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