Compared with calculation of Sprigings et. Relative forward velocity of racket-head to shoulder resulted mainly from internal rotation, elbow extension and ulnar flextion during racket-head accelerative phase, and from horizontal adduction and pronation during follow-through. By the DLT method three-dimensional displacements of digitized points were reconstracted.
One male high-performance player\u27s flat service was recorded by two video cameras.
Each term of angular velocity is cross-product of angular velocity vector and vector from joint to racket-head. Each anguler velocity vector has direction of rotational axis and magnitude of numerical differential. Each angle is calculated as relative angle between adjacent segment coordinates. Upper limb\u27s articulations have seven degrees of freedom horizontal abduction/adduction, abduction/adduction, internal/external rotation, elbow flextion/extension, pronation/supination, ulnar/radial flextion and palmar/dorsal flextion.
The velocity of racket-head sum up terms of angular velocity which is accurately in accordance with three-dimensional angular definition which is defined in reference to ISB recommendations for standardization in the reporting of kinematic data.
0 kommentar(er)
