In Part 1, the relative risks and important screening areas prior to cervical manipulation were discussed. In this second installment, the effectiveness and a theoretical framework for utilizing cervical manipulation will be laid out.
According to the Neck Pain Guidelines published by Cleland et al, manual therapy (mobilization and manipulation) was graded both an ‘A’ (strong evidence) and a ‘1’ (evidence from high-quality RCT, prospective, or diagnostic studies) in the treatment of neck pain. These guidelines advocate both manipulative and lower grade mobilization in reducing neck pain and cervicogenic headache symptoms. Published in the same year as the clinical guidelines, Walker et al conducted an RCT looking into the effectiveness of manual therapy and exercise in the management of mechanical neck pain. Those randomized to the manual therapy and exercise group (MTE) received treatments that ranged from cervical manipulation to soft-tissue mobilization and every technique in between. The intervention period lasted for 3 weeks with a total of 6 treatment sessions during this timeframe. At the conclusion of the study, those patients in the MTE group demonstrated statistically superior improvements in NDI scores at all 3 follow-ups, pain reduction at 3 and 6 weeks, perceived patient improvement on the GRC at all follow-ups, and overall treatment success rates were almost two-times as large for the MTE group in comparison to the minimal intervention group. These results bode well for a comprehensive manual therapy approach, but is there evidence to support the use of cervical manipulation in isolation?
Saavedra-Hernández et al recently published a RCT investigating the short-term effects of spinal manipulation in individuals suffering from chronic neck pain. In this study, patients were either randomized to an isolated cervical manipulation program (CMP) or a comprehensive manipulation program (cervical spine, cervicothoracic junction, and thoracic spine). After treatment (7-day follow-up), those in the CMP program demonstrated a decrease in pain from 4.8 to 2.7, NDI from 23.7 to 16.8, and increased ROM in all planes. While these values did reach statistical significance and this does lend evidence in support of cervical manipulation, those in the comprehensive program did achieve a greater reduction in disability than the CMP group. This lends support to a thorough manual therapy approach but does not necessarily discredit the use of manipulation. With so many options available to the treating clinician, how do we know when to use manipulation?
Tseng et al investigated what predictors helped to identify those patients who would demonstrate an immediate reduction in pain intensity, significant perceived improvement, and/or a high satisfaction level following cervical manipulation. After analyzing the outcomes of the 100 patients included and grouping them into either the ‘responder’ or ‘non-responder’ group, 6 variables were determined to be predictors of a positive response. These variables included initial scores on Neck Disability Index < 11.5, having a bilateral involvement pattern, not performing sedentary work greater than 5 h/day, feeling better while moving the neck, did not feel worse when extending the neck, and the diagnosis of spondylosis without radiculopathy. If 4 of these variables were present, the probability of success increased from 60% to 89% following manipulation. More recently, Puentedura et al conducted a similar study attempting to develop a clinical prediction rule identifying those who would respond favorably to cervical manipulation. Eighty-two consecutive patients presenting to an outpatient physical therapy clinic received manipulation of the cervical spine. Of the patients in this study, only 32/82 (39%) reported a favorable outcome. However, of those 32 who met the criteria for a favorable response, there were 4 variables that proved to be predictive. These items included symptom duration less than 38 days, positive expectation that manipulation will help, the side-to-side difference in the cervical rotation range of motion of 10° or greater, and pain with posteroanterior spring testing of the middle cervical spine. When > 3 of the 4 variables were present, the likelihood of a positive response increased from 39% to 90%. These are overwhelmingly positive findings, but it must be noted that these are merely preliminary findings and further supplemental research needs to be conducted in order to validate Puentedura and colleagues’ findings.
Many clinicians will argue that cervical manipulation should be abandoned in favor of less ‘dangerous’ interventions. The justification is primarily due to a lack of overwhelmingly superior outcomes compared to thoracic manipulation and/or cervical mobilization. While theoretically, these may be considered more conservative, are the outcomes really the same? Puentedura et al evaluated the outcomes of cervical manipulation versus those of thoracic manipulation in a small RCT. At the conclusion of the study, patients randomized to the cervical manipulation + exercise (CME) group demonstrated superior improvement in pain and disability in comparison to the thoracic manipulation + exercise group (TME). Additionally, there were no serious adverse events reported for either group, however, the TME group reported significantly more side effects than the CME group (8 side effects versus 1). So, can we honestly say thoracic manipulation is safer and equally effective? This study seems to disagree. While this was a very small study (n = 24) and all subjects were treated by one clinician, it still offers sufficient evidence to compare the two interventions.
The second intervention that is typically used in place of manipulation is a lower grade joint mobilization (grades I-IV). Dunning et al set out to determine whether a combination of thoracic and cervical thrust manipulation was more effective than non-thrust techniques. At follow-up (48 hours post-intervention), those in the manipulation group demonstrated superior improvements in disability, pain, atlantoaxial ROM, and motor performance of the deep neck flexor musculature. While this study only included data immediately following treatment, the benefits of manipulation seem to outweigh those of joint mobilization (in the short-term at least). This study is in agreement with an older study (Cassidy et al) that directly compared the short-term effects of cervical manipulation to mobilization. Both groups demonstrated similar improvements in ROM, but the manipulation group yielded superior improvements in pain intensity. However, contrary to the findings of these two studies, there have also been several studies that have found a lack of significant improvements between manipulation and mobilization. Hurwitz et al, Boyles et al, and Leaver et al all found a lack of discernible improvement in patient outcomes between manipulation and mobilization. Additionally, Saavedra-Hernández et al conducted a RCT comparing the effects of cervical manipulation to those of Kinesiotape in patients with mechanical neck pain. Both groups had similar reductions in neck pain and cervical ROM… This does not lend supporting evidence to Kinesiotape, rather it provides evidence against manipulation. Understandably, it is easy to use the findings of these studies as evidence to support the avoidance of manipulation, but what key concept are all of these studies lacking?
Cervical manipulation, actually manipulation in general, is not an intervention that should be used with every patient presenting with a particular diagnosis. There are specific sub-groups where manipulation is highly beneficial and then there are patients that will show no improvement with its use. Look at the Cochrane Review published on spinal manipulation for low back pain (LBP)… It was determined that, when analyzing all of the data, manipulation was no better than other inert interventions. However, based on the most recent developments in sub-grouping and treatment-based classification, matched treatment with regards to manipulation results in a positive likelihood ratio of 13.2. This is why one of the caveats included within the Cochrane Review is that more research needs to be done looking into the benefits of sub-grouping within this patient population. This is the route that cervical manipulation and its subsequent research needs to take (recent studies by Puentedura et al are a step in the right direction). As seen by the early results (improving probability of benefit from 39% to 90%), those patients who are likely to respond deserve to be provided the appropriate intervention. Not all patients need to be manipulated. In fact, not very many will need cervical manipulation at all, but to eliminate the intervention from those who will likely benefit seems counterproductive to me.
Based on the risk (albeit very minimal) and similar therapeutic effects from other seemingly less provocative interventions, I propose that cervical manipulation should be a potential intervention, but only for specific patient presentations. In general, I believe if you have exhausted other typical treatment approaches and the patient has not responded adequately, it may be time to consider more aggressive methods. My treatments are determined based on patient presentation and response to treatment, but if possible I try to progress from distal to proximal and from low grade to high-velocity low amplitude in terms of manual therapy interventions. In addition, motor control, stabilization, and direction preference exercises must not be left out. As seen in several studies throughout this article, benefits are far superior when coupled with appropriate therapeutic exercise… This is further supported by a systematic review conducted by Gross et al who found combined treatment (manual therapy + exercise) to be superior to any treatment in isolation. It is our job as clinicians to develop and implement a comprehensive program utilizing manual therapy, exercise, pain modulation, and our patient’s beliefs and experiences. Use best evidence and clinical reasoning to determine an appropriate plan of care and your patient will demonstrate far superior outcomes compared to any intervention in isolation.
Thoracic Manipulation → Cervicothoracic Manipulation → Cervical Mobilization (Grade III/IV) → Meet CPR? → Cervical Manipulation (Grade V)