A fourth order mass/spring/damper (MSD) mechanical model with linear coefficients was used to estimate axial tibial accelerations following impulsive heel impacts. A generic heel pad with constant stiffness was modeled to improve the temporal characteristics of the model. Subjects (n = 14) dropped (~5 cm) onto a force platform (3 trials), landing on the right heel pad with leg fully extended at the knee. A uni-axial accelerometer was mounted over the skin on the anterior aspect of the medial tibial condyle inferior to the tibial plateau using a Velcro™ strap (normal preload ~45 N). Model coefficients for stiffness (k1, k2) and damping (c1, c2) were varied systematically until the minimum difference in peak tibial acceleration (%PTAmin) plus maximum rate of tibial acceleration (%RTAmax) between the estimated and measured curves was achieved for each trial. Model responses to mean subject and mean group model coefficients were also determined. Subject PTA and RTA magnitudes were reproduced well by the model (%PTAmin = 1.4 ± 1.0 %, %RTAmin = 2.2 ± 2.7%). Model estimates of PTA were fairly repeatable for a given subject despite generally high variability in the model coefficients, for subjects and for the group (coefficients of variation: CVk1 = 57; CVk2 = 59; CVc1 = 48; CVc2 = 85). Differences in estimated parameters increased progressively when subject and group mean coefficients (%PTAsub = 8.4 ± 6.3%, %RTAsub = 18.9 ± 18.6%, and %PTAgrp = 19.9 ± 15.2 %, %RTAgrp = 30.2 ± 30.2%, respectively) were utilized, suggesting that trial specific calibration of coefficients for each subject is required. Additional model refinement seems warranted in order to account for the large intra-subject variability in coefficients.
David M. Andrews and James J. Dowling
Stephan Swinnen, Joost Vandenberghe and Erik Van Assche
This study sought to determine the relationships between the cognitive styles field dependence-independence and reflection-impulsivity and the acquisition of a gross motor skill in an unstructured learning environment. In reference to the first cognitive style construct, it was hypothesized that field-independent subjects perform better than field-dependent subjects because they provide organization when the material to be learned lacks structure, leading them to rely on their analyzing and restructuring ability. The second construct refers to cognitive inhibition required for response uncertainty tasks as well as motor impulse inhibition. Subjects (57 boys, 65 girls) were 13-year-old junior high school students. Several visual perceptual tests were administered and gymnastic performance scores were measured at pretest, during the learning session, and posttest. The hypothesis that field-independent subjects are more successful in an unstructured learning environment than field-dependent subjects was confirmed for boys only. The correlations between the reflection-impulsivity variables and gymnastic performance were generally low, and no support could be found for the hypothesis that reflective subjects are more successful in learning the skill than impulsive subjects.
Tim Woodman, Matt Barlow, Comille Bandura, Miles Hill, Dominika Kupciw and Alexandra MacGregor
Although high-risk sport participants are typically considered a homogenous risk-taking population, attitudes to risk within the high-risk domain can vary considerably. As no validated measure allows researchers to assess risk taking within this domain, we validated the Risk Taking Inventory (RTI) for high-risk sport across four studies. The RTI comprises seven items across two factors: deliberate risk taking and precautionary behaviors. In Study 1 (n = 341), the inventory was refined and tested via a confirmatory factor analysis used in an exploratory fashion. The subsequent three studies confirmed the RTI’s good model–data fit via three further separate confirmatory factor analyses. In Study 2 (n = 518) and in Study 3 (n = 290), concurrent validity was also confirmed via associations with other related traits (sensation seeking, behavioral activation, behavioral inhibition, impulsivity, self-esteem, extraversion, and conscientiousness). In Study 4 (n = 365), predictive validity was confirmed via associations with mean accidents and mean close calls in the high-risk domain. Finally, in Study 4, the self-report version of the inventory was significantly associated with an informant version of the inventory. The measure will allow researchers and practitioners to investigate risk taking as a variable that is conceptually distinct from participation in a high-risk sport.
Karen C. Smith, Griffin L. Michl, Jeffrey N. Katz and Elena Losina
characteristics that can act as barriers to activity include high impulsivity (discounting) and low barrier self-efficacy. 11 – 13 Among environmental factors, it is well documented that meteorologic factors (weather conditions) affect physical activity levels. 14 , 15 Increased rainfall, lower temperatures
Teun Remmers, Ester F.C. Sleddens, Stef P.J. Kremers and Carel Thijs
Physical activity (PA) enjoyment may be an important determinant of long-term habitual, self-sustained PA behavior in children. The objective of the current study was to contribute toward a better understanding of how children’s PA enjoyment is associated with PA behavior by examining the influence of age, gender, BMI, and impulsivity as theoretically hypothesized moderators of this relationship.
PA was measured in 171 children (77 boys, 91 girls) using accelerometers, and PA enjoyment was assessed with the validated Physical Activity Enjoyment Scale in 9-year-old children from the KOALA Birth Cohort Study, the Netherlands. Linear regressions were fitted. Moderation was tested by adding interaction terms between PA enjoyment and the potential moderators.
We found a significant 3-way interaction (PA enjoyment × gender × impulsivity) for all intensities of PA behavior. In boys, impulsivity strengthened the relationship between PA enjoyment and PA behavior, whereas in girls impulsivity weakened this relationship.
In girls, this may be explained by the relative automatic occurrence of PA behavior in impulsive girls (independent of PA enjoyment). In boys, the possibility that impulsivity is associated with hyperactivity may explain this moderation. The current study may encourage researchers to investigate these interactions in future studies.
Harry H. Kwon and Ketra L. Armstrong
This two-stage study investigated a proposed model of impulse buying of sport team licensed merchandise among college students (N = 464) enrolled in a large Midwestern university. The proposed model included measures of impulsivity, psychological attachment to sport, and financial situation. The proposed model was tested with structural equation modeling. The results indicated that the proposed model (RMSEA = .058; NFI = .916; CFI = .947, χ2/df = 2.57), along with the partial models of impulsivity (RMESA = .062, NFI = .96, CFI = .98, χ2/df = 2.78) and psychological attachment (RMSEA = .057; NFI = .98; CFI = .988, χ2/df = 2.50), fit the data with a degree of reasonable fit. This study illustrates how personal, psychosocial, and situational factors might interact to influence impulse buying of sport team licensed merchandise.
Clément Carpentier, Josep M. Font-Llagunes and József Kövecses
The impulsive dynamics associated with the impact of the crutch with the ground is an important topic of research, since this is known to be the main cause of energy loss during crutch gait. In this article, a four-segmental 2D model based on anthropometric body segment parameters is used to analyze various dynamics aspects of such impact. For this purpose, a novel formulation based on the decomposition of the tangent space of the biomechanical system to two subspaces associated with the constrained and admissible motions is developed. Detailed numerical analysis is presented to discuss the effects of body configuration and crutch length on the kinetic energy redistribution, velocity change and impulsive contact forces generated. The conclusions reached via this analysis give guidelines for optimal crutch selection or crutch-use teaching that can be applied to injured subjects. For instance, to reduce energy consumption which leads to a reduction of muscular fatigue.
Phillip D. Tomporowski
A review of the literature indicates that acute bouts of physical activity exert short-term positive benefits on the behavior and cognitive functioning of youths without clinical disorders and on youths who have difficulty focusing attention, controlling impulsive actions, or who evidence high levels of motor activity. Prior research conducted has been largely atheoretical. Information-processing models are suggested to provide a framework for assessing the impact of physical activity and cognition and behavior.
Danielle Arigo, Paul Rohde, Heather Shaw and Eric Stice
Moderate-to-vigorous physical activity (MVPA) is critical for maintaining a healthy weight, although little is known about psychological barriers to maintaining MVPA in at-risk groups. Identifying characteristics associated with poor MVPA maintenance in obesity prevention programs could improve participant outcomes.
Toward this end, we examined predictors of MVPA in an obesity prevention trial for college students at risk for weight gain (n = 333; 72% female, mean BMI = 23.4 kg/m2). Participants engaged in 1 of 3 weight control interventions and in 4 assessments over 12-month follow-up (ie, measured height/weight, self-reports of psychosocial characteristics, 4 days of accelerometer wear).
Multilevel modeling analyses showed that across conditions, participants decreased total MVPA minutes per week over 12 months (B = –5.48, P < .01). Baseline self-report scores for both impulsiveness and cognitive dissonance regarding engaging in unhealthy behaviors negatively predicted MVPA over time. Participants higher (vs. lower) in baseline impulsiveness (B = –6.89, P = .03) and dissonance (B = –4.10, P = .04) began the study with more MVPA minutes, but showed sharper declines over time.
Targeted MVPA-focused intervention for students who show elevated impulsiveness and cognitive dissonance may improve both MVPA and weight control outcomes for these individuals.
Claudine Sherrill and Jean L. Pyfer
Many learning disabled students demonstrate psychological/behavioral and perceptual motor characteristics that affect physical education placement and programming. Among the characteristics exhibited by these students are hyperactivity, disorders of attention, impulsivity, poor self-concept, social imperception, delay in social play development, and deficiencies in body equilibrium, visual motor control, bilateral coordination, repetitive finger movements, and fine motor coordination. Activities found to benefit learning disabled students are jogging, relaxation, highly structured teacher-directed routines, and noncompetitive games, all of which must be carefully sequenced. Testing must be done to determine the type and extent of the learning disabled students’ problems, and activities must be selected on the basis of the results of such tests.