Research Review By Dr. Dana Lawrence ©

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Date Posted:

December 2010

Study Title:

A randomized controlled trial comparing manipulation with mobilization for recent onset neck pain

Authors:

Leaver AM, Maher CG, Herbert RD et al.

Author's Affiliations:

Faculty of Health Sciences, University of Sydney (Leaver, Refshauge); George Institute for Global Health (Maher, Herbert, Latimer); Neuroscience Research Australia (McAuley), Sydney; Division of Physiotherapy, University of Queensland, Brisbane (Jull), Australia

Publication Information:

Archives of Physical Medicine & Rehabilitation 2010; 91:1313-1318.

Background Information:

The goal of this study was to determine whether neck manipulation (SMT) using a high-velocity low-amplitude (HVLA) procedure was more effective than a mobilization (MOB) procedure using a low-velocity variable-amplitude (LVVA) technique for patients with recent onset neck pain.

In designing this study, the researchers noted that there has been concern raised about the safety of cervical manipulation with regard to stroke, but that such complications were not associated with mobilization. Both interventions were seen to be beneficial for neck pain. If indeed manipulation is more effective than mobilization, that risk (which is noted to be small, but present) might be justified.

Pertinent Results:

  • The main conclusion by the authors was that the use of HVLA manipulation for recent onset neck pain did not confer a more rapid recovery from the neck pain than did a course of LVVA mobilization. In fact, SMT did not confer greater benefit for any secondary measure.
  • The level of compliance in both groups was very high; 89/91 of the manipulation group and 88/91 from the mobilization group completed the study.
  • At baseline, the groups were essentially equivalent in all important factors: previous episodes of neck pain, use of analgesic medications, neck pain level on the NRS, disability, function and SF-12 scores.
  • Those patients who underwent neck manipulation did not experience a faster recovery than those who underwent mobilization, and the median time for recover for the manipulation group was 47 days compared to 43 days for the mobilization group.
  • The manipulation group did not experience a more rapid recovery of normal activity either (22 days vs. 24 for the mobilization group).
  • There were no statistically significant differences in any secondary measures between the groups.
  • Notably, though, twice as many patients suffered a relapse of neck pain in the manipulation group compared to the mobilization group at the 12-week follow-up (14 vs. 7).
  • No serious adverse events were reported; minor events included increased neck pain and headache.

Clinical Application & Conclusions:

It is worth noting that both groups demonstrated rapid improvement in their pain scores (6.0+2.0 to 2.5+2.1 at 2 weeks). However, readers should bear in mind that there was no control group so it is not possible to determine if this is due to the actual treatment effect or to natural history or some other explanation. Ultimately, this suggests that if safety is indeed a concern, mobilization confers equal benefit for recent onset neck pain compared to an HVLA manipulation.

But as I read this, I also wonder what types of manipulations were used in the manipulation group. This was indeed pragmatic, so it was left up to individual treating therapists to decide which techniques to use. Some of these practitioners were physical therapists (n=7), some osteopaths (n=1) and some were chiropractors (n=5). All were required to have 2 years of clinical experience and to routinely use neck manipulation and mobilization in their practices.

The context and rationale for the use of manipulation differs between these groups, and it might have been good to break out the results by discipline as well for a subgroup analysis. The findings in this paper are harmonious with those of Hurwitz and colleagues (1,2). Both forms of therapy confer a benefit, but the risks are lower with mobilization.

Keeping this in context, where there are concerns related to possible adverse events or higher risk for stroke, treatment of patients with recent acute neck pain should involve the LVVA methods of mobilization rather than the HVLA mechanisms involved in HVLA adjusting.

Study Methods:

182 subjects were randomized into 2 groups of 91, and each group received 4 treatments over a 2-week period of time. The primary outcome for this study was the number of days it took to recover from the neck pain. Secondary measures were more numerous and included time taken for recovery of normal activity, pain (using the NRS), Neck Disability Score, function (using the Patient Specific Functional Scale), global perceived effort and health-related quality of life (as measured via the SF-12).

This study was conceived as a pragmatic trial in which clinicians were free to select the techniques used for each group of patients and could also offer manipulation or mobilization in other parts of the body. Patients were referred to the study by practitioners willing to do so, and these included physical therapists, chiropractors and osteopaths.

Those so referred were sent at the time the practitioner decided that a course of manipulation should be initiated; at that time, the patient was then randomized to one of the 2 groups (after completion of a screening procedure to rule out exclusion criteria).

Study Strengths / Weaknesses:

The authors note that one of the general criticisms of trials involving manipulation is that they are prescriptive; that is, they define the manipulation procedures to be used. This trial avoids that pitfall by allowing treating therapists to use their own judgment as to what procedures to use.

However, I also note that they could not choose the number of treatments each participant underwent; that was set at only 4 treatments over 2 weeks, and this needs to be taken into account, since it does not reflect the reality of practice. As noted above, there was a mix of practitioners involved in this study, each bringing a different perspective and rationale to the use of manipulation.

The study might have addressed this concern by looking at subgroup results for the chiropractors, physical therapists and osteopath involved, though with such small numbers the data would likely not have great strength. Nonetheless, the HVLA procedures used by each profession could conceivably vary wildly in application, and aggregating information might end up misleading.

Additional References:

  1. Hurwitz EL, Aker PD, Adams AH, Meeker WC, Shekelle PG. Manipulation and mobilization of the cervical spine: A systematic review of the literature. Spine 1997;22:1676-1677.
  2. Hurwitz EL, Morgenstern H, Harber P, Kominski GF, Yu F, Adams AH. A randomized trial of chiropractic manipulation and mobilization for patients with neck pain: clinical outcomes for the UCLA neck-pain study. Am J Public Health 2002;92:1634-1641.