Impact of Handedness Consistency on Bimanual and Unimanual Continuous Movements

Bimanual coordination is an essential human function requiring efficient interhemispheric communication to produce coordinated movements. Previous research suggests a “bimanual advantage” phenomenon, where completing synchronized bimanual tasks results in less variability than unimanual tasks. Additionally, of hand dominance has been shown to influence coordinated performance. The present study examined the bimanual advantage in individuals with consistent and inconsistent handedness. It was predicted that participants with consistent handedness would not display a bimanual advantage unlike those with inconsistent handedness. Fifty-six young adults completed a finger-tapping paradigm in five conditions: unimanual tapping with either left or right hand, in-phase bimanual tapping, and out-of phase bimanual tapping led by either left or right hand. Results were not consistent with the hypothesis that participants with consistent handedness displayed the “bimanual advantage”. However, the “bimanual advantage” was not evident for the inconsistent handers when the temporal consistency was measured with either the left or right hand only. Overall, the “bimanual advantage” may be dependent upon consistency of hand preference, as well as the direction of hand dominance.     

Self-Healing Forces and Concepts of Health and Disease. A Historical Discourse

The phenomenon of self-healing forces has again and again challenged doctors in the different historical periods of medical science. They relied on effects of self-healing forces in diagnosis and therapy. They also tried to explain these effects based on the current model of organism. The understanding of this phenomenon has always influenced the understanding of therapy and played a role in defining the concept of health and disease. In the 17th and 18th century the idea of self-healing force was interpreted as a phenomenon related to the organic forces, whereas in the 19th century the explanation was reduced to a materialistic mechanism. Nowadays the knowledge of heath-shock-proteins open the way of a new understanding of the organic defense mechanisms. This revised version was published online in August 2006 with corrections to the Cover Date.     

Internal Forces During Static Prehension: Effects of Age and Grasp Configuration

The authors studied effects of healthy aging on 3 components of the internal force vector during static prehensile tasks. Young and older subjects held an instrumented handle using a 5-digit prismatic grasp under different digit configurations and external torques. Across digit configurations, older subjects showed larger internal normal (grip) and tangential (load-resisting) digit force components and larger internal moment of force. In contrast to earlier reports, safety margin values were not higher in the older subjects. The results show that the increased grip force in older persons is a specific example of a more general age-related problem reflected in the generation of large internal force vectors in prehensile tasks. It is possible that the higher internal forces increase the apparent stiffness of the hand+handle system and, hence, contribute to its stability. This strategy, however, may be maladaptive, energetically wasteful, and inefficient in ensuring safety of hand-held objects.     

A Comparison of Selected Behaviors of Identical Twins,One Blind from Birth

The purpose of this study was to compare differences in mental-emotional, fine perceptual-motor and gross motor behaviors of a set of 13 year-old identical twins, one of whom was blind from birth. In general, the blind twin was superior in performances where total body involvements were minimal and fine manipulative movements of the hands and/or fingers were stressed. The blind twin also appeared to be more well-adjusted emotionally than the sighted twin.     

Governance Processes and Change Within Organizational Participants of Multi-sectoral Community Health Care Alliances: The Mediating Role of Vision,Mission, Strategy Agreement and Perceived Alliance Value

Multi-sectoral community health care alliances are organizations that bring together individuals and organizations from different industry sectors to work collaboratively on improving the health and health care in local communities. Long-term success and sustainability of alliances are dependent on their ability to galvanize participants to take action within their ‘home’ organizations and institutionalize the vision, goals, and programs within participating organizations and the broader community. The purpose of this study was to investigate two mechanisms by which alliance leadership and management processes may promote such changes within organizations participating in alliances. The findings of the study suggest that, despite modest levels of change undertaken by participating organizations, more positive perceptions of alliance leadership, decision making, and conflict management were associated with a greater likelihood of participating organizations making changes as a result of their participation in the alliance, in part by promoting greater vision, mission, and strategy agreement and higher levels of perceived value. Leadership processes had a stronger relationship with change within participating organizations than decision-making style and conflict management processes. Open-ended responses by participants indicated that participating organizations most often incorporated new measures or goals into their existing portfolio of strategic plans and activities in response to alliance participation.