Background: PubMed 23924395Alkan H, Ardic F, Erdogan C, Sahin F, Sarsan A, Findikoglu G. Turkish version of the painDETECT questionnaire in the assessment of neuropathic pain: a validity and reliability study. Pain Med. 2013 Dec;14(12):1933-43. doi: 10.1111/pme.12222. Epub 2013 Aug 7.
- Background: PubMed 37372912Buldys K, Gornicki T, Kalka D, Szuster E, Biernikiewicz M, Markuszewski L, Sobieszczanska M. What Do We Know about Nociplastic Pain? Healthcare (Basel). 2023 Jun 17;11(12):1794. doi: 10.3390/healthcare11121794.
- Individual participant dataSharing planned: Yes. Individual participant data that underlie the results reported in the article (after deidentification) will be made available upon reasonable request to the corresponding author after publication. Data will be shared with researchers who provide a methodologically sound proposal for use in achieving the aims stated in their proposal. Requests should be directed to gulserendmr58@hotmail.com. Data will be available for 12 months following article publication.
Related trials for Pes Planus
Recruiting
Effects of Custom 3D Printed Insoles and Short Foot Exercises in Pes Planus
Pes Planus
Not yet recruiting
Correlation Between Soft Tissue Displacement and Functional Performance in Orthopedic Patients
Hamstring Muscle Strain, Adult Acquired Flatfoot Deformity
Not yet recruiting
The Corrective Power of Subtalar Arthrodesis With Mini/Medial Bone Block (SAMBB) in Patients Affected by Progressive Collapsing Foot Deformity (PCFD): Analysis Using Weight-bearing Cone Beam CT.
Flat Foot
Not yet recruitingObservational study
Tibialis Posterior Muscle Morphology in Flexible Flatfeet Subjects
Flexible Flatfoot
Recruiting
Plantar Stimulation, Whole-Body Vibration, and Baduanjin for Muscle Activation
Flat Feet, Lower-Limb Muscle Activation
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.
The record lists no contact. Use the official record to reach the sponsor.
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 Pes Planus and Flatfoot, run by Bozok 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 5 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: finished, as of the sponsor's last update on 15 Aug 2025. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Pain-DETECT questionnaire (time frame: Baseline). 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 NCT07125781, 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 15 Aug 2025.