Is there a low-back cost to hip-centric exercise? Quantifying the lumbar spine joint compression and shear forces during movements used to overload the hips

The aim of this study was to quantify joint compression and shear forces at L4/L5 during exercises used to overload the hips. Nine men performed 36 "walking" trials using two modalities: (1) sled towing and (2) exercise bands placed around the ankles. Participants completed forward, backward, and lateral trials with bent and straight legs at three separate loads. Surface electromyography (EMG) was recorded bilaterally from eight torso and thigh sites, upper body and lumbar spine motion were quantified, and hand forces were measured. An EMG-driven musculoskeletal model was used to estimate the muscular contribution to joint compression and shear. Peak reaction, muscle and joint compression and shear forces, and peak gluteus medius and maximus activity were calculated. Significant differences were noted in each dependent measure; however, they were dependent on direction of travel, leg position, and load. The highest joint compression and shear forces for the sled and band conditions were 4378 N and 626 N, and 3306 N and 713 N, respectively. In general, increasing the band tension had little effect on all dependent measures, although a load-response was found during the sled conditions. Before using any exercise to improve hip function, the potential benefits should be weighed against "costs" to neighbouring joints.     

Static analysis of programming exercises: Fairness,usefulness and a method for application

This article explores the suitability of static analysis techniques based on the abstract syntax tree (AST) for the automated assessment of early/mid degree level programming. Focus is on fairness, timeliness and consistency of grades and feedback. Following investigation into manual marking practises, including a survey of markers, the assessment of 97 student Java programming submissions is automated using static analysis rules. Initially, no correlation between human provided marks and rule violations is found. This paper investigates why, and considers several improvements to the approaches used for applying static analysis rules. New methods for application are explored and the resulting technique is applied to a second exercise with 95 submissions. The results show a stronger positive correlation with manual assessment, whilst retaining advantages in terms of time cost, pedagogic advantages and instant feedback. This study provides insight into the differences between human assessment and static analysis approaches and highlights several potential pitfalls of simplistic implementations. Finally, this paper concludes that static analysis approaches are appropriate for automated assessment; however, these approaches should be used with care.     

Neural adaptations with sport-specific resistance training in highly skilled athletes

The aim of this study was to assess the effects of variations in the volume and intensity of resistance training in highly skilled athletes on neural adaptive mechanisms: the maximality and pattern of neural drive. The maximality of muscle activation was measured using a high-resolution sample and hold amplifier to record interpolated twitches. The pattern of neural drive was measured by analysing isometric torque-time curves and electromyographic (EMG) characteristics during the performance of rapid isometric contractions at maximal effort. The volume and intensity of training were varied at 4-weekly intervals to systematically emphasize the development of strength, power and motor performance in 14 highly skilled track and field athletes (e.g. discus, hammer, javelin, shot put and weight). Knee extension strength increased significantly by 15% during steady maximal isometric contractions and by 24% during rapid isometric contractions at maximal effort after the 16-week training programme (P < 0.05). Increases in EMG amplitude and rate of EMG activation indicated that improvements to the pattern of neural drive occurred with sport-specific resistance training (P < 0.05). The maximality and pattern of neural drive did not change in the control group.     

Assessment of severe emotional impairment: Practices and problems

The basic purpose of this study was to determine: (a) how school psychologists operationally define severe emotional disturbance as outlined in PL 94–142 (SED), and (b) the extent to which assessment procedures are in compliance with PL 94–142. A total of 83 school psychologists from two north central states participated in the study. Results indicated that a typical battery for assessing SED consisted of the WISC-R, WRAT, Bender-Gestalt, an incomplete sentences test, a behavior-rating scale, classroom observation, and informal interviews. A high correlation was found between the frequency with which psychologists use a type of data and the importance ascribed to that data source. Psychologists generally relied on only one or two criteria when considering severity of emotional disturbance. Special education placement often was contingent upon program availability. Implications for training and practice were presented.     

Speaking to read: The effects of speech recognition technology on the reading and spelling performance of children with learning disabilities

In recent literature on persons with learning disabilities (LD), speech recognition has been discussed primarily as an assistive technology to help compensate for writing difficulties. However, prior research by the authors has suggested that in addition to helping persons to compensate for poor writing skills, speech recognition also may enhance reading and spelling; that is, what was designed as assistive technology appears to serve remedial functions as well. The present study was conducted to determine whether elementary and secondary students with LD who used the technology to write self-selected compositions and class assignments would demonstrate improvements in reading and spelling. Thirty-nine students with LD (ages 9 to 18) participated. Nineteen participants used speech recognition 50 minutes a week for sixteen weeks, and twenty students in a control group received general computer instruction. Results indicated that the speech recognition group showed significantly more improvement than the control group in word recognition (p<.0001), spelling (p<.002) and reading comprehension (p<.01). Pre- and posttests on five reading-related cognitive processing measures (phonological, orthographic, semantic processing, metacognitive reading strategies, and working memory) indicated that for the experimental group, only phonological processing improved significantly over the treatment period when compared to controls (p<.04). Further ANCOVA suggested that growth in phonological processing was associated with significant differences among conditions for all three academic measures: word recognition, spelling, and reading comprehension. Address correspondence to 971 N. Altadena Drive, Pasadena, CA 91107. E-mail center@frostig.org.     

Software for calculating blood lactate endurance markers

Blood lactate markers are used as summary measures of the underlying model of an athlete's blood lactate response to increasing work rate. Exercise physiologists use these endurance markers, typically corresponding to a work rate in the region of high curvature in the lactate curve, to predict and compare endurance ability. A short theoretical background of the commonly used markers is given and algorithms provided for their calculation. To date, no free software exists that allows the sports scientist to calculate these markers. In this paper, software is introduced for precisely this purpose that will calculate a variety of lactate markers for an individual athlete, an athlete at different instants (e.g. across a season), and simultaneously for a squad.