This study examined the effect of a ball-backrest chair on the weakness and tightness of muscles associated with upper crossed syndrome when working at a visual display terminal (VDT). The surface electromyography (EMG) was recorded from the serratus anterior, middle trapezius, and upper trapezius muscles of 20 adults as they performed VDT work, which are known as the weakened and tightened muscles of upper crossed syndrome. The recorded signals were averaged and normalized to the mean amplitude of the EMG signal obtained during submaximal reference voluntary contractions. The significance of differences between the use of a general-purpose backrest and a ball backrest was tested by paired t-test, with the significance cutoff set at alpha=0.05. The activities of the serratus anterior and middle trapezius muscles increased and that of the upper trapezius muscle decreased when sitting in a ball-backrest chair compared to when sitting in a chair with a general-purpose backrest (p<0.05). These results indicate that the use of a ball-backrest chair reduces the risk of patients with upper crossed syndrome developing muscles soreness or injury related to overuse when working at a VDT. 相似文献
Many research papers calculate corporate social performance (CSP) with the net score method, i.e., by subtracting the number of concerns from the number of strengths. Although widely adopted, this method implies, perhaps mistakenly, that each indicator is of equal importance and that however serious the social misconduct a firm may have engaged in, it can be completely offset by some positive social action. The method also implies that a given firm that has done both a lot of harm and a lot of good will have CSP similar to that of another firm that has done little harm and little good. In this study, however, we question the appropriateness of the net score method in terms of its ability to truly reflect CSP and truly identify the real effects of CSP on various characteristics. We therefore propose a data envelopment analysis-based methodology that adopts the assurance region approach for evaluating CSP, through which various CSP indicators are converted into a single composite measure of CSP. Our findings show that our proposed methodology consistently performs better than the net score method in evaluating CSP.
We examined whether pre‐existing parent psychological distress moderated juvenile offenders’ substance use, sexual risk, and mental health outcomes in a randomized trial. Forty‐seven parent–adolescent dyads received either Family‐based Affect Management Intervention (FAMI) for adolescent substance use and HIV prevention or adolescent‐only Health Promotion Intervention (HPI). Parents’ self‐reported distress at baseline significantly moderated adolescents’ self‐reported marijuana use and alcohol use but not other outcomes at 3 months postintervention, producing crossover interactions. FAMI outperformed HPI when parents reported high‐level distress, whereas HPI outperformed FAMI when parents reported low‐level distress. This finding that the relative efficacy of interventions depends on the severity of parent psychological distress could inform efforts to match substance‐using, justice‐involved adolescents with the intervention most likely to benefit them. 相似文献
