Two rugby union forward packs of differing ability levels were examined during scrummaging against an instrumented scrum machine. By systematically moving the front-row of the scrum along the scrum machine, kinetic data on each front-row forward could be obtained under all test conditions. Each forward pack was tested under the following scrummaging combinations: front-row only; front-row plus second-row; full scrum minus side-row, and full scrum. Data obtained from each scrum included the three orthogonal components of force at engagement and the sustained force applied by each front-row player. An estimate of sub-unit contributions was made by subtracting the total forward force on all three front-row players from the total for the complete scrum. Results indicated the primary role of the second-row appeared to be application of forward force. The back-row ('number eight') forward did not substantially contribute any additional forward force, and added only slightly to the lateral and vertical shear force experienced by the front-row. The side-row contributed an additional 20-27% to the forward force, but at the expense of increased vertical forces on all front-row forwards. Results of this investigation are discussed in relation to rule modification, rule interpretation and coaching.

Rugby league is an international collision sport played by junior, amateur, semiprofessional and professional players. The game requires participants to be involved in physically demanding activities such as running, tackling, passing and sprinting, and musculoskeletal injuries are common. A review of injuries in junior and senior rugby league players published in Sports Medicine in 2004 reported that injuries to the head and neck and muscular injuries were common in senior rugby league players, while fractures and injuries to the knee were common in junior players. This current review updates the descriptive data on rugby league epidemiology and adds information for semiprofessional, amateur and junior levels of participation in both match and training environments using studies identified through searches of PubMed, CINHAL, Ovid, MEDLINE, SCOPUS and SportDiscus databases. This review also discusses the issues surrounding the definitions of injury exposure, injury rate, injury severity and classification of injury site and type for rugby league injuries. Studies on the incidence of injuries in rugby league have suffered from inconsistencies in the injury definitions utilized. Some studies on rugby league injuries have utilized a criterion of a missed matchas an injury definition, total injury incidences or a combination of both time-loss and non-time-loss injuries, while other studies have incorporated a medical treatment injury definition. Efforts to establish a standard definition for rugby league injuries have been difficult, especially as some researchers were not in favour of a definition that was all-encompassing and enabled non-time-loss injuries to be recorded. A definition of rugby league injury has been suggested based on agreement by a group of international researchers. The majority of injuries occur in the match environment, with rates typically increasing as the playing level increases. However, professional level injury rates were reportedly less than semiprofessional participation. Only a few studies have reported training injuries in rugby league, where injury rates were reported to be less than match injuries. Approximately 16-30% of all rugby league injuries have been reported as severe, which places demands upon other team members and, if the player returns to playing too early, places them at an increased risk of further injuries. Early research in rugby league identified that ligament and joint injuries were the common injuries, occurring primarily to the knee. More recently, studies have shown a change in anatomical injury sites at all levels of participation. Although the lower limb was the frequent injury region reported previously, the shoulder has now been reported to be the most common injury site. Changes in injury site and type could be used to prompt further research and development of injury reduction programmes to readdress the issue of injuries that occur as a result of participation in rugby league activities. Further research is warranted at all participation levels of rugby l...

In the game of ruby union, the scrum epitomises the physical nature of the game. It is both a powerful offensive skill, affording a base for attacking play, and a defensive skill in denying the opposition clean possession. However, the scrum has also been implicated in a large proportion of serious spinal injuries in rugby union. The majority of injuries are found to occur at engagement where the forces experienced by front-row players (more than two-thirds of a tonne shared across the front-row) can exceed the structural limits of the cervical spine. These large forces are a consequence of the speed of engagement and the weight (and number) of players involved in the scrum. This highlights not only the need for physical preparation of all forwards but particularly player restraint at engagement, and justifies the 'crouch-pause-engage' sequence recently introduced to 'depower' the scrum. As the hooker is the player exposed to the greatest loads throughout the scrum and subsequently most at risk, he should determine the timing of engagement of the 2 front-rows. Stability of the scrum is an indication of front-row players' ability to utilise their strength to transmit the force to their opponents as well as the push of second-row and back-row players behind them in the scrum. This appears to be independent of the size of players. Equally, it reflects the risk of chronic degeneration of the musculoskeletal system through repeated exposure to these large stresses. However, not only are older and more experienced players better able to generate and transmit these forces, they are also able to maintain the integrity of the scrum. A large proportion of individual players' efforts to generate force is lost in their coordinated effort in a normal scrum. It is assumed these forces are dissipated through players re-orientating their bodies in the scrum situation as well as to less efficient shear forces and to the elastic and compressive tissues in the body. It again reinforces the importance of physical preparation for all forwards to better withstand the large forces involved in scrummaging. Despite negative publicity surrounding the risk of serious spinal injury in rugby union, limited research has been conducted to examine either the mechanisms of injury or techniques implicated in causing injury. Biomechanical information can provide systematic bases for modifying existing techniques and assessing the physical capacities necessary to efficiently and safely play in the serum. This will both improve performance of game skills and minimise the potential for injury.

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The purpose of this study was to examine and describe the sequence of events involved in long-term biological reconstruction of a tendon-bone interface following surgical reattachment. Patellar tendon re-attachment in the adult sheep was used to investigate and describe the biological components involved in healing and repair of a tendon enthesis. Light microscopy was used to describe the healing morphology at time intervals of 8, 12, 26, 52 and 104 weeks. By 8 weeks a collagen continuum was observed between the tendon and bone. Over time this fibrous bridge became anchored into the original tissues (tendon and bone), with the resultant enthesis resembling more a fibrous rather than the original fibrocartilagenous enthesis. The associated collagen fibrils between the two tissues gradually changed in morphology over time to reflect the fibres seen in the original tendon tissue. The fibrous tissue of the forming enthesis remained hypercellular when compared with the controls. The resultant long-term morphology may be a reflection of functional adaptation rather than anatomical replication.