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.     

Validity of a portable force platform for assessing biomechanical parameters in three different tasks

The aim of this study was to determine the precision and accuracy of the vertical and anterior–posterior force components of the portable PASCO PS-2142 force plate. Impulse, peak force, and time to peak force were assessed and compared to a gold standard force plate in three different tasks: vertical jump, forward jump, and sprint start. Two healthy male participants performed ten trials for each task, resulting in 60 trials. Data analyses revealed good precision and accuracy for the vertical component of the portable force plate, with relative bias and root mean square (RMS) error values nearly the same in all tasks for the impulse, time to peak force, and peak force parameters. Precision and accuracy of the anterior–posterior component were lower for the impulse and time to peak force, with relative bias and RMS error values nearly the same between tasks. Despite the lower precision and accuracy of the anterior–posterior component of the portable force plate, these errors were systematic, reflecting a good repeatability of the measure. In addition, all variables presented good agreement between the portable and gold standard platforms. Our results provide a good perspective for using the aforementioned portable force plate in sports and clinical biomechanics.     

Contractual school psychological services: Prevalence and practices

This study investigated the prevalence and practices of contract school psychological services in public schools. A survey was sent to all 121 school districts in a southeastern state, with 111 surveys completed for a response rate of 92%. Results indicated that most school districts did not believe that contracting is cost effective. The primary service provided by contractual service providers was triennial reevaluations. The administrator most often charged with the hiring and supervision of contract providers was not a school psychologist. The credential most often required of a contracting psychologist was a State Board of Psychology license, with only a few requiring documentation of relevant coursework or experience. The results of this study indicated that the most pressing concern for the profession of school psychology regarding contractual services is ensuring that contract services are provided and monitored according to appropriate standards of practice. © 2000 John Wiley & Sons, Inc.     

Munchausen syndrome by proxy: A family affair

Munchausen syndrome by proxy is an unusual form of child abuse: a child presents with an illness that has been factitiously produced by a parent, typically the mother. A case of chronic illicit insulin administration to a one-year-old girl is described. Despite temporary separation of the child from the mother and long-term psychiatric intervention, factitious illnesses continued, including urine specimen contamination, laxative-induced diarrhea, suspected bladder catheterization, and suspected poisoning. Retrospective review of the medical records of the mother and two siblings demonstrated previously unrecognized evidence of factitious illnesses. The medical records contained evidence of 30 separate episodes of suspected or documented factitious illness in these four members of the same family. This unique family illustrates the significant morbidity of Munchausen syndrome by proxy and a poor response to psychiatric treatment.     

Advances in the application of information technology to sport performance

This paper overviews the diverse information technologies that are used to provide athletes with relevant feedback. Examples taken from various sports are used to illustrate selected applications of technology-based feedback. Several feedback systems are discussed, including vision, audition and proprioception. Each technology described here is based on the assumption that feedback would eventually enhance skill acquisition and sport performance and, as such, its usefulness to athletes and coaches in training is critically evaluated.