No abstract

No abstract

No abstract

There is limited research to support the notion that heavy resistive exercise immediately before a power movement may acutely enhance performance. Upper-body acute power enhancement during a stretch-shorten cycle (SSC) movement has not been previously investigated. The aim of this project was to determine whether a set of 5 repetitions of 5 repetition maximum (RM) bench press preceding explosive push-ups would significantly influence indicators of power: impulse and maximum rate of force development. Subjects randomly performed either explosive push-ups only over a force platform or a set of 5RM bench press before the explosive push-ups. There were no significant differences for any of the force platform data when the explosive push-ups were preceded by a set of 5RM bench press. It appears that heavy dynamic resistive upper-body exercise on its own before an upper-body power activity is inadequate in augmenting short-term power.

The purpose of this study was to investigate the acute effect of 3 warm-up protocols on peak power production during countermovement jump (CMJ) testing. The intention was to devise and compare practical protocols that could be applied as a warm-up immediately before competition matches or weight training sessions. A group of 22 elite Australian Rules Football players performed 3 different warm-up protocols over 3 testing sessions in a randomized order. The protocols included a series of low load exercises targeting the gluteal muscle group (GM-P), a whole-body vibration (WBV) protocol (WBV-P) wherein the subjects stood on a platform vibrating at 30 Hz for 45 seconds, and a no-warm-up condition (CON). The CMJ testing was performed within 5 minutes of each warm-up protocol on an unloaded Smith machine using a linear encoder to measure peak power output. Peak power production was significantly greater after the GM-P than after both the CON (p < 0.05) and WBV-P (p < 0.01). No significant differences in peak power production were detected between the WBV-P and CON. These results have demonstrated that a low load exercise protocol targeting the gluteal muscle group is effective at acutely enhancing peak power output in elite athletes. The mechanisms for the observed improvements are unclear and warrant further investigation. Coaches may consider incorporating low load exercises targeting the gluteal muscle group into the warm-up of athletes competing in sports requiring explosive power output of the lower limbs.

The neck musculature has an essential role in positioning and stabilising the head and may influence sport performance and injury risk. The objectives of this review are to (1) compare the neck strength of different athletes; (2) report on the outcomes of training programmes; (3) explore the association between neck strength and head stabilisation; (4) examine the relationship between neck strength and sport injury risk; and (5) identify areas for future research. There was a difference in strength between different player positions in football codes, gender and age. Detected differences were partly attributed to variation in neck muscle mass. Neck strength training programmes were generally shown to be effective for untrained and trained participants using dynamic or isometric actions and various types of resistance devices. There was a wide range of reported increases in neck strength; the smallest gains were usually for programmes that utilised lower intensity or frequency. There was limited evidence that greater isometric strength or dynamic training was associated with better head stabilisation during low-level force application, while there is direct evidence of an association between neck isometric training or strength and injury risk. A retrospective analysis of professional rugby union players revealed that isometric training reduced match-related cervical spine injuries and a prospective study found that greater overall isometric neck strength reduced concussion risk in high school athletes. Recommendations for future research include substantiating the link between neck strength and sport injury risk and assessing the effectiveness of neck plyometric and perturbation training on stabilisation and injury risk.

This project measured pre-season balance ability and determined its relationship to knee and ankle ligament injuries during the season for professional Australian footballers. The balance test involved the players stepping onto a foam balance mat on top of a force plate and maintaining single limb balance. Throughout the playing season, injuries were monitored. The results from two hundred and ten players participating in this project were analysed. During the 2003 season, 8 % (17 out of 210) sustained a knee ligament injury and 10 % (21 out of 210) sustained an ankle ligament injury. Multivariate analysis revealed that pre-season balance ability was a significant independent predictor of ankle ligament injury. Players with low balance ability had at least twice as many ankle ligaments injuries as those with average or good balance ability. Balance ability was not a significant predictor of knee ligament injuries. The height of the players was the only significant independent predictor of knee ligament injuries. Low pre-season balance ability was associated with an increased risk of ankle ligament injury. A modifiable injury risk factor has been identified. Research is now required to determine the optimal training regime to enhance balance ability and whether this translates to a reduction in the incidence of ankle injuries.

Along with the enjoyment and the other positive benefits of sport participation, there is also the risk of injury that is elevated in contact sport. This review provides a summary of injury incidence in Australian rules football (ARF), identifies injury risk factors, assesses the efficacy of interventions to reduce injury risk and makes recommendations for future research. The most common injuries were found to be muscle strains, particularly hamstrings; joint ligament sprains, especially ankle; haematomas and concussion. The most severe joint injury was anterior cruciate ligament rupture. Mouthguards are commonly worn and have been shown to reduce orofacial injury. There is evidence that thigh pads can reduce the incidence of thigh haematomas. There is a reluctance to wear padded headgear and an attempt to assess its effectiveness was unsuccessful due to low compliance. The most readily identified risk factor was a history of that injury. There were conflicting findings as to the influence strength imbalances or deficit has on hamstring injury risk in ARF. Static hamstring flexibility was not related to risk but low hip flexor/quadriceps flexibility increased hamstring injury risk. High lower-limb and high hamstring stiffness were associated with an elevated risk of hamstring injury. Since stiffness can be modulated through strength or flexibility training, this provides an area for future intervention studies. Low postural balance ability was related to a greater risk of ankle injury in ARF, players with poor balance should be targeted for balance training. There are preliminary data signifying a link between deficiencies in hip range of motion and hip adductor strength with groin pain or injury. This provides support for future investigation into the effectiveness of an intervention for high-risk players on groin injury rate. Low cross-sectional area of core-region muscle has been associated with more severe injuries and a motor control exercise intervention that increased core muscle size and function resulted in fewer games missed due to injury. A randomized controlled trial of the effectiveness of eccentric hamstring exercise in decreasing hamstring injury rate in ARF players was unsuccessful due to poor compliance from muscle soreness; a progressive eccentric training intervention for ARF should be given future consideration. Jump and landing training reduced injury risk in junior ARF players and it would be advisable to include this component as part of a neuromuscular training intervention. A multifaceted programme of sport-specific drills for hamstring flexibility while fatigued, sport skills that load the hamstrings and high-intensity interval training to mimic match playing conditions showed some success in reducing the incidence of hamstring injuries in ARF. A countermeasure designed to reduce injury risk is more likely to be adopted by coaches and players if it also has the scope to enhance performance.