Study design and participants
We conducted a retrospective chart review, analyzing data of patients treated in our spine outpatient clinic between January 2017 and December 2018, who presented the following criteria on their initial visit: (1) non-specific LBP lasting for more than 3-month duration; (2) normal neurological examination with no findings of motor or sensory deficit; (3) no radicular symptoms or physical findings; (4) no “red flag” signs that may suggest a serious spine pathology (e.g., history of trauma, malignancy, fever, weight loss, neurological deficit, bladder or bowel dysfunction) ; (5) anterior-posterior and lateral lumbar spine radiographs with no pathological findings; (6) no medication prescribed; (7) an age of 18 to 65 years.
Patients who demonstrated these criteria were excluded:(1) radicular signs or neurological deficit; (2) previous spine injury or surgery; (3) systemic conditions which may induce pain (e.g., fibromyalgia, rheumatoid arthritis, malignancy, infection); (4) psychiatric disorders; (5) osteoporosis; (6) serious systemic pathology or pregnancy; (7) body-mass index (BMI) greater than 30 kg/m2 (since palpation of MTP may be less accurate in obese patients [7, 8]).
Clinical data and imaging studies were available for a retrospective review at our hospital medical records. The study was approved by our Institutional Ethics Committee.
All the patients were treated in our spine surgery clinic by one of two spine consultants (E.B and G.G). Medical history and physical examination data were documented in the patient’s file in real time, regardless of the study. According to our routine, after a diagnosis of non-specific LBP without neurological involvement was made, all patients were referred to conservative physical therapy, focusing on stretching and active core muscles strengthening. All patients were treated at the physical therapy department of our hospital by one of several trained physiotherapists experienced in treating patients with musculoskeletal disorders. The physical therapy exercise program included instructional and training sessions of 45 minutes twice a week for 4-6 weeks, in which the patients were instructed how to perform core muscles stretching and strengthening exercises independently at home on a daily basis. Thereafter, all patients attended a weekly check-up exercise session for additional 4-6 weeks. A follow-up visit in our outpatient spine clinic was scheduled for 3-month time. No medication was prescribed for the study cohort.
Patients who were initially seen by E.B, in addition to the aforementioned treatment plan, were also referred to a manual MTP compression therapy program. The manual MTP compression therapy program was supervised by a single manual therapist expert in alternative medicine and experienced in treating patients with musculoskeletal disorders (G.P). During the MTP compression therapy sessions the patients were instructed to lie down in the supine or prone position. Several MTP were identified over the lumbar erector spinae muscles and over the common main muscles associated with LBP (e.g., gluteus maximus, piriformis, hamstrings, quadratus lumborum, iliopsoas, tensor fascia lata) according to previously described diagnostic criteria including: (1) presence of a palpable hypersensitive taut band in the low back and associated muscles; (2) induction of pain similar to the patient's usual symptoms by compression at the MTP; (3) induction of pain by stretching the muscle including the MTP [12,13]. Manual constant pressure was applied to each MTP for a period of 1-2 minutes at controlled intensity aiming to produce pain response ranging between comfortable pain (approximately 4/10 on a 0-10 numerical scale) to maximally tolerable pain (approximately 7/10 on a 0-10 numerical scale) [10-12]. The sequence of MTP compression was repeated for several times during a treatment session of 45 minutes, which was carried out once a week for 6 consecutive weeks.
Patients were asked to complete clinical questionnaires at each outpatient visit, regardless of the study. The questionnaires included patients’ self-reported: (1) back pain during daily activity using a 0 to 10 numerical scale, where 0 indicates no pain and 10 indicates severe pain; (2) back related disability using the Oswestry Disability Index (ODI) on a 0 to 100% scale, where a higher score indicates more disability and poorer function ; and (3) SF-12 life quality questionnaire on a 0 to 100% satisfaction scale, where a higher score indicates more satisfaction and better life quality . We collected the data retrospectively for the purpose of the study from the patients' medical record at the first outpatient clinic before initiating treatment and at 3-month follow-up visit (approximately 1-month after the final MTP compression therapy session in the combined treatment group).
Continuous parameters are presented as means ± standard deviation and categorical parameters are presented as proportions. Comparisons between the MTP group and the control group were performed using unpaired two-tailed t-test for continuous data and the Fisher's exact test for categorical data. Comparisons within each group between outcome measures before and after treatment were performed using paired two-tailed t-test. Data analysis was performed with the use of MedCalc Statistical Software version 19 (MedCalc Software bvba, Ostend, Belgium). With the alpha level set at 0.05, we determined that 34 patients per group would give 80% power of the test to identify a 1-point difference in 0-10 numerical pain score and a10-point difference in ODI between the groups.