Does transversus abdominis function correlate with prone plank and bench bridge holding time in club cricket players?

Background: Bridge and plank holding times are used to evaluate core stability. Transversus abdominis (TA) muscle function is assessed using ultrasound and also provides input on an individual’s core stability. Objectives: A correlation study comparing TA muscle function with bridge and plank holding time in club cricketers. Methods: Seventeen male, premier league cricketers (age: 22.1 ± 3.3 years) participated in this study. Ultrasound was used to measure bilateral TA, internal oblique (OI) and external oblique (OE) muscle thickness at rest and during abdominal hollowing. Muscle function was measured by means of a Pearson’s correlation as the change in muscle thickness from rest to abdominal hollowing and compared to holding time of the bench bridge and prone plank (seconds). Results: TA muscle thickness was preferentially recruited bilaterally (p=0.00001) during abdominal hollowing. No significant correlations were found between TA muscle function and holding time for the bench bridge (dominant (D): r = 0.03 [95% CI:-0.46-0.50]; non-dominant (ND): r = -0.02 [95% CI:-0.50-0.47]) or prone plank (D: r = -0.16 [95% CI:-0.60-0.34]; ND: r = -0.13 [95% CI:-0.57-0.38]). Conclusion: Prone plank and bench bridge holding times are not correlated with TA muscle function during abdominal hollowing. Core stability cannot rely on a single test to evaluate its effectiveness. In particular, the contribution of the local and global muscle system to ‘core stability’ needs to be evaluated independently. Therefore these tests are not sensitive enough to evaluate the contribution of the local muscle system to the global muscle system in a healthy, pain free, sporting population

Shoulder injuries in provincial male fast bowlers - predisposing factors

Objectives. To investigate the relationship between shoulder flexibility and isokinetic strength as possible factors that may predispose provincial fast bowlers to shoulder injuries. Design. Twenty-one players, 12 of whom had no history of shoulder injuries and 9 of whom had experienced a shoulder injury to the bowling arm, were assessed for shoulder strength using a Cybex Norm isokinetic dynamometer. Absolute and relative peak torque measures were obtained at isokinetic speeds of 90°/s and 180°/s, with both concentric and eccentric contractions performed. Shoulder flexibility was tested using a Leighton Flexometer in both internal and external shoulder rotation. The players were classified into a front-on (N = 7), semi front-on (N = 7) or side-on (N = 7) bowling action from video footage recorded after a bowling trial in the nets. Results. Shoulder injuries were more common in fast bowlers with a front-on action (N = 5) than the bowlers with a side-on (N = 2) or semi front-on (N = 2) action. Sixteen of the 21 fast bowlers showed low stability ratios compared with gravity corrected functional ratios, indicating an imbalance and the presence of possible dysfunction. The injured group of fast bowlers showed higher concentric weight-normalised torque values for internal rotation at the higher velocity (180°/s) (65.20 ± 10.03 vs. 45.91 ± 10.26 Nm.kg-1 p < 0.009: injured vs. uninjured), which would suggest greater instability when compared with the uninjured players. This imbalance could indicate the presence of a predisposition to impingement syndrome in the injured subjects. There was an increase in the external rotation ranges of movement for both groups, indicating a degree of hypermobility in both groups. The results indicate that the presence of possible dysfunction in the shoulder rotators, combined with a front-on bowling action and external rotation hypermobility, are possible predisposing factors for chronic shoulder injuries in cricket fast bowlers. South African Journal of Sports Medicine Vol.16(1) 2004: 25-2

Posture and isokinetic shoulder strength in female water polo players

Background: Being overhead athletes, water polo players can present with muscular imbalances of the shoulder, between the internal rotators (IR) and external rotators (ER), leading to changes in posture and an increased risk of injury.Objectives: To assess posture and isokinetic shoulder strength of female club-level water polo players.Methods: A descriptive study assessing posture and isokinetic strength of the IR and ER shoulder muscles in 15 female club-level South African water polo players (age: 21.3 ± 1.5 years) was conducted. Posture was assessed using a posture grid. Isokinetic shoulder rotator muscle strength was tested over five repetitions concentrically and eccentrically at 60°/sec using a Biodex system 3 isokinetic dynamometer. The bilateral, reciprocal and functional dynamic control ratios (DCR) were calculated.Results: Typical postures noted were a forward head, rounded shoulders, increased thoracic spine kyphosis, elevated non-dominant shoulder and mild scapula winging. The mean concentric reciprocal ratios for the dominant (52.2 ± 7%) and non-dominant (51.9 ± 6.4%) sides indicated ER muscle weakness. DCR values were within normal limits for the group. (D: 0.75 ± 0.2 and ND: 0.75 ± 0.1).Conclusion: There is a trend for these female water polo players to have rounded shoulders and forward head postures, as well as ER muscle strength weakness, the combination of which could predispose the athletes to shoulder injury

Training volume and injury incidence in a professional rugby union team

Objective. To describe the incidence of injuries in a professional rugby team, and to identify any associations between injury rates and training volume. Methods. This retrospective, descriptive study included all injuries diagnosed as grade 1 and above in a South African Super 12 rugby team. Injury incidence and injury rates were calculated and compared with training volume and hours of match play. Results. Thirty-eight male rugby players were injured during the study period. The total number of annual injuries decreased from 50 (2002) to 38 (2004) (χ2=0.84, p=0.36). The number of new injuries showed a similar trend (χ2=2.81, p=0.09), while the number of recurring injuries increased over the 3-year period. There was a tendency for total in-season injury rates to decrease over the 3 years (χ2=2.89, p=0.09). The pre-season injury rate increased significantly over the 3 years (χ2=12.7, p<0.01), coupled with a reduction in training exposure over the pre-season phase. Conclusions. One has to be cognisant of the balance between performance improvement and injury risk when designing training programmes for elite rugby players. Although the reduction in training volume was associated with a slight reduction in the number of acute injuries and in-season injury rates over the three seasons, the performance of the team changed from 3rd to 7th (2002 and 2004, respectively). Further studies are required to determine the optimal training necessary to improve rugby performance while reducing injury rates

Training volume and injury incidence in a professional rugby union team

Objective. To describe the incidence of injuries in a professional rugby team, and to identify any associations between injury rates and training volume.Methods. This retrospective, descriptive study included all injuries diagnosed as grade 1 and above in a South African Super 12 rugby team. Injury incidence and injury rates were calculated and compared with training volume and hours of match play.Results. Thirty-eight male rugby players were injured during the study period. The total number of annual injuries decreased from 50 (2002) to 38 (2004) (χ2=0.84, p=0.36). The number of new injuries showed a similar trend (χ2=2.81, p=0.09), while the number of recurring injuries increased over the 3-year period. There was a tendency for total in-season injury rates to decrease over the 3 years (χ2=2.89, p=0.09). The pre-season injury rate increased significantly over the 3 years (χ2=12.7, pConclusions. One has to be cognisant of the balance between performance improvement and injury risk when designing training programmes for elite rugby players. Although the reduction in training volume was associated with a slight reduction in the number of acute injuries and in-season injury rates over the three seasons, the performance of the team changed from 3rd to 7th (2002 and 2004, respectively). Further studies are required to determine the optimal training necessary to improve rugby performancewhile reducing injury rates

Применение сплайн-функций при динамическом контроле температурного поля

Адаптивні методи обробки сигналів у реальному часі, зокрема, зображень, які отримують за допомогою телевізійних засобів вимірювання, дозволяють значно підвищити швидкість обробки без зниження інформативної складової сигналу. До адаптивних методів обробки належить застосування сплайн-функцій в алгоритмі обробки зображень. Метод реалізовано при контролі динамічних параметрів зонної плавки. В основу метода покладено використання телевізійних засобів для вимірювання геометричних, енергетичних та динамічних параметрів різних об’єктів. Метод складається із трьох послідовних стадій: формування телевізійного зображення об’єкту; перетворення зображення об’єкту в цифровий код; адаптивної обробки, яка забезпечує необхідну точність при визначенні параметрів зображення. Застосування методу сплайн-функцій дозволило в 16 раз зменшити час вимірювання.The adaptive methods for real-time signal processing could allow for processing performance gain without lowering the informative content of the signal, in particular, for the images obtained by television measurement instruments. Typical examples of such adaptive methods include spline-functions in the image processing algorithms. This method is implemented in the control of the dynamic parameters of the zoned melting. This method is founded on usage of television instruments for measurement of geometric, energetic and dynamic object parameters. This method suggest three subsequent stages: formation of the television image of an object; converting of the image of an object into the numeric code; usage of the adaptive processing algorithms, which provide the needed defining precision of the image parameters. Application of the spline-functions provide measuring in 16-quick time.Адаптивные методы обработки сигналов в реальном времени, в том числе изображений, которые получают с помощью телевизионных средств измерения, позволяют значительно увеличить скорость обработки без снижения информативной составляющей сигнала. К адаптивным методам принадлежит применение сплайн-функций в алгоритме обработки изображений. Метод реализован при контроле динамических параметров зонной плавки. В основу метода положено применение телевизионных средств для измерения геометрических, энергетических и динамических параметров разных объектов. Метод состоит из трех последовательных стадий: формирования телевизионного изображения объекта; преобразования изображения объекта в цифровой код; адаптивной обработки, которая обеспечивает необходимую точность при определении параметров изображения

This Place Looks Familiar—How Navigators Distinguish Places with Ambiguous Landmark Objects When Learning Novel Routes

We present two experiments investigating how navigators deal with ambiguous landmark information when learning unfamiliar routes. In the experiments we presented landmark objects repeatedly along a route, which allowed us to manipulate how informative single landmarks were (1) about the navigators' location along the route and (2) about the action navigators had to take at that location. Experiment 1 demonstrated that reducing location informativeness alone did not affect route learning performance. While reducing both location and action informativeness led to decreased route learning performance, participants still performed well above chance level. This demonstrates that they used other information than just the identity of landmark objects at their current position to disambiguate their location along the route. To investigate how navigators distinguish between visually identical intersections, we systematically manipulated the identity of landmark objects and the actions required at preceding intersections in Experiment 2. Results suggest that the direction of turn at the preceding intersections was sufficient to tell two otherwise identical intersections apart. Together, results from Experiments 1 and 2 suggest that route knowledge is more complex than simple stimulus-response associations and that neighboring places are tightly linked. These links not only encompass sequence information but also directional information which is used to identify the correct direction of travel at subsequent locations, but can also be used for self-localization

Challenges for identifying the neural mechanisms that support spatial navigation: the impact of spatial scale.

Spatial navigation is a fascinating behavior that is essential for our everyday lives. It involves nearly all sensory systems, it requires numerous parallel computations, and it engages multiple memory systems. One of the key problems in this field pertains to the question of reference frames: spatial information such as direction or distance can be coded egocentrically-relative to an observer-or allocentrically-in a reference frame independent of the observer. While many studies have associated striatal and parietal circuits with egocentric coding and entorhinal/hippocampal circuits with allocentric coding, this strict dissociation is not in line with a growing body of experimental data. In this review, we discuss some of the problems that can arise when studying the neural mechanisms that are presumed to support different spatial reference frames. We argue that the scale of space in which a navigation task takes place plays a crucial role in determining the processes that are being recruited. This has important implications, particularly for the inferences that can be made from animal studies in small scale space about the neural mechanisms supporting human spatial navigation in large (environmental) spaces. Furthermore, we argue that many of the commonly used tasks to study spatial navigation and the underlying neuronal mechanisms involve different types of reference frames, which can complicate the interpretation of neurophysiological data

The Effects of Attentional Engagement on Route Learning Performance in a Virtual Environment: An Aging Study

Route learning is a common navigation task affected by cognitive aging. Here we present a novel experimental paradigm to investigate whether age-related declines in executive control of attention contributes to route learning deficits. A young and an older participant group was repeatedly presented with a route through a virtual maze comprised of 12 decision points (DP) and non-decision points (non-DP). To investigate attentional engagement with the route learning task, participants had to respond to auditory probes at both DP and non-DP. Route knowledge was assessed by showing participants screenshots or landmarks from DPs and non-DPs and asking them to indicate the movement direction required to continue the route. Results demonstrate better performance for DPs than for non-DPs and slower responses to auditory probes at DPs compared to non-DPs. As expected we found slower route learning and slower responses to the auditory probes in the older participant group. Interestingly, differences in response times to the auditory probes between DPs and non-DPs can predict the success of route learning in both age groups and may explain slower knowledge acquisition in the older participant group