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Biomedical subjects

T K Fredericks

Publications and source records attributed to T K Fredericks.

3 recordsLinked to original sources

Kienböck's disease. I. Anatomy and Etiology.

Cumulative trauma disorders (CTD) pose a major industrial problem in terms of increased medical costs, lost productivity and degraded worker health and safety. From an anatomical view, CTD's are classified into three major categories: tendon disorders, neurovascular disorders and nerve disorders. Up until recently these categories seemed to cover CTD of the upper extremity, however, Kienböck's disease, a typically less common disease and one that does not fit into the established CTD categories, has been observed to exhibit CTD characteristics and does appear in the manufacturing environment. The most common types of employment observed to exhibit individuals with this disease are carpentry, jobs involving the use of pneumatic tools (wrench), spot welders, sheet metal work, farmers and factory workers. The present article makes a critical examination of the relevant anatomy and etiologic aspects of this disease.

Cumulative Trauma Disorders↗

Kienböck's disease. II. Risk factors, diagnosis, and ergonomic interventions.

The term CTD has been used to refer to those musculoskeletal impairments that appear to be work-related and tend to be chronic. Upper extremity CTD are categorized in three major groups: tendon disorders, neurovascular disorders, and nerve. Kienböck's disease, on the other hand, has been documented in the workplace and has a similar etiology, but due to current anatomic classifications cannot be considered a CTD. With this in mind, the present article reviews risk factors, diagnosis, and treatment, with the purpose of providing physicians, engineers, and designers with information to reduce the risk of workers developing this potentially debilitating disease. Furthermore, additional support will be accumulated and combined with Part I of this article with the intent of introducing into the literature a new category of upper extremity CTD: Bone Disorders.

Ergonomics↗

Psychophysically acceptable weights for a combination lifting task using bags with handles.

This paper presents a study on a combination lift and lower manual handling task and was designed to simulate the loading of grocery bags into a car trunk. Twelve male subjects performed an externally paced task of lifting grocery bags loaded with weights from 15 cm above the floor and over a wooden sill. There were two different sill heights of 70 cm and 90 cm, and for each of these heights there were two frequencies of 3 and 6 lifts per cycle. The dependent variables were maximum acceptable weight of lift (MAWOL). A unique lifting sequence and a modified version of the psychophysical methodology were used to determine MAWOL. There was a significant difference in the MAWOL across the two sill heights as well as the MAWOL at the two different frequencies. Plastic bags were determined to increase the average load lifted by 27% as compared to paper bags. At normal grocery bag weights, the increased load carrying capacity represents an increase in the safety factor. Not only can the risk of lower back injuries be decreased by using plastic bags with handles but the risk of developing a cumulative trauma disorder could also be decreased.

Adult↗