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Force Platform
Force platforms or force plates are measuring instruments that measure the ground reaction forces generated by a body standing on or moving across them, to quantify balance, gait and other parameters of biomechanics. Most common areas of application are medicine and sports. Operation The simplest force platform is a plate with a single pedestal, instrumented as a load cell. Better designs have a pair of rectangular plates, although triangular can also work, one over another with load cells or triaxial force transducers between them at the corners. Like single-force platforms, dual-force platforms can be used to assess performance in double leg tests and strength and power asymmetries in unilateral jump and isometric tests. However, they also provide an additional level of intelligence on neuromuscular status by evaluating the force distribution between limbs during double-limb tests, revealing critical information on strength asymmetries and compensatory strategies. The simple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strain Gauge
A strain gauge (also spelled strain gage) is a device used to measure Deformation (mechanics)#Strain, strain on an object. Invented by Edward E. Simmons and Arthur C. Ruge in 1938, the most common type of strain gauge consists of an Electrical insulation, insulating flexible backing which supports a metallic foil pattern. The gauge is attached to the object by a suitable adhesive, such as cyanoacrylate. As the object is deformed, the foil is deformed, causing its electrical resistance to change. This resistance change, usually measured using a Wheatstone bridge, is related to the strain by the quantity known as the gauge factor. History Edward E. Simmons and Professor Arthur C. Ruge independently invented the strain gauge. Simmons was involved in a research project by Dätwyler and Clark at Caltech between 1936 and 1938. They researched the stress-strain behavior of metals under shock loads. Simmons came up with an original way to measure the force introduced into the sample b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posturography
Posturography is the technique used to quantify postural control in upright stance in either static or dynamic conditions. Among them, Computerized dynamic posturography (CDP), also called test of balance (TOB), is a non-invasive (medical), non-invasive specialized clinical assessment technique used to quantify the central nervous system adaptive mechanisms (sensory system, sensory, motor system, motor and central) involved in the control of Human position, posture and balance, both in normal (such as in physical education and sports training) and abnormal conditions (particularly in the medical diagnosis, diagnosis of balance disorders and in physical therapy and postural re-education). Due to the complex interactions among sensory, motor, and central processes involved in posture and balance, CDP requires different Clinical trial protocol, protocols in order to differentiate among the many defects and impairments which may affect the patient's posture control system. Thus, CDP chall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wii Balance Board
The is an accessory for the Wii and Wii U video game consoles. Unlike the usual balance board for exercise, it does not rock but instead tracks the user's center of balance. Along with ''Wii Fit'', it was introduced on July 11, 2007, at the Electronic Entertainment Expo. Design The Wii Balance Board is shaped like a household body scale, with a plain white top and light gray bottom. It runs on four AA batteries as a power source, which can power the board for about 60 hours. The board uses Bluetooth technology and contains four pressure sensors that are used to measure the user's center of balance—the location of the intersection between an imaginary line drawn vertically through the center of pressure and the surface of the Balance Board—and weight. In an interview conducted by gaming web site IGN, Shigeru Miyamoto stated that the Balance Board's ability to measure weight is probably more accurate than that of a typical bathroom scale. Although the Japanese packaging ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nintendo
is a Japanese Multinational corporation, multinational video game company headquartered in Kyoto. It develops, publishes, and releases both video games and video game consoles. The history of Nintendo began when craftsman Fusajiro Yamauchi founded the company to produce handmade ''hanafuda'' playing cards. After venturing into various lines of business and becoming a public company, Nintendo began producing toys in the 1960s, and later video games. Nintendo developed its first arcade games in the 1970s, and distributed its first system, the Color TV-Game in 1977. The company became internationally dominant in the 1980s after the arcade release of ''Donkey Kong (1981 video game), Donkey Kong'' (1981) and the Nintendo Entertainment System, which launched outside of Japan alongside ''Super Mario Bros.'' in 1985. Since then, Nintendo has produced some of the most successful consoles in the video game industry, including the Game Boy (1989), the Super Nintendo Entertainment Syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inverse Dynamics
Inverse dynamics is an inverse problem. It commonly refers to either inverse rigid body dynamics or inverse structural dynamics. Inverse rigid-body dynamics is a method for computing forces and/or moments of force (torques) based on the kinematics (motion) of a body and the body's inertial properties (mass and moment of inertia). Typically it uses link-segment models to represent the mechanical behaviour of interconnected segments, such as the limbs of humans or animals or the joint extensions of robots, where given the kinematics of the various parts, inverse dynamics derives the minimum forces and moments responsible for the individual movements. In practice, inverse dynamics computes these internal moments and forces from measurements of the motion of limbs and external forces such as ground reaction forces, under a special set of assumptions.Robertson DGE, et al., Research Methods in Biomechanics, Champaign IL:Human Kinetics Pubs., 2004. Applications The fields of robotics an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power (physics)
Power is the amount of energy transferred or converted per unit time. In the International System of Units, the unit of power is the watt, equal to one joule per second. Power is a Scalar (physics), scalar quantity. Specifying power in particular systems may require attention to other quantities; for example, the power involved in moving a ground vehicle is the product of the aerodynamic drag plus traction (engineering), traction force on the wheels, and the velocity of the vehicle. The output power of a Engine, motor is the product of the torque that the motor generates and the angular velocity of its output shaft. Likewise, the power dissipated in an electrical element of a electrical circuit, circuit is the product of the electric current, current flowing through the element and of the voltage across the element. Definition Power is the Rate (mathematics), rate with respect to time at which work is done or, more generally, the rate of change of total mechanical energy. It is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Work (physics)
In science, work is the energy transferred to or from an Physical object, object via the application of force along a Displacement (vector), displacement. In its simplest form, for a constant force aligned with the direction of motion, the work equals the Product (mathematics), product of the force strength and the distance traveled. A force is said to do ''positive work'' if it has a component in the direction of the displacement of the point of application. A force does ''negative work'' if it has a component opposite to the direction of the displacement at the point of application of the force. For example, when a ball is held above the ground and then dropped, the work done by the gravitational force on the ball as it falls is positive, and is equal to the weight of the ball (a force) multiplied by the distance to the ground (a displacement). If the ball is thrown upwards, the work done by the gravitational force is negative, and is equal to the weight multiplied by the dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acceleration
In mechanics, acceleration is the Rate (mathematics), rate of change of the velocity of an object with respect to time. Acceleration is one of several components of kinematics, the study of motion. Accelerations are Euclidean vector, vector quantities (in that they have Magnitude (mathematics), magnitude and Direction (geometry), direction). The orientation of an object's acceleration is given by the orientation of the ''net'' force acting on that object. The magnitude of an object's acceleration, as described by Newton's second law, is the combined effect of two causes: * the net balance of all external forces acting onto that object — magnitude is Direct proportionality, directly proportional to this net resulting force; * that object's mass, depending on the materials out of which it is made — magnitude is Inverse proportionality, inversely proportional to the object's mass. The International System of Units, SI unit for acceleration is metre per second squared (, \ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinematics
In physics, kinematics studies the geometrical aspects of motion of physical objects independent of forces that set them in motion. Constrained motion such as linked machine parts are also described as kinematics. Kinematics is concerned with systems of specification of objects' positions and velocities and mathematical transformations between such systems. These systems may be rectangular like Cartesian coordinate system, cartesian, Curvilinear coordinates like polar coordinates or other systems. The object trajectories may be specified with respect to other objects which may themselve be in motion relative to a standard reference. Rotating systems may also be used. Numerous practical problems in kinematics involve constraints, such as mechanical linkages, ropes, or rolling disks. Overview Kinematics is a subfield of physics and mathematics, developed in classical mechanics, that describes the motion of points, Physical object, bodies (objects), and systems of bodies (group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Stress
Shear stress (often denoted by , Greek alphabet, Greek: tau) is the component of stress (physics), stress coplanar with a material cross section. It arises from the shear force, the component of force vector parallel to the material cross section. ''Normal stress'', on the other hand, arises from the force vector component perpendicular to the material cross section on which it acts. General shear stress The formula to calculate average shear stress or force per unit area is: \tau = ,where is the force applied and is the cross-sectional area. The area involved corresponds to the material face (geometry), face parallel to the applied force vector, i.e., with surface normal vector perpendicular to the force. Other forms Wall shear stress Wall shear stress expresses the retarding force (per unit area) from a wall in the layers of a fluid flowing next to the wall. It is defined as:\tau_w := \mu\left.\frac\_,where is the dynamic viscosity, is the flow velocity, and is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
