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Comparison of plugin and redundant marker sets to analyze gait kinematics between different populations

BackgroundGait model consists of a marker set and a segment pose estimation algorithm. Plugin marker set and inverse kinematic algorithm (IK.) are prevalent in gait analysis, especially musculoskeletal motion analysis. Adding extra markers for the plugin marker set could increase the robustness to marker misplacement, motion artifacts, and even markers occlusion. However, how the different marker sets affect the gait analysis's kinematic output is unclear. Therefore, this study aims to investigate the effect of marker sets on the kinematic output during level walking in different populations.ResultsIn all three planes, there are significant differences (P < 0.05) between marker sets in some kinematic variables at the hip, knee, and ankle. In different populations, the kinematic variables that show significant differences varied. When comparing the kinematic differences between populations using the two marker sets separately, the range of motion (ROM) of hip flexion was only found to be a significant difference using the redundant marker set, while the peak internal rotation at the knee was only found a significant difference using plugin marker set. In addition, the redundant marker set shows less intra-subject variation than the plugin marker set.ConclusionThe findings in this study demonstrate the importance of marker set selection since it could change the result when comparing the kinematic differences between populations. Therefore, it is essential to increase the caution in explaining the result when using different marker sets. It is crucial to use the same marker set, and the redundant marker set might be a better choice for gait analysis.

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Examining the factors influencing postpartum musculoskeletal pain: a thorough analysis of risk factors and pain assessment indices.

Musculoskeletal disorders after childbirth are common, but current studies often have a narrow focus, concentrating on particular areas and neglecting a thorough evaluation of pain locations and overall severity. This research aimed to determine the occurrence, spread, severity, and root causes of musculoskeletal discomfort in females during the 6-8week period after giving birth, focusing on investigating the link between pain and posture. This study collected data from 432 postpartum women, 6-8weeks post-delivery, focusing on ten posture angles captured photographically and analysed using Exbody software. Participants also filled out structured questionnaires on pregnancy history, the Short Form McGill Pain Questionnaire (SF-MPQ) scores, physical activity patterns, and involvement in household and neonatal care tasks. In our research, 49.8% of the respondents experienced pain after childbirth in different regions of their bodies. Utilising SF-MPQ, the mean Pain Rating Index was 7.35 (SD = 5.93) and Present Pain Intensity and Visual Analog Scale was 3.13 (SD = 2.09). Among the evaluated postural angles, only the Q-angle exhibited a noteworthy correlation with knee discomfort. Individuals with less involvement in household and newborn care tasks had a significantly lower occurrence of postpartum pain, with a decrease of 76% (OR = 0.243, p = 0.001). Similarly, those who shared these responsibilities had a 53% decreased likelihood (OR = 0.468, p = 0.008) of experiencing postpartum pain. Many postpartum women experience moderate-intensity pain in various body regions. Pain's correlation with posture was limited. Reducing physical strain during infant care notably decreased postpartum pain, underscoring the need for holistic support for postpartum women.

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Spatiotemporal dynamics of flood regulation service under the joint impacts of climate change and Urbanization: A case study in Baiyangdian Lake Basin, China

Estimating the supply–demand relationship’s future dynamics and trend of Flood Regulation Service (FRS) is important for preventing flood risks and choose an appropriate future development path. Less attention has been given to assessing the future trends in this relationship under the joint influence of climate change and urbanization. This paper aims to quantify future trends in the FRS supply–demand relationship under the joint impacts of climate change and urbanization. To this end, we took the Baiyangdian Lake Basin as an example and developed a “Climate Change-Urbanization-FRS supply and demand” framework by combining future climate scenarios from the ScenarioMIP (Scenario Model Intercomparison Project) dataset and socioeconomic data from the SSPs (Shared Socioeconomic Pathways) to estimate the FRS supply and demand dynamics during the period from 2020 to 2050. The results show that the framework has a reasonable ability to estimate the FRS supply–demand relationship. The correlation coefficients between estimated supply–demand ratios and the historical values exceeded 0.9. The average FRS supply–demand ratio among the four scenarios shows a significantly downward trend between 2020 and 2050. The FRS is expected to decrease by 0.159 (36.6 %), resulting in the imbalanced area increasing from 38.3 km2 (4.1 % of the whole basin) to 11049.7 km2 (36.2 %). We believe that although urbanization is the dominant factor contributing to the intensified imbalance trend (with a contribution of 71.2 %), influences from climate change also cannot be ignored (with a contribution of 28.8 %). Therefore, adaptation actions to climate change should be actively taken to reduce urban flood risks in the future.

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The effect of different posterior inclinations of tibial component on tibiofemoral contact pressures after unicompartmental knee arthroplasty

BackgroundDifferent posterior inclinations of tibial component after unicompartmental knee arthroplasty (UKA) may lead to different biomechanical characteristics of the knee joint. This finite element study was designed to investigate the tibiofemoral contact pressures after UKA with different posterior inclinations of tibial component.MethodsFinite element model of a healthy knee joint was constructed, and mobile-bearing (MB) UKA models with 5 different posterior inclinations (3°, 5°, 7°, 9° and 11°) of tibial components were simulated. The maximum contact pressures of tibial plateau cartilage in the lateral compartment and polyethylene insert in the medial compartment were calculated based on the ground reaction force and the angle of the knee flexion obtained by 3D motion capture system.ResultsThe loading ratio of medial and lateral compartments during standing stance (medial 54.49%, lateral 45.51%) and tibial anterior displacement (134 N, 3.89 mm) of healthy knee was basically consistent with previous experimental data. The maximum contact pressures of the medial meniscus and lateral tibial plateau cartilage of the healthy knee during standing stance were 2.14 MPa and 1.57 MPa, respectively. At the static standing phase, the maximum contact pressures of the polyethylene insert decreased from 17.90 to 17.29 Mpa, and the maximum contact pressures of the tibial plateau cartilage in the lateral compartment increased from 0.81 to 0.92 Mpa following an increase in the posterior inclination of the tibial component. At the first peak of ground reaction force, the maximum contact pressures of polyethylene insert increased from 22.37 to 25.16 MPa, and the maximum contact pressures of tibial plateau cartilage in the lateral compartment increased from 3.03 to 3.33 MPa, with the increase in the posterior inclination of the tibial component. At the second peak of ground reaction force, the maximum contact pressures of polyethylene insert decreased from 2.34 to 2.22 MPa with the increase in posterior inclination of tibial component.ConclusionThe preoperative and postoperative finite element models of MB UKA were well established. The results showed that the maximum contact pressures of the polyethylene insert did not change significantly with the increase in the posterior inclination of the tibial prosthesis, while the maximum contact pressures of the tibial plateau cartilage of the lateral compartment increased when the posterior inclination of the tibial prosthesis was > 7°. Our results also show that the maximum contact pressures were greater with an excessive inclination angle (11°) of the tibial component, and the pressures of the tibial plateau cartilage in the lateral compartment were more concentrated on the posterior area. This study, therefore, proposes that excessive osteotomy should be avoided.

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The effects of walking aids on shoulder joint kinematics in older persons: an initial study

BackgroundMany older persons with degenerative physical functions use walking aids to improve their ambulation ability. The aim of this study was to investigate the effects of walking aids with different configurations on shoulder joint motion in older persons.MethodsThe 3D motion capture system VICON was applied to collect data on gait parameters and shoulder motion characteristics of 6 older persons walking either independently or with the assistance of a footed walking frame and a wheeled walking frame. The different effects of walking aids on gait parameters and the shoulder joint motion of older individuals were quantitatively analyzed.ResultsThe gait parameters of the older individuals changed significantly when they used walking frames to assist walking. Compared to independent walking, the range of motion of the shoulder joint was reduced by 79.92% in flexion when walking with a wheeled walking frame. Meanwhile, the range of motion in flexion, extension, and external rotation increased by 76.04%, 85.55%, and 110.99%, respectively, when walking with a footed walking frame.ConclusionThe motion characteristics of shoulder joints in older persons were significantly affected by using different walking aids. These changes in shoulder joint motion characteristics will lead to potential diseases related to the shoulder musculoskeletal system. These findings are beneficial to determine a walking aid for older people.

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Fluid evolution and mineralizing process of the Bawang Fe-Zn-Sn deposit, Danchi Fold-and-Thrust belt, South China

The Bawang deposit, a newly discovered Fe-Zn-Sn deposit occurred in the paleokarst in the Youjiang Basin, South China, offers an excellent opportunity to understand the ore-forming process and genesis of this unique tin mineralization, thus enriching the tin mineralization theories. Mineralogy, X-ray photoelectron spectroscopy (XPS), and laser ablation-inductively coupled plasma-mass (LA-ICP-MS) analysis were performed on sphalerite to investigate the fluid evolution and mineralizing process of the Bawang deposit. The formation of the deposit involved hydrothermal-cassiterite-sulfides and oxidation periods. The hydrothermal-cassiterite-sulfides period is dominated by the mineralization of Zn- (stage 1), Sn- (stage 2), and Sb- (stage 3) in order. Three types of sphalerite were identified in these hydrothermal stages. Mineralogical studies and spectrum data show that the massive sphalerite in stage 1 (Sp1) is euhedral coarse-grained and characterized by high Fe contents (9.67–15.69 wt%), with obvious pyrrhotite blebs, pyrite laths, stannite and/or chalcopyrite solid solutions. The sphalerite with 5.56–11.31 wt% Fe contents in stage 2 (Sp2) occurs as fine-grained, euhedral to subhedral crystals (15–50 μm) and coexists with cassiterite, arsenopyrite, and quartz. The sphalerite in stage 3 (Sp3) is characterized by low Fe content (0.59–2.99 wt%) and is generally micro-fine-grained (10–30 μm) associated with stibnite, sulfosalts, and carbonates. LA-ICP-MS analyses of sphalerite suggest that Sp1 and Sp2 have similar characteristics and are enriched in Fe, Cu, Sn, Ga, and Cd, whereas Sp3 is enriched in Sb, Pb, Ag, Bi, and Tl. The principal component analysis (PCA), boxplots, and bivariate plots of trace elements from sphalerite, combined with previous Raman spectroscopy data for fluid inclusions and H-O-Cd isotopic compositions, indicate two types of ore-forming fluids were involved in the mineralization of the Bawang deposit. The early Fe-Zn-Sn-Cu-In-rich fluids originated from granitic magma and underwent Zn- and Sn-dominated mineralization in order in a slowly cooling closed system. The later hydrothermal fluids with the addition of oil field brine were enriched in Sb, Pb, Ag, and Bi elements in the Sb-sulfosalts-carbonates stage in an open system with a drop in temperature. The mineralization process of the Bawang deposit can be concluded as follows: The early ore-forming fluids derived from an inferred concealed intrusion infilled into the paleokarst (below 350 m of the altitude) and caused the massive euhedral ferroan sphalerite (stage 1) to precipitate. The deposition of sphalerite decreased sulfur fugacity (fS2) in a slowly cooling closed system, and increased relative oxygen fugacity (fO2) which promoted cassiterite to precipitate in stage 2. The foreign hydrothermal fluids lowered the temperatures of residual ore-forming fluids due to the addition of oil field brine. Then the Pb-Sb sulfides and Pb-Sb-Ag-Bi-bearing sulfosalts (stage 3) crystallized at shallow depths (350 to 500 m of the altitude).

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