Does intensive pre-season strength training protect rugby players from non-contact injury?

[Summary: Players at a leading Australian rugby club who undertook a high-intensity off-season strength training program experienced dramatically fewer non-contact injuries during the playing season than their less committed club mates. It is suggested that the lower incidence of injury might be attributable to an emphasis on improving basic strength and the use of rugby-specific strength equipment.]

Each year the Sydney University Football Club selects a group of players for its Elite Development Squad to prepare for the next season. For 2005 a squad of 50 was chosen which did not include any of the Club's seven Wallabies nor any of the players on Super 12 contracts. Players committed themselves to around fourteen weeks of intensive training involving six to seven sessions per week of weights, skills and fitness work despite either being full time students or working full time.

At the conclusion of the season the Club's doctor, Katherine Rae, and physiotherapist, Keiran Cleary, jointly issued a Medical Report analysing the injury experience of the Club's eight teams. They particularly highlighted the members of the Elite Development Squad, noting that during the season "the EDS squad suffered only two non contact injuries, both muscle strains, which resulted in only four games lost to injury."

More specifically, among the 36 players who completed the full EDS program there was "only one calf strain and one hamstring strain ... . They had no back pain or groin pain necessitating loss of game time." By contrast, for the Club as a whole, there were 28 instances of low back pain, 27 hamstring injuries, 27 groin injuries and 6 quadriceps strains.

Two non contact injuries in over 1000 hours of playing time is an extraordinarily low figure in itself, and certainly by comparison with the Club's other players who accumulated over 80 comparable injuries. The injury incidence for the Club as a whole seems to be broadly in line with that reported in various scientific studies including those focussed on professional players.

It is obviously unwise to attach too much significance to the experience of one club over a single season. However the disparity in injury rates between those in the EDS group and their team mates is so great that it is very unlikely to be attributable to mere chance. Therefore it is necessary to explore possible reasons for this very favorable outcome. I believe that there were three relevant factors at work:

Duration and intensity of the training program

An off-season involving around 90 uninterrupted training sessions creates a near ideal opportunity for players to enhance their basic strength and fitness for rugby.Very few non-professional players would have the commitment and dedication to stick to such an exacting schedule. And very few professional players would have such a large block of time available. For example, Australian full-time players normally participate in at least two of the three tiers of club, provincial and international rugby and are therefore playing through most of the year.

The EDS squad also had on-campus access to physiotherapists, doctors and nutritionists plus regular dietary supplementation. Thus, even though the squad members were not paid, they were training in a very professional environment.

Emphasis on basic strength development

Strength and conditioning in the EDS program was structured and administered by Martin Harland, a sports scientist who had previously worked with professional rugby league, Australian football and basketball teams. His programs for rugby players place a high degree of emphasis on basic strength development and rugby-specific fitness. A distinguishing feature of his approach is a concentration on heavy lower body work through exercises such as squats, deadlifts and cleans.


Use of the ScrumTruk

In addition to their free weights exercises the group regularly used the rugby specific MyoQuip ScrumTruk as a core component of their leg strength work. Certain unique attributes of this apparatus might be relevant to protection against injury. Although it works basically the same muscle groups as the barbell squat, the fact that the resistance is in the horizontal rather than the vertical plane means that there is no adverse loading on the lumbar spine. It is also more quadriceps specific than the squat and exercises effectively the muscles of the calf.

But its main benefit in injury minimization may be in relation to the hamstrings. The ScrumTruk specifically works this muscle group as well as adjacent areas such as the glutes, quadriceps and core stabilizers. But the most important effect might relate to the frequently observed importance of eccentric loading in developing the hamstrings. Both the barbell squat and the conventional leg press deliver constant resistance. When performing these movements concentrically the muscles involved are only under very partial load as the hip and knee joints move to full extension. By contrast the ScrumTruk's operation provides continually increasing resistance throughout the exercise movement. Because of this, the muscles involved are strongly activated over the full exercise range and most critically are working at close to full load at the conclusion of the movement. It would seem to follow logically that the more that muscles are being activated concentrically, the greater the eccentric load when the movement is reversed. Thus there is heavy eccentric loading on the hamstrings when they are near fully extension.

The low injury incidence by Sydney University's elite training squad seems to suggest that other teams might benefit similarly by implementing a long and intensive off-season training program concentrating on the development of basic lower body strength through complex free weight movements and the use of the ScrumTruk. The potential improved injury outcomes are additional to the very substantial strength gains from such a program.