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Biomedical subjects

W Knox

Publications and source records attributed to W Knox.

5 recordsLinked to original sources

Social support for exercise: relationship to physical activity in young adults.

BACKGROUND: Physical inactivity is an independent risk factor for cardiovascular disease, yet little is known concerning factors which influence participation in physical activity or exercise. Two studies assessed the relationships between self-reported physical activity and social support for exercise. METHOD: One study involved a biracial sample of middle-class male and female teachers (mean age = 38.5 +/- 8.9 years) and one involved a biracial sample of lower- to middle-class males and females (mean age = 35.8 +/- 5.1 years). RESULTS: In both studies the social support scales had high internal consistencies and a two-component solution identical to the original validation study. In both studies, social support for exercise positively correlated with physical activity, but the relationships were mediated by race, gender, specific types of support (i.e., family, friend), and dimensions of physical activity (i.e., global, work, sports, and leisure). In both studies, regardless of work status and race, women's overall activity, particularly during leisure time, was positively related to family support for exercise. In both studies white women's overall activity levels, especially sports and leisure activities, were positively related to friend support. In both studies, black women's sports activity was positively associated with family support. Among white men in both studies, sports activities and total energy expenditure were positively related to family and friend support. Black men's sports-related activity was positively related to family support among the teachers and to friend support among subjects in the second study. CONCLUSION: Findings are discussed in terms of future research directed toward identification of other familial and sociocultural variables which might influence individuals' involvement in physical activity.

Adult

Prosthetic shape replication using a computer controlled carving technique.

This paper describes a carving machine which is the most recently developed module in the suite of CAD/CAM equipment for high technology manufacture and supply of prostheses. It provides the link between the Computer Aided Socket Design (CASD) system and the Rapidform socket manufacturing process. Using the coordinate data produced by the CASD system this machine, under computer guidance, carves from a large block of suitable material a three dimensional object; the equivalent of the rectified plaster model produced by conventional techniques. This provides the form for the fabrication of a socket and the facility completes an integrated system for fabricating, rapidly and cheaply, high quality lightweight prostheses for patients.

Amputation Stumps

The Rapidform process for automated thermoplastic socket production.

This paper describes the genesis of the Rapidform process and its pioneering place in the new developments leading to complete control of the processes of manufacture of prostheses. The materials and geometric considerations involved in the development of a double deformation process under microprocessor control are described. Stages in the development of the system show the advance from the initial application to modular below-knee prostheses through extensions to special suspension systems (supracondylar and suprapatellar) to Syme's and above-knee sockets. The clinical and laboratory results are summarized along with an account of the current aspects of the project, ie advanced clinical trials, testing and analysis. Setting the scene historically for the other computer based modules in this high technology approach to prosthetics, Rapidform has proven to be swift, accurate and economical in its operation. Also, in common with the rest of the suite of equipment, this socket production facility, despite its flexibility and technical sophistication, requires no special services beyond standard single phase mains electricity supply.

Amputation Stumps

Thermoplastic alignment couplings for prostheses.

In the context of modern engineering practice, this paper describes the exploitation of thermoplastic materials for the provision of lightweight, low cost, corrosion free, alignment devices for lower limb prostheses. After setting out design requirements, four newly developed devices are described and discussed. These are respectively a four jack system, a serrated wedge system, a spherical alignment system and a serrated slider. The level of laboratory fatigue testing and experimental field performance is reported and examples are shown of the application of these systems to tapered column thermoplastic below-knee prostheses.

Biomedical Engineering