An inferential investigation into how stride length influences temporal parameters within the baseball pitching delivery

Motion analyses of lower body mechanics offer new schemas to address injury prevention strategies among baseball pitchers, where the influence of stride length remains unknown. This study examined the temporal effect of stride length at constituent pitching events and phases. Nineteen competitive pitchers (15 collegiate, 4 high school) were randomly assigned to pitch two simulated, 80-pitch games at ±25% of their desired stride length. An integrated, three-dimensional motion capture system recorded each pitch. Paired t-tests were used to determine whether differences between stride conditions at respective events and within phases were significantly different. The results demonstrate the shorter strides mediated earlier onset of stride foot contact, reduced time in single support whereas double support intervals increased (p < .001). The opposite was observed with the longer strides. However, the acceleration phase, which comprises the highest throwing arm kinematics and kinetics, remained unchanged. The interaction between stride length, stride foot contact onsets, and time in single support is inferentially evidenced. The equivalent acceleration phases suggest stride length alone influenced time in single and double support by altering the onset of stride foot contact, which perhaps affects the mechanics in preparing the throwing arm for maximal external shoulder rotation.     

Shoulder Muscle Activity Dampens Arm Swing Motion When Altering Upper Limb Mass Characteristics During Locomotion

Weighting the arms during locomotion results in decreased swing motion and increased shoulder muscle activity. To determine the functional relevance of this activity, participants walked on a treadmill with the arms unweighted, or weighted unilaterally or bilaterally. Similar to past work, the weighted arms decreased in swing amplitude and increased their shoulder muscle activity. A close examination of shoulder muscle activities in specific regions of the arm swing cycle suggested these muscles primarily acted eccentrically for all weighting conditions. These findings suggest that the increased shoulder muscle activities when weighting the arms act to dampen the arms when the inertial characteristics of the arms are altered, as opposed to assisting in driving swing of the heavier arms.     

以腹腔镜手术为代表的微创技术在泌尿外科的应用

随着科学技术的进步,微创医学正在形成和发展。泌尿外科是微创医学最活跃的专业之一。腹腔镜手术已被公认是现代微创外科技术的代表,正逐渐走向成熟,趋于标准化和规范化。目前多种泌尿外科腹腔镜手术已成为首选治疗方法。近年出现的机器人手术、计算机辅助外科与虚拟现实技术被认为是在腹腔镜手术基础上产生的第3代手术,正在走向现实。我们要对微创泌尿外科有一个再认识,更加准确把握微创泌尿外科的适应证,促进微创泌尿外科更加健康地发展。     

The Shoulder and Elbow Joints and Right and Left Sides Demonstrate Similar Joint Position Sense

Proper orientation of the shoulder and elbow is necessary for accurate and precise positioning of the hand. The authors’ goal was to compare these joints with an active joint position sense task, while also taking into account the effects of joint flexion angle and arm dominance. Fifteen healthy subjects were asked to replicate presented joint angles with a single degree of freedom active positioning protocol. There were no significant differences in angular joint position sense errors with respect to joint (shoulder vs. elbow) and side (left vs. right). However, when considering linear positioning, errors were lower for the elbow, due to a shorter lever arm. Also, as flexion angles increased toward 90°, there was a consistent pattern of lower errors for both joints.     

Higher Processes in Motor Learning

A linear displacement task was used to study the effects of post-KR verbal activity and the time of its introduction in the learning process on the acquisition of a simple discrete motor task. The temporal occurrence of the interpolated act was systematically varied (3 and 10 sec. immediately following KR). Reading polysyllables during the post-KR delay interval interfered with the learning process. Interference occurred whether the post-KR delay interval lasted 3 or 10 sec.     

TREATING SELF-INJURY: WATER MIST SPRAY VERSUS FACIAL SCREENING OR FORCED ARM EXERCISE

In three experiments, the effect of water mist spray on self-injurious and collateral behaviors was compared with either facial screening or forced arm exercise. Water mist spray was as effective as facial screening in suppressing face-slapping in Experiment 1. However, it was not as effective as facial screening for self-injurious finger-licking in Experiment 2 or forced arm exercise for excessive ear-rubbing in Experiment 3. These results suggest that while water mist spray is effective, it may be less so than alternative procedures. In Experiments 2 and 3 there was a consistent decrease in the occurrence of untreated maladaptive behaviors. In addition, there was a moderate increase in appropriate social interaction in Experiment 2 and a substantial increase in Experiment 3.     

Neonatal finger and arm movements as determined by a social and an object context

What kind of hand and finger movements are newborn infants preoccupied with, and how are these movements organized and controlled? These questions were studied in two experiments under three conditions: a social condition, in which the mother (in expt 1) or the experimenter (in expt 2) sat face to face with the infant; an object condition, in which a ball moving slowly and irregularly was presented to the infant; and a baseline condition (in expt 1) without ball or mother present. The size of the ball and the distance to it was chosen so that it approximately corresponded to the visual angle of the head of the model. Twenty-six neonates participated in the study ranging from 2 to 6 days of age at the time of observation. All infants were in an alert, optimal awake state during the experiments. The infants' finger movements were scored from video recordings. The result revealed a large variety of relatively independent finger movements. It was found that finger movements differed both in quantity and quality between the three conditions. There were many more finger movements in the social condition than in the object and baseline conditions. In addition, there were relatively more transitional finger movements and flexions of the hand in the social condition, and relatively more thumb-index finger activity and extensions of the hand in the object condition. Finally, the arms were more often forward extended in the object condition than in the social condition. The results support the notion that neonates show different modes of functioning towards people and objects.     

Damage to the retrosplenial cortex produces specific impairments in spatial working memory

Mounting evidence indicates that the retrosplenial cortex (RSP) has a critical role in spatial navigation. The goal of the present study was to characterize the specific nature of spatial memory deficits that are observed following damage to RSP. Rats with RSP lesions or sham lesions were first trained in a working memory task using an 8-arm radial arm maze. Rats were allowed 5 min to visit each arm and retrieve food pellets and a 5-s delay was imposed between arm choices. Consistent with previous research, rats with RSP damage committed more errors than controls. In particular, RSP-lesioned rats committed more errors of omission (failing to visit an arm of the maze), but there were no lesion effects on errors of commission (revisiting an arm). Neither group of rats exhibited a turn bias (i.e., always turning a certain direction when choosing an arm). At the end of the training phase of the experiment, both groups had reached asymptote and committed very few errors. In the subsequent test phase, a longer delay (30-s) was imposed during some sessions. Both control and RSP-lesioned rats continued to make few errors during sessions with the standard 5-s delay, but RSP-lesioned rats were impaired at the 30-s delay and committed more errors of commission, consistent with an increase in taxing spatial working memory.     

Archaic man meets a marvellous automaton: posthumanism,social robots,archetypes

Posthumanism is associated with critical explorations of how new technologies are rewriting our understanding of what it means to be human and how they might alter human existence itself. Intersections with analytical psychology vary depending on which technologies are held in focus. Social robotics promises to populate everyday settings with entities that have populated the imagination for millennia. A legend of A Marvellous Automaton appears as early as 350 B.C. in a book of Taoist teachings, and is joined by ancient and medieval legends of manmade humanoids coming to life, as well as the familiar robots of modern science fiction. However, while the robotics industry seems to be realizing an archetypal fantasy, the technology creates new social realities that generate distinctive issues of potential relevance for the theory and practice of analytical psychology.