STUDY DESIGN: Randomized clinical trial. OBJECTIVES: To investigate if patients with mechanical neck pain receiving thoracic spine thrust manipulation would experience superior outcomes compared to a group not receiving thrust manipulation. BACKGROUND: Evidence has begun to emerge in support of thoracic thrust manipulation as an intervention in the management of mechanical neck pain. However, to make a strong recommendation for a clinical technique it is necessary to have multiple studies. METHODS AND MEASURES: Forty-five patients (21 females) were randomly assigned to 1 of 2 groups: the control group received electro/thermal therapy for 5 treatment sessions, and the experimental group received the same electro/thermal therapy and a thoracic spine thrust manipulation once a week for 3 consecutive weeks. Mixed model ANOVAs were used to examine the effects of treatment on pain (100 mm visual analogue scale), disability (100 point disability scale), and cervical range of motion with group as the between subject variable, and time as the within subjects variable. The primary analysis was the Group * Time interaction for pain. RESULTS: The Group*Time interaction effects for the ANOVA models were statistically significant for pain, mobility, and disability (P< 0.05), indicating greater improvements in the manipulation group for all the outcome measures. Patients receiving thoracic manipulation experienced greater improvements in pain at the 5^th (final) visit and at the 2-week and 4-week follow-up periods (P < 0.001) with pain improvement scores in the manipulation group of 16.8 mm and 26.5 mm greater than those in the comparison group at the 2 and 4-week follow-up period, respectively. The experimental group also experienced significantly greater improvements in disability with a between-group difference of 8.8 points (95% CI 7.5, 10.1, P < 0.001) at the 5^th visit and 8.0 points (95% CI, 5.8, 10.2; P < 0.001) at the 2 week follow-up. CONCLUSIONS: The results of our study suggest that thoracic spine thrust manipulation results in superior clinical benefits that continue to persist at the 1-month follow-up period for patients with acute neck pain. Future studies should continue to investigate the effects of thoracic spine thrust manipulation as compared to other physical therapy interventions in a population with mechanical neck pain. LEVEL OF EVIDENCE: Therapy, level 1b.

J Orthop Sports Phys Ther., Epub 19 September 2008. doi:10.2519/jospt.2009.2914

KEY WORDS: cervical spine, clinical trial, manual therapy, mobilization, thrust manipulation

DESIGN: Case-control study. OBJECTIVE: To analyze the differences in muscle size and shape of cervical multifidus between patients with bilateral chronic neck pain and healthy subjects. BACKGROUND: Researchers have demonstrated atrophy of lumbar multifidus in patients presenting with low back pain; however, there are only few published reports on cervical multifidus muscle size in individuals with chronic neck pain. METHODS AND MEASURES: Bilateral ultrasound images of multifidus muscle from the third to sixth cervical vertebrae (C3 to C6) were taken in 20 women with bilateral chronic neck pain and 20 healthy women. Cross-sectional area (CSA [cm²]) and muscle shape ratio (ratio between lateral [Lat] and anterior-posterior [AP] dimensions, [Lat/AP]) were measured without knowledge of group assignment. Two separate 3-way (4 x 2 x 2) mixed-model analyses of variance (ANOVAs) with cervical level (C3 to C6) and side (right, left) as within-subject factors and group (patient, control) as the between-subject factor, were used to evaluate differences in CSA and muscle shape ratio between groups, sides, and cervical levels. RESULTS: The ANOVA for CSA indicated a significant effect for cervical level (F = 6.81, P<.001) and group (F = 20.27, P<.001), but not for side (F = 1.26, P = .36). There were no significant interactions among the variables (P>.5). Post hoc analysis showed that the CSA of the C3 multifidus was smaller than the CSA of the C4 (P = .025), C5 (P<.001) or C6 (P<.01) multifidus. There was no significant difference between C4, C5, and C6 multifidus CSA (P>.05). The patients with neck pain had a smaller CSA of the cervical multifidus at all levels compared to controls (P<.001). The ANOVA for muscle shape ratio indicated a significant effect for level (F = 7.84, P<.001) and group (F = 12.501, P<.001), but not for side (F = 0.654, P = .58). There was a significant interaction between level and group (F = 3.651, P = .01). Patients had a wider ovoid shape (greater values in muscle shape ratio) of the C3 (P<.001) and C6 (P<.01) cervical multifidus compared to controls. Further, the C4 multifidus had a smaller shape ratio compared to C6 (P<.001), but was not significantly different than the shape ratio of the C3 and C5 (P>.05) multifidus. CONCLUSIONS: Females with bilateral chronic neck pain had generalized smaller CSA of the cervical multifidus muscles compared to healthy females. LEVEL OF EVIDENCE: Diagnosis, level 5.

J Orthop Sports Phys Ther. 2008;38(4):175-180, published online 7 December 2007. doi:10.2519/jospt.2008.2598

KEY WORDS: cervical spine, rehabilitative ultrasound imaging, ultrasonography

STUDY DESIGN: A placebo, control, repeated measures, single-blinded randomized study. OBJECTIVES: To compare the immediate effects on pressure pain threshold (PPT) tested over the lateral elbow region following a single cervical high-velocity low-amplitude (HVLA) thrust manipulation, a sham-manual application (placebo), or a control condition; and to analyze if a different effect was evident on the side ipsilateral to, compared to the side contralateral to the intervention. BACKGROUND: Previous studies investigating the effects of spinal manual therapy used passive mobilization procedures. There is a lack of studies exploring the effect of cervical manipulative interventions. METHODS: Fifteen asymptomatic volunteers (7 male and 8 female; aged 19 to 25 years) participated in this study. Each subject attended 3 experimental sessions on 3 separate days at least 48 hours apart. At each session, subjects received either the manipulation, placebo, or control intervention provided by an experienced therapist. The manipulative intervention was directed at the posterior joint of the C5-6 vertebral level. PPT over the lateral epicondyle of both elbows was assessed preintervention and 5 minutes postintervention by an examiner blinded to the treatment allocation of the subject. A 3-way analysis of covariance (ANCOVA) with intervention, side, and time as factors, and gender as covariate was used to evaluate changes in PPT. RESULTS: The analysis of variance detected a significant effect for intervention (F = 31.46, P<.001) and for time (F = 33.81, P<.001), but not for side (F = 0.303, P>.5). A significant interaction between intervention and time (F = 15.74; P<.001) was also found. Gender did not influence the comparative analysis (F = 0.252; P>.6). Post hoc analysis revealed that the application of a HVLA thrust manipulation produced a greater increase of PPT in both elbows, as compared to placebo or control interventions (P<.001). No significant changes in PPT levels were found after the placebo and control intervention (P>.6). Within group effect sizes were large for PPT levels in both elbows after the manipulative procedure (d>1.0), but small after placebo or control intervention (d<0.1). CONCLUSIONS: The application of a manipulative intervention directed at posterior joint of the C5-6 vertebral level produced an immediate increase in PPT over the lateral epicondyle of both elbows in healthy subjects. Effect sizes for the HVLA thrust manipulation were large, suggesting a strong effect of unknown clinical importance at this stage, whereas effect sizes for both placebo and control procedures were small, suggesting no significant effect.

J Orthop Sports Phys Ther. 2007;37(6):325-329, Epub 29 May 2007. doi:10.2519/jospt.2007.2542

KEY WORDS: hypoalgesia, manual therapy, neck pain, thrust manipulation

STUDY DESIGN: Case-control, descriptive pilot study. OBJECTIVE: To describe the differences in the performance of the craniocervical flexion test (CCFT) between individuals with chronic tension-type headache (CTTH) and healthy controls. To assess the relationship between the CCFT, forward head posture, and several clinical variables related to the intensity and temporal profile of headache. BACKGROUND: Musculoskeletal impairments of the craniocervical region might play an important role on the pathogenesis of CTTH. Deficits in the performance of the CCFT have been reported in patients with cervicogenic headache, nonspecific neck pain, and whiplash injury, but not in individuals with CTTH. MATERIAL AND METHODS: Ten patients with CTTH and 10 comparable controls without headache were studied. A headache diary was kept for 4 weeks to substantiate the diagnosis and to record the pain history. The CCFT was performed with the subject supine and required performing a gentle head-nodding action of craniocervical flexion. The activation pressure score (pressure that the subject can achieve and hold for 10 seconds), the performance pressure index (calculated by multiplying the activation pressure score by the number of successful repetitions), and the highest pressure score (the highest level that each subject was able to hold for 10 seconds from 20 to 30 mm Hg) were measured. Side-view pictures of each subject were taken in both sitting and standing positions to assess forward head posture (FHP) by measuring the craniovertebral angle. All measures were taken by an assessor blinded to the subject’s condition. RESULTS: Patients with CTTH had significantly lower values in both active pressure score and performance pressure index (P<.001), but not in the highest pressure score (P = .057), compared to controls. Patients with CTTH had a smaller craniovertebral angle (mean ± SD, 42.0° ± 6.6°), indicating a more FHP than controls (48.8° ± 2.5°), in the standing position (P<.01); but not in the sitting position (CTTH, 39° ± 8.9°; controls, 42.8° ± 8.9°, P = .10). No association between FHP and any of the CCFT variables was found (P>.05). Headache intensity and frequency did not seem to be related to the CCFT variables, but there was a positive association between headache duration and activation pressure score (r_s = 0.746, P = .02) and highest pressure score (r_s = 0.743, P = .02). CONCLUSIONS: These findings suggest possible impairments of the musculoskeletal system in individuals with CTTH, although it is not possible to determine if these impairments contributed to the etiology of CTTH or are as a result of the chronic headache condition.  

J Orthop Sports Phys Ther. 2007;37(2):33-39. doi:10.2519/ jospt.2007.2401

KEY WORDS: cervical spine, head, neck, pain

Study Design: Literature review of quality of clinical trials. Objective: To determine the methodological quality of published randomized controlled trials in the last decade that used spinal manipulation and/or mobilization to treat patients with tension-type headache (TTH), cervicogenic headache (CeH), and migraine (M). 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 was used for TTH, CeH, and M that were published in a peer-reviewed journal as full text and included at least 1 clinically relevant outcome measure (ie, headache intensity, duration, or frequency) were reviewed. Two reviewers using a set of predefined criteria independently assessed the methodological quality of the studies. 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 that analyzed 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 neither 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.

J Orthop Sports Phys Ther. 2006;36(3):160-169. doi:10.2519/jospt.2006.2126

Key Words: cervical spine, head, manual therapy, neck