The effects of osteopathic manipulative treatment on pain and disability in patients with chronic low back pain: a single-blinded randomized controlled trial

Participants

• Number: 80 people (49 female and 31 male, mean age 44 years).

• Criteria of inclusion: age between 21 and 65 years; ability to walk independently; ability to speak and read English, understand study procedures and follow them throughout the study; musculoskeletal pain (primarily in the lower back, with possible irratiation to the thighs); pain of at least 3 out of 10 according to the NRS; ODI of at least 26%.
• Criteria of exclusion: inability or unwillingness to give written informed consent; having received physio therapy or manual medicine treatments, acupuncture or spinal injections in the month prior to recruitment; receipt of compensation from employment insurance in the past 3 months or pending medical lawsuits; possible pregnancy; body mass index greater than 32; use of electrical implants (eg, cardiac pacemakers, drug delivery pumps); medical history of spinal surgery, vertebral fractures, spinal infections or cancer; unresolved symptoms from head trauma, inner ear infection with balance or coordination problems, orthostatic hypotension, uncontrolled hypertension or vestibular disorders; diagnosis of significant spinal deformities (ex. scoliosis greater than 20°), ankylosing spondylitis, grade III or IV spondylolisthesis, horsetail syndrome, rheumatoid arthritis, osteoporosis, angina or congestive heart failure symptoms, acute hemorrhage or infections in the back, blindness, seizures, neurological or neurodegenerative diseases; conditions recognized by a physician during the course of the study (signs of neurological deficits, symptoms not consistent with mechanical findings, other conditions preventing the implementation of the protocol).
  • Exclusion criteria were periodically rechecked during the study.

• Groups of study: 2 groups obtained by randomization, with cross over
  • Group 1: OMT and tehn waiting list, 40 people (24 female and 16 male, mean age 44.3 years).
  • Gruppo 2: waiting list and post OMT, 40 people (25 female and 15 male, mean age 43.55 years).
  • On average, the participants had been suffering from low back pain for more than 12 years with a pain rate of 6 out of 10.

Interventions and evaluations

• Assessment of current pain and average pain in the last week by NRS, where 0 = “no pain” and 10 = “worst pain imaginable”. Assessment of disability by modified ODI and PROMIS 29 v1.0 pain and Physical Function Interference Scales.
• Assessment of the PROMIS scales of social satisfaction, sleep disturbance, fatigue, depressive symptoms and anxiety. Assessment of kinesiophobia using FABQ.
• Adverse effects were monitored immediately after treatment and in the following days by email, telephone calls, or  interviews in person. An increase in symptom severity of more than two points on a scale of 0 to 10 was considered an adverse effect.
• Data were collected at the time of recruitment, after one session of OMT or equivalent time for the wait list group, at the end of all OMT sessions or equivalent time for the wait list group, and at the end of the study (ie, after the groups crossed over the interventions).
• Data were collected through online databases (REDCap) and interviews carried out in person.
• 3-4 30-minute OMT sessions weekly, spaced between 3 and 14 days along a 4-6 week period.
• OMT:
  • standardized osteopathic evaluation (protocol defined by Licciardone in his studies) looking for somatic dysfunction at the thoracic, lumbar, pelvic, and sacral levels to define personalized treatment;
  • semi-structured treatment that always included high-velocity, low-amplitude techniques and a combination (at the operator’s discretion) of soft tissue, muscle energy, myofascial and articulatory techniques.
• Waiting list: during the waiting period, people did not receive any kind of treatment.
• OMT performed by one of five osteopathic physicians specializing in OMT (three specializing in osteopathic neuromusculoskeletal medicine and two certified in physical therapy and rehabilitation – PM&R).
• Participants were able to continue their therapies.

Results

Because of the risk of bias due to the cross-over design of the study, the data were compared only before the cross-over had taken place. At this stage Group 1 had received only OMT while Goup 2 had only done the waiting list.

• Primary outcomes: at the end of all sessions, the OMT group showed a statistically significant improvement in average perceived pain  compared to the waiting list group during the course of the week.
  After rhemoving three participants (1 from the OMT group and 2 from the waiting list group) because they were not found to have chronic low back pain, the analyses showed the same results, which were both statistically and clinically significant.
• Secondary outcomes: after one OMT session and at the end of all sessions, the group that received OMT showed statistically significant improvement in sleep and anxiety symptoms compared to the waitlist.
  After removing three participants (1 from the OMT group and 2 from the waiting list group) because they were not found to have chronic low back pain, the analyses showed the same results, which were both statistically and clinically significant. However, at the end of the treatments, there were no statistically significant differences with regards to sleep, although an important difference still emerged from a clinical point of view.
• Further analyses: 122 adverse effects were noted, but none were grade 4 or higher (ie, severe). 31 of these events could be attributed to OMT and involved a mild or moderate increase in pain, muscle discomfort, stiffness, and others. Almost all of these 31 events resolved completely.

Discussion

OMT was shown to be effective in reducing pain in patients with chronic low back pain compared to a wait list control group. The detected improvement can be regarded as clinically significant as it was more than 0.5 standard deviation from the pre-treatment level. Anxiety symptoms were also reduced by OMT.

In this regard, it is interesting how anxiety decreased immediately after one session, while the average pain felt during the week decreased at the end of the 4 sessions. The reason may lie in the link between anxiety and fear on one side and pain on the otehr in chronic situations, whereby changes in pain tend to be secondary to changes in symptoms of anxiety, fear, and catastrophism.

Given these effects on pain, anxiety symptoms, and sleep, the study shows that OMT has the potential to act on multiple mechanical pathways at the neuromusculoskeletal level.

Given that the effect on pain occurred only after 4 sessions, it is possible that several effects may only manifest themselves over time and, therefore, in situations such as chronic low back pain it may take several sessions to achieve significant effects (a consideration also based on other studies in the literature with the same results).

Unexpectedly, on the other hand, the OMT did not show statistically significant effects on disability as measured by the ODI or even in the other PROMIS scales, including physical function. Probably more sessions would have been needed to see such results, although the study was not designed to detect such differences, which might as well have been the cause of such outcomes. However, other studies have reported how OMT does not differ from sham OMT (sham treatment) in improving disability-related scores. Therefore, more studies are needed on this aspect since classically OMT is indicated to recover physical function.

A limitation of the study is the lack of long-term follow-up. In addition, participants were recruited simply because they had reported suffering from low back pain, and not because they were seeking treatment for their condition. Also, because this study grew out of a validation study to evaluate postural control, an active treatment control group or a sham treatment group or any other controls were not included.