We investigated the effects of extensive practice of rapid aiming on bradykinesia and, more specifically, generation of peak velocity, in discrete rapid aiming and in transfer to reach-to-grasp. Twenty-one participants (seven young adults, seven older adults, and seven adults with mild to moderate Parkinson’s disease (PD) while on medication) engaged in eight practice periods per week for three weeks (> 700 trials), with changes in performance measured weekly. Retention was measured weekly for three weeks postpractice. Movement time decreased with one week of practice, primarily due to a decrease in time-to-peak velocity. With practice and after retention, the PD group generated peak velocity as consistently as both neurologically healthy groups, but remained more variable in time-to-peak velocity. Transfer was observed in the neurologically healthy groups, but not in the PD group. We concluded that short-term practice (one week in our paradigm) is sufficient for decreasing movement time, but more extensive practice is needed to improve consistency of rapid aiming performance for people with mild to moderate PD.
Ann L. Smiley-Oyen, Sonja A. Hall, Kristin A. Lowry and John P. Kerr
Lilian G. Perez, Terry L. Conway, Adrian Bauman, Jacqueline Kerr, John P. Elder, Elva M. Arredondo and James F. Sallis
Background: Associations between the built environment and physical activity (PA) may vary by sociodemographic factors. However, such evidence from international studies is limited. This study tested the moderating effects of sociodemographic factors on associations between perceived environment and self-reported total PA among adults from the International Prevalence Study. Methods: Between 2002 and 2003, adults from 9 countries (N = 10,258) completed surveys assessing total PA (International Physical Activity Questionnaire-short), perceived environment, and sociodemographics (age, gender, and education). Total PA was dichotomized as meeting/not meeting (a) high PA levels and (b) minimum PA guidelines. Logistic models tested environment by sociodemographic interactions (24 total). Results: Education and gender moderated the association between safety from crime and meeting high PA levels (interaction P < .05), with inverse associations found only among the high education group and men. Education and gender also moderated associations of safety from crime and the presence of transit stops with meeting minimum PA guidelines (interaction P < .05), with positive associations found for safety from crime only among women and presence of transit stops only among men and the high education group. Conclusions: The limited number of moderating effects found provides support for population-wide environment–PA associations. International efforts to improve built environments are needed to promote health-enhancing PA and maintain environmental sustainability.