Biodynamics forces

This loyalty is reflected in her reaction when Sister Laurentia mentioned in a letter that Maye E. Bruce was one of her advisors and in the following letter asked her to show understanding for Bruce s behaviour. In 1937 there was a quarrel between Maye E. Bruce and the representatives of the Anthroposophic Society in England because Miss Bruce used the same herbs that were specially prepared for biodynamic preparations and combined them in a simpler method in her Quick-Retum-Preparation, which she then sold. For Erika Riese this conduct was inexcusable, as we know from a handwritten note on Dombrowski s letter Maye Bruce s behaviour is hardly fair and she does not understand the preparation. Incidentally, we also appreciate collaboration With we, Erika Riese clearly shows her affiliation to the biodynamic movement and, thus, the Anthroposophic Society. It shows that Miss Riese felt solidarity with the anthroposophist movement over her solidarity with women. Perhaps, under certain circumstances she would have joined forces with men against women. 

An exception to the work pattern of men in positions of authority and women doing routine and preparatory work, can be found in the case of Lili Kolisko (1889-1976), who was a real pioneer woman (Gisbert Husemann, 1978 and 1997). Lili founded the Biodynamic Research Laboratory in Stuttgart where she worked with various assistants. She was personally urged by Rudolf Steiner to study the formative forces. In comparative experiments she studied crystallization and growth promotion of hundreds of substances. Among other things, she was able to prove scientifically that that there is a relationship... 

The equations of motion are dynamic expressions relating kinematics with forces and moments. In a musculoskeletal biodynamic system, the forces and moments will consist of joint reactions internal forces, such as muscle, tendon, or ligament forces and/or externally applied loads. Consequently, the equations of motion can provide a critical understanding of the forces experienced by a joint and effectively model normal joint function and joint injury mechanics. They can yield estimates for forces that cannot be determined by direct measurement. For example, muscle forces, which are typically derived from other quantities such as external loads, center of mass locations, and empirical data including anatomical positioning and/or electromyography, can be estimated. 

The energy method approach uses Lagrange s equation (and/or Hamilton s principle, if appropriate) and differs from die newtonian approach by the dependence upon scalar quantities and velocities. This approach is particularly useful if the dynamic system has several degrees of freedom and the forces experienced by the system are derived from potential functions. In summary, the energy method approach often simplifies the derivation of the equations of motion for complex multibody systems involving several degrees of freedom as seen in human biodynamics. 

For certain problems where constraint forces are considered, a Newtonian approach, or the aj li-cation of both techniques, may be necessary. The following sections will present some applications of Lagrange s equation as qiplicable to human anatmnical biodynamics. Other mechanically based examples are easily found within the cited literature (Baruh, 19W Moon, 1998 Wells, 1967). 

Equinoxious frequency contours may be estimated from epidemiological studies of health effects, or from the response of human subjects, animals, cadavers, or biodynamic models to the stimuli of interest Human subjects cannot be subjected to injurious accelerations and forces for ethical reasons, and so little direct information is available from this source. Some information has been obtained from studies of accidents, though in most cases the input acceleration-time histories are poorly known. 

Knowledge of tolerable limits for human exposure to vibration, shock, and impact is essential for maintaining health and performance in the many environments in which man is subjected to dynamic forces and accelerations. As already noted, humans cannot be subjected to injurious stimuli for etbical reasons, and so little direct information is available fixim this source. In these circumstances, the simulation of human response to potentially life-threatening dynamic forces and accelerations is desirable, and is commonly undertaken using biodynamic models, and anthropometric or anthropomorphic manikins. They are also used in the development of vehicle seats and, in the case of hand-arm models, of powered hand-held tools. 

Biodynamics Database (accessed June 17, 2010). The Biodynamics Data Bank (BDB) was established in 1984 by a team of researchers at the U.S. Air Force Research Laboratory (AFRL). The primary objective was to provide a national repository of biodynamics test data accessible to the entire research community. The contents of the BOB include data from approximately 7,000 acceleration impact tests conducted at the Biodynamics and Acceleration Branch of AFRL as well as information on the associated test facilities, test programs, and test subjects. The test data include measured forces, accelerations, and motions of both human and manikin subjects. Users must register to use the site. 

The methods discussed earlier are applied to the seat-occupant-restraint system of an aircraft. A description of a computer-aided analysis environment, including a multibody model of the occupant and a nonlinear finite element model of the seat, is provided, which can be used to re-construct variety of crash scenarios. These detailed models are useful in studies of the potential human injuries in a crash environment, injuries to the head, the upper spinal column, and the lumbar area, and also structural behavior of the seat. The problem of reducing head injuries to an occupant in case of a head contact with the surroundings (bulkhead, interior walls, or instrument panels), is then considered. The head impact scenario is re-constructed using a nonlinear visco-elastic type contact force model. A measure of the optimal values for the bulkhead compliance and displacement requirements is obtained in order to keep the possibility of a head injury as little as possible. This information could in turn be used in the selection of suitable materials for the bulkhead, instrument panels, or interior walls of an aircraft. The developed analysis tool also allows aircraft designers/engineers to simulate a variety of crash events in order to obtain information on mechanisms of crash protection, designs of seats and safety features, and biodynamic responses of the occupants as related to possible injuries. 

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