Study setting
The whole study will be performed in the School of Rehabilitation Sciences of Iran University of Medical Sciences (IUMS) which is located in Iran country. All of the participants' data needed for this study will be collected by manually writing them on papers.
Eligibility criteria
Individuals can be involved in the study after meeting all inclusion criteria including 1) Non-athletes patients aged between 18 to 45 years [38]; 2) Having moderate pain intensity (between 30 to 60) based on Numerical Pain Rating Scale (NPRS) 24 h average [39]; 3) Having TrPs in the QL and LM; 4) Symptoms provocation with passive accessory intervertebral movements on at least one segment of the lumbar spine [36]; 5) Being able to write and read Persian.
The exclusion criteria are 1) Complications that can influence the treatment procedure such as infectious conditions [40]; 2) History of lumbar surgery [11]; 3) Specific LBP; 4) Long history of steroid use; 5) Pregnancy; 6) Unexplained weight loss during the last month (more than 10 lbs) [41]; and 7) Needle phobia [42].
Who will take informed consent?
On the first visit, the compliance of patients with the inclusion/exclusion criteria will be checked. If appropriate, they will be given the information they need to participate in the study. If they agree, they will sign the informed consent form and join the study consciously.
Interventions
Intervention description
Both experimental and control groups will receive routine physiotherapy (RPh) including low-power laser plus core stability training [43], detailed in Appendix A.1.
Experimental group: The treatments of this group will be DN and sham mobilization in addition to RPh:
A) Dry needling: The method of LM and QL DN is inspired by Dommerholt et al. (2018) method which is detailed in Appendix A.2 [7]. The needles will be inserted to obtain a local twitch response (LTR) which is a brisk contraction of the taut bands in skeletal muscle. This procedure will resume until no more LTRs occur in each treatment session. Afterwards, the needles will be left in place for 20 minutes.
B) Sham mobilization for the lumbar spine: Mobilization will be conducted on the spinous process (SP) of the lumbar vertebrae at the level of the skin surface (less than the first degree of the Maitland's mobilization) using thumbs.
Control group: The treatments of this group will contain sham DN and mobilization plus RPh:
A) Sham Dry needling: It will be conducted in the place of QL and all of the LM muscles just like the actual method but the needles will only penetrate the surface of the skin and then will be left in place for twenty minutes [45]. B) Maitland's mobilization: For executing lumbar spine mobilization, Maitland’s anterior-posterior mobilization method, will be utilized which is explained in Appendix A.3.
Criteria for discontinuing or modifying allocated interventions
(1) Participant request to leave the study for any reason; and (2) Participant Absence for more than two consecutive sessions.
Relevant concomitant care and interventions that are permitted or prohibited during the trial
Prohibited interventions include (1) Any specific intervention for LBP which is performed by a health practitioner; (2) Muscle relaxants; and (3) Narcotics.
Outcomes
The primary outcomes include changes in pain intensity based on NPRS and FD based on Oswestry Disability Index (ODI) questionnaire. The secondary outcomes include LM and QL muscles’ function based on ultrasound measurements, lumbar ROM by Goniometer and PPT by algometer, Dry needling side effects, and adherence to the treatment. Primary and secondary outcomes will be assessed at baseline and 3 to 7 days after the final treatment session.
Participant timeline
In general, both groups will be treated for 8 sessions over 4 weeks (treatment frequency: 2×/week) [22, 46]. The number of treatment sessions is selected based on the average number of treatment sessions in a study conducted by Coulter et al. [22]. The study length for each participant will be approximately five weeks. The timing of data collection and intervention is detailed in Table 1.
Insert Table 1 here.
Sample size
The method of sampling in this study will be simple, non-random, continuous and purposive. In this study, we use a priori sample size estimation which is based on the minimal clinically important difference (MCID). The sample size is estimated by using Stata software to compare the differences between the two groups, and it is based on a 2019 study by Griswold et al. [36]. The data will be collected by using non-probability sampling from the available community. Finally, the test power was set at 80%, and the type I error was set at 0.05. The MCID for ODI is 10 points [47]. The sample size was determined by Stata 16.0 software using the sampsi command which is detailed in Appendix A.4. According to the calculation, 23 people will be needed for each group. But with a Possibility of 20% drop-out, 28 people will be accepted into each group. Totally, 56 patients with CNLBP will be recruited that are individually matched in terms of height, age, body mass index and weight according to the caliper method. Also, patients will be matched based on the three confounding variables in LBP, namely smoking [48], fear of movement (TSK) [49] and depression (BDI- II) [50].
Assignment of interventions: allocation
Patients will be randomly admitted to either the first or second group with a 1:1 allocation ratio by utilizing permuted block randomization method (restricted randomization), that is made of blocks with different sizes and are created with numbers 1 and 2. After finishing random allocation, the random treatment list will be created by a third person and be put in the forms of numbers 1 and 2 inside the sealed, sequential numbered envelopes which are opaque. Number 1 manifests experimental/first group and Number 2 manifests control/second group. Following the primary assessment of the participant by the assessor, the care provider will give the numbered envelopes to the participant. Based on the envelopes, the care provider will give each participant a specific code/number (randomly an odd number for the experimental group and an even number for the control group). Afterwards, she will assign the participant to the interventions.
Assignment of interventions: blinding
Who will be blinded
In this study, the participants, data analysts and outcome assessors will stay blinded to the intervention assignment. Due to the nature of the interventions, the care provider cannot be blinded to allocation, but she has been told not to disclose participants' allocation status during the study.
Data collection and management
Plans for assessment and collection of outcomes
Primary outcomes:
1. Pain: Pain intensity will be determined using NPRS, which is a divided form of the Visual Analogue Scale that covers the entire range of pain and patients score their pain from 0 to 100. Number zero indicates the absence of pain and number 100 indicates the most imaginable pain [51]. The Participant will show the average intensity of his/her pain over 24 hours [36]. MCID for NPRS is 15 mm [47].
2. Functional disability: The Persian version of the ODI will be used to assess the disability degree which is valid and reliable (Cronbach's a = 0.75, Pearson correlation coefficients = -0.66) [52]. This questionnaire contains 10 activities of daily living with a total of 50 scores. The overall score will be calculated and interpreted based on the Fairbank study [53]. MCID for ODI is 10 points [47].
Secondary outcomes:
1. LM and QL muscles CF: QL and LM muscles function will be assessed by attaining thickness measurement during rest and sub-maximal contraction. Ultrasound B-mode images assessment of the QL and LM muscles will be attained using an Affiniti 70 ultrasound machine (Philips, Amsterdam, Netherlands) with a 5MHz curvilinear transducer. The imaging parameters will be the same in all measurements [54, 55]. All ultrasound measurements will be performed by an experienced radiologist with more than 7 years of experience. To increase the accuracy, the muscle thickness will be measured 3 times and then the average of the measured values will be estimated [56, 57]. The use of ultrasound to assess changes in muscle function is a non-invasive, promising and reliable method [11, 58, 59] and also it has been shown that ultrasound imaging is a valid tool for measuring activation of the trunk muscles through most sub-maximal isometric contractions [60]. QL and LM muscles' CF will be calculated utilizing the ensuing formula: [(thickness contraction – thickness rest)/thickness rest × 100] [55].
A) LM thickness measurement method: LM will be imaged bilaterally in the parasagittal section (longitudinally) to allow the zygapophysial joint to be observed at the fourth lumbar vertebra's level [23, 61]. The participant will lie on his/her back, with his/her head in the midline and a pillow will be placed under the participant's belly until the lumbar lordosis is reduced to less than 10 degrees (which will be checked using an inclinometer placed on the sacrum). The participant will be instructed to relax, then 3 images will be taken at rest. To measure muscle thickness during voluntary muscle contraction, the participant will lie on his/her back with their opposite upper limb lift a weight (which is determined by the Participant's mass: 1) Participant's mass less than 68.2 kg = weight 0.68 kg 2) Participant's mass between 68.2 to 90.9 kg = weight 0.9 kg 3) Participant's mass more than 90.9 kg = weight 1.36 kg) 5 cm above the bed, while their elbow flexed at 90 degrees and upper arm abducted to 120 degrees. The weight will be adjusted so that the contraction of the LM is equal to 30% of the maximum voluntary contraction of the muscle and based on a study by Kiesel et al. (2007) at this rate of LM contraction (between 19-34% maximal voluntary contractions) there is a strong linear relationship (r = 0.79) between EMG activity and ultrasound measures of thickness [62]. Participants will be instructed to hold their breath at the end of the exhalation (to reduce the effect of breathing on muscle thickness) and to hold the contraction for 3 seconds. Each participant practices this process 3 times before performing the main assessment. The muscle thickness will be measured using linear measurements from the tip of the zygapophysial joint to the inner edge of the upper border of the LM (Figure 2). Measurements of the LM muscle are highly reliable (ICC ¼ 0.97e0.99), responsive to change (MDC ¼ 1.6 mme2.8 mm) [63], repeatable and valid [56, 64].
Insert Figure 2 here.
B) QL thickness measurement Method: To measure the thickness of the QL, the participant will lie on his side and the ultrasound convex probe will be placed transversely in the abdominal flank above the iliac crest. Then the probe will be slightly tilted posteriorly until obtaining a sufficient image from QL. The participant will be instructed to relax, then 3 images will be taken at rest. To measure muscle thickness during voluntary muscle contraction, the participant will be asked to lift the pelvic with a weight of 0.5 kg on the ipsilateral leg. All of the images will be taken at the L3-L4 level (Figure 3) [54].
Insert Figure 3 here.
2. Lumbar range of motion: A goniometer will be used to measure the lumbar flexion, extension and lateral flexion. For measuring Lumbar flexion/extension ROM, the participant will be asked to stand with his/her hands on the chest and feet shoulder-width apart. The location of the goniometer will be in line with the midaxillary line and at the level of the last rib. The goniometer axis will be along the midaxillary line at the level of the lowest rib, the fixed goniometer arm will be perpendicular to the ground and the moving arm will be along the midaxillary line. The participant will be asked to keep his knees straight and bend forward / backward as far as possible which shows lumbar flexion/extension ROM. To measure lumbar lateral flexion ROM, the participant will be asked to stand and place his hands next to his body. The goniometer axis will be located on the SP of the S1 vertebra, the fixed arm will be Vertical to the floor and the moving arm will be in the direction of the SP of the C7 vertebra. Then, the participant will be asked to bend to both sides (right/left) as far as possible which shows lumbar right/left lateral flexion ROM (Appendix A.5) [65].
3. Pain pressure threshold: PPT will be measured using a digital algometer (Jtech Medical Commander, United States). The participant will lie on his/her back with his/her hands under his forehead. The algometer tip with a 1 cm square cross-section will be placed vertically on the most painful point of the QL and LM at each lumbar level which is 1.5 cm outside the SP of the lumbar vertebrae and perpendicular to the muscle belly of the LM, on the painful side. If muscles on both sides are equally painful, the painful side will be determined randomly. To stimulate the participant's pain, the pressure will gradually increase at a rate of approximately 5 N/s and the participant will be asked to announce the onset of pain. The exact location will also be noted for the next examination by algometer (in 7 days after the last treatment session). This process will be repeated three times and the average will be calculated to reduce the variability (Appendix A.6) [11]. PPT measures are responsive to change and highly reliable [66], especially when they are taken only by one assessor (ICC ¼ 0.94 to 0.97, Minimal Detectable Change ¼ 4.3e9.8 N/ cm2) [66].
4. Dry needling side effects: In this study, DN side effects will be assessed as a secondary outcome. This assessment will be done using the table provided in a study by Boyce [67]. In each treatment session, participants will be asked if they have had DN side effects including bleeding, bruising, pain during or after DN, aggravated symptoms, drowsiness, feeling faint, headache and nausea.
5. Adherence: The participant's adherence rate will be measured based on the ratio of the number of treatment sessions in which the participant will participate to the total number of treatment sessions.
Data management and confidentiality
The data obtained from the measurements will be manually recorded in the relevant paper forms. Also, they will be checked and illogical values will be corrected. All data will be collected in folders that are encoded with the participant identification code and then will be stored in a drawer to which access is restricted. Participant information will not be disclosed outside the study without the participant's permission.
Statistical methods
Statistical methods for primary and secondary outcomes
Statistical analyses will be performed on a personal laptop using STATA version 16 (StataCorp LLC). A mixed-model 2-way analysis of variance (ANOVA) for each dependent variable, with the 2 factors being group (DN/mobilization) and time (preintervention/postintervention) will be used. In addition, an intention-to-treat analysis will be conducted if any protocol deviation is observed at the end of the study due to attrition or loss to follow-up. Perceived pain and FD will be compared with consensus standards for minimal clinically important difference (MCID) [47]. Ostelo et al. [47] considered the MCID for NPRS as 15 mm and for ODI as 10 points for patients with LBP. Effects sizes will be also measured using the Cohen d [68]. The significance level used for statistical analysis will be two-sided with confidence intervals at the 95% level. No multiple amputation will be undertaken for this study.
Plans to give access to the full protocol, participant-level data, and statistical code
This article only contains information about the protocol of the study and readers should contact the authors for more information.
Oversight and monitoring
Composition of the coordinating center and trial steering committee
This study is a single-center trial. All activities will be conducted and organized within the School of Rehabilitation Sciences of IUMS. Each study personnel's duty is elaborated in detail in the following:
1. Principal investigator, research care provider and Recruitment coordinator (Hamide Mirzaie): a) Preparing protocol and revisions b) Reporting research records c) screening, Recruiting, and attaining medical clearance for potential participants d) Communicating with participants during the research e) Designing the method.
2. Scientific director (Mohammadreza Pourahmadi): a) Monitoring the conduction and exactness of the study protocol and treatment delivery b) Performing study statistical analysis b) Writing statistical sections of the study protocol c) Revising the study contents d) Designing the method.
3. First Outcome assessor (Mohamad reza Ayoubpour): a) Measuring LM and QL contractile function using ultrasound imaging at baseline and 3 to 7 days after the final treatment session b) Writing ultrasound measurement sections of the study protocol.
4. Second Outcome assessor (Bahare Firouze): Measuring pain intensity, functional disability, lumbar ROM and PPT at baseline and 3 to 7 days after the final treatment session b) Helping in writing the study protocol.
Data monitoring
This research does not have a Data Monitoring Committee. The scientific director and principal investigator will be in charge of supervising protocol exactness and managing data during the research.
Adverse event reporting and harms
In this study, adverse events of DN are considered secondary outcomes. In each treatment session, the care provider asks the participant if his\her general health has gotten worse compared to the previous treatment session and if this change relates to the study treatments.
Dissemination plans
Results from this research will be announced publicly.