Selective activation of lower leg muscles during maximum voluntary isometric contractions

The pronators and supinators play a key role in the medio-lateral stability of the ankle joint complex (i.e. talo-crural and subtalar joints). We hypothesized that each shank muscle has a specific activation pattern determined by its anatomical course around the axes of the subtalar and talo-crural joints. A secondary objective was to examine the effect of foot posture on these activation patterns. Forty-nine young adults (25 normal-arched feet, 24 flat-arched feet) performed maximum voluntary isometric contractions against manual resistance in four movement directions: plantarflexion (PF), dorsiflexion (DF), pronation (PRO) and supination (SUP). Electromyographic activity was recorded from tibialis posterior (TP) and peroneus longus (PL) with intramuscular electrodes, and gastrocnemius medialis (GM) and tibialis anterior (TA) with surface electrodes. When compared to their agonist function, all muscles were co-activated at significantly lower levels in their synergistic function (GM: 23% during SUP, TA: 72% during SUP; TP: 42% during PF, PL: 52% during PF) (p < 0.001). A significant interaction between foot posture and contraction type was evident for TA. During isometric contractions, the electromyographic activity of the shank muscles is geared to their biomechanical advantage according to their position relative to the subtalar and talo-crural joint axes.     

Comparing the effects of varied and constant preferred items on improving tummy time for typically developing infants

Tummy time involves placing an infant in a prone position to help build muscle strength. Pediatricians recommend tummy time because it helps with infant development related to milestones such as crawling, rolling over, and sitting up. However, parents sometimes avoid tummy time due to whining or crying when the infant is placed in the prone position. The current study compared two interventions incorporating preferred leisure items (i.e., varied or constant) for five typically developing infants to increase head elevation and decrease negative vocalizations during tummy time. Improvements occurred in infant performance regardless of the preferred items used. In addition, the mothers who implemented the tummy time procedures found the treatment to be socially valid and were more likely to select the use of the constant item when given the opportunity to choose.     

年幼儿童人物画结构变化及其影响因素

儿童人物画突出的结构特点是比例不协调。该研究考察了三百多名４．５－６．５岁幼儿的人物画,发现４．５岁到６．５岁幼儿自由画人躯干面积和头的面积的比值平均为１．３０,头的面积稍小于躯干的面积;自由画人躯干与头的面积的比值在４．５到６．５岁之间,变化曲线呈“Ｎ＂字形;这一比值的变化是和幼儿对于人体结构的认知发展有关的;临摹标准比例范画对于幼儿人物画的结构有显著影响,但是除了４．５－５岁之外,临摹画人与自由画人躯干／头的比值变化趋势基本一致;改变绘画顺序以及身体部位的功能性夸大对于幼儿人物画结构都有显著影响。     

A Biopsychosocial Model for Understanding Relationship Aggression

SUMMARY

Aggression in adult, intimate relationships is a significant problem with far reaching effects on victims, perpetrators, their families, and society. Recognizing the import of the problem, the U.S. Department of Justice has established a Violence Against Women office, and many states have enacted legislation to protect victims and deal with perpetrators. It is urgent that we understand the dynamics of relationship aggression so that effective interventions and preventive programs can be developed. This article reviews the current status of research on relationship aggression and identifies several omissions, most notably, ignorance of the potential contributions of biological factors. Recent research regarding the relevance of biological factors is reviewed and a Biopsychosocial model is presented. Finally, some suggestions are made for future research.     

Postural Asymmetries in Response to Holding Evenly and Unevenly Distributed Loads During Self-Selected Stance

The authors examined postural asymmetries during quiet stance and while holding evenly or unevenly distributed loads. Right-hand dominant subjects preferentially loaded their right lower limb when holding no load or a load evenly distributed in both hands, but no differences in center of pressure (CoP) were observed between the left and right limbs. However, longer CoP displacement was observed under the preferentially loaded limb, which may reflect a functional asymmetry that allows quick movement of one limb in response to a potential perturbation. When a load was held only in the nondominant hand, sample entropy decreased in the left (loaded) limb but increased in the right (unloaded) limb, suggesting the unloaded foot compensated for a loss of control flexibility in the loaded foot.     

Pre-schoolers use head gestures rather than prosodic cues to highlight important information in speech

Previous evidence suggests that children's mastery of prosodic modulations to signal the informational status of discourse referents emerges quite late in development. In the present study, we investigate the children's use of head gestures as it compares to prosodic cues to signal a referent as being contrastive relative to a set of possible alternatives. A group of French-speaking pre-schoolers were audio-visually recorded while playing in a semi-spontaneous but controlled production task, to elicit target words in the context of broad focus, contrastive focus, or corrective focus utterances. We analysed the acoustic features of the target words (syllable duration and word-level pitch range), as well as the head gesture features accompanying these target words (head gesture type, alignment patterns with speech). We found that children's production of head gestures, but not their use of either syllable duration or word-level pitch range, was affected by focus condition. Children mostly aligned head gestures with relevant speech units, especially when the target word was in phrase-final position. Moreover, the presence of a head gesture was linked to greater syllable duration patterns in all focus conditions. Our results show that (a) 4- and 5-year-old French-speaking children use head gestures rather than prosodic cues to mark the informational status of discourse referents, (b) the use of head gestures may gradually entrain the production of adult-like prosodic features, and that (c) head gestures with no referential relation with speech may serve a linguistic structuring function in communication, at least during language development.     

Off-Unit Activities Programming for Long-Stay Psychiatric Inpatients

The significance of program site for inpatient therapeutic activities offered to chronic patients is rarely discussed. This paper reviews experiences with the development of a facility-wide off-unit activities program in a state psychiatric center. The organizational, clinical, and administrative implications of off-unit proramming are examined in relation to on-unit treatment ractices. iecommendations are made to assist the successful introauction of off-unit programming and the identification of the most effective location for specific activities.     

Preschoolers' use of dynamic facial, bodily, and vocal cues to emotion

In daily experience, children have access to a variety of cues to others’ emotions, including face, voice, and body posture. Determining which cues they use at which ages will help to reveal how the ability to recognize emotions develops. For happiness, sadness, anger, and fear, preschoolers (3-5 years, N = 144) were asked to label the emotion conveyed by dynamic cues in four cue conditions. The Face-only, Body Posture-only, and Multi-cue (face, body, and voice) conditions all were well recognized (M > 70%). In the Voice-only condition, recognition of sadness was high (72%), but recognition of the three other emotions was significantly lower (34%).     

When soothing succeeds: Simulating a risk for repeated shaking in abusive head trauma in infants

PurposeTo investigate the observation that perpetrators of abusive head trauma engage in repeated shakings because shaking “works” to quiet the infant.MethodsSixty first-time parent couples individually cared for a programmable model infant in two consecutive 7-min trials. After six minutes of consolable followed by inconsolable crying, parents selected one of three soothing techniques. For trial one, parents were randomized to a “Successful” or “Failed” Soothing Condition. Whether the soothing technique was repeated after trial two was determined by the study investigators. Parents rated their frustration after each trial.ResultsAs hypothesized, parents were more likely to repeat a soothing technique that “worked” in trial one. Compared to fathers, mothers reported more frustration when soothing failed.ConclusionsThat caregivers were more likely to repeat a successful soothing technique converges with perpetrator confessions that crying cessation after shaking may be a reason why shaking is used repeatedly in response to crying.     

肢体识别的倒置效应

肢体识别加工的研究常常以倒置肢体作为对象.肢体倒置效应是指, 与正立肢体相比, 人们识别倒置肢体的时间更长,正确率更低.该现象为探究肢体识别提供了新的思路.近些年, 研究者们使用多种技术考察了这一效应及肢体构形加工的特异机制与神经基础.其中, 头部信息在肢体倒置效应中的作用引起了一些研究者的争论.此外, 构形加工理论和构形加工连续量理论都肯定了构形加工在该效应产生中的作用, 但对于构形加工所包含的子成分还存在一些分歧.未来需要进一步拓展该领域的特殊群体研究, 揭示头部信息的具体作用, 完善相关理论解释以及探索更具有生态效度的肢体倒置效应.