Protocol for a Randomized Controlled Trial Comparing the Effectiveness of Mechanical Diagnosis and Therapy Versus Generalized Exercise for Reducing Pain in Surgeons With Chronic Spinal Pain

Protocol for a Pragmatic, Randomized Controlled, Parallel-group Superiority Trial Comparing the Effectiveness of Mechanical Diagnosis and Therapy Versus Generalized Exercise for Reducing Pain in Surgeons With Chronic Spinal Pain and a Directional Preference

Surgeons frequently experience chronic spinal pain due to prolonged static postures and repetitive movements during surgical procedures. Exercise therapy is recommended, but it is unclear which type of exercise is most effective for this population.

This randomized clinical trial will compare Mechanical Diagnosis and Therapy (MDT), also known as the McKenzie Method, with a structured program of generalized exercise in surgeons with chronic spinal pain who demonstrate a directional preference (i.e., movement in a specific direction that reduces symptoms).

Participants will be randomly assigned to one of the two interventions and followed for 26 weeks. The primary outcome is spinal pain intensity at 12 weeks measured on a 0-10 scale. Secondary outcomes include function, quality of life, and psychological factors.

This pragmatic trial is conducted in outpatient physiotherapy settings and aims to determine whether an individualized exercise approach (MDT) is more effective than generalized exercise in this occupational group.

Study Overview

• Status: Not yet recruiting
• Conditions: Chronic Spinal Pain
• Intervention / Treatment: Behavioral: Mechanical Diagnosis and Therapy (MDT); Behavioral: Generalized Exercise

Detailed Description

Chronic spinal pain is common among surgeons due to prolonged static postures and physical demands during surgical procedures. Exercise therapy is recommended as first-line treatment, but the relative effectiveness of different exercise approaches remains unclear.

This study is a pragmatic, randomized, parallel-group trial comparing Mechanical Diagnosis and Therapy (MDT) with generalized exercise in surgeons with chronic spinal pain who demonstrate a directional preference. MDT is a classification-based approach that prescribes exercises based on symptom response to repeated movements, whereas generalized exercise includes strengthening, stretching, and endurance training without targeting directional preference.

Participants will be recruited from surgical specialties in Denmark and randomized 1:1 to MDT or generalized exercise. Interventions will be delivered by physiotherapists in outpatient clinical settings.

The primary objective is to compare the effect of MDT versus generalized exercise on spinal pain intensity at 12 weeks. Secondary objectives include effects on function, quality of life, and psychological factors.

The trial is designed to reflect routine clinical practice and to evaluate whether an individualized, classification-based exercise approach provides additional benefit compared with a guideline-based generalized exercise program.

• Study Type: Interventional
• Enrollment (Estimated): 62
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Claus Kjærgaard, M.Sc Health Science; Phone Number: +4599409940; Email: clauskja@dcm.aau.dk
• Study Contact Backup: Name: Tommy K. Nielsen, Consultant, PhD, Assoc Prof; Phone Number: +4599409940; Email: t.kjaergaard@rn.dk

Study Locations

• Denmark
  • Aalborg
    • Aalborg, Aalborg, Denmark, 8200
      • Aalborg University Hospital
      • Contact: Tommy K. Nielsen, Consultant, PhD, Assoc Prof; Phone Number: +4597663008; Email: t.kjaergaard@rn.dk

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age 25-70 years
• Currently working as a resident, fellow, or attending surgeon
• Chronic spinal pain (low back, thoracic, or neck) lasting more than 3 months
• Demonstrated directional preference on standardized clinical examination (i.e., movement in a specific direction reduces symptoms)
• Sufficient proficiency in Danish to complete trial questionnaires
• Willing and able to attend treatment sessions at designated physiotherapy clinics
• Provide written informed consent

Exclusion Criteria:

• Serious spinal pathology (e.g., fracture, malignancy, infection, inflammatory disease)
• Cauda equina syndrome
• Significant neurological deficits requiring urgent medical attention
• Any diagnosed medical condition preventing safe participation in physical activity
• Sick leave longer than 6 months at baseline
• Pregnancy or having given birth within the past 3 months
• Scheduled for major surgery within the next 3 months
• Current participation in structured physiotherapy or spinal interventions outside the trial protocol

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Mechanical Diagnosis and Therapy (MDT); Individualized exercise-based rehabilitation delivered according to the Mechanical Diagnosis and Therapy (MDT) approach. Treatment is based on a standardized assessment to identify directional preference, with exercises prescribed accordingly. Participants receive education, self-management advice, and ergonomic guidance relevant to their work. Up to six physiotherapy sessions are provided over 26 weeks, with home exercises prescribed and progressed between visits.	Behavioral: Mechanical Diagnosis and Therapy (MDT); A classification-based physiotherapy intervention in which exercises are prescribed based on the individual's directional preference identified during assessment. Treatment includes repeated movements and/or sustained positions, supported by education and advice to promote self-management. Delivered by physiotherapists trained in MDT.
Active Comparator: Generalized Exercise; Non-direction-specific, guideline-based exercise rehabilitation for chronic spinal pain. The program includes strengthening, flexibility, and endurance exercises tailored to the individual but not based on directional preference. Participants receive education, self-management advice, and ergonomic guidance. Up to six physiotherapy sessions are provided over 26 weeks, with home exercises prescribed and progressed between visits.	Behavioral: Generalized Exercise; A structured exercise program including strengthening, stretching, and endurance training, adapted to the individual's symptoms and capacity. The intervention does not target directional preference and reflects usual physiotherapy care for chronic spinal pain. Delivered by physiotherapists experienced in musculoskeletal rehabilitation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Average spinal pain intensity	Average spinal pain intensity over the preceding seven days measured using the Numeric Pain Rating Scale (0-10), where higher scores indicate greater pain. The primary analysis will compare the between-group difference at 12 weeks, adjusted for baseline pain intensity.	12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient-Specific Functional Scale	Patient-Specific Functional Scale (PSFS). Self-reported functional limitations assessed on a scale from 0 to 10 for each activity, where 0 indicates inability to perform the activity and 10 indicates ability to perform at the pre-injury level. Higher scores indicate better function. Total score will be analyzed as change from baseline by group mean.	Baseline, 4 weeks, 12 weeks, 26 weeks
Short Form-12	Short Form-12 Health Survey (SF-12). Health-related quality of life assessed using Physical Component Summary (PCS) and Mental Component Summary (MCS) scores, each ranging from 0 to 100, where higher scores indicate better health status. Scores will be analyzed as change from baseline by group mean.	Baseline, 4 weeks, 12 weeks, 26 weeks
Fear-Avoidance Beliefs Questionnaire	Fear-Avoidance Beliefs Questionnaire (FABQ). Fear of movement and work-related beliefs assessed on a scale from 0 to 96, where higher scores indicate greater fear-avoidance beliefs. Total score will be analyzed as change from baseline by group mean.	Baseline, 4 weeks, 12 weeks, 26 weeks
Pain Catastrophizing Scale	Pain Catastrophizing Scale (PCS). Pain catastrophizing assessed on a scale from 0 to 52, where higher scores indicate greater catastrophizing. Total score will be analyzed as change from baseline by group mean.	Baseline, 4 weeks, 12 weeks, 26 weeks
Pain Self-Efficacy Questionnaire	Pain Self-Efficacy Questionnaire (PSEQ). Pain self-efficacy assessed on a scale from 0 to 60, where higher scores indicate greater confidence in performing activities despite pain. Total score will be analyzed as change from baseline by group mean.	Baseline, 4 weeks, 12 weeks, 26 weeks
Working Alliance Inventory	Working Alliance Inventory (WAI). Therapeutic alliance assessed on a scale from 12 to 84, where higher scores indicate stronger therapeutic alliance. Total score will be analyzed as change from prior assessment by group mean.	4 weeks, 12 weeks, 26 weeks (no baseline)
Exercise Adherence Rating Scale	Exercise Adherence Rating Scale (EARS). Exercise adherence assessed on a scale from 0 to 24, where higher scores indicate greater adherence to prescribed exercise. Total score will be analyzed as change from prior assessment by group mean.	4 weeks, 12 weeks, 26 weeks (no baseline)
Patient Global Impression of Change	Patient Global Impression of Change (PGIC). Patient-rated global improvement assessed on a 7-point scale from 1 (very much improved) to 7 (very much worse), where lower scores indicate greater improvement. Scores will be summarized by group at each follow-up.	4 weeks, 12 weeks, 26 weeks (no baseline)

Collaborators and Investigators

• Sponsor: Claus Kjærgaard
• Collaborators: Aalborg University
• Investigators: Principal Investigator: Claus Kjærgaard, M.Sc. Health Science, Aalborg University Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): March 30, 2026
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): December 1, 2027

Study Registration Dates

• First Submitted: December 8, 2025
• First Submitted That Met QC Criteria: December 8, 2025
• First Posted (Actual): December 19, 2025

Study Record Updates

• Last Update Posted (Actual): March 20, 2026
• Last Update Submitted That Met QC Criteria: March 18, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: chronic pain; exercise; rehabilitation; occupational health; musculoskeletal pain; spinal pain; surgeons
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Musculoskeletal Diseases; Muscular Diseases; Pathological Conditions, Signs and Symptoms; Behavior; Signs and Symptoms; Musculoskeletal Pain; Chronic Pain; Motor Activity; Therapeutics
• Other Study ID Numbers: N-20240046

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data underlying published results (text, tables, figures, appendices) will be made available no earlier than 12 months after publication of the primary results and for up to 5 years. Access will be granted for academic purposes to qualified researchers upon reasonable request and approval by the Principal Investigator. Data sharing will require a formal application and a data use agreement, and data will be provided through secure transfer.
• IPD Sharing Time Frame: De-identified individual participant data and supporting documents will be available beginning 6 months after publication of trial results and remain available for 5 years.
• IPD Sharing Access Criteria: Data will be shared with qualified researchers for academic purposes only. Access requires submission of a reasonable request and a formal application to the Principal Investigator. Approved applicants will receive de-identified data and supporting materials through secure data transfer.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE

Drug and device information, study documents

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