Mechanography | |
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Purpose | assessment of muscle function |
Mechanography (also referred to as jumping mechanography or Muscle Mechanography [1] ) is a medical diagnostic measurement method for motion analysis and assessment of muscle function and muscle power by means of physical parameters. The method is based on measuring the variation of the ground reaction forces over the time for motion patterns close to typical every day movements (e.g. chair rise or jumps). From these ground reaction forces centre of gravity related physical parameters like relative maximum forces, velocity, power output, kinetic energy, potential energy, height of jump or whole body stiffness [2] are calculated. If the ground reaction forces are measured separately for left and right leg in addition body imbalances during the motions can be analysed. This enables for example to document the results of therapy. [3] [4] The same methodology can also be used for gait analysis [5] [6] or for analysis of stair climbing, [7] grip strength [8] and Posturography. [9] Due to the utilization of every-day movements reproducibility is high over a wide age range [10]
Typical fields of applications of Mechanography are in the field of geriatrics [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] [22] especially in the field of Sarcopenia [23] but also for Master Athletes. [24] Mechanography is also used frequently in pediatrics for basic research ins muscle function and growth, [25] [26] [27] [28] [29] [30] [31] [32] [33] reference Data [8] [34] [35] as well as in specific diseases like Prader–Willi syndrome, [36] Obesity, [37] [38] Osteogenesis Imperfecta [39] [40] [41] [42] and cerebral palsy. [43] In opposite to many other established measurements methods like Chair Rising Test, Stand-up and Go test and others [44] [45] the maximum power output relative to body weight during a jump of maximum height measured by Mechanography is a much better reproducible and does not have a training effect even when repeated more frequently. [46]
Based on this test (maximum relative power output of a jump as high as possible) Runge et al. and Schönau et al. defined reference values of a fit population in order to match the individual power output in relation to bodyweight, age and gender [14] [31] Tsubaki [47] [48] showed when using identical selection criteria as Runge that the relative Power of the Japanese population is identical with western European population which delimits the need for localized reference data. Runge et al. also showed the interrelation between the measured individual power output and the neuromuscular caused fall risk. [49]
Due to this objective and highly reproducible quantification of typical every day movements by means of physical parameters the Mechanography is well suited to document the physical state of a person [14] [50] [51] as well as the effects of training or therapy. [3] [17] [38] [52] [53] [54] [55] Because of this it is also one of the standard measurements in recent and current Bed Rest Studies of the European Space Agency (ESA). [53] [56] [57] [58] and the Mars500 Mission. [59]
Mechanography has also been used to explore the relation between muscle and bone. According to the Mechanostat theorem muscle function influences bone growth. By combining functional measurement methods like Mechanography and quantitative computer tomographic measurements analysing bone density, geometry and strength this relationship can be assessed. [28] [60] [61] [62] [63] [64] [13] [65] [66] In sports research Mechanography has been used to assess principle training effects. [67] [21] [68]
The standard Mechanography measurement devices as used in all referenced articles are the Leonardo Mechanograph™ systems supplied by Novotec Medical GmbH, Pforzheim, Germany.
Androgen insensitivity syndrome (AIS) is a difference in sex development involving hormonal resistance due to androgen receptor dysfunction.
Primary hyperparathyroidism is a medical condition where the parathyroid gland produce excess amounts of parathyroid hormone (PTH). The symptoms of the condition relate to the resulting elevated serum calcium (hypercalcemia), which can cause digestive symptoms, kidney stones, psychiatric abnormalities, and bone disease.
Isolated hypogonadotropic hypogonadism (IHH), also called idiopathic or congenital hypogonadotropic hypogonadism (CHH), as well as isolated or congenital gonadotropin-releasing hormone deficiency (IGD), is a condition which results in a small subset of cases of hypogonadotropic hypogonadism (HH) due to deficiency in or insensitivity to gonadotropin-releasing hormone (GnRH) where the function and anatomy of the anterior pituitary is otherwise normal and secondary causes of HH are not present.
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Glucose transporter 3, also known as solute carrier family 2, facilitated glucose transporter member 3 (SLC2A3) is a protein that in humans is encoded by the SLC2A3 gene. GLUT3 facilitates the transport of glucose across the plasma membranes of mammalian cells. GLUT3 is most known for its specific expression in neurons and has originally been designated as the neuronal GLUT. GLUT3 has been studied in other cell types with specific glucose requirements, including sperm, preimplantation embryos, circulating white blood cells and carcinoma cell lines.
Homeobox expressed in ES cells 1, also known as homeobox protein ANF, is a homeobox protein that in humans is encoded by the HESX1 gene.
Whole body vibration is a generic term used when vibrations of any frequency are transferred to the human body. Humans are exposed to vibration through a contact surface that is in a mechanical vibrating state. Humans are generally exposed to many different forms of vibration in their daily lives. This could be a driver's seat, a moving train platform, through a power tool, a training platform, or one of countless other devices. It is a potential form of occupational hazard, particularly after years of exposure.
The human gene SRD5A2 encodes the 3-oxo-5α-steroid 4-dehydrogenase 2 enzyme, also known as 5α-reductase type 2 (5αR2), one of three isozymes of 5α-reductase.
The Mechanostat is a term describing the way in which mechanical loading influences bone structure by changing the mass and architecture to provide a structure that resists habitual loads with an economical amount of material. As changes in the skeleton are accomplished by the processes of formation and resorption, the mechanostat models the effect of influences on the skeleton by those processes, through their effector cells, osteocytes, osteoblasts, and osteoclasts. The term was invented by Harold Frost: an orthopaedic surgeon and researcher described extensively in articles referring to Frost and Webster Jee's Utah Paradigm of Skeletal Physiology in the 1960s. The Mechanostat is often defined as a practical description of Wolff's law described by Julius Wolff (1836–1902), but this is not completely accurate. Wolff wrote his treatises on bone after images of bone sections were described by Culmann and von Meyer, who suggested that the arrangement of the struts (trabeculae) at the ends of the bones were aligned with the stresses experienced by the bone. It has since been established that the static methods used for those calculations of lines of stress were inappropriate for work on what were, in effect, curved beams, a finding described by Lance Lanyon, a leading researcher in the area as "a triumph of a good idea over mathematics." While Wolff pulled together the work of Culmann and von Meyer, it was the French scientist Roux, who first used the term "functional adaptation" to describe the way that the skeleton optimized itself for its function, though Wolff is credited by many for that.
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Arzoxifene is a selective estrogen receptor modulator (SERM) of the benzothiophene group which was never marketed. It is a potent estrogen antagonist in mammary and uterine tissue while acting as an estrogen agonist to maintain bone density and lower serum cholesterol. Arzoxifene is a highly effective agent for prevention of mammary cancer induced in the rat by the carcinogen nitrosomethylurea and is significantly more potent than raloxifene in this regard. Arzoxifene is devoid of the uterotrophic effects of tamoxifen, suggesting that, in contrast to tamoxifen, it is unlikely that the clinical use of arzoxifene will increase the risk of developing endometrial carcinoma.
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Cyril Y. Bowers, M.D., Emeritus Professor of Medicine at Tulane University School of Medicine, attended medical school at the University of Oregon and did an internship at the University of Washington. He then studied biochemistry at Cornell University and attended the Postgraduate School of Medicine at the University of Pennsylvania. From 1961-2004 he was the director of the Section of Endocrinology & Metabolism in the Department of Medicine at Tulane University School of Medicine. Dr. Bowers has served on the editorial board of several endocrine journals, was a member of the National Institute of Diabetes and Digestive and Kidney Diseases Study Section for eight years and has written over 400 articles in peer reviewed journals including chapters in books and over 200 abstracts.
Mild androgen insensitivity syndrome (MAIS) is a condition that results in a mild impairment of the cell's ability to respond to androgens. The degree of impairment is sufficient to impair spermatogenesis and / or the development of secondary sexual characteristics at puberty in males, but does not affect genital differentiation or development. Female genital and sexual development is not significantly affected by the insensitivity to androgens; as such, MAIS is only diagnosed in males. The clinical phenotype associated with MAIS is a normal male habitus with mild spermatogenic defect and / or reduced secondary terminal hair.
Michael F. Holick is an American adult endocrinologist, specializing in vitamin D, such as the identification of both calcidiol, the major circulating form of vitamin D, and calcitriol, the active form of vitamin D. His work has been the basis for diagnostic tests and therapies for vitamin D-related diseases. He is a professor of medicine at the Boston University Medical Center and editor-in-chief of the journal Clinical Laboratory.
Bruck syndrome is characterized as the combination of arthrogryposis multiplex congenita and osteogenesis imperfecta. Both diseases are uncommon, but concurrence is extremely rare which makes Bruck syndrome very difficult to research. Bruck syndrome is thought to be an atypical variant of osteogenesis imperfecta most resembling type III, if not its own disease. Multiple gene mutations associated with osteogenesis imperfecta are not seen in Bruck syndrome. Many affected individuals are within the same family, and pedigree data supports that the disease is acquired through autosomal recessive inheritance. Bruck syndrome has features of congenital contractures, bone fragility, recurring bone fractures, flexion joint and limb deformities, pterygia, short body height, and progressive kyphoscoliosis. Individuals encounter restricted mobility and pulmonary function. A reduction in bone mineral content and larger hydroxyapatite crystals are also detectable Joint contractures are primarily bilateral and symmetrical, and most prone to ankles. Bruck syndrome has no effect on intelligence, vision, or hearing.