Tattoo artists and dental workers have similar musculoskeletal pain patterns.

BACKGROUND: Tattoo artists are an understudied population with regards to musculoskeletal (MSK) pain. AIMS: To explore the characteristics of MSK pain among Israeli tattoo artists and determine whether they are similar to those of dental workers. METHODS: An online survey including demographics and the Hebrew version of the Extended Nordic Musculoskeletal Questionnaire was disseminated via Israeli social media groups. We directly compared tattoo artists, dental workers and office workers as a reference group. RESULTS: Altogether, 114 tattoo artists, 161 dental workers and 296 office workers responded. The most prevalent pain sites were lower back (56%), neck (47%) and hand (36%) among office workers; neck (67%), lower back (62%) and upper back (42%) among the dental workers; and lower back (72%), neck (66%) and hand (55%) among tattoo artists. Contrast analysis suggested office workers were less likely to report pain in the previous 12 months compared with dental workers and tattoo artists (adjusted odds ratios [95% confidence intervals]: ORs [95% CIs] for upper limb pain: 1.13 [1.01-1.28], neck pain: 1.3 [1.15-1.47], upper back pain: 1.27 [1.12-1.43] and low back pain: 1.15 [1.02-1.3]). No significant differences were observed between dental workers and tattoo artists (upper limb pain: 1.18 [0.9-1.54], neck pain: 1.06 [0.81-1.4], upper back pain: 1.22 [0.94-1.58] and low back pain: 1.24 [0.95-1.64]). CONCLUSIONS: Tattoo artists and dental workers have similar MSK pain characteristics and are different from those of office workers. These characteristics are seemingly a direct result of the physical demands associated with their line of work.

Three single leg standing tests for clinical assessment of chronic plantar heel pain syndrome: static stance, half-squat and heel rise.

OBJECTIVE: To assess reliability and validity of three single leg standing clinical tests in patients with plantar heel pain syndrome (PHPS). DESIGN: Cross-sectional reliability study. PARTICIPANTS: Forty patients diagnosed with PHPS. MAIN OUTCOME MEASURES: Patients stood on their affected foot in a static stance for up to 30seconds, a half squat for up to 10 repetitions, and a heel rise for up to 10 repetitions. The first sensation of pain (p1) determined the termination of each test, and established a positive test result. The level of p1 was measured using a visual analogue scale (VAS); time or repetitions for each test were recorded. Prior to performing the tests, all patients completed the Foot & Ankle Computerized Adaptive Test to measure functional status (FS). RESULTS: Detection of p1 in each test showed good reliability for inter- and intrarater assessment (Kappa=0.60 to 0.78 and 0.56 to 0.77, respectively). The intraclass correlation coefficient for the VAS measures was 0.85 to 0.95 for inter-rater assessment and 0.78 to 0.92 for intrarater assessment. However, the Bland and Altman limits of agreement were wide, indicating that these measures were less reliable than the correlation coefficients suggested. Thirty-five patients (88%) experienced a positive pain response to at least one test. Significant correlations were found between the VAS measures in each test and FS (r=0.63 to 0.72). CONCLUSIONS: The static stance, half squat and heel rise tests were easily implemented, and found to be reliable and valid according to one analysis, yet less reliable with another, for pain provocation and VAS levels in patients with PHPS. All three VAS levels correlated well with FS.

Joint range of motion and patellofemoral pain in dancers.

The aim of the present study was to determine the association between joint range of motion (ROM) and patellofemoral pain syndrome (PFPS) in young female dancers. The study population included 1 359 female dancers, aged 8-20 years. All dancers were clinically examined for current PFPS, and their joint ROM was measured at the lumbar spine and the lower extremities. 321 of the 1 359 dancers (23.6%) experienced PFPS. Prevalence of the syndrome increased with the dancer's age (p<0.001). Dancers with hypo ROM in hip external rotation, ankle plantar-flexion, ankle/foot pointe, hip abduction, hip extension, and limited hamstrings and lumbar spine were significantly less prone to developing PFPS compared to dancers with average ROM: 19.2% vs. 26.2% (p=0.014); 13.7% vs. 26.1% (p<0.001); 12.2% vs. 26.2% (p<0.001); 10.0% vs. 25.3% (p<0.001); 12.6% vs. 24.2% (p<0.001); and 9.3% vs. 28.2% (p<0.001), respectively. The group with the smallest prevalence of PFPS (10.2%) manifested restricted ROM at both the hip and ankle/foot joints. Dancers with decreased hip and ankle/foot joints ROM are less prone to develop PFPS. When making an association between joint ROM and injuries, not only the ROM at the targeted joint should be considered, but also the ROM at neighboring joints.

Lumbar shape characterization of the neural arch and vertebral body in spondylolysis: A comparative skeletal study.

The lumbar vertebral shape is an important causative factor in spondylolysis (SP). However, a complete characterization of this shape, that would shed light on its pathophysiology enhance its earlier diagnosis, is still missing. The aim of this study was to evaluate the shape distinctiveness of the lumbar (L1-L5) vertebral body (VB) and neural arch (isthmus, lamina, vertebral canal, spinous, and transverse processes) in SP. Using a three-dimensional (3D) digitizer, the VB length, width, height, and sagittal wedging as well as the lengths of the isthmus, lamina spinous, and transverse processes of all lumbar vertebrae (L1-L5) were measured from 115 male skeletons with bilateral SP at L5 and compared with 120 normal ones. Compared with the normal group, the following results were indicated in SP [analysis of variance (ANOVA), P < 0.05]: the VB's are significantly longer at the superior surfaces of L1-L4 and inferior surfaces of L1-L3 (total mean difference = 7.61 mm and 3.94 mm, respectively), and wider at the superior surfaces of L1-L4 and inferior surfaces of L1-L5 (total mean difference = 10.06 mm and 12.90 mm, respectively); The L5 VB is significantly shorter posteriorly (mean difference = 3.05 mm) and more lordotic (+1° of dorsal wedging); L5 is manifested with longer lamina (mean difference = 1.85-2.18 mm), longer isthmus (mean difference = 3.24-4.69 mm), and longer and wider vertebral canal (mean differences = 3.64 mm and 1.13 mm, respectively); The L2-L5 spinous processes are significantly longer (total mean difference = 7.45 mm). Clinically, detecting the aforementioned unique lumbar vertebral morphometric features in individuals suffering from chronic low back pain may facilitate the early diagnosis of SP.

Shape variation of the neural arch in the thoracic and lumbar spine: characterization and relationship with the vertebral body shape.

Quantifying the human vertebral geometry is important for accurate medical procedures. We aimed to characterize the neural arch (NA) shape at T1-L5. All T1-L5 dry vertebrae (N = 4,080) of 240 individuals were measured and analyzed by age, gender, and ethnicity. A 3D digitizer was used to measure the dimensions of the spinous (SP) and transverse (TP) processes, vertebral canal (VC), laminae, and isthmus. Most parameters were independent of age and ethnicity, yet greater in males than in females. Isthmus length increases from T1 (9.8 mm) to T12 (19.87 mm) and decreases from T12 to L5 (9.68 mm) with right > left in the thorax and oppositely in the lumbar region. The SP is longer than its thickness both decreasing in the upper thorax (by ca. 4mm), increasing in the lower thoracic and upper lumbar vertebrae (by 7 mm for length and ca. 14.5 mm for thickness) and decreasing again along the lower lumbar vertebrae (both by 8 mm). The TP length decreases at T1-T12 (by 13 mm) and increases at L1-L5 with left > right at T1-L5 (P < 0.003). The laminar length decreases from T1 (8.72 mm) through T5 (4.76 mm) and increases toward L5 (8.4 mm) with right > left at T1-L5 (P < 0.003). The VC is oval-shaped at T1 and T11-L5 (width > length), rounded-shape at T2 and T10 (width = length), and inverted oval-shaped at T3-T9 (length > width). In conclusion, the NA is systematically asymmetrical and dynamic in shape along the thoracic and lumbar spine. The inter-relationship with the vertebral body and articular facets is discussed.

Degenerative lumbar spinal stenosis and lumbar spine configuration.

As life expectancy increases, degenerative lumbar spinal stenosis (DLSS) becomes a common health problem among the elderly. DLSS is usually caused by degenerative changes in bony and/or soft tissue elements. The poor correlation between radiological manifestations and the clinical picture emphasizes the fact that more studies are required to determine the natural course of this syndrome. Our aim was to reveal the association between lower lumbar spine configuration and DLSS. Two groups were studied: the first included 67 individuals with DLSS (mean age 66 ± 10) and the second 100 individuals (mean age 63.4 ± 13) without DLSS-related symptoms. Both groups underwent CT images (Philips Brilliance 64) and the following measurements were performed: a cross-section area of the dural sac, vertebral body dimensions (height, length and width), AP diameter of the bony spinal canal, lumbar lordosis and sacral slope angles. All measurements were taken at L3 to S1. Vertebral body lengths were significantly greater in the DLSS group at all levels compared to the control, whereas anterior vertebral body heights (L3, L4, L5) and middle vertebral heights (L3, L5) were significantly smaller in the LSS group. Lumbar lordosis, sacral slope and bony spinal canal were significantly smaller in the DLSS compared to the control. We conclude that the size and shape of vertebral bodies and canals significantly differed between the study groups. A tentative model is suggested to explain the association between these characteristics and the development of degenerative spinal stenosis.

The reproducibility of quantitative measurements in lumbar magnetic resonance imaging of children from the general population.

STUDY DESIGN: Quantitative lumbar magnetic resonance imaging (MRI) measurements in children were taken twice and analyzed for intra- and intertester reproducibility. OBJECTIVE: To evaluate the reproducibility of a variety of lumbar quantitative measurements taken from MRIs of children from the general population. SUMMARY OF BACKGROUND DATA: The reproducibility of lumbar quantitative measurements has never been tested on MRIs of children from the general population. This is a prerequisite for a reliable anatomic characterization of the immature spine in normal and pathologic conditions. METHODS: Lumbar quantitative measurements from 40 T2-weighted lumbar (L1-S1) MRIs of children from the general population were taken twice by 1 tester for intratester reproducibility and compared with the same measurements (L4-S1) of the same MRIs taken by a second tester for intertester reproducibility. The following parameters were measured using the iQ-VIEW system (IMAGE Information Systems Ltd., version 1.2.2, Plauen, Germany): Linear measurements--zygoappophyseal facets and interfacet widths, and vertebral body (VB), pedicle and intervertebral discs heights, widths, and lengths. Angular measurements--zygoappophyseal tranverse superior facet angles, sagittal VB, and disc wedging, lumbar lordosis, and sacral inclination. Statistical analysis included the concordance correlation coefficient (CCC), and Bland and Altman's limits of agreement (LOA). RESULTS: A total of 6160 measurements were analyzed. Good to excellent intratester reproducibility (0.75 < or =CCC < or =0.99) was indicated for all linear measurements (except for pedicle heights) (LOA: -4.76; 5.74 mm) and for angular measurements related to the facets orientation, lumbar lordosis, and sacral inclination (LOA: 11.22 degrees ; 12.34 degrees). VB and disc sagittal wedging manifested poor intratester reproducibility (CCC < 0.75). Good to excellent intertester reproducibility was indicated for 70% of all linear measurements (LOA: -5.83; 4.59 mm) and for all angular measurements in the lumbar spine (L4-S1) (LOA: -9.96 degrees ; 14.62 degrees) except for VB and disc sagittal wedging at L5 (CCC < 0.75). CONCLUSION: Quantitative lumbar MRI measurements in children from the general population were found to be reproducible indicating a good visualization of immature vertebral anatomic margins on MRIs and an accurate definition of the measurement protocol.

A method for patient-specific evaluation of vertebral cancellous bone strength: in vitro validation.

BACKGROUND: In the context of osteoporosis, important determinants of the fracture risk are the apparent strength and stiffness of cancellous bone, as well as its brittleness and energy absorption capacity. Standard medical imaging, however, cannot measure these mechanical properties directly. Consequently, an estimation of the risk for fracture is made by correlating relative density or mineral density at a skeletal site with statistics of fracture occurrence, which provides limited and partial indications on fracture risks. A better method for evaluating the patient-specific mechanical properties of cancellous bone is therefore required. METHODS: In order to asses the mechanical properties of vertebral cancellous bone, we developed a finite element parametric model of lattice trabecular architecture that, in the future, will be suitable for use with bone imaging modalities. The model inputs are apparent morphological parameters (trabecular thickness and trabecular separation) and the bone mineral density. We conducted uniaxial compression tests on 36 canine vertebral cancellous bone specimens (C7 and L1) to validate model predictions of strength and stiffness in vitro. FINDINGS: Predictions of strength and stiffness matched the experimental results within relative absolute errors of 17.7% and 12.8%, respectively (average of differences between model-predicted and measured values, divided by the average of measured values). We also employed the model for evaluation of strength and stiffness of human L1 and L5 vertebrae and found mean strength of 1.67 MPa (confidence interval 0.42 MPa) and mean elastic modulus of 190 MPa (confidence interval 50 MPa), which are well within the range of previously reported apparent strength and stiffness properties. INTERPRETATION: The present model can be used to improve medical imaging-based evaluation of the spine in osteoporotic individuals by providing more specific information on the individual bone's susceptibility to fracture once clinical bone scans will be able to provide more reliable measures of trabecular thickness and separation.