Racket properties may affect tennis elbow development. Shock and vibration to the arm is influenced by the location of ball impacts on the racket head, racket stiffness, and grip force. Beginners experience increased arm loads, and they hit the ball lower on the racket head. Tennis rackets behave differently during actual play compared with the performance predicted by physics.

Hard disk drives function perfectly satisfactorily when used in a stable environment, but in certain applications they are subjected to shock and vibration. During the work reported in this thesis it has been found that when typical hard disk drives are subjected lo vibration, data transfer failure is found to be significant at frequencies between 440Hz and 700Hz, at an extreme, failing at only...

The aim is to develop vibration control of flexible spacecraft by adaptive controller. A case study will be carried out which simulates planar motion of flexible spacecraft as a coupled hybrid dynamics of rigid body motion and the flexible arm vibration. The notch filter and adaptive vibration controller, which updates filter and controller parameters continuously from the sensor measurement, a...

OBJECTIVE The aim of this study was to investigate the exposure-response relationship of hand-arm vibration exposure to neurological symptoms (numbness) of the hand in a cohort of vibration-exposed workers. METHODS The baseline cohort comprised 241 office and manual workers with and without exposure to hand-arm vibration. Numbness (the symptom or event) in the hand was assessed for all subjec...

Vibration syndrome is generally considered to consist of disorders in the upper extremities which are directly exposed to vibration. However, it has been shown that vibration syndrome patients have circulatory disturbances in the foot as well: several chain-saw operators, who were little exposed to vibration of the foot, had Raynaud's phenomenon of the toes, and those with frequent attacks of v...

OBJECTIVES Operation of handheld power tools results in exposure to hand-arm vibrations, which over time lead to numerous health complications. The objective of this study was to evaluate protective equipment and working techniques for the reduction of vibration exposure. METHODS Vibration transmissions were recorded during different work techniques: with one- and two-handed grip, while weari...

BACKGROUND Assessing past cumulative vibration exposure is part of assessing the risk of hand-arm vibration syndrome (HAVS) in workers exposed to hand-arm vibration and invariably forms part of a medical assessment of such workers. AIMS To investigate the strength of relationships between the presence and severity of HAVS and different cumulative exposure metrics obtained from a self-reportin...

This study investigated the biodynamic response (BR) distributed at the palm of the hand subjected to a random vibration. Twelve male subjects were used in the experiment. Each subject applied three coupling actions (grip-only, push-only, and combined grip and push) on a simulated tool handle at three different levels (50, 75, and 100 N) of palm force. This study found that the hand-arm system ...

The biodynamics of human hand-arm system is one of the most important foundations for the measurement, evaluation, and risk assessment of hand-transmitted vibration (HTV) exposure. This paper presents a new conceptual model relating factors influencing cause-effect relationships for HTV exposure, a new study strategy, and a comprehensive review of the recent advances in the biodynamics closely ...