The aim of the present study was to evaluate the effects of a middle school physical activity and healthy eating intervention, including an environmental and computer-tailored component, and to investigate the effects of parental involvement. A random sample of 15 schools with seventh and eight graders was randomly assigned to one of three conditions: (i) intervention with parental involvement, (ii) intervention alone and (iii) control group. In 10 schools, an intervention, combining environmental changes with computer-tailored feedback, was implemented over 2 school years. In five intervention schools, increased parental support was added. Physical activity was measured with questionnaires in the total sample and with accelerometers in a sub-sample of children. Fat intake, fruit, water and soft drink consumption were measured using food-frequency questionnaires. Results showed significant positive intervention effects on physical activity in both genders and on fat intake in girls. Parental involvement did not increase intervention effects. It can be concluded that physical activity and eating behaviours of middle school children can be improved by school-based strategies combining environmental and personal interventions. The use of personalized computer-tailored interventions seems to be a promising tool for targeting adolescents but needs to be further explored.

The strength of the plantar flexors and amount of dorsiflexion excursion were identified as significant predictors of an Achilles tendon overuse injury. A plantar flexor strength lower than 50.0 N.m and dorsiflexion range of motion higher than 9.0 degrees were possible thresholds for developing an Achilles tendon overuse injury.

These findings provide evidence that static and ballistic stretching have different effects on passive resistive torque and tendon stiffness, and both types of stretching should be considered for training and rehabilitation programs.

BackgroundTrunk bridging exercises are often used as therapeutic exercises for lumbopelvic stabilization. These exercises focus on the retraining of muscle coordination patterns in which optimal ratios between local segmental stabilizing and global torque producing muscle activity are assumed to be essential. However, a description of such ratios is lacking. The purpose of this study was to investigate both relative (as a percentage of maximal voluntary isometric contraction) muscle activity levels and ratios of local to global muscle activity, during bridging stabilization exercises.MethodsThirty healthy university students (15 men, 15 women) with a mean age of 19.6 year volunteered to perform 3 bridging exercises (single bridging, ball bridge and unilateral bridging). The surface electromyographic activity of different trunk muscles was evaluated on both sides.ResultsDuring all bridging exercises, the ratio of the internal oblique to the rectus abdominis was very high due to minimal relative activity of the rectus abdominis. In general, the ratio of the internal/external abdominal oblique activity was about 1. However, during the unilateral bridging exercise, the ipsilateral internal/external abdominal oblique activity ratio was 2.79 as a consequence of the significant higher relative activity of the internal oblique compared to the external oblique. The relative muscle activity and the ratios of the back muscles demonstrated similar activity levels for all back muscles, resulting in ratios about 1.ConclusionBoth the minimal relative activity of the rectus abdominis and the high internal oblique to the rectus abdominis activity ratio reported in the present study are in accordance with results of other trunk stabilization exercises. The relative muscle activity and the ratio of the abdominal obliques seem to alter depending on the task and the presumable need for stability. The findings concerning the relative muscle activity and the ratios of the back muscles support the assumption that during these bridging exercises, all back muscles contribute in a similar way to control spine positions and movements in a healthy population.

The outcomes of the evaluation study confirm that a school-based anti-bullying intervention strategy can be effective in reducing problems with bullying, especially within primary schools. It was argued that the developmental characteristics of secondary school students interfered with the programme outcomes. In addition, the findings revealed no extra effects of specific training sessions.