Home-based Approaches for Subacute Low Back Pain in Active Duty: Randomized, Controlled Trial
Phase: NA
Conditions: Subacute Low Back Pain
Sponsor: University of Tennessee

Study Protocol Document Cover Page 
 
Official Title of the Study: Home-based Approaches for Subacute Low Back Pain in Active Duty: 
Randomized, Controlled Trial  
 
NCT Number: NCT03502187 
 
Date of Document: April 17, 2018 
 
 

Home-based approaches for subacute low back pain in Active Duty: Randomized control trial 
Objective 
The overall objective of this project is to compare three home-managed treatment regimens for 
subacute low back pain: Progressive Exercise Plan (PEP), NMES core strength training and standard 
primary care management (PCM).  Each of the treatment arms will be supplemented by PCM and 
compared to a group receiving standard PCM alone. Our central hypothesis is that the NMES core 
strength training alone and PEP alone will show significantly greater improvements in muscle strength, 
pain, mobility/function, daily activity, and quality of life (QOL) than PCM alone in military members with 
low back pain lasting three to twelve weeks.  
Design 
This study is a randomized clinical trial with repeated measures over time to compare the effects of 
NMES and PEP on strength, mobility, symptoms, and QOL in military members with subacute LBP to the 
effects of a standard primary care management. All groups will participate in the standard primary care 
management protocol; all groups will have an intensive 9-week program. 
Participants will be randomly assigned to 1) NMES core strength training plus PCM, 2) PEP plus PCM and 
3) standard primary care management (PCM).  We will not randomize participants until after the pre-
treatment assessment has been completed. Participants will be familiarized with the test procedures 
prior to baseline testing, and then assessed again at 3, 6 and 9 weeks. The primary outcome measures 
are lower back muscle strength, activity, and mobility; and the secondary measures are symptoms/pain 
and QOL. 
Methods 
Intervention: The rationale for the number of weeks of intervention and the number and timing of 
assessments is based on our previous work. NMES was found to increase strength after 36 sessions of 
training. We will test participants at baseline, 3-weeks, 6-weeks, and 9-weeks when all outcome 
measures will be tested. The intervention weekly logs to determine pain and difficulty during home 
exercise, NMES and TENS will be reviewed and adjusted, as necessary. We will have weekly contact with 
participants during the 9 weeks of the study (baseline – week 9) either by in-person clinic visits, phone 
checks, text messaging or email.  
Standard Primary Care Management (PMC): All participants will receive standard primary care 
management for subacute LBP. Primary Care Management follows the clinical practice guidelines for low 
back pain. Service members are to stay as active as possible and progressively increase their activity. 
Medications prescribed begin with paracetamol and NSAIDs as first-line drugs. Second-line drugs include 
antidepressants, benzodiazepines, tramadol, and opioids. All participants will receive an information 
sheet on LBP advising then to remain active and use self-care options such as heat application. To 
provide an attention control, the PMC only group will receive weekly communication from the study 
coordinator regarding pain and medication usage. 
Progressive Exercise Program (PEP): The primary goal of PEP is to reduce back pain, disability, and 
improve trunk flexibility, strength, and endurance through controlled, gradual, progressive back 
exercises. PEP teaches muscle strengthening exercises and self-management strategies to promote back 

fitness. The PEP sessions provide the participant with a standardized self-management framework for 
performing the exercises at home. PEP is performed every other day/week for about ~1 hour over a 
period of 9 weeks. PEP consists of 3 sequential phases with each phase lasting 3 weeks. As the 
participant progresses through each phase, the exercises become progressively more difficult and 
intense, focusing on back stretching and strengthening that progressively load and unload the lumbar 
spine by means of flexion/extension exercises. During the baseline visit, participants will be provided a 
handout and given a demonstration of the Phase 1 exercises to be performed at home for 3 weeks. The 
participant will perform a return demonstration to be sure of proper form and performance of the 
exercises. At each return 3-week visit, the same parameters (described above) will be used to teach 
Phase 2 and 3. The PEP group will perform 31 exercise sessions for 60 minutes on alternating days. Pain 
status will be assessed at each visit. 
Data collection:   Variables and Their Measurement  
Clinical and Demographic Variables: Information will be collected on age, sex, co-morbidities, 
medication use, use of assistive aids, symptom duration, history of  injuries/trauma, changes in 
frequency, duration and intensity of training, previous surgeries, imaging studies and other self-care 
methods currently being used to improve pain and/or mobility. Height and weight will be measured 
without shoes with the head held horizontal and chin parallel to the floor while standing on a flat 
surface using a calibrated balance beam scale and stadiometer; they will be used to calculate body mass 
index (BMI: weight in kg divided by square of height in meters). Resting blood pressure (B/P) will be 
measured in triplicate in a seated position. The lowest of three blood pressure measurements will be 
recorded. Resting heart rate will be measured using the radial pulse over 1 minute's duration.  
Outcome Measures: The primary measures to be studied are lower back muscle strength, 
physical activity, and mobility; secondary measures are symptoms of LBP and QOL.  
Assessment of Torso Muscle Strength: The strength of torso flexion and extension muscles will 
be measured using a modified version of the U of Michigan strength test system (Workability Systems, 
West Chester, Ohio) and a Chattanooga-Baseline® HandDynamometer - Digital LCD Gauge - ER™ 300 lb 
capacity (DJO Global, Chattanooga, Vista, CA USA). For trunk flexion, the participant will stand upright in 
the testapparatus with buttocks against the padded board and the superior edge set at the level of the 
iliac crest. The participant is strapped to the apparatus by a canvas belt placed snugly around the chest 
and under the arms horizontal to the force-measuring dynamometer secured to the apparatus frame. 
For measurements of trunk extension, the participant stands upright with their lower anterior abdomen 
against the padded board at the iliac crest level. The belt is placed snugly around the posterior back and 
runs under the arms horizontal to the dynamometer. 
Participants will be instructed to pull against the belt as forcefully as they can without injuring 
themselves and not to use their arms for support; thus, the force exerted will be by the trunk muscles. 
For each test, participants will perform two maximal efforts maintaining each voluntary isometric 
exertion for 5 seconds, separated by 30-second rest; the highest value of the two trials will be accepted 
in kilograms. All subjects will be given the visual analog scale (VAS) for pain to quantify pain during 
testing. Reproducibility of maximum exerted forces by repeat testing differed by a mean of 22% 
extension and 13% flexion. Intra-individual performance ratios differed by a mean of 20% for extension-
to-flexion. A reasonable percent variance for strength-testing. 

Assessment of Mobility and Physical Activity: Mobility will be measured by these procedures: 2-
minute push-up test, 2-minute sit-up test, lumbar trunk muscle test and a 6-minute walk test. Additional 
physical activity measures will be the monitoring of steps walked and energy expenditure. After 
completing the tests, a VAS for pain will be administered to quantify pain during the effort. 
The 2-minute push-up and sit-up tests will be completed in accordance with the Army APFT 
protocol, and are similar to that described by the ACSM. Starting in a prone position, the participant is 
positioned with their hands on the ground (shoulder width apart), toes in contact with the floor, spine 
parallel to the floor, elbows and hips in extension. The body moves as a single rigid unit and is lowered 
to the ground until elbows are at 90° angle. The body is then returned to the starting position by 
pushing the arms up to full extension. A push-up is counted if the elbows were brought to flexion of 90° 
or greater and then return to full extension, while keeping the body elevated on the toes. The number 
of push-ups performed in 2-minutes is recorded. The 2-minute sit-up test tests trunk flexion and 
abdominal endurance. Starting in a supine position, the knee joints are flexed at a 90° angle, with fingers 
behind the head, soles of the feet and shoulder blades in contact with the floor. With the command to 
begin, the upper body is raised forward by flexing the abdominal muscles and then lowered. A sit-up is 
counted if the hands are behind the head, bringing the base of the spine to a vertical position and then 
returning the shoulder blades to the floor. The number of repetitions performed in 2-minutes is 
recorded.  
The Lumbar Trunk Muscle Test will assess back extension and endurance. Participants will be 
asked to lie in a prone position while holding the trunk in 15° of extension(sternum off the floor) for as 
long as they are able. A small pillow will be placed under the lower abdomen and to decrease lumbar 
lordosis. Participants will be asked to maintain maximum flexion of the cervical spine while contracting 
the gluteal muscles. The time during which the subject keeps the upper body straight and horizontal is 
recorded. For subjects who experience no difficulty in holding the position, the test is stopped after 300 
seconds (5 minute).  
The 6-Minute Walk Test (6-MWT) measures the distance a participant walks at a “fast” pace 
over a 6-minute period. Participants will “walk as quickly as you can” with the opportunity to stop and 
rest if required. This test measures functional capacity of walking. Normal reference for healthy adults 
on the 6-min walk distance has been published.  
Physical Activity Measures: Physical activity will be measured using the Fitbit Charge 2 (San 
Francisco, CA). The Charge 2 is a wrist-worn three-axis accelerometer that measures steps walked, 
distance traveled, energy expenditure and floors climbed. The unique feature of this device is a wireless 
function that automatically uploads data to designated mobile phone devices or computers. Batteries 
are rechargeable and last 5-7 days. Fitbit products use similar accelerometry for all their products. Thus, 
we assume that each of their products have similar validity and reliability. In our personal experience 
comparing the Charge to the Jawbone and the well validated Digiwalker, we found very similar accuracy 
of steps. Subsequently, the device will be worn daily for 9 weeks. 
Assessment of Symptoms of Low Back Pain: Pain associated with daily activity (walking, sitting, 
standing, bending, sport, resting, work) and body functions (pain, sleep, bending, leg weakness, loss of 
feeling) will be measured by the Clinical Back Pain Questionnaire (CBPS), also known as Aberdeen LBP 
scale, a 19-item back pain specific self-report questionnaire. Scores range from 0 to 100 with higher 
scores indicating greater disability.  

LBP-related disability and functional limitation will be measured by the Oswestry Disability Index 
(ODI), a well standardized outcomes questionnaire that is LBP-specific for activities of daily living and 
degree of disability. The 10-section instrument assesses pain, personal hygiene, lifting, walking, sitting, 
standing, sleeping, sex life, social life, and traveling for those with back pain. Each section contains six 
statements, ranging from 0 to 5, the final score is calculated using a standard scoring method. The ODI 
has demonstrated reliability and construct validity in comparison to other pain and disability measures. 
The Visual Analog Scale (VAS) of pain will be used to assess pain at rest and after activity. Participants 
will complete this scale following the push-ups, sit-ups, 6-minute walk and the lumbar trunk muscle test. 
This VAS pain subscale is a 100-mm horizontal line index with descriptive anchors at each end. At the far 
left (0.0 cm) is “no pain” and at the far right (10 cm) is “worst possible pain”. The participant is 
instructed to place a vertical line at some point between the anchors to describe his/her level of pain.  
Assessment of Quality of Life (QOL): The SF-12v2 Health Survey will be used to determine each 
participant’s overall health-related quality of life. It is a shorter version of the MOS 36-item Short Form 
Health Survey (SF-36) demonstrating similar reliability and maintaining the eight health domains with 
one or twoquestions per domain. This widely used multidimensional scale has two summary scores for 
physical and mental health as well as eight subscale scores. In addition, depressive symptoms will be 
measured by the Centers for Epidemiologic Studies Depression instrument, a self-administered 
questionnaire that contains 20 items.  
Compliance/Adherence to Treatments: Compliance/adherence to the interventions will be 
measured at multiple levels. Adherence to the standard PCM protocol, PEP and NMES will be computed 
as the number of home sessions reported on the participant’s log divided by the total number of 
sessions prescribed (daily). Adherence to NMES back training will be defined as the number of sessions 
achieved in each phase divided by the number of sessions prescribed. The Recovery Back system has a 
hidden internal compliance timer that records the amount of time the stimulator was used. This time 
will be compared to the training logs. Individual NMES reliability will be assessed from the total 
stimulation time recorded in the stimulator compliance monitor and by cross checking with training logs 
in which participants record their daily stimulation time. 
Study population:  
To obtain a sample size of 135 adults with subacute LBP (45 per group), we will draw upon Active 
Duty members and Reserve/National Guard members on active duty status through the physical therapy 
clinic, family practice clinic and satellite clinics at BACH. All racial, ethnic, and gender groups will be 
recruited for the study.  Active duty members who meet eligibility criteria and agree to participate in the 
study will be asked to participate.   
Inclusion Criteria 
 
The study will be open to all active duty personal who are:  
- Active Duty at time of diagnosis.  
-  LBP greater than 3 weeks and less than 12 weeks since the onset of the episode of LBP;  
- age ≥18 and < 45 years; and  
- ability to provide freely given informed consent.  
 

 Exclusion Criteria 
Those who might be at risk of adverse outcomes from the study interventions will be excluded. 
This includes individuals with 
- Eecurrence of LBP that is less than 3 months from prior episode;  
- A significant co-morbid medical condition (such as severe hypertension, neurological disorder 
or pacemaker/defibrillator) in which NMES strength training or unsupervised exercise is 
contraindicated and would pose a safety threat or impair ability to participate;  
- Previous back surgeries;  
- Inability or unwillingness to participate in an exercise or strengthening program;  
- Pregnancy;  
- Vision impairment, where participant is classified as legally blind;  
- Unwillingness to accept random assignment; or  
- A score of 23 or greater on the Center for Epidemiological Studies-Depression scale (CES-D). 
 
 
Statistical Methods – See Statistical Analysis Plan.