Pain Phenotypes in Individuals With Chronic Low Back Pain

Pain Phenotypes in Chronic Low Back Pain Based on IASP Criteria

This observational cross-sectional study aims to determine pain phenotypes in individuals with chronic low back pain (CLBP). Participants will be classified according to a mechanism-based clinical pain phenotyping algorithm as having nociceptive, neuropathic, nociplastic, or mixed pain. Clinical history, quantitative sensory assessment, pain characteristics and distribution, central sensitization-related symptoms, disability, health-related quality of life, and pain catastrophizing will be assessed. In addition, the intra-rater and inter-rater reliability of the pain phenotyping algorithm will be investigated, and the clinical characteristics of different pain phenotypes will be compared.

Study Overview

• Status: Recruiting
• Conditions: Chronic Low-back Pain (cLBP)
• Intervention / Treatment: Diagnostic test: Pain classification method

Detailed Description

Chronic low back pain is a common and disabling musculoskeletal condition that may involve different underlying pain mechanisms. Mechanism-based pain phenotyping may facilitate a better understanding of individual pain presentations and contribute to more personalized management strategies.

In this cross-sectional observational study, individuals with chronic low back pain will undergo a comprehensive clinical assessment. Pain phenotypes will be determined using a contemporary clinical pain phenotyping algorithm based on criteria for nociceptive, neuropathic, and nociplastic pain. Participants presenting features of more than one pain mechanism will be classified as having mixed pain.

Assessment will include a detailed clinical history, quantitative sensory assessment, pain intensity and distribution, neuropathic pain characteristics, central sensitization-related symptoms, low back pain-related disability, health-related quality of life, and pain catastrophizing. Quantitative sensory assessment will include static tactile mechanical detection, thermal perception, static mechanical allodynia, dynamic mechanical allodynia, and vibration perception.

The study will also examine the intra-rater and inter-rater reliability of the pain phenotyping algorithm using standardized case scenarios derived from participants' clinical assessments.

• Study Type: Observational
• Enrollment (Estimated): 80

Contacts and Locations

• Study Contact: Name: Ismail Saracoglu, PhD; Phone Number: 3501 00902742651300; Email: ismail.saracoglu@ksbu.edu.tr

Study Locations

• Turkey (Türkiye)
  • Türkiye
    • Kütahya, Türkiye, Turkey (Türkiye), 43100
      • Recruiting
      • Kutahya Health Sciences University Physical Medicine and Rehabilitation Department
      • Sub-Investigator: Merve Akdeniz LEBLEBİCİER, MD
      • Contact: Ismail Saracoglu, PhD; Phone Number: 3501 002742651300; Email: ismail.saracoglu@ksbu.edu.tr
      • Principal Investigator: Merve YERLİKAYA, Mac

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Participants meeting the inclusion criteria will be taken for this cross-sectional study. Individuals with cLBP who apply to Kutahya Health Sciences University Hospital Physiotherapy Department will be screened for eligibility by their clinic physicians and will then be asked to participate in this study.

Description

Inclusion Criteria:

• Low back pain persisting for at least 3 months or present for at least 3 months during the previous 6 months, defined as pain located between the posterior lower costal margins and the inferior gluteal folds
• Pain intensity ≥2 on the Numeric Rating Scale
• Willingness to participate in the study

Exclusion Criteria:

• Inability to read and write Turkish
• History of lumbar surgery
• Presence of a systemic condition affecting sensory function
• History of spinal surgery within the previous 6 months or suspected spinal fracture
• Inability to complete the study assessments

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quantitative sensory test: static tactile mechanical threshold	Von Frey Monofilaments (2 gr- 26 gr) will be used assessment for the static tactile mechanical detection threshold.	10 minutes
Quantitative sensory test: hot-cold pain threshold	Coins will be used for the hot-cold pain threshold. The cold sensing test will be done with a coin held at room temperature. The hot sensing test will be done in the form of a coin placed in the pocket and applied to the participant after waiting for 30 minutes.	5 minutes
Quantitative sensory test: static mechanical allodynia	A digital algometer device (JTech) will be used for static mechanical allodynia (pressure pain threshold). In the device, the pain sensation will be tested by applying 4 kg of pressure to the participant.	5 minutes
Quantitative sensory test: dynamic mechanical allodynia	A soft brush will be used for dynamic mechanical allodynia. The brush will be gently moved over the skin at a speed of 3-5 cm per second in a fixed direction over the patients primary painful area.	5 minutes
Quantitative sensory test: vibration sense	128 Hz tuning fork will be used in vibration assessment. The device will be applied over the bony prominences in the painful area of the patient.	5 minutes
Margolis Pain Diagram	The Margolis Pain Diagram, consists of a dorsal and a ventral drawing body, is used to assess the location and distribution of the pain [20]. Participants will ask to point out the place where they experience pain during the preceding 4 weeks for at least 24 hours.	1 minute

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Central Sensitization Inventory (CSI)	Central sensitization-related symptoms will be assessed using the 25-item Central Sensitization Inventory. Each item is scored from 0 to 4, resulting in a total score ranging from 0 to 100. Higher scores indicate greater central sensitization-related symptom burden.	5 minutes
Oswestry Disability Index (ODI)	Low back pain-related disability will be assessed using the Oswestry Disability Index. The questionnaire consists of 10 sections, with each section scored from 0 to 5. Higher scores indicate greater disability and poorer functional status.	5 minutes
Health-Related Quality of Life - SF-12	Health-related quality of life will be assessed using the 12-item Short Form Health Survey (SF-12). Physical and Mental Component Summary scores will be calculated, with higher scores indicating better health-related quality of life.	5 minutes
Pain Catastrophizing Scale (PCS)	Pain catastrophizing will be assessed using the 13-item Pain Catastrophizing Scale. Items are scored from 0 to 4 and assess rumination, magnification, and helplessness. Higher scores indicate greater pain catastrophizing.	5 minutes
Numeric pain rating scale	The NPRS was used to assess the participants' pain levels. In the NPRS, patients are asked to verbally rate the severity of their pain on a scale. The scale is composed of 0 (no pain at all) to 10 (worst imaginable pain).	1 minute

Collaborators and Investigators

• Sponsor: Kutahya Health Sciences University

Study record dates

Study Major Dates

• Study Start (Actual): January 2, 2025
• Primary Completion (Estimated): October 30, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: August 11, 2026
• First Submitted That Met QC Criteria: August 11, 2026
• First Posted (Actual): August 14, 2026

Study Record Updates

• Last Update Posted (Actual): August 18, 2026
• Last Update Submitted That Met QC Criteria: August 14, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: chronic pain; nociplastic pain; pain phenotype; pain science
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Chronic Pain; Nociplastic Pain
• Other Study ID Numbers: MerveClassificationofLBP

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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