The aim of this study was to provide detailed information on rationales, calculations, and results of common methods used to quantify reproducibility in plantar pressure variables. Recreational runners (N = 95) performed multiple barefoot running trials in a laboratory setup, and pressure variables were analyzed in nine distinct subareas of the foot. Reproducibility was assessed by calculating intraclass correlation coefficients (ICC) and the root mean square error (RMSE). Intraclass correlation coefficients ranged from 0.58 to 0.99, depending on the respective variable and type of ICC. Root mean square errors ranged between 2.3 and 3.1% for relative force–time integrals, between 0.07 and 0.23 for maximum force (Fmax), and between 107 and 278 kPa for maximum pressure (Pmax), depending on the subarea of the foot. Force–time integral variables demonstrated the best within-subject reproducibility. Rear-foot data suffered from slightly increased measurement error and reduced reproducibility compared with the forefoot.
Christian Maiwald, Stefan Grau, Inga Krauss, Marlene Mauch, Detlef Axmann and Thomas Horstmann
Robin C. Jackson, Kelly J. Ashford and Glen Norsworthy
Attentional processes governing skilled motor behavior were examined in two studies. In Experiment 1, field hockey players performed a dribbling task under single-task, dual-task, and skill-focused conditions under both low and high pressure situations. In Experiment 2, skilled soccer players performed a dribbling task under single-task, skill-focused, and process-goal conditions, again under low and high pressure situations. Results replicated recent findings regarding the detrimental effect of skill-focused attention and the facilitative effect of dual-task conditions on skilled performance. In addition, focusing on movement related process goals was found to adversely affect performance. Support for the predictive validity of the Reinvestment Scale was also found, with high reinvesters displaying greater susceptibility to skill failure under pressure. Results were consistent with explicit monitoring theories of choking and are further discussed in light of the conceptual distinction between explicit monitoring and reinvestment of conscious control.
Carol A. Boliek, Reyhaneh Bakhtiari, Lauren Pedersen, Julia R. Esch and Jacqueline Cummine
pressures that subsequently influence chest wall configuration, kinematics, and inspiratory and expiratory muscular activity ( Hixon, Goldman, & Mead, 1973 ; Siafakas, Morris, & Green, 1979 ). The cortical control of chest wall muscle activity associated with maximal performance and speaking tasks is not
Kathy J. Simpson, Eugene G. Jameson and Susan Odum
Patellofemoral dysfunctions due to abnormal force loading are significant problems for dancers. Increased jump length was predicted to require increased quadriceps force during landing, which would increase patellofemoral forces and pressures. Six female dancers performed 10 traveling jumps each at 30, 60, and 90% maximum jump displacements (JDs). A sagittal view of the landing onto a force platform (500 Hz) was filmed (100 fps). Repeated-measures ANOVA (JD) and Scheffé post hoc analyses (p < .05) showed that greater peak patellofemoral pressures occurred at longer JDs and the corresponding times to these events decreased and knee flexion increased. Previous research and these findings indicate that different regions of the patella may endure higher loads at greater JDs even though the contact areas increase with greater patellofemoral forces. However, greater knee flexion and velocity could indicate more rapid distribution of load to various patellar regions, which would reduce the time any given patellofemoral region would be subjected to high loads.
Anne Krendl, Izzy Gainsburg and Nalini Ambady
Although the effects of negative stereotypes and observer pressure on athletic performance have been well researched, the effects of positive stereotypes on performance, particularly in the presence of observers, is not known. In the current study, White males watched a video either depicting Whites basketball players as the best free throwers in the NBA (positive stereotype), Black basketball players as the best free throwers in the NBA (negative stereotype), or a neutral sports video (control). Participants then shot a set of free throws, during which half the participants were also videotaped (observer condition), whereas the other half were not (no observer condition). Results demonstrated that positive stereotypes improved free throw performance, but only in the no observer condition. Interestingly, observer pressure interacted with the positive stereotype to lead to performance decrements. In the negative stereotype condition, performance decrements were observed both in the observer and no observer conditions.
Wing Kai Lam, Jon P. Maxwell and Richard Masters
The efficacy of analogical instruction, relative to explicit instruction, for the acquisition of a complex motor skill and subsequent performance under pressure was investigated using a modified (seated) basketball shooting task. Differences in attentional resource allocation associated with analogy and explicit learning were also examined using probe reaction times (PRT). Access to task-relevant explicit (declarative) knowledge was assessed. The analogy and explicit learning groups performed equally well during learning and delayed retention tests. The explicit group experienced a drop in performance during a pressured transfer test, relative to their performance during a preceding retention test. However, the analogy group's performance was unaffected by the pressure manipulation. Results from PRTs suggested that both groups allocated equal amounts of attentional resources to the task throughout learning and test trials. Analogy learners had significantly less access to rules about the mechanics of their movements, relative to explicit learners. The results are interpreted in the context of Eysenck and Calvo's (1992) processing efficiency theory and Masters's (1992) theory of reinvestment.
Katharina Geukes, Christopher Mesagno, Stephanie J. Hanrahan and Michael Kellmann
Trait activation theorists suggest that situational demands activate traits in (pressure) situations. In a comparison of situational demands of private (monetary incentive, cover story), mixed (monetary incentive, small audience), and public (large audience, video taping) high-pressure situations, we hypothesized that situational demands of private and mixed high-pressure conditions would activate self-focus traits and those of a public high-pressure condition would activate self-presentation traits. Female handball players (N = 120) completed personality questionnaires and then performed a throwing task in a low-pressure condition and one of three high-pressure conditions (n = 40). Increased anxiety levels from low to high pressure indicated successful pressure manipulations. A self-focus trait negatively predicted performance in private and mixed high-pressure conditions, and self-presentation traits positively predicted performance in the public high-pressure condition. Thus, pressure situations differed in their trait-activating situational demands. Experimental research investigating the trait–performance relationship should therefore use simulations of real competitions over laboratory-based scenarios.
Scott W. Cheatham and Morey J. Kolber
neurological mechanism may be responsible for this crossover effect which is consistent with previous reports. 4 , 6 , 10 Other studies have measured the direct and crossover pressure pain threshold (PPT) in lower extremity muscle groups after a RM intervention. Pearcy et al 3 measured the effects of foam
Sae Yong Lee and Jay Hertel
Altered foot dynamics due to malalignment of the foot may change plantar-pressure properties, resulting in various kinds of overuse injuries.
To assess the effect of foot characteristics on plantar-pressure-related measures such as maximum pressure, maximum pressure–time, and pressure–time integral underneath the medial aspect of the foot during running.
Laboratory. Participants: 8 men and 17 women.
Main Outcome Measures:
Static non-weight-bearing rear-foot and forefoot alignment and navicular drop were measured. Plantar-pressure data were collected while subjects jogged at 2.6 m/s on a treadmill. Maximum pressure, time to maximum pressure, and pressure–time integral of the medial side of the foot were extracted for data analysis. Multiple-regression analysis was used to examine the effect of arch height and rear-foot and forefoot alignment on maximum pressure and pressure–time integral in the medial side of the foot.
In the medial rear-foot and midfoot regions, only rear-foot alignment had a significant effect on the variance of maximum pressure and pressure–time integral. There were no significant difference effects in the medial forefoot region.
Rear-foot alignment was found to be a significant predictor of maximum plantar pressure and pressure–time integral in the medial rear-foot and midfoot regions. This indicates that control of rear-foot alignment may help decrease plantar pressure on the medial region of the foot, which may potentially prevent injuries associated with excessive rear-foot eversion.
Kelly J. Ashford and Robin C. Jackson
The present study examined the effectiveness of a priming paradigm in alleviating skill failure under stress. The priming intervention took the form of a scrambled sentence task. Experiment 1: Thirty-four skilled field-hockey players performed a dribbling task in low- and high-pressure situations under single task, skill-focused, and priming conditions. Results revealed a significant increase in performance time from low to high pressure. In addition, performance in the priming condition was significantly better than in the control and skill-focused conditions. Experiment 2: Thirty skilled field-hockey players completed the same dribbling task as in Experiment 1; however, in addition to the control and skill-focused conditions, participants were allocated to either a positive, neutral, or negative priming condition. Results revealed significant improvements in performance time from the skill focus to the control to the priming condition for the positive and neutral groups. For the negative group, times were significantly slower in the priming condition. Results are discussed in terms of utilizing priming in a sporting context.