Pressure pain sensitivity maps of the neck-shoulder and the low back regions in men and women

<p>Abstract</p> <p>Background</p> <p>Musculoskeletal pain in the low back and neck-shoulder regions is a major problem among the working population all over the world. The prevalence of musculoskeletal pain is found to be higher among women. Women also have lower pressure pain thresholds (PPTs) than men. Pressure pain topography aims at mapping the spatial distribution of PPT within a muscle in an attempt to track changes in mechanical sensitivity. In order to assess gender differences in the pain topography, it is necessary to map the distribution in both healthy men and women. The aim of this study was to assess PPT maps from the cervico-thoracic and lumbar regions in men and women.</p> <p>Methods</p> <p>Eleven men and eleven women without any known musculoskeletal disorders participated in the study. PPT was measured twice at 36 points over the trapezius muscle of the dominant arm, at 36 points over the trapezius muscle on the contralateral side and at 12 points over the spine between the left and right trapezius. Further, 11 points were measured over the erector spinae muscle on the left side of the spine between the first and the fifth lumbar vertebrae, 11 on the right side and 5 points on the spine itself. The measurements on each trapezius muscle were divided according to anatomical subdivisions. Three-way and two-way ANOVAs were used to analyse the differences in PPTs with the following factors: gender, locations and sub-divisions (only for cervico-thoracic region).</p> <p>Results</p> <p>There were no differences between left and right side in neither the cervico-thoracic nor the lumbar region, but there were (large effect) differences between the subdivisions in the trapezius with the lowest values in the upper part (P < 0.001; partial η²= 0.19). Women had (small effect) lower PPT in both cervico-thoracic and lumbar regions (P ≤ 0.001; partial η²= 0.02 for both regions), but gender had no effect on neither location nor subdivisions.</p> <p>Conclusions</p> <p>The pain topography was not found to be different between genders in the cervico-thoracic and lumbar regions. This study can be used as basis for further clinical studies on musculoskeletal disorders.</p

Prevalence and anatomical location of muscle tenderness in adults with nonspecific neck/shoulder pain

<p>Abstract</p> <p>Background</p> <p>Many adults experience bothersome neck/shoulder pain. While research and treatment strategies often focus on the upper trapezius, other neck/shoulder muscles may be affected as well. The aim of the present study is to evaluate the prevalence and anatomical location of muscle tenderness in adults with nonspecific neck/shoulder pain.</p> <p>Methods</p> <p>Clinical neck/shoulder examination at two large office workplaces in Copenhagen, Denmark. 174 women and 24 men (aged 25-65 years) with nonspecific neck/shoulder pain for a duration of at least 30 days during the previous year and a pain intensity of at least 2 on a modified VAS-scale of 0-10 participated. Exclusion criteria were traumatic injuries or other serious chronic disease. Using a standardized finger pressure of 2 kg, palpable tenderness were performed of eight anatomical neck/shoulder locations in the left and right side on a scale of 'no tenderness', 'some tenderness' and 'severe tenderness'.</p> <p>Results</p> <p>In women, the levator scapulae, neck extensors and infraspinatus showed the highest prevalence of severe tenderness (18-30%). In comparison, the prevalence of severe tenderness in the upper trapezius, occipital border and supraspinatus was 13-19%. Severe tenderness of the medial deltoid was least prevalent (0-1%). In men, the prevalence of severe tenderness in the levator scapulae was 13-21%, and ranged between 0-8% in the remainder of the examined anatomical locations.</p> <p>Conclusions</p> <p>A high prevalence of tenderness exists in several anatomical locations of the neck/shoulder complex among adults with nonspecific neck/shoulder pain. Future research should focus on several neck/shoulder muscles, including the levator scapulae, neck extensors and infraspinatus, and not only the upper trapezius.</p> <p>Trial Registration</p> <p><a href="http://www.controlled-trials.com/ISRCTN60264809">ISRCTN60264809</a></p

Visual analog scale and pressure pain threshold for delayed onset muscle soreness assessment

Objectives: To investigate the relationship between two assessments to quantify delayed onset muscle soreness [DOMS]: visual analog scale [VAS] and pressure pain threshold [PPT]. Methods: Thirty-one healthy young men [25.8 ± 5.5 years] performed 10 sets of six maximal eccentric contractions of the elbow flexors with their non-dominant arm. Before and one to four days after the exercise, muscle pain perceived upon palpation of the biceps brachii at three sites [5, 9 and 13 cm above the elbow crease] was assessed by VAS with a 100 mm line [0 = no pain, 100 = extremely painful], and PPT of the same sites was determined by an algometer. Changes in VAS and PPT over time were compared amongst three sites by a two-way repeated measures analysis of variance, and the relationship between VAS and PPT was analyzed using a Pearson product-moment correlation. Results: The VAS increased one to four days after exercise and peaked two days post-exercise, while the PPT decreased most one day post-exercise and remained below baseline for four days following exercise [p < 0.05]. No significant difference among the three sites was found for VAS [p = 0.62] or PPT [p = 0.45]. The magnitude of change in VAS did not significantly correlate with that of PPT [r = −0.20, p = 0.28]. Conclusion: These results suggest that the level of muscle pain is not region-specific, at least among the three sites investigated in the study, and VAS and PPT provide different information about DOMS, indicating that VAS and PPT represent different aspects of pain

Is One Trial Sufficient to Obtain Excellent Pressure Pain Threshold Reliability in the Low Back of Asymptomatic Individuals? A Test-Retest Study.

The assessment of pressure pain threshold (PPT) provides a quantitative value related to the mechanical sensitivity to pain of deep structures. Although excellent reliability of PPT has been reported in numerous anatomical locations, its absolute and relative reliability in the lower back region remains to be determined. Because of the high prevalence of low back pain in the general population and because low back pain is one of the leading causes of disability in industrialized countries, assessing pressure pain thresholds over the low back is particularly of interest. The purpose of this study study was (1) to evaluate the intra- and inter- absolute and relative reliability of PPT within 14 locations covering the low back region of asymptomatic individuals and (2) to determine the number of trial required to ensure reliable PPT measurements. Fifteen asymptomatic subjects were included in this study. PPTs were assessed among 14 anatomical locations in the low back region over two sessions separated by one hour interval. For the two sessions, three PPT assessments were performed on each location. Reliability was assessed computing intraclass correlation coefficients (ICC), standard error of measurement (SEM) and minimum detectable change (MDC) for all possible combinations between trials and sessions. Bland-Altman plots were also generated to assess potential bias in the dataset. Relative reliability for both intra- and inter- session was almost perfect with ICC ranged from 0.85 to 0.99. With respect to the intra-session, no statistical difference was reported for ICCs and SEM regardless of the conducted comparisons between trials. Conversely, for inter-session, ICCs and SEM values were significantly larger when two consecutive PPT measurements were used for data analysis. No significant difference was observed for the comparison between two consecutive measurements and three measurements. Excellent relative and absolute reliabilities were reported for both intra- and inter-session. Reliable measurements can be equally achieved when using the mean of two or three consecutive PPT measurements, as usually proposed in the literature, or with only the first one. Although reliability was almost perfect regardless of the conducted comparison between PPT assessments, our results suggest using two consecutive measurements to obtain higher short term absolute reliability