Lumbar Extension Strengthening in Addition to Manual Therapy and Exercise for Chronic Low Back Pain

July 18, 2026 updated by: Benjamin Campbell, Brooke Army Medical Center

The Effect of Adding Lumbar Extension Strengthening to a Program of Manual Therapy & Motor Control Exercise in Individuals With Chronic Low Back Pain: A Randomized Control Trial

The goal of this clinical trial is to determine the effect of adding lumbar strengthening exercises to a program of manual therapy and motor control exercises (standard therapy) in adults with chronic low back pain (cLBP). Researchers will compare individuals with cLBP that receive lumbar extensor strengthening in addition to standard therapy compared to standard therapy alone to determine if there are differences in patient reported outcomes, lumbar multifidus thickness, low back endurance, and healthcare utilization between the groups.

All participants will engage in 8-weeks of physical therapy, receiving manual therapy and motor control exercises. Those in the intervention group will have additional low back strengthening exercises.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Detailed Description

Purpose:

The purpose of this study is to determine the effect of adding lumbar strengthening exercises to a program of manual therapy and motor control exercises in individuals with chronic low back pain.

Primary Aim:

  • Compare patient reported outcomes in individuals with cLBP that receive lumbar extensor strengthening in addition to a standard program of manual therapy & motor control exercises compared to manual therapy & motor control exercises alone.

Secondary Aims:

  • Compare lumbar multifidus morphology (thickness) and extensor endurance in individuals with cLBP that receive lumbar extensor strengthening in addition to a standard program of manual therapy & motor control exercises compared to manual therapy & motor control exercises alone.
  • Compare the amount and type of healthcare utilization between the two groups during the study period and the 12-month period following enrollment in the study.

Study Design:

This will be a parallel randomized control trial with two arms. Participants will be randomly assigned to either the experiment (manual therapy, motor control, & lumbar strengthening) or control (manual therapy & motor control) group.

Procedures:

The following procedures will be conducted once the participant has signed and received their Informed Consent Document (ICD) and HIPAA Authorization. The initial baseline visit involves the participant completing the electronic questionnaires, lumbar multifidus assessment (via ultrasound), back endurance test, randomization, and an initial physical therapy evaluation.

INITIAL VISIT - BASELINE MEASURES & START OF TREATMENT

Baseline Questionnaires:

Participants will be provided a tablet to complete research questionnaires electronically, described below, using REDCap. If a tablet or the internet is not available, participants will fill out a paper copy that the research team will later transfer on to REDCap. REDCap is a secure, HIPAA-compliant web application used to build, administer, and record surveys.

Baseline Ultrasound Measurement - Lumbar Multifidus Thickness: Once the surveys have been completed, study participants will have their lumbar multifidus thickness measured. The subject will lie prone with a pillow underneath their pelvis. Ultrasound images, using a curvilinear probe, of the lumbar multifidus muscle at rest will be captured. Three measurements of the muscles thickness will be captured, and the average on each side will be recorded at two vertebral segments (L4/L5 & L5/S1). Images will be saved on a facility device for measurement.

Baseline Back Endurance Performance: After completing the ultrasound measurements, subjects will perform a back endurance test (Biering-Sørensen test) on the variable angle roman chair. Subjects will be positioned prone at a 0 degree angle with their iliac crests at the edge of the hip pads and their legs stabilized on the ankle pads. The time starts once their trunk is horizontal with their hands crossed at the chest. The test will continue until the participant breaks from the horizontal posture.

Randomization:

Following completion of the above procedures, participants will be randomized into one of the following groups: the standard physical therapy group (SPT) consisting of manual therapy & motor control exercises, or the experimental group consisting of the standard physical therapy protocol plus lumbar extensor strengthening exercises (SPT+LEX). The method of group assignment will be sequentially numbered opaque sealed envelopes. To minimize the risk of predicting the treatment assignment of the next eligible subject, randomization will be performed in permuted blocks of 2 or 4 with random variation of the blocking number.

Both groups will begin standard physical therapy treatment on the same day as their baseline examination and will be scheduled for their subsequent appointments at the Physical Therapy clinic. The initial physical therapy evaluation will last approximately 60 minutes.

The treatment groups are outlined below:

Group 1- Standard Physical Therapy (SPT):

Participants randomized to the SPT group (control group) will receive pragmatic treatments of manual therapy and motor control exercises based on their clinical presentation, which is consistent with standard patient care management of chronic lower back pain. They will attend a total of 10-14 visits over a course of 8 weeks, as is typical for routine care of individuals with cLBP. The treating physical therapist will use manual therapy and motor control exercise interventions that will be tailored to the patient's individual presentation. Manual therapy is used by physical therapists to improve and restore movement patterns of the spine and extremities in individuals with LBP. Examples of manual therapy interventions include joint mobilization or manipulation, manual muscle stretching, and soft-tissue mobilization. Motor control exercises (MCE) are designed to restore the coordination and timing of trunk musculature.

Group 2- Standard Physical Therapy Plus Lumbar Extensor Strengthening (SPT+LEX):

Participants randomized to the SPT+LEX group (experimental group) will receive the same pragmatic treatments of manual therapy and MCE as the SPT group over the same number of visits (10-14). In addition to MCE and manual therapy, this group will perform specific lumbar extensor strengthening (LEX) exercises toward the end of each physical therapy treatment visit. These LEX exercises target the lumbar extensor muscle group (to include the lumbar multifidus) and may be performed by lying prone on the edge of a bench or mat and lifting the legs to parallel while the torso is stabilized. Alternatively, they may be performed by stabilizing the hips and legs while lifting the torso to varying angles from horizontal with or without weights. LEX exercises are progressed by increasing hold times or weight, depending on the participant's tolerance and clinical progression

Total time spent with the participant will be equal in both groups (40 minutes)

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Not Applicable

Contacts and Locations

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

Study Locations

  • United States
    • Texas
      • Fort Sam Houston, Texas, United States, 78234
        • CPT Jennifer Moreno Primary Care Clinic - Physical Therapy

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Tricare Beneficiary
  • 18-65 years old
  • LBP ≥ 3 months without symptoms below the knee
  • mODI ≥ 24%
  • English speaking
  • Available to actively take part in the study for 12 weeks

Exclusion Criteria:

  • History of spine surgery or expecting spinal surgery
  • Suspected or confirmed serious pathology (infection, cancer, fracture, cauda equina)
  • Diagnosis of any vertebral fracture in the last 6 months
  • Osteoporosis requiring pharmacologic treatment other than vitamin D, calcium supplements, or bisphosphonates
  • History of any bone-related cancer or cancer that metastasized to the bone
  • Diagnosed rheumatological or inflammatory disease
  • Progressive neurological disease
  • Leg pain as the primary complaint (radiculopathy, peripheral vascular disease, stenosis)
  • Contraindications to exercise and manual therapy
  • Currently pregnant, self-reported or post-partum within the past 6 months
  • Received physical therapy treatment for LBP in the past 6 months
  • In the last 3 months, received injections, nerve ablation or blocks or is seeking such services
  • Uncontrolled drug/alcohol addiction
  • Currently under litigation related to cLBP
  • Pending or expecting a Medical Evaluation Board (MEB)
  • Retiring from the military within 18 months

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

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Standard Physical Therapy
Other: Standard Physical Therapy
Participants randomized to the SPT group (control group) will receive pragmatic treatments of manual therapy and motor control exercises (MCE) based on their clinical presentation, which is consistent with standard patient care management of chronic lower back pain. They will attend a total of 10-14 visits over a course of 8 weeks, as is typical for routine care of individuals with cLBP. The treating physical therapist will use manual therapy and motor control exercise interventions that will be tailored to the patient's individual presentation.
Other Names:
  • Manual Therapy
  • Motor Control Exercise
Experimental: Standard Physical Therapy Plus Lumbar Extensor Strengthening
Other: Lumbar Extensor Strengthening plus Standard Physical Therapy
Participants randomized to the SPT+LEX group (experimental group) will receive the same pragmatic treatments of manual therapy and MCE as the control group over the same number of visits (10-14). In addition to MCE and manual therapy, this group will perform specific lumbar extensor strengthening. These exercises target the lumbar extensor muscle group (to include the lumbar multifidus) and may be performed by lying prone on the edge of a bench or mat and lifting the legs to parallel while the torso is stabilized. Alternatively, they may be performed by stabilizing the hips and legs while lifting the torso to varying angles from horizontal with or without weights.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Modified Oswestry Disability Index (mODI)
Time Frame: Enrollment, 4, 8, 12, and 26-weeks
A 10-item disability questionnaire administered to evaluate the patient's symptoms and the functional impact of low back pain. Each item is scored on a 0-5 Likert scale. The total score is converted to a 0-100% disability index, with 0% indicating no functional limitation and 100% representing complete disability or a bedbound state.
Enrollment, 4, 8, 12, and 26-weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
PROMIS-29
Time Frame: Enrollment, 4, 8, 12, and 26-weeks
A 29-item self-reported questionnaire that assesses seven key health domains; physical function, pain interference, fatigue, sleep disturbance, depression, anxiety, social participation, plus a single item for pain intensity. Ratings are on a 1-5 Likert scale. The PROMIS-29 is a core outcome measure in chronic LBP research.
Enrollment, 4, 8, 12, and 26-weeks
Lumbar Spine Instability Questionnaire (LSIQ)
Time Frame: Enrollment
A 15-item self-reported questionnaire designed for patients with low back pain to assess perceived lumbar spinal instability. Items address symptom triggers, alleviating factors and movement-related behaviors. Higher scores reflect greater perceived instability.
Enrollment
Patient Acceptable Symptom State (PASS)
Time Frame: Enrollment, 4, 8, 12, and 26-weeks
A dichotomous questionnaire to determine if the participant believes their symptoms are acceptable
Enrollment, 4, 8, 12, and 26-weeks
Healthcare Utilization
Time Frame: Enrollment, 4, 8, 12, 26-weeks
Participants will be queried on the healthcare resources they have used up to the time of taking this questionnaire. Items include other interventions, medication use, and specialty referrals
Enrollment, 4, 8, 12, 26-weeks
Lumbar Multifidus Thickness: L4-L5, L5-S1 bilaterally
Time Frame: Enrollment, 8, and 12-weeks
Resting Lumbar Multifidus (LM) Thickness is a physical measure of muscle thickness of the lumbar multifidus. Measured in one plane, it is a surrogate measure for overall hypertrophy of the muscle. Thickness of the LM is measured in millimeters from the most posterior aspect of the facet joint to the thoracolumbar fascia.
Enrollment, 8, and 12-weeks
Back Endurance
Time Frame: Enrollment, 8, and 12-weeks
The back endurance test (Biering-Sørensen test) will be conducted on a variable angle roman chair. Subjects will be positioned prone at a 0 degree angle with their iliac crests at the edge of the hip pads and their legs stabilized on the ankle pads. The time starts once their trunk is horizontal with their hands crossed at the chest. The test will continue until the participant breaks from the horizontal posture.
Enrollment, 8, and 12-weeks

Collaborators and Investigators

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

Sponsor

Brooke Army Medical Center

Investigators

  • Study Chair: Benjamin Hando, PT, DSc, PhD, Army-Baylor Doctoral Fellowship in Orthopedic Manual Physical Therapy

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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 (Estimated)

August 3, 2026

Primary Completion (Estimated)

June 30, 2027

Study Completion (Estimated)

June 30, 2028

Study Registration Dates

First Submitted

July 18, 2026

First Submitted That Met QC Criteria

July 18, 2026

First Posted (Actual)

July 22, 2026

Study Record Updates

Last Update Posted (Actual)

July 22, 2026

Last Update Submitted That Met QC Criteria

July 18, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • C.2026.044d / eIRB #992009

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

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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