Biomedical subjects

J Steven Moore

Publications and source records attributed to J Steven Moore.

6 recordsLinked to original sources

PubMed2006

Workplace interventions to prevent musculoskeletal and visual symptoms and disorders among computer users: a systematic review.

BACKGROUND: The literature examining the effects of workstation, eyewear and behavioral interventions on musculoskeletal and visual symptoms among computer users is large and heterogeneous. METHODS: A systematic review of the literature used a best evidence synthesis approach to address the general question "Do office interventions among computer users have an effect on musculoskeletal or visual health?" This was followed by an evaluation of specific interventions. RESULTS: The initial search identified 7313 articles which were reduced to 31 studies based on content and quality. Overall, a mixed level of evidence was observed for the general question. Moderate evidence was observed for: (1) no effect of workstation adjustment, (2) no effect of rest breaks and exercise and (3) positive effect of alternative pointing devices. For all other interventions mixed or insufficient evidence of effect was observed. CONCLUSION: Few high quality studies were found that examined the effects of interventions in the office on musculoskeletal or visual health.

Computer Peripherals↗

PubMed2005

Postural versus chair design impacts upon interface pressure.

An investigation of postural and chair design impacts upon seat pan interface pressure has been performed in an effort to identify whether differences in posture or chair design result in greater pressure differences. Investigation of postural variables focused on trunk-thigh angle and use of armrests. Twelve ergonomic office chairs were used to assess chair design differences. Both male and female subjects were included. Gender effects were controlled through use of a repeated Latin square design, with squares defined by gender. Significant gender-based interaction was observed amongst postural treatments and chair effects. Postural treatments, chairs designs, and participant effects all resulted in significant interface pressure differences, though gender-based interaction yielded some non-additivity of results between males and females. The final conclusion drawn from the results is that chair design differences had the greatest effect on seat pan interface pressure, followed by participant effects, and lastly postural treatments.

Adaptation, Physiological↗

PubMed2005

Test-retest repeatability of the Strain Index.

Fifteen raters individually, and in five teams of three, evaluated the test-retest repeatability of published data collection and rating methods of the Strain Index by analyzing 61 job video files twice over a 5-month period. Raters estimated average and peak hand forces, measured Duration of Exertion, cycle time, and exertions per job cycle, calculated percent Duration of Exertion and Efforts per Minute, and assigned ratings for five of the six Strain Index task variables. Twelve additional jobs were analyzed to determine Strain Index Score and hazard classification. Intraclass correlation (ICC) coefficients for task variable ratings and accompanying data ranged from 0.66 to 0.95 for both individuals and teams. The Strain Index Score ICC(2,1) for individuals and teams were 0.56 and 0.82, respectively. Intra-rater reliability for the hazard classification was 0.81 for individuals and 0.88 for teams. The results indicate that the Strain Index has good test-retest reliability.

Cumulative Trauma Disorders↗

PubMed2004

Inter-rater reliability of the strain index.

The Strain Index is one of several tools available to evaluate exposure to musculoskeletal stressors in the workplace in order to predict whether workers are at an increased risk of developing distal upper extremity disorders. The purpose of this study was to determine the inter-rater reliability of the Strain Index. Fifteen raters initially estimated or measured data for five Strain Index task variables: (1) intensity of exertion, (2) duration of exertion, (3) efforts per minute, (4) hand/wrist posture, and (5) speed of work, using a computer to view 61 video segments of single task jobs. Video segments were organized to provide a balanced number for each of the five variables under study, where each segment was used to provide data for a single variable. Raters then assigned rating values to each task according to published procedures. For an additional 12 segments, raters performed complete Strain Index analyses, including calculation of Strain Index scores, which were used to determine hazard classifications. Raters assessed the tasks both as individuals and as members of five three-person teams. Inter-rater reliabilities of the procedures leading to and including the Strain Index scores were assessed using an intraclass correlation coefficient, (ICC(2, 1)). Inter-rater reliability for the dichotomous hazard classification was assessed using Kuder-Richardson-20 (KR-20, an ICC for dichotomous data). For task variables and estimated data, ICC(2, 1) varied between 0.66-0.84 for individuals and 0.48-0.93 for teams. The Strain Index score had an ICC(2, 1) of 0.43 and 0.64 for individuals and teams, respectively. For the most important variable, hazard classification, KR-20 was 0.91 for the individuals and 0.89 for the teams.

Arm Injuries↗

PubMed2002

Biomechanical models for the pathogenesis of specific distal upper extremity disorders.

BACKGROUND: Knowledge of the pathogenesis of most disorders that occur in the distal upper extremity is generally lacking. The individual roles of postulated etiologic factors, such as biomechanical or psychosocial exposures, are poorly understood and their potential interactions even less so. This article proposes biomechanical or physiological models of pathogenesis for specific distal upper extremity disorders. METHODS: Tendon entrapment of the dorsal wrist compartments (tenosynovitis), peritendinitis, lateral epicondylitis, and carpal tunnel syndrome are common specific neuromusculoskeletal disorders of the upper extremities observed among workers. The normal anatomy and function of the targeted structures is considered the initial state; their pathology is considered the final state. Using biomechanical or physiological principles combined with clinical observations and experimental studies, pathways leading from the initial state to the final state are proposed. Each model defined a critical biomechanical or physiological attribute that was considered to best characterize 'dose.' Two temporal patterns of exposure (duration vs. repetition) were used to characterize 'dosage.' The roles of long-term exposure vs. unaccustomed work were mentioned, but not incorporated into the models. RESULTS: Compressive force transmitted to the extensor retinaculum was considered the critical factor in the model for tendon entrapment at the dorsal wrist compartments. Two models were proposed for lateral epicondylitis. One emphasized the role of eccentric exertions; the other emphasized contact pressure from the radial head. The model for peritendinitis relied on localized muscle fatigue. Seven plausible models were presented for carpal tunnel syndrome. CONCLUSIONS: It is possible to propose biologically plausible models of pathogenesis that are both coherent with current knowledge of tissue responses and consistent with clinical observations; however, more than one model was plausible for some conditions. Additional research is needed to determine which, if any, of the proposed models might be correct. Such models may be useful to health care providers and ergonomists in the context of primary, secondary, or tertiary prevention.

Biomechanical Phenomena↗

PubMed2002

Predictive validity of the strain index in manufacturing facilities.

The Strain Index is a job analysis method for determining if workers are exposed to increased risk of developing distal upper extremity disorders. Its predictive and external validity was initially demonstrated in a pork processing plant. The purpose of this study was to evaluate its predictive validity in two manufacturing plants. While blinded to health outcomes, investigators analyzed the right and left sides of 28 single-task jobs using the Strain Index and classified them as "hazardous" or "safe" based on the Strain Index score. Subsequently, OSHA 200 logs were used to ascertain the occurrence of distal upper extremity disorders retrospectively. If at least one such disorder occurred on the right or left side during the prior three years, that side was classified as "positive." If no such disorder was reported during the prior three years, that side was classified as "negative." When comparing sides, symmetry between morbidity and hazard classification was required. When comparing jobs, such symmetry was not required. Evidence of association between the hazard classifications and the morbidity classifications for the 56 sides and the 28 jobs was evaluated using 2 x 2 contingency tables. For the sides, the association between hazard classification and morbidity classification was statistically significant with an empirical odds ratio of 73.2. The sensitivity, specificity, positive predictive value, and negative predictive value were 1.00, 0.84, 0.47, and 1.00. Similar results were noted for the jobs--the empirical odds ratio was 106.6, and the sensitivity, specificity, positive predictive value, and negative predictive value were 1.00, 0.91, 0.75, and 1.00. While these results provide additional evidence of the Strain Index's external validity and predictive validity, it should be noted that these jobs involved the performance of single tasks.

Arm Injuries↗