PubMed Health⌕ Search

Biomedical subjects

J Hurrell

Publications and source records attributed to J Hurrell.

3 recordsLinked to original sources
PubMed1996

Evaluation of symptom surveys for occupational musculoskeletal disorders.

Symptom surveys have been used extensively as part of workplace ergonomic screening programs and epidemiologic assessments of musculoskeletal disorders in groups of workers. This paper examines the reliability and validity of two musculoskeletal symptom surveys, the Nordic Musculoskeletal Questionnaire (NMQ) and a survey used in conjunction with epidemiologic assessments by the National Institute for Occupational Safety and Health (NIOSH). Journal articles assessing the validity and reliability of the NMQ were reviewed. A retrospective assessment combining two NIOSH cohorts with a total of 852 workers assessed the reliability and validity of that survey. Reliability was assessed through test-retest methods and interitem correlations between similar questions. Validity was assessed by comparison with results from physical examination assessments of workers and self-reports of workers seeking medical care. Both reliability and validity were found to be acceptable for the purposes of workplace ergonomics programs. Implications for use of these surveys for prevention and treatment outcomes research are discussed.

Chi-Square Distribution↗
PubMed1987

Programming and execution of movement in Parkinson's disease.

Programming and execution of arm movements in Parkinson's disease were investigated in choice and simple reaction time (RT) situations in which subjects made aimed movements at a target. A no-aiming condition was also studied. Reaction time was fractionated using surface EMG recording into premotor (central) and motor (peripheral) components. Premotor RT was found to be greater for parkinsonian patients than normal age-matched controls in the simple RT condition, but not in the choice condition. This effect did not depend on the parameters of the impending movement. Thus, paradoxically, parkinsonian patients were not inherently slower at initiating aiming movements from the starting position, but seemed unable to use advance information concerning motor task demands to speed up movement initiation. For both groups, low velocity movements took longer to initiate than high velocity ones. In the no-aiming condition parkinsonian RTs were markedly shorter than when aiming, but were still significantly longer than control RTs. Motor RT was constant across all conditions and was not different for patient and control subjects. In all conditions, parkinsonian movements were around 37% slower than control movements, and their movement times were more variable, the differences showing up early on in the movement, that is, during the initial ballistic phase. The within-subject variability of movement endpoints was also greater in patients. The motor dysfunction displayed in Parkinson's disease involves a number of components: (1) a basic central problem with simply initiating movements, even when minimal programming is required (no-aiming condition); (2) difficulty in maintaining computed forces for motor programs over time (simple RT condition); (3) a basic slowness of movement (bradykinesia) in all conditions; and (4) increased variability of movement in both time and space, presumably caused by inherent variability in force production.

Adult↗