Effects of a 12-month pedometer walking program on gait, body mass index, and lower extremity function in obese women

This study evaluated the effects of a self-reported pedometer-walking program on gait, lower extremity function, and Body Mass Index for 33 obese women, ages 31-65 years (M = 48.0, SD = 8.0) and whose initial average Body Mass Index was 40.30 +/- 9.60 kg/m2. During the 12-mo. intervention participants wore pedometers and reported the number of daily steps walked. Body Mass Index, three gait parameters, steps/day, and lower extremity function were taken over 3-mo. intervals. All participants increased in gait velocity, % single-leg support, and lower extremity function, and decreased in Body Mass Index over time. Those whose steps/day increased by 2000 over 6 mo. had significantly faster velocities and longer step lengths than those whose steps/day did not increase. The 1-yr. walking program stimulated changes in gait, Body Mass Index, and lower extremity function for these obese women. Ultimately, these changes may reduce the risk of falls for this group of women.     

Influence of restricted vision and knee joint range of motion on gait properties during level walking and stair ascent and descent

Because elderly individuals experience marked declines in various physical functions (e.g., vision, joint function) simultaneously, it is difficult to clarify the individual effects of these functional declines on walking. However, by imposing vision and joint function restrictions on young men, the effects of these functional declines on walking can be clarified. The authors aimed to determine the effect of restricted vision and range of motion (ROM) of the knee joint on gait properties while walking and ascending or descending stairs. Fifteen healthy young adults performed level walking and stair ascent and descent during control, vision restriction, and knee joint ROM restriction conditions. During level walking, walking speed and step width decreased, and double support time increased significantly with vision and knee joint ROM restrictions. Stance time, step width, and walking angle increased only with knee joint ROM restriction. Stance time, swing time, and double support time were significantly longer in level walking, stair descent, and stair ascent, in that order. The effects of vision and knee joint ROM restrictions were significantly larger than the control conditions. In conclusion, vision and knee joint ROM restrictions affect gait during level walking and stair ascent and descent. This effect is marked in stair ascent with knee joint ROM restriction.     

Comparing expert and novice understanding of a complex system from the perspective of structures, behaviors, and functions

Complex systems are pervasive in the world around us. Making sense of a complex system should require that a person construct a network of concepts and principles about some domain that represents key (often dynamic) phenomena and their interrelationships. This raises the question of how expert understanding of complex systems differs from novice understanding. In this study we examined individuals’ representations of an aquatic system from the perspective of structural (elements of a system), behavioral (mechanisms), and functional aspects of a system. Structure-Behavior-Function (SBF) theory was used as a framework for analysis. The study included participants from middle school children to preservice teachers to aquarium experts. Individual interviews were conducted to elicit participants’ mental models of aquaria. Their verbal responses and pictorial representations were analyzed using an SBF-based coding scheme. The results indicated that representations ranged from focusing on structures with minimal understanding of behaviors and functions to representations that included behaviors and functions. Novices’ representations focused on perceptually available, static components of the system, whereas experts integrated structural, functional, and behavioral elements. This study suggests that the SBF framework can be one useful formalism for understanding complex systems.     

Effects of visual focus and gait speed on walking balance in the frontal plane

We investigated how head position and gait speed influenced frontal plane balance responses to external perturbations during gait. Thirteen healthy participants walked on a treadmill at three different gait speeds. Visual conditions included either focus downward on lower extremities and walking surface only or focus forward on a stationary scene with horizontal and vertical lines. The treadmill was positioned on a platform that was stationary (non-perturbed) or moving in a pattern that appeared random to the subjects (perturbed). In non-perturbed walking, medial–lateral upper body motion was very similar between visual conditions. However, in perturbed walking, there was significantly less body motion when focus was on the stationary visual scene, suggesting visual feedback of stationary vertical and horizontal cues are particularly important when balance is challenged. Sensitivity of body motion to perturbations was significantly decreased by increasing gait speed, suggesting that faster walking was less sensitive to frontal plane perturbations. Finally, our use of external perturbations supported the idea that certain differences in balance control mechanisms can only be detected in more challenging situations, which is an important consideration for approaches to investigating sensory contribution to balance during gait.     

Optimization characteristics of walking with and without a load on the trunk of the body

Previous work showed that subjects naturally adopt a walking speed which optimizes energy cost of locomotion and stability of stride; however, no studies have examined whether these criteria are affected by carrying an external load. The purpose of this study was to compare optimization characteristics during loaded or unloaded walking. Energy cost and stride characteristics were measured for 10 subjects with and without a load on the trunk of the body of 10% of the body weight during 4 sessions. The first 2 sessions represent free walking at 2.5, 3, 3.5, 4, 4.5, and 5 km x hr.(-1). The last sessions represent free vs forced walking at constant speed (preferred frequency and +/- 10 PF and +/-20% of preferred frequency). Results show an effect of load on energy cost of walking but no effect on the optimal speed for stability. Furthermore, when carrying a load the subject does not adopt systematically the speed that minimizes physiological cost. Our findings suggest the necessity to consider this effect to prevent gait disturbance and maintain the health benefits of walking.     

The influence of a long term exercise program on lower limb movement variability and walking performance in patients with peripheral arterial disease

The purpose of this study was to examine the effects of a 12 month exercise program on lower limb movement variability in patients with peripheral arterial disease (PAD). Participants (n = 21) with an appropriate history of PAD and intermittent claudication (IC) volunteered for this study and were randomly allocated to either a control group (CPAD–IC) (n = 11), which received normal medical therapy and a treatment group (TPAD–IC) (n = 10), which received normal medical therapy treatment and a 12 month supervised exercise program. All participants underwent 2D joint angular kinematic analysis during normal walking to assess lower limb movement variability and walking speed. Between-group differences were analyzed via mixed measures ANOVA. The 12 month supervised exercise program made no significant impact on the lower limb movement variability or walking speed of the TPAD–IC group as determined by either intralimb joint coordination or single joint analysis techniques. Long term supervised exercise programs do not appear to influence the lower limb movement variability of PAD–IC patients.     

Effect of an Audience on Performance of a Motor Task

40 College Ss were placed in 4 groups and tested on a star-tracing task on 2 occasions under the following conditions: spectators-no-spectators; spectators-spectators; no-spectators-no-spectators; no-spectators—spectators. It was found that the presence or absence of spectators had no noticeable effect on the initial learning phase as contrasted to later stages of performance. When conditions remained the same on both testing occasions, less errors were made. Speed was generally quicker under altered task conditions.     

组间竞争对小学生合作绩效及言语互动策略的影响*

以80名小学生为被试,采用拼图任务,对小组在竞争与非竞争情境下的合作绩效和言语互动策略进行比较。结果发现：（1）组间竞争提升了小学高年级儿童的合作效率,但对低年级儿童的合作绩效无明显影响。（2）组间竞争抑制了低年级儿童在小组合作过程中的言语沟通,而同样情境下高年级小组成员的言语沟通量显著增加。（3）组间竞争促进了高年级小组成员之间的积极言语互动。年级和情境在建议、询问、表扬、应答和指令等言语互动策略上的交互作用显著。由此可见,组间竞争对小学儿童的合作绩效和言语互动策略存在影响,但这种影响在不同年级存在差异。     

Infants' perception of human body orientation and the effect of a surrounding square

We examined two hypotheses about infants' perception of orientation. The first is that infants develop an expectation that the human body is normally vertical. To examine this hypothesis, we compared the preferential looking to vertical and oblique versions of a silhouette of a human body, to an inverted body, and to a grating. Our second hypothesis is that presenting a figure inside a frame affects the perception of orientation. To examine the second hypothesis, we placed the figure inside a surrounding square that was oriented normally or at an oblique angle. Four‐ to seven‐month‐old infants (N = 78) participated. The results showed that 6–7‐month‐old infants preferred the oblique human body presented upright; no such preference was observed for the inverted body or the grating. For all types of displays, the surrounding square influenced preferences. Our results suggest that (a) 6–7‐month‐old infants have specific expectations about the orientation of the human body, and (b) surrounding displays with a square could influence the perception of the orientation of the human body, as well as that of a grating.     

Influence of head orientation on visually and memory-guided arm movements

In the absence of visual supervision, tilting the head sideways gives rise to deviations in spatially defined arm movements. The purpose of this study was to determine whether these deviations are restricted to situations with impoverished visual information. Two experiments were conducted in which participants were positioned supine and reproduced with their unseen index finger a 2 dimensional figure either under visual supervision or from memory (eyes closed). In the former condition, the figure remained visible (using a mirror). In the latter condition, the figure was first observed and then reproduced from memory. Participants' head was either aligned with the trunk or tilted 30° towards the left or right shoulder. In experiment 1, participants observed first the figure with the head straight and then reproduced it with the head either aligned or tilted sideways. In Experiment 2, participants observed the figure with the head in the position in which the figure was later reproduced. Results of Experiment 1 and 2 showed deviations of the motor reproduction in the direction opposite to the head in both the memory and visually-guided conditions. However, the deviations decreased significantly under visual supervision when the head was tilted left. In Experiment 1, the perceptual visual bias induced by head tilt was evaluated. Participants were required to align the figure parallel to their median trunk axis. Results revealed that the figure was perceived as parallel with the trunk when it was actually tilted in the direction of the head. Perceptual and motor responses did not correlate. Therefore, as long as visual feedback of the arm is prevented, an internal bias, likely originating from head/trunk representation, alters hand-motor production irrespectively of whether visual feedback of the figure is available or not.     

Verbal-Motor Attention-Focusing Instructions Influence Kinematics and Performance on a Golf-Putting Task

The authors examined how varying the content of verbal-motor instructions and requesting an internal versus external focus influenced the kinematics and outcome of a golf putting task. On Day 1, 30 novices performed 120 trials with the instruction to focus attention either on performing a pendulum-like movement (internal) or on the desired ball path (external). After 20 retention trials on Day 2, they performed 20 transfer trials with the opposite instruction. Group differences for retention and a group by block interaction showed that external instruction enhanced movement outcome. Kinematic data indicated that specific instruction content influenced outcomes by eliciting changes in movement execution. Switching from the external to the internal focus instruction resulted in a more pendulum-like movement.     

Eye gaze as a means of giving and seeking information during musical interaction

During skilled music ensemble performance, a multi-layered network of interaction processes allows musicians to negotiate common interpretations of ambiguously-notated music in real-time. This study investigated the conditions that encourage visual interaction during duo performance. Duos recorded performances of a new piece before and after a period of rehearsal. Mobile eye tracking and motion capture were used in combination to map uni- and bidirectional eye gaze patterns. Musicians watched each other more during temporally-unstable passages than during regularly-timed passages. They also watched each other more after rehearsal than before. Duo musicians may seek visual interaction with each other primarily, but not exclusively, when coordination is threatened by temporal instability. Visual interaction increases as musicians become familiar with the piece, suggesting that they visually monitor each other once a shared interpretation of the piece is established. Visual monitoring of co-performers’ movements and attention may facilitate feelings of engagement and high-level creative collaboration.     

Social Beliefs and Visual Attention: How the Social Relevance of a Cue Influences Spatial Orienting

We are highly tuned to each other's visual attention. Perceiving the eye or hand movements of another person can influence the timing of a saccade or the reach of our own. However, the explanation for such spatial orienting in interpersonal contexts remains disputed. Is it due to the social appearance of the cue—a hand or an eye—or due to its social relevance—a cue that is connected to another person with attentional and intentional states? We developed an interpersonal version of the Posner spatial cueing paradigm. Participants saw a cue and detected a target at the same or a different location, while interacting with an unseen partner. Participants were led to believe that the cue was either connected to the gaze location of their partner or was generated randomly by a computer (Experiment 1), and that their partner had higher or lower social rank while engaged in the same or a different task (Experiment 2). We found that spatial cue‐target compatibility effects were greater when the cue related to a partner's gaze. This effect was amplified by the partner's social rank, but only when participants believed their partner was engaged in the same task. Taken together, this is strong evidence in support of the idea that spatial orienting is interpersonally attuned to the social relevance of the cue—whether the cue is connected to another person, who this person is, and what this person is doing—and does not exclusively rely on the social appearance of the cue. Visual attention is not only guided by the physical salience of one's environment but also by the mental representation of its social relevance.     

Emotion effects during reading: Influence of an emotion target word on eye movements and processing

Recently, Scott, O'Donnell and Sereno reported that words of high valence and arousal are processed with greater ease than neutral words during sentence reading. However, this study unsystematically intermixed emotion (label a state of mind, e.g., terrified or happy) and emotion-laden words (refer to a concept that is associated with an emotional state, e.g., debt or marriage). We compared the eye-movement record while participants read sentences that contained a neutral target word (e.g., chair) or an emotion word (no emotion-laden words were included). Readers were able to process both positive (e.g., happy) and negative emotion words (e.g., distressed) faster than neutral words. This was true across a wide range of early (e.g., first fixation durations) and late (e.g., total times on the post-target region) measures. Additional analyses revealed that State Trait Anxiety Inventory scores interacted with the emotion effect and that the emotion effect was not due to arousal alone.     

Effect of walking surface,late-cueing,physiological characteristics of aging,and gait parameters on turn style preference in healthy,older adults

Turning while walking is a crucial component of locomotion, often performed on irregular surfaces with little planning time. Turns can be difficult for some older adults due to physiological age-related changes. Two different turning strategies have been identified in the literature. During step turns, which are biomechanically stable, the body rotates about the outside limb, while for spin turns, generally performed with closer foot-to-foot distance, the inside limb is the main pivot point. Turning strategy preferences of older adults under challenging conditions remains unclear. The aim of this study was to determine how turning strategy preference in healthy older adults is modulated by surface features, cueing time, physiological characteristics of aging, and gait parameters. Seventeen healthy older adults (71.5 ± 4.2 years) performed 90° turns for two surfaces (flat, uneven) and two cue conditions (pre-planned, late-cue). Gait parameters were identified from kinematic data. Measures of lower-limb strength, balance, and reaction-time were also recorded. Generalized linear (logistic) regression mixed-effects models examined the effect of (1) surface and cuing, (2) physiological characteristics of ageing, and (3) gait parameters on turn strategy preference. Step turns were preferred when the condition was pre-planned (p < 0.001) (model 1) and when the gait parameters of stride regularity and maximum acceleration decreased (p = 0.010 and p = 0.039, respectively) (model 3). Differences in turn strategy selection under dynamic conditions ought to be evaluated in future fall-risk research and rehabilitation utilizing real-world activity monitoring.     

Mother- and daughter-in-law relationship within a South African context: Influence of family systems

This study explored family system influences on mother-in-law and daughter-in-law relationships in a South African setting. A convenience sample of 20 mothers-in-law (age range from 40 to 86) and 20 daughters-in-law (age range from 20 to 60) were informants. They had been in a mother- and daughter-in-law relationship for at least six months. The participants completed open-ended interviews on their relational experiences in the context of family. Data were analysed applying Interpretative Phenomenological Analysis (IPA). Five family system relational context themes emerged: positive mother- and daughter-in-law relationship, conflicted the mother-son relationship, historic experience of the mother-in-law with her own mother-in-law, and partnership in upbringing of grandchildren.     

词频与阅读方式对词跨行呈现效应的影响

通过使用眼动追踪技术,采用2（呈现条件：同行呈现、跨行呈现）×2（词频：高频、低频）×2（阅读方式：朗读、默读）的被试内实验设计,探讨了词频和阅读方式对词跨行呈现效应的影响。结果发现,呈现条件、词频和阅读方式的主效应显著,跨行呈现、低频和朗读的凝视时间和总注视时间更长、总注视次数更多;呈现条件之间在凝视时间上的差异,高频词大于低频词;呈现条件之间在凝视时间和总注视次数上的差异,朗读大于默读。结果表明,词跨行呈现干扰了阅读,且这种干扰作用受词频和阅读方式的影响。     

Influence of anterior load carriage on lumbar muscle activation while walking in stable and unstable shoes

Load carriage can be harmful for workers, and alternative interventions to reduce back pain while walking and carrying loads are necessary. Unstable shoes have been used to improve balance and reduce back pain, but it is unknown whether walking wearing unstable shoes while carrying loads anteriorly causes excessive trunk extensors muscle activation. The aim of this study was to investigate the effects of different shoe types and anterior load carriage on gait kinematics and lumbar electromyographic (EMG) activity. Fourteen adults that predominantly walk or stand during the work day were asked to walk with and without carrying 10% of body mass anteriorly while wearing regular walking shoes (REG) and unstable shoes (MBT). The effects of shoe type, load carriage, and shoe × load interactions on the longissimus thoracis (LT) and iliocostalis lumborum (IC) EMG, stride duration, and stride frequency were assessed. MBT shoes induced a significant increase in LT (44.4 ± 35%) and IC EMG (33.0 ± 32%, p < .005), while load carriage increased LT (58.5 ± 41%) and IC EMG (55.1 ± 32%, p < .001). No significant shoe × load interaction was found (p>.05). However, walking wearing MBT shoes while carrying loads induced a 46 ± 40% higher EMG activity compared to walking wearing MBT shoes without load carriage. No effects of shoes or load carriage were found on stride duration and stride frequency. It was concluded that walking wearing MBT shoes and carrying 10% of total body mass induced greater activation of trunk extensors muscle compared to these factors in isolation, such a combination may not influence gait patterns.