Chronic pain: The prevalence of chronic pain in patients attending Soshanguve Community Health Centre.

Introduction: Chronic pain is a costly and incapacitating condition, with a projected global prevalence of 20%. In South Africa, almost one in five adults experience chronic pain. The aim of this study was to assess the prevalence of chronic pain and the association between chronic pain intensity and the interference of pain with life domains in patients attending a primary health care center. Methods: We conducted a cross-sectional quantitative study on a sample of 331 patients at Soshanguve Community Health Centre. The data were collected using the Wisconsin Brief Pain Questionnaire, a validated scale for measuring pain. Results: The mean age of participants was 51.6 years (SD = ±15.15, range = 18-86). The median age was 48 years (interquartile range = 40-64). The prevalence of chronic pain was 21.5% (95% confidence interval [CI] 17.0-25.9). Approximately 58% of participants were female, and female patients were affected more frequently than male patients. Chronic pain was observed to be 11.1% more prevalent in females than in males. Chronic pain mildly impacted general activity in 33.8% of patients (95% CI 23.9-45.4), mood in 42.3% (95% CI 31.4-53.8), walking ability in 29.6% (95% CI 20.2-41.0), relationships in 47.9% (95% CI 36.7-59.3), sleep in 31.0% (95% CI 21.4-42.5), enjoyment of life in 39.4% (95% CI 28.9-51.1), and normal working ability in 25.3% (95% CI 16.7-36.6). Conclusions: Findings from this study show that among patients who attended the primary health care clinic, chronic pain was highly prevalent and interfered with their life domains. The intensity of pain was high in a significant proportion of patients. These findings provide invaluable information needed for the improvement of resources at the primary care level to comprehensively evaluate pain in our communities.

Introduction : La douleur chronique est une affection coûteuse et invalidante, dont la prévalence mondiale est estimée à 20 %. En Afrique du Sud, près d'un adulte sur cinq souffre de douleur chronique. Cette étude avait pour but d'évaluer la prévalence de la douleur chronique, de même que l'association entre l'intensité de la douleur chronique et l'interférence de la douleur avec différents domaines de la vie chez les patients fréquentant un centre de soins de santé primaires.Méthodes : Nous avons mené une étude quantitative transversale portant sur un échantillon de 331 patients au Centre de santé communautaire de Soshanguve. Les données ont été recueillies à l'aide du Questionnaire concis sur la douleur du Wisconsin, une échelle validée pour mesurer la douleur.Résultats : L'âge moyen des participants était de 51,6 ans (ÉT = ±15,15, plage = 18­86). L'âge médian était de 48 ans (intervalle interquartile = 40­64). La prévalence de la douleur chronique était de 21,5 % (intervalle de confiance à 95 % [IC] 17,0-25,9). Environ 58 % des participants étaient des femmes, et les patientes étaient affectées plus fréquemment que les patients de sexe masculin. La douleur chronique était 11,1% plus fréquente chez les femmes que chez les hommes. La douleur chronique a eu de légères répercussions sur l'activité générale chez 33,8 % des patients (IC à 95 % 23,9-45,4), l'humeur chez 42,3 % (IC à 95 % 31,4-53,8), la capacité de marcher chez 29,6 % (IC à 95 % 20,2-41,0), les relations chez 47,9 % (IC à 95 % 36,7-59,3), le sommeil chez 31,0 % (IC à 95 % 21,4-42,5), jouissance de la vie chez 39,4 % (IC à 95 % 28,9-51,1) et la capacité de travail normale chez 25,3 % d'entre eux (IC à 95 % 16,7-36,6).Conclusions : Les résultats de cette étude montrent que parmi les patients qui ont fréquenté la clinique de soins de santé primaires, la douleur chronique était très répandue et interférait avec différents domaines de leur vie. L'intensité de la douleur était élevée chez une proportion significative de patients. Ces résultats fournissent des informations inestimables nécessaires à l'amélioration des ressources au niveau des soins primaires pour évaluer de manière exhaustive la douleur au sein de nos collectivités.

Evaluating Pelvis Response During Simulated Underbody Blast Loading.

In recent conflicts, blast injury from landmines and improvised explosive devices (IEDs) has been the main mechanism of wounding and death. When a landmine or IED detonates under a vehicle (an under-body blast), the seat acceleration rapidly transmits a high load to the pelvis of the occupants, resulting in torso and pelvic injury. Pelvic fractures have high mortality rates, yet their injury mechanism has been poorly researched. Three (3) fresh-frozen male pelvic specimens were tested under axial impact loading. The pelvis was impacted mounted upside down by dropping a 12 kg mass at target impact velocities ranging from 1 to 8.6 m/s with time to peak velocity ranging from 3.8 to 5.8 ms. Resulting fractures were broadly categorized as involving a bilateral pubis rami fracture, a bilateral ischium fracture, and sacroiliac joint disruption. The study provides insights into the type and severity of pelvic injury that may occur over a range of under-body blast (UBB)-relevant loading profiles.

Dataset from the uniaxial tensile testing of human curly hair fibers under different conditions.

Individual human hair fibers exhibiting a curly morphology were procured from a female donor within her early thirties (30s). The selected hair fibers donor had refrained from undergoing any form of chemical treatment, including dyeing, relaxing, and bleaching, for a minimum period of six (6) months prior to specimen collection. The isolated single fibers were subjected to uniaxial tensile testing at various strain rates (100.s-1,10-2. s-1 10-3. & 10-4.s-1). Furthermore, the specimens underwent testing under dry conditions at a temperature of 25°C, as well as full immersion in a saline solution at both 25°C and 35°C. The ensuing mechanical attributes, encompassing engineering was analyzed following the tensile testing.

Biomechanical analysis of sheep oesophagus subjected to biaxial testing including hyperelastic constitutive model fitting.

High quality computational model of soft tissues is a function of accurate and reliable mechanical properties. Hyperelastic constitutive models are normally utilised in developing reliable computational models. Therefore, section of proper and reliable constitutive models for soft tissue is critical. This work presents the biomechanical properties of oesophagus subjected to biaxial mechanical tensile test. Additionally, six hyperelastic constitutive models commonly used for modelling behaviour of soft tissues were selected. The experimental data were then fitted on Fung, Choi-Vito, Holzapfel (2000), Holzapfel (2005), Polynomial (Anisotropic) and Four-Fiber Family hyperelastic constitutive models. The sheep oesophagus subjected to equi-biaxial tension has exhibited different stress magnitude in both longitudinal and circumferential directions. There is significant difference between circumferential and longitudinal stresses (p = 0.0034). The average circumferential and longitudinal stresses are recorded to be 82.87 ± 30.36 kPa and 41.42 ± 32.02 kPa, respectively (p = 0.0034). Between six hyperelastic constitutive models, it was observed that Four-Fiber model has produced better fit when compared to others. After fitting biaxial mechanical properties of oesophagus, it was found that the Four-fiber family hyperelastic constitutive model would best fit.

The response of Military Lower Extremity and Hybrid III leg using the Hybrid III and EuroSID-2 ATD in vertical loading impacts.

OBJECTIVE: Antivehicular landmines (AVLs) and underbelly improvised explosive devices (IEDs) are found to be some of the major threats for military vehicles and their occupants. Anthropomorphic test devices (ATDs) such as the 50th percentile Hybrid III (HIII) and EuroSID2-re (ES2-re) are used to assess injury caused by AVLs or IEDs in order to develop mitigation strategies by analyzing lower leg data in tibia load cells. METHODS: This article presents the evaluation of the injury measurement response of the Hybrid III and ES2-re ATDs using both the HIII and Military Lower Extremity (MIL-LX) instrumented lower legs impacted by the Modified Lower Limb Impactor (MLLI). The MIL-LX leg tested with the HIII ATD measures higher forces than when tested with the ES2-re ATD. RESULTS: In general, the MIL-LX upper tibia load cell measures peak forces that are considerably lower than that measured by the HIII lower leg with both the HIII and ES2-re ATD. The HIII leg fails earlier with both the HIII and ES2-re ATD compared to the MIL-LX leg. The study shows that the HIII and MIL-LX lower leg are not equivalent in their assessment of protective capability of armored vehicles when either attached to the HIII or ES2-re ATD. CONCLUSIONS: These results show the importance of selecting the correct lower leg surrogate during AVL or IED testing, which can lead to a pass or fail of the armored vehicle. These findings offer insight into the response of each surrogate lower leg with the different ATDs and can be used to develop new mitigation strategies.

Biaxial Estimation of Biomechanical Constitutive Parameters of Passive Porcine Sclera Soft Tissue.

This study assesses the modelling capabilities of four constitutive hyperelastic material models to fit the experimental data of the porcine sclera soft tissue. It further estimates the material parameters and discusses their applicability to a finite element model by examining the statistical dispersion measured through the standard deviation. Fifteen sclera tissues were harvested from porcine' slaughtered at an abattoir and were subjected to equi-biaxial testing. The results show that all the four material models yielded very good correlations at correlations above 96%. The polynomial (anisotropic) model gave the best correlation of 98%. However, the estimated material parameters varied widely from one test to another such that there would be need to normalise the test data to avoid long optimisation processes after applying the average material parameters to finite element models. However, for application of the estimated material parameters to finite element models, there would be need to consider normalising the test data to reduce the search region for the optimisation algorithms. Although the polynomial (anisotropic) model yielded the best correlation, it was found that the Choi-Vito had the least variation in the estimated material parameters, thereby making it an easier option for application of its material parameters to a finite element model and requiring minimum effort in the optimisation procedure. For the porcine sclera tissue, it was found that the anisotropy was more influenced by the fiber-related properties than the background material matrix-related properties.

Lateral pressure equalisation as a principle for designing support surfaces to prevent deep tissue pressure ulcers.

When immobile or neuropathic patients are supported by beds or chairs, their soft tissues undergo deformations that can cause pressure ulcers. Current support surfaces that redistribute under-body pressures at vulnerable body sites have not succeeded in reducing pressure ulcer prevalence. Here we show that adding a supporting lateral pressure can counter-act the deformations induced by under-body pressure, and that this 'pressure equalisation' approach is a more effective way to reduce ulcer-inducing deformations than current approaches based on redistributing under-body pressure. A finite element model of the seated pelvis predicts that applying a lateral pressure to the soft tissue reduces peak von Mises stress in the deep tissue by a factor of 2.4 relative to a standard cushion (from 113 kPa to 47 kPa)-a greater effect than that achieved by using a more conformable cushion, which reduced von Mises stress to 75 kPa. Combining both a conformable cushion and lateral pressure reduced peak von Mises stresses to 25 kPa. The ratio of peak lateral pressure to peak under-body pressure was shown to regulate deep tissue stress better than under-body pressure alone. By optimising the magnitude and position of lateral pressure, tissue deformations can be reduced to that induced when suspended in a fluid. Our results explain the lack of efficacy in current support surfaces and suggest a new approach to designing and evaluating support surfaces: ensuring sufficient lateral pressure is applied to counter-act under-body pressure.