Relationship Between Central Sensitization and Clinical Features in Plantar Fasciitis

IInvestigation of the Relationship Between Central Sensitization and Clinical, Functional, and Ultrasonographic Parameters In Plantar Fasciitis

Plantar fasciitis is a common cause of heel pain and is traditionally considered a mechanical musculoskeletal disorder. Recent evidence suggests that central sensitization may also contribute to pain in individuals with plantar fasciitis. This study aims to investigate the relationships between neurophysiological variables (pressure pain threshold, central sensitization, and pain intensity), psychological factors (pain catastrophizing, kinesiophobia, anxiety, and depression), ultrasonographic findings (plantar fascia thickness), and functional outcomes (foot function and quality of life) in patients with plantar fasciitis.

Study Overview

• Status: Recruiting
• Conditions: Plantar Fasciitis
• Intervention / Treatment: Other: Pressure Pain Threshold Assessment; Other: Ultrasonographic Assessment

Detailed Description

Heel pain caused by plantar fasciitis is one of the common reasons for visits to Physical Medicine and Rehabilitation outpatient clinics. Plantar fasciitis is characterized by throbbing medial plantar heel pain that occurs especially with the first step in the morning or after long periods of rest and is a musculoskeletal disorder. The diagnosis of plantar fasciitis is usually determined clinically. In ultrasound, findings such as thickening of the plantar fascia and hypoechogenicity in the fascia are advantageous in diagnosis. Although the mechanical aspect of pain has often been emphasized in the treatment of plantar fasciitis, recent studies have gained momentum in suggesting that central sensitization is also among the pain mechanisms of plantar fasciitis. In addition, as with many chronic musculoskeletal pains, the role of psychological factors such as kinesiophobia, catastrophizing pain, depressive symptoms, and anxiety has been investigated in plantar fasciitis. However, data on the relationship between factors such as pressure pain sensitivity, central sensitization, catastrophizing pain, and kinesiophobia in plantar fasciitis are limited. The aim of this study is to contribute to the increasing literature in this field by investigating the relationship between psychological (catastrophizing pain, kinesiophobia, anxiety, and depression), ultrasonographic findings (plantar fascia thickness), and functional status (foot functional index, quality of life) variables with neurophysiological (pressure pain threshold, central sensitization, pain) variables in plantar fasciitis.

• Study Type: Observational
• Enrollment (Estimated): 128

Contacts and Locations

• Study Contact: Name: Feyza Nur Yücel, Assoc. Prof.; Phone Number: +90 2165422000; Email: dr.fny28@gmail.com

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye)
    • Recruiting
    • Sultan Abdulhamid Han Training and Research Hospital
    • Contact: Feyza Nur Yücel; Phone Number: 0216 542 20 00; Email: dr.fny28@gmail.com

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Individuals applying to the Physical Medicine and Rehabilitation Outpatient Clinic of Sultan 2. Abdülhamid Han Training and Research Hospital will be evaluated, and those who meet the inclusion criteria for the groups and sign the voluntary consent form will be included in the study.

Description

Plantar Fasciitis Group

1. Inclusion criteria

   • Be between the ages of 18-65
   • Have unilateral heel pain that has been ongoing for at least 3 months, particularly worsening with the first few steps in the morning and increasing with weight-bearing activities throughout the day
   • Have tenderness on palpation of the medial calcaneal tubercle
   • Have read and signed the volunteer consent form (VCF)

2. Exclusion criteria

   • Being under 18 years old or over 65 years old
   • Having a history of physical therapy, injection, radiation, or surgery targeting the plantar fascia within the last 6 months
   • Calcaneus fracture, tumor, or cyst related to the plantar fascia
   • Foot deformity (club foot, pes cavus, calcaneovalgus, etc.)
   • Lumbosacral radiculopathy, tarsal tunnel syndrome, peripheral neuropathy
   • Rheumatic diseases such as rheumatoid arthritis, ankylosing spondylitis, gout
   • Foot and ankle osteoarthritis
   • Presence of osteomyelitis or skin infection in the foot
   • Systemic diseases such as kidney and liver failure, diabetes, peripheral arterial vascular disease

Healthy Control

1. Inclusion criteria

   • Being completely healthy
   • Being between the ages of 18 - 65
   • Having read and signed the volunteer consent form (BGOF)

2. Exclusion criteria

   • Being under 18 or over 65 years old
   • Having any acute or chronic illness
   • Being illiterate and not giving consent to participate in the study

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Plantar fasciitis group; Participants with clinically diagnosed plantar fasciitis.	Other: Pressure Pain Threshold Assessment; Pressure pain threshold measurements will be performed using a pressure algometer to assess pain sensitivity.; Other: Ultrasonographic Assessment; Ultrasonographic evaluation will be performed to measure plantar fascia thickness and assess plantar fascia morphology.
Healthy Volunteers (control group); Age- and sex-matched healthy adults without plantar fasciitis.	Other: Pressure Pain Threshold Assessment; Pressure pain threshold measurements will be performed using a pressure algometer to assess pain sensitivity.; Other: Ultrasonographic Assessment; Ultrasonographic evaluation will be performed to measure plantar fascia thickness and assess plantar fascia morphology.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Forearm Pressure Pain Threshold (PPT)	Pressure pain threshold is defined as the minimal pressure level that causes pain. The measurement will be applied twice for each region with a 1-minute interval, and the average of these applications will be recorded. A trial test will be conducted on the patient before the actual test. Pressure will be applied to selected points with a pressure algometer until pain is induced, and the test for that area will be terminated when the patient feels pain. The measurement will be taken from the calcaneus bone (the starting point of the plantar fascia) and from the forearm, which is a distant, painless, and unrelated area, using the Wagner manual pressure algometer (1 cm² probe-10 kg/20 lb). The reliability of the measurement in these areas has been demonstrated.	Baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Numeric Pain Rating Scale, NPRS	Pain severity will be evaluated using a scale rated from 0 (no pain) to 10 (unbearable pain). Participants will be asked to rate the pain felt with the first step after waking up in the morning and the average pain level over the past week.	Baseline
Short Form-12 (SF-12)	Physical Component Summary and Mental Component Summary	Baseline
Foot Function Index	The Foot Function Index is a self-report-based scale developed to evaluate the effects of foot and ankle-related problems on pain, functional limitation, and daily life activities in individuals, with its validity and reliability demonstrated. AFI consists of three sub-dimensions: pain, disability (functional limitation), and activity limitation. The scale allows individuals to evaluate foot-related problems they have experienced recently in the context of daily life activities. Each sub-dimension and total score reflect the level of impairment in foot functions. Increasing AFI scores indicate that the severity of foot pain and the limitations in foot functions have increased, thereby negatively affecting foot-related quality of life. AFI is widely used in clinical and research settings to evaluate the functional effects of foot pathologies.	Baseline
Pain Catastrophizing Scale	It is a valid and reliable self-report scale developed to assess individuals' exaggerated negative thoughts and emotional responses toward their pain experience. The scale measures cognitive and emotional responses that occur during or following pain and consists of three sub-dimensions: rumination (excessive focus on pain), magnification (exaggeration of the threatening consequences of pain), and helplessness.	Baseline
Tampa Scale for Kinesiophobia	It is a valid and reliable self-report scale developed to assess individuals' fear and avoidance behaviors toward movement and physical activity. The scale measures the level of fear of movement (kinesiophobia) that develops based on the belief that pain will reoccur or worsen.	Baseline
Central Sensitization Inventory	The central sensitization scale is a tool used to assess the hypersensitivity of the central nervous system. This scale includes questions that examine individuals' pain perception and its effects on daily life to detect the effects of central sensitization, which are generally observed in chronic pain conditions. The scale evaluates how individuals perceive pain in response to physical contact or other stimuli (pain sensitivity), changes in their sensitivity to heat, cold, or pressure (sensory changes), how the persistence of pain affects their daily activities, and the impact of pain on their emotional state (anxiety, depression, etc.).	Baseline
Thickness of the plantar fascia in ultrasonographic imaging	In the study, the evaluation with ultrasound will be conducted while the participants are in a prone position on the examination table, with their feet hanging off the table and in a dorsiflexed position. A linear probe will be placed longitudinally over the medial tubercle of the calcaneus to ultrasonographically examine the plantar fascia thickness (PFT). PFK will be measured 1 cm distal to the calcaneus attachment point. A PFK of 4 mm or greater will be considered evidence of fasciitis. It has been shown that this measurement technique has good intra-rater reliability. The Sonosite M-Turbo device will be used for ultrasonography and will be performed by a physical therapy and rehabilitation specialist with 10 years of experience.	Baseline
Hospital Anxiety and Depression Scale	It is a 14-item self-report scale that quickly, reliably, and independently of medical conditions assesses patients' anxiety and depression symptoms over the past week.	CROSS-SECTIONAL
Weight-Bearing Lunge Test	The range of motion of ankle dorsiflexion will be evaluated under load. The participant will be asked to keep their heel in contact with the ground and move their knee toward the wall, and the maximum distance between the thumb and the wall will be recorded in centimeters.	Baseline
FOOT POSTURE INDEX	The participant's foot will be observationally scored based on six anatomical criteria in a standing natural posture, and the total score will be recorded.	Baseline

Collaborators and Investigators

• Sponsor: Sultan Abdulhamid Han Training and Research Hospital, Istanbul, Turkey
• Investigators: Principal Investigator: Feyza Nur Yücel, Saglik Bilimleri Universitesi

Publications and helpful links

General Publications

• Bennell KL, Talbot RC, Wajswelner H, Techovanich W, Kelly DH, Hall AJ. Intra-rater and inter-rater reliability of a weight-bearing lunge measure of ankle dorsiflexion. Aust J Physiother. 1998;44(3):175-180. doi: 10.1016/s0004-9514(14)60377-9.
• Sabir N, Demirlenk S, Yagci B, Karabulut N, Cubukcu S. Clinical utility of sonography in diagnosing plantar fasciitis. J Ultrasound Med. 2005 Aug;24(8):1041-8. doi: 10.7863/jum.2005.24.8.1041.
• Redmond AC, Crosbie J, Ouvrier RA. Development and validation of a novel rating system for scoring standing foot posture: the Foot Posture Index. Clin Biomech (Bristol). 2006 Jan;21(1):89-98. doi: 10.1016/j.clinbiomech.2005.08.002. Epub 2005 Sep 21.
• Nijs J, Malfliet A, Nishigami T. Nociplastic pain and central sensitization in patients with chronic pain conditions: a terminology update for clinicians. Braz J Phys Ther. 2023 May-Jun;27(3):100518. doi: 10.1016/j.bjpt.2023.100518. Epub 2023 Jun 14. No abstract available.
• Jayaseelan DJ, Fernandez-de-Las-Penas C, Blattenberger T, Bonneau D. Altered Central Pain Processing in Patients With Chronic Plantar Heel Pain: A Critically Appraised Topic. J Sport Rehabil. 2021 Feb 16;30(5):812-817. doi: 10.1123/jsr.2020-0371.
• Plaza-Manzano G, Rios-Leon M, Martin-Casas P, Arendt-Nielsen L, Fernandez-de-Las-Penas C, Ortega-Santiago R. Widespread Pressure Pain Hypersensitivity in Musculoskeletal and Nerve Trunk Areas as a Sign of Altered Nociceptive Processing in Unilateral Plantar Heel Pain. J Pain. 2019 Jan;20(1):60-67. doi: 10.1016/j.jpain.2018.08.001. Epub 2018 Aug 16.
• Cotchett M, Lennecke A, Medica VG, Whittaker GA, Bonanno DR. The association between pain catastrophising and kinesiophobia with pain and function in people with plantar heel pain. Foot (Edinb). 2017 Aug;32:8-14. doi: 10.1016/j.foot.2017.03.003. Epub 2017 Mar 20.

Study record dates

Study Major Dates

• Study Start (Actual): April 7, 2026
• Primary Completion (Estimated): September 20, 2026
• Study Completion (Estimated): September 20, 2026

Study Registration Dates

• First Submitted: June 1, 2026
• First Submitted That Met QC Criteria: June 5, 2026
• First Posted (Actual): June 11, 2026

Study Record Updates

• Last Update Posted (Actual): June 11, 2026
• Last Update Submitted That Met QC Criteria: June 5, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: kinesiophobia; central sensitization; plantar fasciitis; pain pressure threshold
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Mental Disorders; Foot Diseases; Phobic Disorders; Anxiety Disorders; Fasciitis; Kinesiophobia; Fasciitis, Plantar
• Other Study ID Numbers: E-54230385-929-301089224

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data collected during this study will not be made available to other researchers.

Drug and device information, study documents

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