Biomedical subjects

Nancy A Baker

Publications and source records attributed to Nancy A Baker.

6 recordsLinked to original sources

PubMed2006

Kinematics of the fingers and hands during computer keyboard use.

BACKGROUND: Although there has been extensive research about the kinematics of the neck, arm, and wrist during computer keyboarding, there is almost no information concerning the kinematics of the fingers, thumbs, and hands. The purpose of this descriptive study was to establish normative values of the kinematics of the fingers and hands during computer keyboard use. METHODS: This study describes the angles, angular velocities, and angular accelerations of the metacarpophalangeal joints and proximal interphalangeal joints for the right and left hands of 20 computer keyboard users during a word-processing task. A new kinematic variable for computer keyboard use, hand/wrist displacement, is also defined and examined. Hand/wrist displacement refers to the translational movements of the hands in which the entire hand is repositioned to strike the keys. Kinematics of both hands of the keyboard users were captured using a three-dimensional motion capture system. FINDINGS: Metacarpophalangeal joint kinematics in flexion/extension and abduction/adduction are reported during typing. Proximal interphalangeal joint kinematics in flexion/extension are also reported. The means and standard deviations for finger postures, velocities and acceleration were generally not significantly different between the right and left hands, with the exception of the 1st digit (thumb). Hand/wrist displacement was significantly different between the right and left hands for side to side movements. Differences in kinematics among the fingers are discussed in view of their potential to be a risk factor for musculoskeletal disorders. INTERPRETATION: This study establishes baseline understanding of the kinematics of computer keyboard use. This information will be useful in future studies of potential risk factors associated with keyboard use.

Adult↗

PubMed2006

Role of endothelial nitric oxide synthase in the regulation of SREBP activation by oxidized phospholipids.

Oxidized-1-palmitoyl-2-arachidonyl-sn-glycero-3-phosphorylcholine (Ox-PAPC), found in atherosclerotic lesions and other sites of chronic inflammation, activates endothelial cells (EC) to synthesize chemotactic factors, such as interleukin (IL)-8. Previously, we demonstrated that the sustained induction of IL-8 transcription by Ox-PAPC was mediated through the activation of sterol regulatory element-binding protein (SREBP). We now present evidence for the role of endothelial nitric oxide synthase (eNOS) in the activation of SREBP by Ox-PAPC. Ox-PAPC treatment of EC induced a dose- and time-dependent activation of eNOS, as measured by phosphorylation of serine 1177, dephosphorylation of threonine 495, and the conversion of L-arginine to L-citrulline. Activation of eNOS by Ox-PAPC was regulated through a phosphatidylinositol-3-kinase/Akt-mediated mechanism. These studies also demonstrated that pretreatment of EC with NOS inhibitor, Nomega-nitro-L-arginine-methyl ester (L-NAME), significantly inhibited Ox-PAPC-induced IL-8 synthesis. Because SREBP activation had been previously shown to regulate IL-8 transcription by Ox-PAPC, we examined the effects of L-NAME on Ox-PAPC-induced SREBP activation. Our data demonstrated that Ox-PAPC-induced SREBP activation and expression of SREBP target genes were significantly reduced by pretreatment with L-NAME. Interestingly, treatment of EC with NO donor, S-nitroso-N-acetylpenicillamine, did not activate SREBP, suggesting that NO alone was not sufficient for SREBP activation. Rather, our findings indicated that superoxide (O2*-), in combination with NO, regulated SREBP activation by Ox-PAPC. We found that Ox-PAPC treatment generated O2*- through an eNOS-mediated mechanism and that mercaptoethylguanidine, a peroxynitrite scavenger, reduced SREBP activation by Ox-PAPC. Taken together, these findings propose a novel role for eNOS in the activation of SREBP and SREBP-mediated inflammatory processes.

Animals↗

PubMed2005

Developing an observational instrument to evaluate personal computer keyboarding style.

While computer use is considered to be a risk factor for musculoskeletal disorders of the upper extremity (MSD-UE), there is currently little information on how the fingers, hand and thumb are used during keyboarding, and no means to document their postures and motions. A computer keyboarding observational instrument, termed the Personal Computer Keyboarding Style (PeCKS), is being developed to meet this need. The goal of this paper is to describe the process by which the PeCKS was developed. Literature on MSD-UE was reviewed and discussions were held with content experts to develop criterion-based items considered to be potential risk factors for MSD-UE during keyboard use. These items were systematically reviewed and rated by seven experts using the Delphi technique. These ratings were used to determine which items to retain and which to discard, resulting in 19 items to define keyboarding style. The PeCKS, when further psychometric testing is completed, will be useful to document and assess keyboarding to identify those individuals who may be at risk for MSD-UE.

Computer Peripherals↗

PubMed2003

The nature of working in the United States: an occupational therapy perspective.

Although working is considered by occupational therapy practitioners to be an important life role, there is very little information about the nature of working in the occupational therapy literature. This article reviews the construct of working in three ways: 1) The history of working and how it has shaped the modern beliefs about working; 2) The nature of working; and 3) The health promoting attributes of working. The paper will also discuss research done on how working is viewed by individuals with disabilities and will touch on some of the implications of the cultural bias in the workplace toward workers with disabilities. Through this increased knowledge of the nature of working, occupational therapy practitioners and other vocational rehabilitation professionals will be better equipped to break down the subtle cultural barriers, and help individuals with disabilities to participate in working.

Civil Rights↗

PubMed2002

The association between children's computer use and musculoskeletal discomfort.

UNLABELLED: As American children spend more time working at computers, they may be putting themselves at risk for musculoskeletal disorders and other conditions that can result from overuse. There is little research that describes the home computer use of American middle school children or that describes the prevalence of musculoskeletal discomfort in this population. This study provides a general description of the computer set-up and home use of 152 6th grade children and looks at the association between overall musculoskeletal discomfort and various ergonomic variables. METHOD: 152 6th grade children completed the Musculoskeletal Discomfort Questionnaire and a survey of home computer use. RESULTS: More than half of the children reported some musculoskeletal discomfort within the last year. This pain could be made worse by computer use. Students reported that they had three computers in their house, and that they generally did not have furniture specifically designed for computer use. There was a significant association between the number of hours on the computer and overall musculoskeletal discomfort (r = 0.19, p = 0.05). The odds ratios between having furniture designed for the computer and touch typing and musculoskeletal discomfort were borderline significant, but suggested that students without proper furniture were more likely to have musculoskeletal discomfort (OR = 1.89, 95% CI = 0.94-3.84) and that those who could touch type were less likely to have musculoskeletal discomfort (OR = 0.54, 95%, CI = 0.26-1.10), OR). CONCLUSION: American children are reporting moderate amounts of musculoskeletal discomfort and this discomfort can be associated with computer use. Risk factors associated with computer use and discomforts are similar to those reported in the adult literature. Further study is necessary to understand the similarities and differences between adult and children computer use and how to protect both from developing musculoskeletal discomfort.

Child↗

PubMedDate not supplied

The effect of three alternative keyboard designs on forearm pronation, wrist extension, and ulnar deviation: a meta-analysis.

The growth of computer keyboard use in the workplace is believed to be one important determinant of the increased prevalence of work-related musculoskeletal disorders of the upper extremity (MSD-UE). One possible contributing factor to the development of MSD-UE is the flat standard keyboard, which places the forearm and wrist in biomechanically awkward postures. This meta-analysis examines the efficacy of three alternative keyboard designs, adjustable slope (AS), split fixed-angle (FA), and adjustable open-tented (AT), in reducing forearm pronation, wrist extension, and ulnar deviation. Analyses of pooled effect size from six studies indicated that the AT had a large effect on pronation (r= 0.85) and ulnar deviation whereas the FA had a large effect only on ulnar deviation (r= 0.79). The AS was found to have a large effect (r= 0.66) on wrist extension. The FA had a moderate effect on pronation (r= 0.33) and wrist extension (r= 0.30). None of these keyboards were found to have a significant effect on all three postures. This meta-analysis has implications for clinicians by providing objective information that may assist with the selection of an alternative keyboard that best reduces an identified problematic posture.

Biomechanical Phenomena↗