the repetitious nature of propelling a wheelchair has been associated with the high incidence of injury among manual wheelchair users (mwus), mainly in the shoulder, elbow and wrist. recent literature has found a link between handrim biomechanics and risk of injury to the upper extremity. the valid measurement of three‑dimensional net joint forces and torques, however, can lead to a better unde...

Background/Objective: The high demand on the upper limbs during manual wheelchair (WC) use contributes to a high prevalence of shoulder pathology in people with spinal cord injury (SCI). Leveractivated (LEVER) WCs have been presented as a less demanding alternative mode of manual WC propulsion. The objective of this study was to evaluate the shoulder muscle electromyographic activity and propul...

John R. Brophy , Jet Propulsion Laboratory, Caltech Louis Friedman ,Executive Director Emeritus, The Planetary Society Nathan J. Strange, Jet Propulsion Laboratory, Caltech Thomas A. Prince . Director, Keck Institute for Space Studies, Caltech Damon Landau, Jet Propulsion Laboratory, Caltech Thomas Jones . Florida Institute for Human and Machine Cognition Russell Schweickart , B612 Foundation C...

Purpose: This study aimed to first investigate synchronous (SYN) versus asynchronous (ASY) mode of propulsion and, second, investigate the wheel camber effects on sprinting performance as well as temporal parameters. Method: Seven wheelchair basketball players performed four maximal eight-second sprints on a wheelchair ergometer. They repeated the test according to two modes of propulsion (SYN ...

BACKGROUND It has been suggested that a higher intra-individual variability benefits the motor learning of wheelchair propulsion. The present study evaluated whether feedback-induced variability on wheelchair propulsion technique variables would also enhance the motor learning process. Learning was operationalized as an improvement in mechanical efficiency and propulsion technique, which are th...

NASA researchers recently demonstrated successful real-time fault detection and isolation of a virtual reusable launch vehicle main propulsion system. Using a detailed simulation of a vehicle propulsion system to produce synthesized sensor readings, the NASA team demonstrated that advanced diagnostic algorithms, running on flight-like computers, can, in real time, successfully diagnose the pres...

Full scale measurements of the propulsion power, ship speed, wind speed and direction, sea and air temperature, from four different loading conditions has been used to train a neural network for prediction of propulsion power. The network was able to predict the propulsion power with accuracy between 0.8-2.8%, which is about the same accuracy as for the measurements. The methods developed are i...

Vampyroteuthis infernalis is a cosmopolitan cephalopod that lives in the oxygen minimum layer between 600 and 800 m depth. Morphometric and physiological studies have indicated that V. infernalis has little capacity for jet propulsion and has the lowest metabolic rate ever measured for a cephalopod. Because fin swimming is inherently more efficient than jet propulsion, some of the reduction in ...