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Contribution of Bioavailable Silicon in Human Health
Published in Debasis Bagchi, Manashi Bagchi, Metal Toxicology Handbook, 2020
As mentioned before, stabilized preparations of silicic acid have been developed, e.g., choline-stabilized OSA, permitting water-soluble preparations with higher concentrations and also markedly enhanced bioavailability. In a randomized controlled animal study, long-term treatment with choline-stabilized OSA prevented partial femoral bone loss and exerted a positive, beneficial effect on bone turnover.47 In this study, ovariectomized aged rodents were used suggesting a potential interrelationship between estrogen and bone health and silicon metabolism. Bae et al. showed that short-term administration of water-soluble silicon improved mineral density of the femur and tibia in ovariectomized rats.121 In an in vitro study, the effect of OSA (0, 0.5, 1, 5, and 10 µM) on gene expression in human osteoblast cells isolated from trabecular bone was measured. Results showed that collagen type I mRNA expression was increased by the addition of OSA, alkaline phosphatase message was suppressed, and osteocalcin levels were decreased.122 Macdonald et al. have reported that dietary silicon interacts with estrogen to influence bone health as noted in the Aberdeen Prospective Osteoporosis Screening study.123 It has also been shown that silicon supplementation increased hip bone mineral density in men and pre-menopausal, but not post-menopausal, women although a subsequent study showed increases in the spine and femur of both pre- and post-menopausal women currently prescribed hormone replacement therapy.123,124
Functional Anatomy and Biomechanics
Published in Emeric Arus, Biomechanics of Human Motion, 2017
The hip girdle joints should be classified into two categories:Ligamentous reinforcers for the hip girdle. Some of them are Sacroiliac ligament (ventral and dorsal) which unites the ilium and the sacral bone; Iliolumbar ligament unites the ilium and the lumbar region of the vertebral column; Sacrococcygeal ligament; sacrolumbar ligament; interpubian disc; ischiosacral ligament; and sacrotuberous ligament, and so on. These ligaments are reinforcers of the pelvic bones. They have no or extremely limited possibilities of movement. Figure 3.15a shows the pelvis and the most important ligamentous reinforcers (joints of the pelvis bone).Coxofemoral articulations (related to hip and femur bones). In sport or fitness, the experts usually speak about the coxofemoral articulations only. The hip bone and the femur bone articulate through their surfaces: The head of the femur and the acetabulum of the coxa bone are an example. The acetabulum is a hollow space where the head of the femur communicates through sliding and rotating. Figure 3.15b shows the coxofemoral articulations.
Overview: An Evolving State of the Art in Tissue Engineering
Published in Claudio Migliaresi, Antonella Motta, Scaffolds for Tissue Engineering, 2014
products. In many respects, the use of computer-aided design and manufacturing (CAD/CAM) techniques that are employed for these purposes have been found to be applicable to the design of tissue-engineered scaffolding. Engineers and material scientists initially explored the application of solid mechanics, fluid mechanics, and CAD/CAM, using "top-down" reverse engineering strategies in the design of orthopedic and orthotic devices manufactured from biocompatible metal alloys, ceramics, and fiber reinforced plastics. Total hip replacements consisting of a femoral ball that fits into the socket of the hip bone and a shaft tapered to fit into a reamed medullary canal of the femur,20 prosthetic limbs consisting of a socket, shank, and foot for amputees,21 composite disc prostheses,22 and tailor-made, and computer-designed cranial implants used to minimize risks of brain surgery23 are examples of the many biomedical applications described in the literature. In these cases, the primary biological criterion for the materials employed was that they were "biocompatible" in the sense that there was minimal risk of inflammation of surrounding tissues.
Reliable and effective novel home-based training set-up for application of an evidence-based high-loading stimulus to improve triceps surae function
Published in Journal of Sports Sciences, 2021
Goran Radovanović, Jona Kunz, Sebastian Bohm, Adamantios Arampatzis, Kirsten Legerlotz
Participants were advised to sit with extended knees. The forefoot (with shoes) was placed in the foot plate with the widest part of the shoe (i.e. ball of the foot) positioned in the sagittal centre of the foot plate pad to ensure a standardised contact point. The participants were advised to always use the same shoes with a rigid sole. The ratchet was individually set and fixed as tightly as possible, to allow for maximal isometric plantar flexor contractions at a standardised ankle angle position (90°) (Figure 2). The straps on both sides of the pelvis were placed as close as possible to the hip bone (i.e. os ilium) to reduce spinal load. It was recommended to place one hand on the ground behind the body providing a hip (i.e. femur-to-spine) angle of >90°. For standardised alignment during the contractions, both legs had to be parallel in the frontal plane and in neutral rotational position in the hip joints in the transverse plane.
Surgical drilling of curved holes in bone – a patent review
Published in Expert Review of Medical Devices, 2019
Alexander Sendrowicz, Marta Scali, Costanza Culmone, Paul Breedveld
This group (3) describes drills which are able to form a multi-curved path instead of only a single-curved path but do not allow for any adjustments of the path after the insertion of the drill into the bone [1,10,13,15,25,35–46]. One of the mechanical working principles describes the formation of a double curved hole by rotation and propulsion of the drill head which is able to be guided without an external guiding mechanism. In this simple mechanism, the anatomical structure, through which the drill moves, acts as the guidance, and the instrument is ‘passively steered’. Gillespie et al. [35] describe a drill with a flexible outer tube used to drill soft trabecular bone, which is located between the cortical plates of the ilium, the uppermost part of the hip bone (Figure 4(a)). The cortical plates are harder than the trabecular bone, and by choosing the path of the least resistance, the drill deviates from its initial direction through the trabecular bone in the desired direction. Breguet [36] describes a similar mechanical working principle, for drilling a root canal (the cavity in the root of a tooth) to the desired shape. This drill is sufficiently flexible to follow the sharply curved areas in the root canal and to form a curved hole. Similarly, Sullivan and Myers [10] describe a flexible drill for the drilling of medullary canals. Since medullary canals of bone are rarely straight, a drill capable of following the anatomy of the medullary canal is preferred over a straight and stiff drill. The flexible outer tube can be made out of a polymer or a composite, usually polyether ether ketone (PEEK).
A finite element analysis study based on valgus impacted femoral neck fracture under diverse stances
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Haowei Zhang, Xinsheng Xu, Shenghui Wu, Ying Liu, Jiong Mei
Boundary conditions and loads: In the hip joint, a contact surface is created between the acetabulum and the femoral head to achieve frictional contact with the articular cartilage. The friction coefficient is 0.26. Since the femoral neck produces a fractured surface, relative slippage, and frictional contact will occur between the fractured ends of the femoral neck (Zou et al. 2013). Therefore, a contact pair is formed between the two cross-sections, and the friction coefficient is 0.4. The simulation conditions of contact are established in Abaqus (Gok et al. 2017; Haider et al. 2018). The fixation is the lower end simply supported distal fixation, and the 6 degrees of freedom on the X, Y, and Z axes of the distal femur nodes are 0 (Jeon and Kim 2011). The load condition assumes that the weight of the upper part of the human body is evenly transmitted through the hip joints to the lower extremities when standing with both legs. Therefore, when standing on one foot, the pressure on the femoral head is half of 2.75 times of the body mass (Zhao et al. 2009) and the load direction is along the tangential direction of the contact between the sacrum and the hip bone on the oval contact surface of the hip bone. After defining the contact point, defining the boundary condition, and defining the working condition, then the task is selected and submitted before analyzing (Kang et al. 2017). The boundary conditions of the hip joint are set as shown in Figure 4. Due to the large number of three-dimensional solid units of the model, the mesh is densely divided, the computer is configured with 8 G memory and i5 processor, and the simulation calculation time of the hip joint model using Abaqus is about 5–6 h. When Abaqus displays Abaqus/Explicit completed successfully, the analysis ends.