Data analysis was performed using One-way repeated measures ANOVA with Tukey’s post-hoc correction for multiple comparisons. The SWE stiffness of the repaired supraspinatus tendon increased in a ...curvilinear fashion, healing in 6-months post-arthroscopic rotator cuff repair. ...patients who have undergone rotator cuff repair should not return to activities without restriction until at least 6-months post-operatively. From 6-months, deltoid muscle elastographic stiffness increased, corresponding to the time when the repaired supraspinatus tendon had healed and patients were instructed to return to activities without restriction.
Abstract To address the current problems of low accuracy and poor reliability of the discrete element model of cotton stalks, as well as the difficulty of guiding the design and optimization of the ...equipment through simulations, the discrete element modeling and physical-mechanical tests of cotton stalks in machine harvested film-stalk mixtures are carried out. The peak tensile force $$F_{\rm j}^{\max }$$ F j max , the peak pressure $$F_{\rm y}^{\max }$$ F y max , the peak bending force $$F_{\rm w}^{\max }$$ F w max , the peak shear force $$F_{\rm j}^{\max }$$ F j max , and the force-displacement ( F – x ) curves of cotton stalks are obtained from the physical tests. The discrete element model of double-layer cotton stalks based on the flat-joint model is established with the PFC $$^{\rm 3D}$$ 3 D software. The $$F_{\rm y}^{\max }$$ F y max is taken as the response value, and the microscopic parameters of the cotton stalk model are used as the test factors, then the Plackett–Burman test, the steepest climb test, and the Box–Behnken test are sequentially designed using Design-Expert software. The second-order regression model describing the relationship between the $$F_{\rm y}^{\max }$$ F y max and the microscopic parameters is established. The optimal parameter combinations of the microscopic parameters are obtained, and then they are utilized to construct the compression, bending, and shear models of cotton stalks and to carry out the validation tests. The results confirm that the established discrete element model could accurately characterize the biomechanical properties of cotton stalks and that the parameter calibration method is reasonable, which could provide a reference for the discrete element modeling of cotton stalks and other stalks, and also offer a theoretical basis for the research of the crushing and separation mechanism of the film-stalk mixtures and the development of the equipment.
The potential of biomechanics for improving human health and performance is well established in many parts of the world. However, across most of Africa, biomechanics remains relatively ...underdeveloped. The discussion around biomechanics in the continent has increased in recent times and young African scientists are pursuing career opportunities in biomechanics-related fields within Africa and in other parts of the world. New institutions and programmes that focus on biomechanics teaching and research are also starting up around the continent. The advent of the National Biomechanics Day event, formation of the first formal biomechanics society in South Africa, along with many collaborations with relevant stakeholder organizations around the world underpin the expansion of biomechanics in Africa. This article aims to summarize the current state and describe aspirations for the future of biomechanics in Africa.
Abstract Aim Abdominal wall hernias result from a mechanical conflict between forces acting on the wall (mainly intra-abdominal pressure (IAP)) and its ability to deform. An abdominal binder ...instrumented with sensors has been developed to non-invasively quantify the deformation during straining. Methods A prospective study was conducted on eight healthy subjects. External deformations were evaluated by a patented connected binder instrumented with resistive sensors covering anterolateral area. IAP was evaluated by intragastric ingested sensor (SmartPill™, Medtronic), and wall muscles deformation by dynamic MRI (semi-automated segmentation method applied to rectus abdominis (RA) and lateral muscle (LM)). The relationship between these signals has been investigated during Valsalva maneuver. Results The binder provided time-related mapping of the abdominal deformation. Two different patterns were individualized corresponding to RA and LM areas. Deformation rate (mean 1.21mV/s for RA and 1.66mV/s for LM) and maximum signal (mean 3.03mV for RA and 4.24mV for LM) were recorded. These binder patterns were both correlated with the deep deformation in abdominal muscles observed in MRI (Pearson R=0.89 for RA, and R=0.94 for LM; p<0.005). The binder patterns were also significantly correlated with the IAP variation (Pearson R=0.98 for RA and R=0.99 for LM; p<0.005). Conclusion This non-invasive connected and instrumented abdominal binder simply and quickly reflects the abdominal wall muscles deformation and IAP variation during Valsalva maneuver. A larger study is needed to investigate inter-individual variability, and to evaluate the links between quantitative mechanical behavior and surgical outcomes during hernia surgery.
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