Exploration of somatosensory impairments in subjects with mechanical idiopathic neck pain: a preliminary study.

OBJECTIVES: The purpose of this study was to investigate the differences in pressure and thermal pain hypersensitivity between patients with acute and chronic neck pain and healthy subjects. METHODS: Five patients with acute neck pain, 7 patients with chronic neck pain, and 6 matched controls participated. Pressure pain thresholds (PPTs) were assessed over the supraorbital, infraorbital, mental, median, ulnar, and radial nerves; the C5-C6 zygapophyseal joint; the second metacarpal; and the tibialis anterior muscle by an assessor blinded to the subjects' condition. Head pain threshold and cold pain threshold (CPT) were measured over the cervical region and over the tibialis anterior muscle. RESULTS: The analysis of variance found significant differences between groups, but not between sides, for PPT over the supraorbital, mental, median, ulnar and radial nerves; the C5-C6 joint; the second metacarpal; and the tibialis anterior muscle: patients with chronic neck pain showed bilateral lower PPTs as compared with controls (P < .01). Patients with acute neck pain also showed lower PPT (P < .01) over the median and ulnar nerves. No significant differences between groups or sides for head pain threshold over the cervical area or the tibialis anterior muscle were found. Significant differences between groups, but not between sides, for CPT over the neck and the tibialis anterior muscles were found: CPT was also reduced in patients with chronic, but not acute, neck pain (P < .01). CONCLUSIONS: We found widespread decreased PPT in patients with chronic, but not acute, mechanical neck pain as compared with controls. Patients with chronic neck pain also showed cold pain hypersensitivity as compared with patients with acute neck pain and controls. These results support the existence of different sensitization mechanisms between patients with acute and chronic mechanical insidious neck pain.

Changes in neck pain and active range of motion after a single thoracic spine manipulation in subjects presenting with mechanical neck pain: a case series.

OBJECTIVE: Our aim was to report changes in neck pain at rest, active cervical range of motion, and neck pain at end-range of cervical motion after a single thoracic spine manipulation in a case series of patients with mechanical neck pain. METHODS: Seven patients with mechanical neck pain (2 men, 5 women), 20 to 33 years old, were included. All patients received a single thoracic manipulation by an experienced manipulative therapist. The outcome measures of these cases series were neck pain at rest, as measured by a numerical pain rating scale; active cervical range of motion; and neck pain at the end of each neck motion (eg, flexion or extension). These outcomes were assessed pre treatment, 5 minutes post manipulation, and 48 hours after the intervention. A repeated-measures analysis was made with parametric tests. Within-group effect sizes were calculated using Cohen d coefficients. RESULTS: A significant (P < .001) decrease, with large within-group effect sizes (d > 1), in neck pain at rest were found after the thoracic spinal manipulation. A trend toward an increase in all cervical motions (flexion, extension, right or left lateral flexion, and right or left rotation) and a trend toward a decrease in neck pain at the end of each cervical motion were also found, although differences did not reach the significance (P > .05). Nevertheless, medium to large within-group effect sizes (0.5 < d < 1) were found between preintervention data and both postintervention assessments in both active range of motion and neck pain at the end of each neck motion. CONCLUSIONS: The present results demonstrated a clinically significant reduction in pain at rest in subjects with mechanical neck pain immediately and 48 hours following a thoracic manipulation. Although increases in all tested ranges of motion were obtained, none of them reached statistical significance at either posttreatment point. The same was found for pain at the end of range of motion for all tested ranges, with the exception of pain at the end of forward flexion at 48 hours. More than one mechanism likely explains the effects of thoracic spinal manipulation. Future controlled studies comparing spinal manipulation vs spinal mobilization of the thoracic spine are required.

Methodological quality of randomized controlled trials of spinal manipulation and mobilization in tension-type headache, migraine, and cervicogenic headache.

STUDY DESIGN: Literature review of quality of clinical trials. OBJECTIVE: To determine the methodological quality of published randomized controlled trials that used spinal manipulation and/or mobilization to treat patients with tension-type headache (TTH), cervicogenic headache (CeH), and migraine (M) in the last decade. BACKGROUND: TTH, CeH, and M are the most prevalent types of headaches seen in adults. Individuals who have headaches frequently use physical therapy, manual therapy, or chiropractic care. Randomized controlled trials are considered an optimal method with which to assess the efficacy of any intervention. METHODS: Computerized literature searches were performed in MEDLINE, EMBASE, COCHRANE, AMED, MANTIS, CINHAL, and PEDro databases. Randomized controlled trials in which spinal manipulation and/or mobilization had been used for TTH, CeH, and M published in a peer-reviewed journal as full text, and with at least 1 clinically relevant outcome measure (ie, headache intensity, duration, or frequency) were reviewed. The methodological quality of the studies was assessed independently by 2 reviewers using a set of predefined criteria. RESULTS: Only 8 studies met all the inclusion criteria. One clinical trial evaluated spinal manipulation and mobilization together, and the remaining 7 assessed spinal manipulative therapy. No controlled trials analyzing exclusively the effects of spinal mobilization were found. Methodological scores ranged from 35 to 56 points out of a theoretical maximum of 100 points, indicating an overall poor methodology of the studies. Only 2 studies obtained a high-quality score (greater than 50 points). No significant differences in quality scores were found based on the type of headache investigated. Methodological quality was not associated with the year of publication (before 2000, or later) nor with the results (positive, neutral, negative) reported in the studies. The most common flaws were a small sample size, the absence of a placebo control group, lack of blinded patients, and no description of the manipulative procedure. CONCLUSIONS: There are few published randomized controlled trials analyzing the effectiveness of spinal manipulation and/or mobilization for TTH, CeH, and M in the last decade. In addition, the methodological quality of these papers is typically low. Clearly, there is a need for high-quality randomized controlled trials assessing the effectiveness of these interventions in these headache disorders.