Biomedical subjects

F Gerr

Publications and source records attributed to F Gerr.

42 records · Page 3Linked to original sources

PubMedDate not supplied

Criteria for progressive modification of neurobehavioral batteries.

Six specific issues affecting the progressive modification of neurobehavioral test batteries used in field studies of populations exposed to neurotoxicants are discussed and test review recommendations are provided addressing each issue. The issues include: (a) general test review standards, (b) comprehensive assessment, (c) tailored batteries, (d) incorporation of new tests and techniques, (e) personnel and mechanisms for review, and (f) development of a battery assessing peripheral nervous system function.

Behavior↗

PubMedDate not supplied

Standing steadiness measurements: empirical selection of testing protocol and outcome measures.

A variety of methods for measuring the effects of neurotoxic exposure have been developed and applied in epidemiologic studies of exposed workers. Although impairment of equilibrium is a common complaint among workers exposed to neurotoxicants, only a few studies have been published in which quantitative measurement of standing steadiness was used to assess occupational neurotoxicity. Possible reasons for limited use of these measures include inadequate evaluation and validation of testing protocols. The current project was undertaken to address some of these issues. Specifically, two studies of normal subjects were undertaken a) to compare standing steadiness measurements made with feet together or feet apart, and b) to assess the reliability of a number of potential summary measures for estimating standing steadiness. Study 1 was performed on eight subjects tested on 2 consecutive days. It demonstrated that a) a feet-together position resulted in greater systematic variance than a feet-apart position, b) sway varied systematically within 60-s trials, c) three 60-s eyes-open/eyes-closed trial pairs did not appear to provide more information than two pairs of trials. In Study 2, 30 subjects were tested on two occasions separated by 2 to 7 days using the procedure selected on the basis of the results from Study 1. Overall, the most reliable of several summary measures of standing steadiness was observed to be speed of sway.

Adult↗

PubMedDate not supplied

A comparison of standing steadiness measurements from two devices: covariates and normal values.

Quantifying standing steadiness may be a useful method of detecting neurotoxicity in epidemiological studies. Unfortunately, use of quantitative standing steadiness outcomes in epidemiologic studies has been limited by lack of standardization of methods, insufficient availability of normative data, and inadequately characterized effects of covariates. Additionally, the current gold standard method, the force platform (FP), has been expensive and unwieldy for use in field studies. A relatively inexpensive and portable head position monitor (HPM) has been introduced as an alternate method for measuring standing steadiness. In this study 211 subjects were tested with one or both devices using a common testing protocol. The correlations between measurements obtained with the FP and the HPM were high and similar to those obtained during repeated measurements with each device separately. The effects of potential covariates on outcome measures were investigated. There was significant age x sex interaction in the FP standing steadiness measurements in this population with decreased steadiness among older men but not older women. Information for estimating normal values for the outcome measures is provided. This study suggests that measures of standing steadiness obtained with the HPM are similar, but not identical, to measures obtained with a conventional FP and that the HPM may be useful in field studies of occupational exposure to neurotoxicants.

Adolescent↗

PubMedDate not supplied

Vibrotactile threshold measurement for detecting neurotoxicity: reliability and determination of age- and height-standardized normative values.

Damage to the peripheral nervous system by neurotoxic agents can result in elevated sensory thresholds. In this study, the results of two studies in a program of validation of vibrotactile threshold test performance are presented. First, the test-retest reliability and time efficiency of two methods for generating vibrotactile thresholds were determined in a sample of subjects known to be at risk for peripheral neuropathy, 22 diabetics. Specifically, a forced-choice method was compared to a method-of-limits procedure. The method of limits was found to be as reliable as the forced-choice procedure and required less time to administer. The second study was undertaken to determine the magnitude of major effect modifiers on vibrotactile thresholds. Vibration thresholds were determined using a method-of-limits procedure in 131 blue-collar workers who were 29-76 y of age. Equations relating vibrotactile threshold estimated by the method-of-limits procedure to age and height are presented for the upper and lower extremities.

Adult↗

PubMedDate not supplied

Peripheral neurologic abnormalities among roofing workers: sentinel case and clinical screening.

Peripheral neuropathy developed in a 52-y-old roofer who was exposed to multiple solvents in one-ply roofing systems. Forty roofers who were exposed to various roofing systems were assessed by symptoms, occupational history, standardized physical examination, and measurement of vibrotactile thresholds of the upper and lower extremities. After exclusion of roofers who were predisposed to peripheral neuropathy, we detected abnormal vibrotactile thresholds in 42% (p < .001) of roofers' dominant toes and in 36% (p < .001) of roofers' nondominant toes; fewer roofers had abnormal sensory physical examinations or reported neuritic symptoms. Roofing workers may be at increased risk of peripheral neuropathy, perhaps resulting from exposure to solvents--particularly n-hexane, associated with one-ply roofing systems.

Construction Materials↗

PubMedDate not supplied

Computer users' postures and associations with workstation characteristics.

This investigation tested the hypotheses that (1) physical workstation dimensions are important determinants of operator posture, (2) specific workstation characteristics systematically affect worker posture, and (3) computer operators assume "neutral" upper limb postures while keying. Operator head, neck, and upper extremity posture and selected workstation dimensions and characteristics were measured among 379 computer users. Operator postures were measured with manual goniometers, workstation characteristics were evaluated by observation, and workstation dimensions by direct measurement. Considerably greater variability in all postures was observed than was expected from application of basic geometric principles to measured workstation dimensions. Few strong correlations were observed between worker posture and workstation physical dimensions; findings suggest that preference is given to keyboard placement with respect to the eyes (r = 0.60 for association between keyboard height and seated elbow height) compared with monitor placement with respect to the eyes (r = 0.18 for association between monitor height and seated eye height). Wrist extension was weakly correlated with keyboard height (r = -0.24) and virtually not at all with keyboard thickness (r = 0.07). Use of a wrist rest was associated with decreased wrist flexion (21.9 versus 25.1 degrees, p < 0.01). Participants who had easily adjustable chairs had essentially the same neck and upper limb postures as did those with nonadjustable chairs. Sixty-one percent of computer operators were observed in nonneutral shoulder postures and 41% in nonneutral wrist postures. Findings suggest that (1) workstation dimensions are not strong determinants of at least several neck and upper extremity postures among computer operators, (2) only some workstation characteristics affect posture, and (3) contrary to common recommendations, a large proportion of computer users do not work in so-called neutral postures.

Adult↗