Separating neural influences from peripheral mechanics: the speed-curvature relation in mechanically constrained actions

Physically interacting with kinematic constraints is commonplace in everyday actions. We report a study of humans turning a crank, a circular constraint that imposes constant hand path curvature and hence should suppress variations of hand speed due to the power-law speed-curvature relation widely reported for unconstrained motions. Remarkably, we found that, when peripheral biomechanical factors are removed, a speed-curvature relation reemerges, indicating that it is, at least in part, of neural origin.

Correlations between Performance in a Virtual Reality Game and the Movement Assessment Battery Diagnostics in Children with Developmental Coordination Disorder

We aimed to compare the performance in a Virtual Reality (VR) game between Typically Developed (TD) children and children with Developmental Coordination Disorder (DCD). We then compared the performance in a VR game with the sub-grades of the Movement Assessment Battery for Children (MABC). Twenty TD children (10 boys; mean and SD age 5.1 ± 0.6) and 10 children with DCD (4 boys; mean and SD age 5.6 ± 0.6) participated in the study. The parents filled out the DCD questionnaire. The MABC was administered. Each subject stood on a pressure pad and played a non-immersive VR game. The game score, hand path length, and movement of center of pressure were recorded. The game score achieved by the control group was ~22% higher compared to the game score achieved by the research group (p = 0.042). The path length of the right hand strongly correlated with the visual-motor coordination MABC subcategory score (r = 0.902, p < 0.001), with the balance MABC subcategory score (r = 0.769, p = 0.009), and with the total MABC score (r = 0.667, p = 0.035). This VR game might provide a preliminary distinction between TD children and children with DCD. Furthermore, investigation of hand path length may reflect the visual-motor coordination impairment of the child.

Children With Developmental Coordination Disorder Play Active Virtual Reality Games Differently Than Children With Typical Development

BackgroundActive virtual reality gaming (AVG) may be useful for children with developmental coordination disorder (DCD) to practice motor skills if their movement patterns are of good quality while engaged in AVG.ObjectiveThis study aimed to examine: (1) the quality of motor patterns of children with DCD participating in AVG by comparing them with children with typical development (TD) and (2) whether differences existed in the motor patterns utilized with 2 AVG types: Sony PlayStation 3 Move and Microsoft Xbox 360 Kinect.DesignThis was a quasi-experimental, biomechanical laboratory–based study.MethodsTwenty-one children with DCD, aged 10 to 12 years, and 19 age- and sex-matched children with TD played a match of table tennis on each AVG type. Hand path, wrist angle, and elbow angle were recorded using a motion analysis system. Linear mixed-model analyses were used to determine differences between DCD and TD groups and Move and Kinect AVG type for forehands and backhands.ResultsChildren with DCD utilized a slower hand path speed (backhand mean difference [MD]=1.20 m/s; 95% confidence interval [95% CI]=0.41, 1.98); greater wrist extension (forehand MD=34.3°; 95% CI=22.6, 47.0); and greater elbow flexion (forehand MD=22.3°; 95% CI=7.4, 37.1) compared with children with TD when engaged in AVG. There also were differences in movement patterns utilized between AVG types.LimitationsOnly simple kinematic measures were compared, and no data regarding movement outcome were assessed.ConclusionsIf a therapeutic treatment goal is to promote movement quality in children with DCD, clinical judgment is required to select the most appropriate AVG type and determine whether movement quality is adequate for unsupervised practice.

“Intuitive, Receptive, Dark”

The article discusses some of the debates over the construction of gender taking place in the satanic and Left-hand Path (LHP) milieu, in particular the different varieties of upvaluing of “the feminine.” This includes disputes over what the term feminism entails, what the best strategies for women to gain more power are, and if “feminine” is an essence that can be contrasted with a fixed “masculine.” Notions of gender polarity as necessary for magical practice or cosmic balance are given special attention, as are borrowings from feminist terminology (e.g. “patriarchy”) by figures that are far from feminist in orientation. Aside from textual sources, the article draws on communication with 44 informants. Three basic approaches to gender can be discerned in the milieu: 1) Gender as an insignificant category, 2) Gender as a natural polarity, 3) Gender as false consciousness. Of these, number two is the most common, while number one is quite seldom seen—gender is a major issue, one way or another. Femininity is frequently discussed by both men and women, while masculinity is a less popular topic. Femininity, then, is a particularly contested matter in the milieu. Overall, the dominant view of gender is that the two sexes should be strictly dichotomized. The article concludes that with some exceptions most organizations in the milieu are numerically dominated by men. However, some important groups have periodically been led by women, and there are several female key producers of ideology. The partly reactionary views concerning gender issues held by some female leaders indicate that female leadership does not necessitate that a conventional feminism would permeate the organization. Further, it is difficult to see any absolute correlation between female leadership and upvaluing of the feminine in mythology. Moreover, the article demonstrates, such upvaluing does not in itself always signify an underlying ideology of political feminism.

Angular Momentum

In the last decade, a ‘sinister milieu’ has developed out of the eponymous ‘traditional’ Satan-ism promoted and further developed by the Order of Nine Angles, which emerged in the British occult scene in the 1980s. This milieu includes a diversity of Satanic and post-Satanic currents which have established the ‘sinister’ as a significant sub-category of Left-Hand Path ideology. Some groups affiliated with the Order of Nine Angles to varying degrees have ad-vanced the concept of the sinister in novel directions removed from the category of ‘Satan-ism,’ further specifying the sinister milieu’s conception of the Left-Hand Path.

At the Threshold of the Inverted Womb

During the 1980s and 1990s anti-cosmic Satanism emerged in the UK and Scandinavia as an attempt to merge ancient forms of Gnostic thought, highly performative, blasphemous manifestations of heavy metal subculture, and certain death-oriented, magical traditions from the Caribbean and Latin America. While culturally wide-ranging and syncretic in its theological outlook, anti-cosmic Satanism consistently emphasizes the abandonment of the physical body and a violent apocalyptic merger with an infinite satanic power. Anti-cosmic Satanism has risen in tandem with the popularity of Nordic black metal music, to which it is indelibly connected, making it one of the most controversial left-hand path traditions that has arisen since the 1980s. Paradoxically, anti-cosmic Satanism also borrows much from the folklore and narrative structures of Conservative Christianity regarding the existence of sincerely evil satanic cults. The hyper-transgressive attitudes and anti-Christian rhetoric of both black metal and anti-cosmic Satanism assert a fetishised morbidity, associating death with ultimate liberation.