Critique of thoracic manipulation for chronic mechanical neck pain

¶ … Thoracic Manipulation on Patients with Chronic Mechanical Neck Pain: A Randomized Controlled Trial

The objective of this work in writing is to critique the study reported in the work of Lau, Chiu, and Lam (2011) entitled "The Effectiveness of Thoracic Manipulation on Patients with Chronic Mechanical neck pain -- A Randomized Controlled Trial" reported in the Journal of Manual Therapy.

The aim of the study reported by Lau, Chiu, and Lam is stated to be assessment of the effectiveness of "thoracic manipulation (TM) on patients with chronic neck pain." (2011, p.141) Lifetime prevalence of neck pain is stated at 66.7% and 12-month prevalence at 53.6%. (Lau, Chiu, and Lam, 2011, p.141) Neck pain is expensive to treat in addition to the suffering of the individual and lost work time due to employee absenteeism. (Lau, Chiu, and Lam, 2011, paraphrased)

There is growing evidence, which has demonstrated that manipulation with exercise and mobilization with exercise in treatment of neck pain results in more positive clinical outcomes "than other major and common modalities." (Greenman, 1996, Gross, et al., 2002, and Flynn et al., 2007 in: Lau, Chiu, and Lam, 2011, p.141) Lau, Chiu, and Lam (2011) report that "disturbances in the biomechanics of the thoracic spine, due to intrinsic biomechanical linkage with the cervical spine, might be primary in contributing to neck pain. (Flynn et al., 2007 and Lau, Chiu, and Lam, 2011, paraphrased)

III. Literature Reviewed in: Lau, Chiu, and Lam (2011)

The work of Lau, Chiu, and Lam (2011) cite other cases in which thoracic manipulation was used resulting in "immediate improvement in neck pain." (Lau, Chiu, and Lam, 2011, p.141) It is stated that TM has been adopted "intuitively…to treat neck pain patients although there is a lack of scientific evidence." (Lau, Chiu, and Lam, 2011, p. 141) Studies that examine the impact of TM in the treatment of acute and subacute mechanical neck pain are reviewed and it is related that thus far "no studies have investigated the effect in patients with chronic neck pain." (Lau, Chiu, and Lam, 2011, p.141 Fernandez-de-las-Penas, et al., 2007; Gonzalez-Iglesias et al., 2009a,b) In a randomized controlled trial, it is related that the researchers demonstrated "an immediate analgesic effect in patients with mechanical neck pain." (Lau, Chiu, and Lam, 2011, p. 141)

This study is contrasted with another study conducted and reports by Parkin-Smith and Penter (1988) who demonstrated "that the combination of cervical and TM did not result in any significant benefit than cervical manipulation alone." (Lau, Chiu, and Lam, 2011, p.141) In yet another study it is reported that when comparing "the effect of TM and instructed exercise in the management of neck-shoulder pain revealed that there was a statistically significant reduction in the level of perceived worst pain after 12-monnths follow-up." (Savolainen, et al., 2004 in Lau, Chiu, and Lam, 2011, p.142)

IV. Methodology, Collection, and Analysis of Data

The study reported in the work of Lau, Chiu, and Lam (2011) reports a sampling of 120 patients who were diagnosed with chronic mechanical neck pain by primary care physicians. These patients included random allocation to a TM group (Group A) and a control group (Group B). Patient ages ranged between 18 years of age and 55 years of age with a diagnosis of mechanical neck pain for longer than three months duration. Patient conditions that resulted in exclusion from participation were inclusive of the following stated conditions:

(1) contradiction to manipulation;]

(2) History of whiplash or cervical surgery;

(3) Diagnosis of fibromyalgia syndrome;

(4) Having undergone spinal manipulative therapy in the previous 2 months; or (5) Loss of standing balance. (Lau, Chiu, and Lam, 2011, p.142)

V. Outcome Measures

Outcomes measures in the study included the verbal Numeric Pain Rating Scale (NPRS) on a scale from 0 to 10 with 0 being the least and 10 being the most pain. Two sets of questionnaires were also completed by the participants; (1) Northwick Park Questionnaire (NPQ); and (2) SF36 health-related quality of life questionnaire (sF36) as subjective measurements. Objective measurements were taken through use of the Hanoun Multi-Cervical Unit (MCRU). Finally, the craniovertebral (CV) angel of the subjects was measured using an Electronic Head Posture Instrument (EHPI). (Lau, Chiu, and Lam, 2011) Rationale for the calculation of the sample size was conducted.

VII. Data Analysis

Data analysis was conducted through use of SPSS (Version 16.0) in comparing the control group at the baseline by independent t-tests. Following the intervention, statistical analysis for the differences of all outcome measures in both groups was compared by using repeated-measures analysis of variance (ANOVA). Calculated were mean difference and their standard deviation and ANOVA was used for investigating whether any change took place following the intervention in each group. Stated additionally is "Paired t-tests with Bonferroni adjustment were adopted for the post-hoc analysis. Between-group effect size was calculated using Partial Eta squared. A p value of less than 0.05 was considered statistically significant." (Lau, Chiu, and Lam, 2011, p. 143)

VIII. Limitations

Limitations stated in the study include that "only recruited patients with chronic nonspecific neck pain" were included and the study results may not be applicable to patients with acute neck pain conditions. Additionally, it is reported that the sample size in the present study was such that "did not allow subgroup analysis of the effects of TM on patients of different genders or age groups." (Lau, Chiu, and Lam, 2011, p. 147) Finally it is reported that the time spent in the TM in the treatment group was higher than the control group." (Lau, Chiu, and Lam, 2011, p.147)

X. Findings of the Study

Findings of the study reported by Lau, Chiu, and Lam (2011) include that the effect of TM "was shown to be positive in reducing neck pain, improving dysfunction and neck postures and neck ROM up to half a year post-treatment. In treating patients with chronic mechanical neck pain, TM could be a choice for effective management." (Lau, Chiu, and Lam, 2011, p. 147) Adverse effects have been described in various studies including those of Leboeu-Yde, et al., (1997); Sentad et al. (1997), Barrett and Breen, (2000), Cagnie et al. (2004), and Hurwitz, et al., (2004). Included in adverse events are those that are mild to moderate it their intensity and which are reported to have "little to no influence on daily activities of living." (Lau, Chiu, and Lam, 2011, p. 147)

XI. Examination of Other Research Findings

The work of Cleland, et al. (2004) reports that mechanical neck pain "is a common occurrence in the general population resulting in a considerable economic burden." It is reported that physical therapists often integrate manual therapies focused on the cervical spine to include such as "joint mobilization and manipulation into the management of patients with cervical pain." (Cleland, et al., 2004) The study reported by Cleland, et al. investigates the immediate effects of thoracic spin manipulation on perceived pain levels in patients presenting with neck pain and states that more study is needed in order to make a determination of the effects of thoracic spin manipulation in patients with neck pain on long-term outcomes including function and disability." (2004) The work of Lyndal Sharples (2010) reports a study that examines whether a single thrust manipulation of the upper thoracic spine increase neck range of motion. Sharples states that thoracic spinal thrust technique is a "direct method of manipulation treatment that uses high velocity/low amplitude (HVLA) activation to move a joint that is exhibiting somatic dysfunction through its restrictive barrier so that when the joint resets itself, appropriate physiologic motion is restored." (Sharples, 2010) The HVLA manipulation is reported to involve a quick thrust over a short distance through what is termed a pathologic barrier. The movement is within a joint's normal ROM and does not exceed the anatomic barrier or ROM." (Sharples, 2010) When the patient is properly positioned HVLA makes a requirement of very little force and is specifically targeted to spinal segments." (Sharples, 2010) Treatment goals include "restoration of joint play or a desirable gap between articulating surfaces." (Sharples, 2010) This technique is stated to be effective in restoration of joint motion with little risk of worsening of symptoms. Sharples reports that the "biomechanical influence of manipulation is to improve the plasticity and elasticity of shortened and thickened soft tissue." (Sharples, 2010) In addition, fluid dynamic such as blood, lymph and synovial fluid" and is a model that focuses on "diminishing muscle tone and modulating pain." (Sharples, 2010)