Immediate changes in widespread pressure pain sensitivity, neck pain, and cervical range of motion after cervical or thoracic thrust manipulation in patients with bilateral chronic mechanical neck pain: a randomized clinical trial.

STUDY DESIGN: Randomized clinical trial. OBJECTIVES: To compare the effects of cervical versus thoracic thrust manipulation in patients with bilateral chronic mechanical neck pain on pressure pain sensitivity, neck pain, and cervical range of motion (CROM). BACKGROUND: Evidence suggests that spinal interventions can stimulate descending inhibitory pain pathways. To our knowledge, no study has investigated the neurophysiological effects of thoracic thrust manipulation in individuals with bilateral chronic mechanical neck pain, including widespread changes on pressure sensitivity. METHODS: Ninety patients (51% female) were randomly assigned to 1 of 3 groups: cervical thrust manipulation on the right, cervical thrust manipulation on the left, or thoracic thrust manipulation. Pressure pain thresholds (PPTs) over the C5-6 zygapophyseal joint, lateral epicondyle, and tibialis anterior muscle, neck pain (11-point numeric pain rating scale), and cervical spine range of motion (CROM) were collected at baseline and 10 minutes after the intervention by an assessor blinded to the treatment allocation of the patients. Mixed-model analyses of covariance were used to examine the effects of the treatment on each outcome variable, with group as the between-subjects variable, time and side as the within-subject variables, and gender as the covariate. The primary analysis was the group-by-time interaction. RESULTS: No significant interactions were found with the mixed-model analyses of covariance for PPT level (C5-6, P>.210; lateral epicondyle, P>.186; tibialis anterior muscle, P>.268), neck pain intensity (P = .923), or CROM (flexion, P = .700; extension, P = .387; lateral flexion, P>.672; rotation, P>.192) as dependent variables. All groups exhibited similar changes in PPT, neck pain, and CROM (all, P<.001). Gender did not influence the main effects or the interaction effects in the analyses of the outcomes (P>.10). CONCLUSION: The results of the current randomized clinical trial suggest that cervical and thoracic thrust manipulation induce similar changes in PPT, neck pain intensity, and CROM in individuals with bilateral chronic mechanical neck pain. However, changes in PPT and CROM were small and did not surpass their respective minimal detectable change values. Further, because we did not include a control group, we cannot rule out a placebo effect of the thrust interventions on the outcomes. LEVEL OF EVIDENCE: Therapy, level 1b.J Orthop Sports Phys Ther 2012;42(9):806-814, Epub 18 June 2012. doi:10.2519/jospt.2012.4151.

Changes in pressure pain sensitivity in latent myofascial trigger points in the upper trapezius muscle after a cervical spine manipulation in pain-free subjects.

OBJECTIVE: This study analyzed the immediate effects on pressure pain threshold (PPT) in latent myofascial trigger points (MTrPs) in the upper trapezius muscle of a single cervical spine manipulation directed at the C3 through C4 level. METHODS: Seventy-two volunteers (27 men and 46 women; mean age, 31 years; SD, 10 years) participated in this study. Subjects underwent a screening process to establish both the presence of MTrPs in the upper trapezius muscle as described by Simons et al (Myofascial pain and dysfunction: the trigger point manual, vol 2. 3rd ed. Baltimore: Williams & Wilkins, 1999. p. 23-34) and the presence of intervertebral joint dysfunction at the C3 through C4 level by the lateral gliding test for the cervical spine. Subjects were divided randomly into 2 groups: manipulative group, which received a cervical spine manipulation directed at the C3 through C4 level, and a placebo group, which received a sham manual procedure. The outcome measure was the PPT on the MTrP in the upper trapezius muscle ipsilateral to the side of the joint dysfunction, which was assessed pretreatment and 1, 5, and 10 minutes posttreatment by an assessor blinded to the treatment allocation of the subject. RESULTS: The analysis of variance showed a significant effect for time (F = 5.157; P = .02) but not for side (F = 0.234; P = .63). Furthermore, an interaction between group and time was also found (F = 37.240; P < .001). The experimental group showed a trend toward an increase in PPT levels after the manipulative procedure, whereas the control group showed a trend toward a decrease in PPT. Positive within-group effect sizes ranging from medium to small were found in the manipulative group (0.1

Immediate effects on neck pain and active range of motion after a single cervical high-velocity low-amplitude manipulation in subjects presenting with mechanical neck pain: a randomized controlled trial.

PURPOSE: The objective of this study is to analyze the immediate effects on neck pain and active cervical range of motion after a single cervical high-velocity low-amplitude (HVLA) manipulation or a control mobilization procedure in mechanical neck pain subjects. In addition, we assessed the possible correlation between neck pain and neck mobility. METHODS: Seventy patients with mechanical neck pain (25 males and 45 females, aged 20-55 years) participated in this study. The lateral gliding test was used to establish the presence of an intervertebral joint dysfunction at the C3 through C4 or C4 through C5 levels. Subjects were divided randomly into either an experimental group, which received an HVLA thrust, or a control group, which received a manual mobilization procedure. The outcome measures were active cervical range of motion and neck pain at rest assessed pretreatment and 5 minutes posttreatment by an assessor blinded to the treatment allocation of the patient. Intragroup and intergroup comparisons were made with parametric tests. Within-group effect sizes were calculated using Cohen's d coefficient. RESULTS: Within-group changes showed a significant improvement in neck pain at rest and mobility after application of the manipulation (P < .001). The control group also showed a significant improvement in neck pain at rest (P < .01), flexion (P < .01), extension (P < .05), and both lateral flexions (P < .01), but not in rotation. Pre-post effect sizes were large for all the outcomes in the experimental group (d > 1), but were small to medium in the control mobilization group (0.2 < d < 0.6). The intergroup comparison showed that the experimental group obtained a greater improvement than the control group in all the outcome measures (P < .001). Decreased neck pain and increased range of motion were negatively associated for all cervical motions: the greater the increase in neck mobility, the less the pain at rest. CONCLUSIONS: Our results suggest that a single cervical HVLA manipulation was more effective in reducing neck pain at rest and in increasing active cervical range of motion than a control mobilization procedure in subjects suffering from mechanical neck pain.