Both acute and chronic lower-back pain (LBP) are exceedingly common, costly, and a significant cause of short- and long-term disability. These conditions are responsible for more than 20 million ambulatory medical care visits in the United States each year, and lifetime prevalence has been estimated to be as high as 84%. In a great many cases, patients seek spinal manipulative therapy (SMT) for their LBP; however, the effectiveness of this approach remains controversial and largely unsupported by high-quality evidence. Three recently reported studies of SMT, performed by either chiropractors or osteopathic physicians, raise further confusion and doubts about the prudence of recommending SMT for persons with nonspecific low-back pain of any duration.
1. Adding Chiropractic to Standard Medical Care for Acute LBP
In the first study, Christine M. Goertz, DC, PhD — vice chancellor for research and health policy at Palmer College of Chiropractic, Davenport, Iowa — and colleagues conducted a naturalistic, prospective, randomized study comparing changes in pain levels and physical functioning in response to standard medical care (SMC) versus SMC plus chiropractic manipulative therapy (CMT) for the treatment of low-back pain (LBP) [Goertz et al. 2013]. Subjects were active-duty U.S. military personnel ages 18 to 35 years, 86% males, with acute LBP of less than 4-weeks duration.
The primary outcome measures were changes in back-related pain on a 0-to-10 numerical rating scale (NRS) and physical functioning at 4 weeks on the Roland-Morris Disability Questionnaire (RMQ) and back pain functional scale (BPFS). Participant enrollment was originally planned for 50 patients per group, and there were 32 in the SMC group and 41 in the SMC+CMT group for final analysis.
Writing in the April 15, 2013 edition of the journal Spine, the researchers reported the following results:
- Adjusted mean RMQ scores were significantly better in the SMC+CMT group than in the SMC group at both week 2 (8.9 vs 12.9; p=<0.001) and week 4 (8.0 vs 12.0; p=0.004), and scores on the BPFS were similarly improved.
- Mean NRS pain scores were significantly improved in the group that received SMC+CMT when compared with SMC alone at both week 2 (3.9 vs 6.1; p=<0.001) and week 4 (3.9 vs 5.2; p = <0.02).
- 73% of participants in the SMC+CMT group rated their global improvement as pain completely gone, much better, or moderately better — as compared with 17% in the SMC group.
Goertz et al. conclude the results of this trial suggest that CMT in conjunction with SMC offers a significant advantage for decreasing pain and improving physical functioning when compared with only standard care, for men and women between 18 and 35 years of age with acute LBP. However, there were numerous shortcomings of the study design (see below) and the researchers concede that there is a need for additional, high-quality randomized controlled trials to confirm the role of chiropractic therapy in larger and diverse populations.
2. Osteopathic Manual Therapy (OMT) for Chronic LBP
In a second study reported recently in the literature, John C. Licciardone, DO — with the Osteopathic Research Center, University of North Texas Health Science Center, Fort Worth, Texas — and associates assessed the comparative efficacy of osteopathic manual therapy (OMT) and ultrasound therapy (UST) for nonspecific chronic LBP of greater than 3-month’ duration [Licciardone et al. 2013]. Subjects included 455 patients, median age 41 years (range 29-51), and 62% were females.
The researchers used a randomized, double-blind, sham-controlled design. The 455 patients were randomized to 1 of 4 groups: a) OMT plus UST; b) OMT plus sham UST; c) sham OMT plus UST; d) sham OMT plus sham UST. In each treatment session, the real or sham OMT procedure was delivered first, followed by the real or sham UST intervention.
Six treatment sessions were provided to all subjects during 8 weeks. An intention-to-treat analysis was performed to assess moderate and substantial improvements in LBP — categorized ≥30% or ≥50% pain reductions from baseline, respectively — at week 12. Five secondary outcomes, safety, and treatment adherence were also assessed.
Writing in the March/April 2013 edition of Annals of Family Medicine, the researchers report that there was no statistical interaction between OMT and UST, and ultrasound therapy was not efficacious. Patients receiving OMT were more likely than patients receiving sham OMT to achieve moderate (Response Ratio [RR] = 1.38; 95% CI, 1.16-1.64; p<0.001) and substantial (RR = 1.41; 95% CI, 1.13-1.76; p=0.002) improvements in LBP at week 12. Overall, these improvements amounted to medium-sized effects for pain relief.
Back-specific functioning, general health, work disability specific to LBP, safety outcomes, and treatment adherence did not differ between patients receiving OMT and sham OMT. Nevertheless, patients in the OMT group were more likely to be very satisfied with their back care throughout the study (p<0.001). Patients receiving OMT also used prescription drugs for LBP significantly less frequently during the 12 weeks than did patients in the sham OMT group.
The researchers conclude that the OMT regimen was effective for pain relief, reduced the need for adjunctive prescription drugs, was safe, and well accepted by patients. Although, OMT did not achieve corresponding improvements in back-specific functioning, general health, or work disability. By contrast, ultrasound therapy, UST, was not efficacious in relieving chronic LBP.
3. OMT Doubtful for Chronic LBP in Systematic Review
The third study, intended as a systematic review and possible data meta-analysis of clinical research on osteopathic interventions for chronic, nonspecific lower-back pain, was by Paul J Orrock and Stephen P Myers, both of Southern Cross University, Lismore, Australia [Orrock and Myers, 2013]. Their literature search was up to August 2011, and included only papers that reported clinical trials, had adult participants, and tested the effectiveness and/or efficacy of osteopathic manual therapy (OMT) interventions applied by osteopaths. For this review, OMT was defined specifically as “manual intervention and lifestyle advice applied by an osteopath which would be considered by the osteopathic community to be consistent with osteopathic practice.”
The initial searches revealed 809 papers, 772 of which were excluded on the basis of their abstracts alone. Of the remaining 37 papers, 35 were excluded after detailed review of the full text. The 2 remaining papers describing clinical trials had a lack of methodological and clinical homogeneity, precluding a meta-analysis. The trials used different comparators with regard to the primary outcomes, the number of treatments, the duration of treatment, and the duration of follow-up.
One of the papers found that the osteopathic intervention was similar in effect to a sham intervention, and the second paper suggested similarity of effect between OMT, exercise, and physiotherapy. The reviewers conclude that there is a paucity of quality clinical trials testing OMT in adult patients with chronic nonspecific LBP, and more data are required. Further clinical trials into this subject are needed, applying consistent and rigorous methods, including appropriate controls, and using interventions that reflect actual practice.
COMMENTARY: Practitioners and patients usually agree that effective management of lower-back pain (LBP) should go beyond merely prescribing strong pain-relievers for either short- or long-term use. However, there is considerable disagreement and controversy surrounding what adjunctive therapies would be most appropriate and effective when addressing nonspecific acute, subacute, or chronic LBP.
Is some form of spinal manipulation therapy (SMT) to be recommended as an effective and safe approach? Judging by the latest available evidence described above, the research on this topic appears to be muddled or inadequate, so a definitive answer seems uncertain.
In the first study, by Goertz et al. studying chiropractic for acute LBP, the researchers noted that chiropractic treatments consisted of HVLA (high-velocity, low-amplitude) manipulation as the primary approach in all cases, with ancillary treatments at the doctor’s discretion, including brief massage, the use of ice or heat in the lumbar area, stretching exercises, McKenzie exercises, advice on activities of daily living, postural/ergonomic advice; and mobilization. HVLA manipulation was described as involving...
“…a single load or impulse “thrust” to body tissues. Patients were placed in a lateral recumbent or side-lying position with the superior or free hip and knee flexed and adducted across the midline. The chiropractor stabilized the patient’s free leg with his own leg while holding the patient’s superior shoulder. The manipulative load was applied by using a pisiform contact on the patient’s lumbar spine or sacroiliac joint while preventing motion of the patient through stabilizing holds on the shoulder and hip. The single impulse load, or thrust, was delivered by a quick, short controlled movement of the shoulder, arm, and hand combined with a slight body drop.”
Whether or not this HVLA procedure was applied exactly the same and properly in all subjects is unknown, and there was no 3rd group examining this procedure in isolation to determine its efficacy. The discretionary “ancillary treatments,” as noted, would engender a multimodal therapeutic regimen, with many components similar to those provided during standard medical care; so, the differential and beneficial contribution of the chiropractic manipulation seems unclear.
Numbers of subjects for final analyses fell below the 50 planned for adequate statistical power, largely due to patients lost to followup and particularly in the SMC group. Patients in the SMC group had a mean of 1.4 visits to the practitioner; whereas, those in the SMC+CMT group visited the medical practitioner an average of 1 time and the CMT practitioner a median of 7 times (range 2-8 visits).
Neither practitioners nor patients in this study could be blinded as to group allocation. The additional contact with a healthcare provider among SMC+CMT participants, particularly repeated visits to the chiropractor, may have played an important role in both actual and perceived improvement in this group.
At the 4-week end point, effects sizes for differences between groups on outcome measures were only small to moderate. Calculated from data in the study report, Cohen’s d for NRS=0.32, RMQ=0.44, BPFS=0.43. At the same time, there was a large effect favoring SMC+CMT (d=1.52) on a measure of patient satisfaction with overall results at 4 weeks, which might have been strongly influenced by more frequent interactions with a healthcare provider in this group. Finally, it seems worth noting that most of the study investigators were chiropractors themselves and the study was supported by a chiropractic institute.
The second study, by Licciardone et al. studying osteopathic manipulative therapy for chronic LBP, was complicated by a 2x2 factorial design that did not allow for the assessment of OMT and UST completely independently of each other to adequately determine placebo effects of their sham versions. Also, since UST, whether real or sham, followed OMT in each case as an add-on treatment, it is difficult to know if OMT by itself might have the same impact.
Licciardone and colleagues described the interventions in their study as follows:
“The OMT techniques were delivered after a standard diagnostic evaluation at each treatment session. The lumbosacral, iliac, and pubic regions were targeted using high-velocity, low-amplitude (HVLA) thrusts; moderate-velocity, moderate-amplitude thrusts; soft tissue stretching, kneading, and pressure; myofascial stretching and release; positional treatment of myofascial tender points; and patient’s isometric muscle activation against the physician’s unyielding and equal counter-force. Time permitting, optional techniques could be used if the physician judged 1 or more of the 6 designated techniques to be contraindicated or ineffective.”
“Sham OMT was aimed at the same anatomical regions as active OMT. Sham OMT involved hand contact, active and passive range of motion, and techniques that simulated OMT but that used such maneuvers as light touch, improper patient positioning, purposely misdirected movements, and diminished physician force.”
“The UST intervention was delivered after the OMT intervention, using the Sonicator 730, with a 10 cm² applicator at an intensity of 1.2 W/cm² and frequency of 1 MHz in continuous mode. Conductivity gel was used to enhance absorption and produce deep muscle thermal effects. About 150 to 200 cm² of the lower back were treated. Sham UST was delivered in the same manner at a subtherapeutic intensity (0.1 W/cm²).”
There were considerable similarities of OMT in this study with CMT in the study noted above, and ancillary approaches that may have confounded results were components of both studies. Furthermore, Licciardone et al. noted that their sham OMT regimen produced a considerable placebo effect, which probably accounted for the lack of differential improvements in back-specific functioning, general health, and work disability specific to LBP. It also is interesting that ultrasound therapy, UST, was clearly judged to be unbeneficial; although, as noted above, UST always was performed after real or sham OMT and was not studied in isolation, so it is unknown whether there was an ordering effect that diminished results for UST.
This study by Licciardone et al. was funded by grants from the National Center for Complementary and Alternative Medicine (NCCAM) at NIH and the Osteopathic Heritage Foundation. All of the researchers were affiliated with the Osteopathic Research Center at the University of North Texas Health Science Center.
The third study above, a systematic review, was severely limited by its focus on spinal manipulative therapy (SMT) as delivered by osteopaths for chronic LBP. The reviewers, who do not appear to have osteopathic medicine or chiropractic affiliations, could find only 2 studies qualifying for inclusion. And, unlike the study by Licciardone et al. (which was too recent to have been included in this review), Orrock and Myers found that osteopathic interventions were either similar to sham/placebo, or no better than exercise or physiotherapy.
The ambiguous results of these 3 recent investigations are consistent with previous examinations of this topic. In a prior Pain-Topics UPDATE [here], we discussed a Cochrane Systematic Review and Meta-analysis examining evidence for SMT in chronic LBP conditions. Using fairly liberal definitions of SMT — which included either chiropractic or osteopathic approaches — and searching the literature up to June 2009, the investigators found 26 randomized controlled trials (RCTs) qualifying for review. Overall, they concluded that there is no clinically relevant superiority of SMT compared with other interventions, such as standard medical care, exercise therapy, pharmacotherapy, or physiotherapy.
More recently, another UPDATE [here] discussed a Cochrane Systematic Review and Meta-analysis of trials examining SMT compared with other therapies for acute (<6-weeks duration) LBP conditions. The literature search spanning 2000 to July 2012 produced 20 qualifying RCTs. Many of the trials were of low quality and/or reported inadequate data. The researchers concluded that SMT was no more effective than inert (eg, sham/placebo) interventions or than other commonly recommended active therapies for acute LBP.
In sum, there appears to have been extensive research on spinal manipulative therapies for nonspecific LBP. At the same time, most of those investigation have been of low quality, producing weak or equivocal evidence to support the benefits of either CMT or OMT. Whether there are genuine differences in the way manipulative therapy is delivered by chiropractors or osteopaths seems uncertain — results have been similarly unspectacular in trials involving either specialty. Individual practitioner technical and interpersonal skills, and their use of ancillary approaches, may play important roles in outcome success for individual patients.
While spinal manipulative therapies, CMT or OMT, appear to be relatively safe, and there are abundant anecdotal reports of patients benefitting, the research suggests that those therapies should be considered at most as but one component of multimodal approaches — possibly, not the most important part. Patient preferences, insurance coverage, access to care, and other factors may be important influences in the selection of SMT of any type for nonspecific lower-back pain conditions of any duration.
> Goertz CM, Long CR, Hondras MA, et al. Adding Chiropractic Manipulative Therapy to Standard Medical Care for Patients With Acute Low Back Pain: Results of a Pragmatic Randomized Comparative Effectiveness Study. Spine. 2013(Apr 15); 38(8):627-634 [abstract here].
> Licciardone JC, Minotti DE, Gatchel RJ, et al. Osteopathic Manual Treatment and Ultrasound Therapy for Chronic Low Back Pain: A Randomized Controlled Trial. Ann Fam Med. 2013;11(2):122-129 [article here].
> Orrock PJ, Myers SP. Osteopathic intervention in chronic non-specific low back pain: a systematic review. BMC Musculoskeletal Disorders. 2013;14(129) [PDF here].
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