Children in physical education classes, special education classes, and rehabilitation programs have extremely varied abilities and deficits in motor tasks. Among the problems faced by the teachers, therapists, and other specialists is the identification of the underlying mechanisms that produce the problems observed in these children. In addition, teachers and others must design an appropriate intervention strategy. This paper discusses two approaches being used to study the underlying systems and computations that contribute to the control and regulation of movement. The systems approach focuses on the problems that children with specific pathologies have in regulating their balance and equilibrium. The computational or modular approach addresses the motor deficits observed in certain children in terms of three possible computational units: timing, force production, and motor sequencing. These approaches may provide additional techniques for identifying the pathology underlying the behavioral deficits of children with motor impairment. Also, with these tools it may be possible to design alternative programs that will address the causes as well as the effects of the deficits observed in certain groups of children.
Heidi Sveistrup, Patricia A. Burtner and Marjorie H. Woollacott
Theresa L. Grant, Nancy Edwards, Heidi Sveistrup, Caroline Andrew and Mary Egan
This qualitative study examined older people’s walking experiences in 4 Ottawa neighborhoods. Seventy-five adults age 65 years and older who had lived in their neighborhoods for at least 2 yr participated in focus groups and individual interviews. Four themes were identified through data analysis: multidimensional personal meanings, navigating hostile walking environments, experiencing ambiguity, and getting around. Neighborhood walking was experienced within the continuum of personal and environmental change. Findings indicated that the concept of pedestrian connectivity must incorporate aspects of both intersection regulation and design to ensure relevance for an aging population. Participants called for more clarity about policies that affect pedestrian safety for older people. The overarching theme of getting around indicated that walkability assessments must consider how walking fits within an integrated transportation system and how accessible this system is for older people.
Olinda Habib Perez, Coren Walters-Stewart, D.G.E. Robertson, Natalie Baddour and Heidi Sveistrup
Rhythmic behavior in nonlinear systems can be described as limit cycles or attractors. System perturbations may result in shifts between multiple attractors. We investigated individual cycle-to-cycle leg movement kinematics of three prewalking skilled infant bouncers (10.6 ±0.91 months) during four different spring frequencies (0.9, 1.15, 1.27 and 1.56 Hz). A novel visual analysis phase-plane methodology was introduced to analyze the lower body joint kinematics. It was found that as infants’ bounce frequency increased to match the natural frequency of the system, their joint ranges of motion decreased and lower extremity dynamics shifted from forced to simple harmonic motion. All infants produced highly synchronized and coordinated movements, as supported by moderate to high inter- and intralimb correlations. This study extends from previous work (Habib Perez et al., 2015) by focusing on the lower extremity kinematic movements, joint coordination and the occurrence of different movement patterns for individual bounce cycles over four spring conditions.