The musculoskeletal models have been improved to estimate accurate knee compression force (KCF) and have been used to reveal the causal relationship between KCF and muscle weakness. Previous studies ...have explored how muscle weakness influences the KCF during gait; however, the influence of muscle weakness is possibly larger during activities that require deeper knee flexion (e.g., stair ambulation) than other activities (e.g., gait) because of the small knee contact area of articular surfaces.
To explore how muscle weakness influences the KCF during stair ambulation.
Ten young adults performed stair ascent and descent tasks at a comfortable speed. Based on a previous study, we created muscle weakness models of rectus femoris (RF), vastus muscles (VAS), gluteus medius (Gmed), and gluteus maximus (Gmax), and the medial and lateral KCF (KCFmed and KCFlat) during stair ambulation were calculated.
Similar to the gait, the Gmed weakness increased KCFmed and decreased KCFlat during stair ascent and descent. Whereas, unlike the gait, the Gmax weakness increased KCFmed during stair ascent and the VAS weakness decreased KCFmed and KCFlat during stair ascent and descent. Moreover, the percentage changes in KCF were similar (or large) during stair ambulation compared with those during gait.
Considering the KCF alterations caused by each muscle weakness, the weaknesses in Gmax and Gmed might lead to cartilage loss and pain in the knee, and the VAS weakness might lead to low stability of the knee. The symptom during stair ambulation might help precisely identify the muscle requiring rehabilitation.
•Musculoskeletal models is useful to explore how muscle weakness affects knee compression force.•We explored which muscle weakness influences knee compression force during stair ambulation.•Gluteus medius and maximus weaknesses induced high medial and low lateral knee compression force.•Vastus weakness induced low medial and lateral knee compression force.
The objective of this study was to compare the relationships between instrumental texture measurements and subjective woody breast (WB) scores in raw broiler breast fillets. A total of 181 broiler ...breast fillets were scored based on palpable hardness and rigidity ranging from 1.0 to 3.0 in 0.5 increments. Texture properties of raw fillets were measured with 3 different instrumental methods: compression force, blunt Meullenet-Owens Razor Shear (BMORS), and Meullenet-Owens Razor Shear (MORS). Compression force was measured based on % of fillet height (30%) and distance (10 mm). Blunt Meullenet-Owens Razor Shear and MORS measurements included peak force, energy, and peak counts. One-way ANOVA of instrumental texture measurements were performed. Spearman correlations between WB scores and instrumental texture measurements and Pearson correlations between 3 instrumental measurements were analyzed. ANOVA results showed that the best means separations between WB scores were found with the compression method. The weakest means separations were observed with MORS force and BMORS peak counts. Spearman correlation coefficients showed that there were significant relationships between WB scores and instrumental measurements. The strongest correlations were found between subjective WB scores and compression force measurements (r = 0.58–0.73, P < 0.0001), followed by BMORS force and energy (r = 0.55–0.56, P < 0 0.0001), MORS energy and peak count (r = 0.47–0.50, P < 0 0.0001), and BMORS peak count (r = −0.18, P = 0.015). The weakest correlation was found between the WB scores and MORS force (r = 0.17, P = 0.023). Pearson correlation coefficients between 3 different instrumental texture methods were also significant (P < 0.0001). These results demonstrate that there are significant correlations between subjective WB scores and instrumental texture measurements but that correlation strength varies with the instrumental method. Instrumental texture measurements can be used as references for subjective WB scores. Compression force method has the best potential for assessing subjective WB condition scores.
The objective of this study was to compare the relationships between instrumental texture measurements and subjective woody breast (WB) scores in raw broiler breast fillets. A total of 181 broiler ...breast fillets were scored based on palpable hardness and rigidity ranging from 1.0 to 3.0 in 0.5 increments. Texture properties of raw fillets were measured with 3 different instrumental methods: compression force, blunt Meullenet-Owens Razor Shear (BMORS), and Meullenet-Owens Razor Shear (MORS). Compression force was measured based on % of fillet height (30%) and distance (10 mm). Blunt Meullenet-Owens Razor Shear and MORS measurements included peak force, energy, and peak counts. One-way ANOVA of instrumental texture measurements were performed. Spearman correlations between WB scores and instrumental texture measurements and Pearson correlations between 3 instrumental measurements were analyzed. ANOVA results showed that the best means separations between WB scores were found with the compression method. The weakest means separations were observed with MORS force and BMORS peak counts. Spearman correlation coefficients showed that there were significant relationships between WB scores and instrumental measurements. The strongest correlations were found between subjective WB scores and compression force measurements (r = 0.58–0.73, P < 0.0001), followed by BMORS force and energy (r = 0.55–0.56, P < 0 0.0001), MORS energy and peak count (r = 0.47–0.50, P < 0 0.0001), and BMORS peak count (r = −0.18, P = 0.015). The weakest correlation was found between the WB scores and MORS force (r = 0.17, P = 0.023). Pearson correlation coefficients between 3 different instrumental texture methods were also significant (P < 0.0001). These results demonstrate that there are significant correlations between subjective WB scores and instrumental texture measurements but that correlation strength varies with the instrumental method. Instrumental texture measurements can be used as references for subjective WB scores. Compression force method has the best potential for assessing subjective WB condition scores.
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The Process Analytical Technology (PAT) and the Quality-by-Design (QbD) approaches can efficiently facilitate the shift to the desired continuous manufacturing and real time release ...testing (RTRT). By this, it is vital to develop new, in-line analytical methods which fulfil the pharmaceutical requirements. The fast-developing digital imaging-based machine vision systems can provide revolutionary solutions not just in the automotive industry but in the pharmaceutical technology, as well. This study aimed to explore the capabilities of UV/VIS-based machine vision in tablet inspection as a PAT tool for the determination of compression force and crushing strength, drug content and drug distribution in tablets using meloxicam a yellow model drug. In the case of determining the compression force and crushing strength, the application of multivariate wavelet texture analysis (MWTA) based models provided relatively low prediction errors. To predict the drug content of meloxicam tablets CIELAB or RGB colorspace based algorithms were successfully developed and validated. UV/VIS imaging was also used to map the particle size distribution and spatial distribution of meloxicam, the results were compared to chemical maps obtained by Raman microscopy. Digital imaging combined with multivariate data analysis might be a valuable, high throughput, in-line PAT tool for automated inspection of pharmaceutical tablets.
Background: The objective of this study was to determine the interfragmentary compression forces generated in a foam model as a function of headless compression screw type (fully threaded and central ...threadless) and fracture location. Methods: Eighty-eight polyurethane foam models were fixed across a simulated transverse fracture with either a fully threaded screw or a central threadless screw. The location of the transverse fracture varied along the length of the foam model in 2 mm increments for 11 fracture locations. The force generated at the fracture site upon fixation was utilized to determine the interfragmentary compression. Interfragmentary compression was compared using a paired t test and 2-way analysis of variance, with significance set at P < .05. Results: Interfragmentary compression was found to vary based on fracture location and screw type. The fully threaded screw generated significantly greater compression for fracture locations at 12 mm and 18 mm from the top edge of the foam model, while the central threadless screw generated significantly greater compression for fractures located 2 mm from the top edge of the foam model. Conclusions: The central threadless screw and the fully threaded screw had different fracture locations where maximum compression force occurred. The fully threaded screw generated greater compression force toward the screw center due to greater thread purchase. However, the central threadless screw generated greater compression at the most proximal fracture location due to its greater thread pitch toward the screw head. Maximizing interfragmentary compression may aid in reducing nonunion rates associated with the internal fixation of proximal scaphoid fractures.
The effects of automotive-related lithium-ion module design, i.e. module stiffness and initial compression during module assembly on cell aging, swelling and pressure evolution are still largely ...unknown. This paper presents the results of a long-term aging study of 12 large-format automotive graphite/NMC 622 pouch cells, cycled for different module stiffnesses and initial compressions using design of experiments. Statistical analysis of mechanical and aging data revealed significant nonlinear (interaction) effects of both factors on pressure evolution, capacity loss and increase in internal resistance of the cells. Pressure dependent cell aging is observed over 1000 cycles, which was related to loss of active material at the cathode from differential voltage analysis. Post-mortem analysis confirmed a cathode active material loss via half- and full-cell measurements of harvested electrodes. Cross-section SEM micrographs revealed increasing NMC-particle cracking with higher pressure. Based on this, a fatigue-based aging model was developed to describe the capacity loss due to pressure dependent particle cracking. The presented approach enables both improved modeling of pressure dependent aging and lifetime optimized module design
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•Cell swelling and aging under module stiffnesses and initial compressions•Significant effects of both factors on cell aging and pressure evolution•Pressure correlates with capacity fade due to loss of cathode active material•Active material loss confirmed by half-cell measurements and SEM cross-sections•Fatigue-based aging model of cathode particle cracking
Lateral platform collapse in fixations of lateral tibial plateau fractures (TPFs) using either double-lag screws fixation (DSF) or locking-plate fixation (LPF) is not rare. This study aimed to ...explore the effect of enhancing the interfragmentary compression force (IFCF) on fixation stability in lateral TPFs in normal and osteoporotic bones using finite element analysis. Finite element models of DSF in normal bone and LPF in normal and osteoporotic bones were established to simulate the fixations of lateral TPF. After model validation, axial compressive forces of 500, 1000, 1500, and 2500 N to the tibial plateau along with an IFCF of 0, 100, 200, and 300 N were applied. The maximum axial micromotion of the lateral fragment (MAM-LF), maximal translational micromotion of the lateral fragment (MTM-LF), peak von Mises stress (VMS), and peak equivalent elastic strain of the lateral fragment (EES-LF) were evaluated. The MAM-LF showed a decreasing trend as the IFCF increased in all models. For DSF models, the peak VMS of implants increased as the IFCF increased when the axial loads were 500 and 1000 N. The peak EES-LF decreased as the IFCF increased under axial loads of 1000, 1500, and 2500 N. For the normal and osteoporotic LPF models, the peak VMS of the implants decreased as the IFCF increased. Peak EES-LF decreased as IFCF increased. In conclusion, enhancing IFCF was beneficial in improving the fixation stability of lateral TPF. The optimal IFCF for DSF and LPF should be as high as reasonably feasible.
Introduction: Farming is a physically demanding occupation that puts farmers at risk of musculoskeletal disorders, particularly when frequently performing activities like heavy lifting, which strains ...the lower back muscles. The present study aimed to assess the ergonomic risk and fatigue during manual lifting tasks pertaining to farming activities. Methods: A study was performed on 20 farmers to analyze the ergonomic risks associated with load lifting through the estimation of the Recommended Weight Limit and Lifting Index using the revised NIOSH lifting equation. The low back compression forces of the participants were estimated using the 3DSSPP software. Surface electromyography was employed to analyze the onset of muscle fatigue during the lifting activity. Results: The results of the study showed a 111.12% increase in the recommended weight limit, a 52.77% reduction in lifting index, and a 28.15% reduction in the low back compression forces for the redesigned lifting technique. The average low-back compression force for the redesigned technique was observed to be well below the back compression design limit of 770 lb. A reduction in the slope of the RMS voltage regression line by 60% and a reduction of 50.23% in the peak spectral power of the sEMG signal, accompanied by a shift in the peak spectral power towards higher frequency region indicated delayed onset of fatigue for the redesigned technique. Conclusion: The outcomes of the study indicated that the ergonomic redesign of the lifting task could significantly reduce the lifting index and alleviate the spinal compression forces well within the back-compression design limit. The redesign was also found to delay the onset of fatigue in the erector spinae muscles.
Introduction: Farming is a physically demanding occupation that puts farmers at risk of musculoskeletal disorders, particularly when frequently performing activities like heavy lifting, which strains ...the lower back muscles. The present study aimed to assess the ergonomic risk and fatigue during manual lifting tasks pertaining to farming activities. Methods: A study was performed on 20 farmers to analyze the ergonomic risks associated with load lifting through the estimation of the Recommended Weight Limit and Lifting Index using the revised NIOSH lifting equation. The low back compression forces of the participants were estimated using the 3DSSPP software. Surface electromyography was employed to analyze the onset of muscle fatigue during the lifting activity. Results: The results of the study showed a 111.12% increase in the recommended weight limit, a 52.77% reduction in lifting index, and a 28.15% reduction in the low back compression forces for the redesigned lifting technique. The average low-back compression force for the redesigned technique was observed to be well below the back compression design limit of 770 lb. A reduction in the slope of the RMS voltage regression line by 60% and a reduction of 50.23% in the peak spectral power of the sEMG signal, accompanied by a shift in the peak spectral power towards higher frequency region indicated delayed onset of fatigue for the redesigned technique. Conclusion: The outcomes of the study indicated that the ergonomic redesign of the lifting task could significantly reduce the lifting index and alleviate the spinal compression forces well within the back-compression design limit. The redesign was also found to delay the onset of fatigue in the erector spinae muscles.
This study was conducted to determine the effectiveness of air deformation on fillet surfaces to assess hardness and identify woody breast (WB) in raw fillets of broilers. Fillets (n = 120) were ...categorized in normal (NORM), mild (MILD) and severe (SEV) WB. All fillets were subjected to compression force (CF) analysis and pressurized air (344 kPa) was directed at the ventral surface of each fillet in the cranial region and the deformation area was measured. Fillets were cooked and sheared using Muellenet Owens Razor Shear (MORS) and blunt version of MORS (BMORS). CF increased as severity of WB increased (P < 0.05). Diameter of deformation area decreased (P < 0.05) as WB severity increased. CF was correlated to air deformation (rs = -0.43 to -0.66, P < 0.05). BMORS force and energy was higher (P < 0.05) in SEV fillets compared to those in MILD and NORM. SEV fillets had higher (P < 0.05) peak counts (PC) of shear curves using MORS or BMORS than MILD and NORM fillets (P < 0.05). The results indicate that WB can be identified by CF and that the use of air deformation in raw fillets which may be potentially utilized as a tool for WB assessment. Using BMORS paired with the peak counting method may be a better texture analysis method to access WB condition.
•Air deformation is a novel method to detect woody breast in raw fillets•Air deformation is a non-contact method of measuring compression•Woody breast severity can be identified by measuring air deformation on raw fillets•Using air deformation to detect WB has potential to be used in an online system•Assessing peak counts of shear curves may be useful in describing meat texture
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