Rugby injuries

Skill-based conditioning games don’t seem to hurt rugby players too much – but aerobic running does

Rugby League is an ‘international collision sport‘ with an elevated risk of injury, compared with many other popular international sports. Some investigations have indicated that injury rates in rugby-league play are as high as 1.4 serious injuries per game, and the frequency of injury in the sport seems to be increasing rather than decreasing (1).

Rugby-league injury rates appear to be high not just during competition but also during training activities, and as a result rugby coaches and athletic trainers have searched for ways to minimise the risk of injury during preparations for matches. Recently, however, the use of skill-based conditioning games has become increasingly popular during rugby workouts. The intensity of these skill-based games can be quite high, and – given that elevated intensity is a demonstrated predictor of injury (2) – it is feared that the inclusion of the conditioning games might be raising the risk of rugby injury during training. Are the skill-based games really risky, and what training activities actually are the major culprits when it comes to injury induction during rugby workouts?

Over to Queensland

To find out, Tim J. Gabbett of the School of Health Science at Griffith University Gold Coast in Queensland, Australia, recently studied training injuries prospectively in 60 semi-professional rugby-league players (average age 22 years) over one full season (from December 1999 to August 2000). All of the players were highly motivated individuals who were concurrently engaged in strength training, and – despite their relative youth – the average playing experience of the athletes was 15 years (3)!

Each player participated in two organised-field-training sessions per week, with each workout lasting approximately 90 minutes. The injury data were collected from a total of 72 training sessions, and injuries were classified as transient (no training missed), minor (one week of missed training), moderate (two to four weeks of training lost), and major (five or more weeks lost); maladies were also categorised according to site (head, neck, face, shoulder, etc.) and type (sprains, contusions, abrasions, etc.).

Gabbett looked at how eight different training activities influenced the risk of getting hurt. These included:

1. Skill-based conditioning games. These are continuous, very intense games played on a modified field; there is no tackling allowed, and a strong emphasis is placed on passing, catching, multiple sprints, and rapid changes in direction. The idea is to develop ball-control skills, strategic thinking, decision-making ability, speed, agility, and even aerobic fitness (since activity is sustained for relatively prolonged periods of time). Special skills such as controlling the ball while exiting from one’s own try-line are developed (4).
2. Traditional conditioning activities (continuous running activities at relatively moderate intensities),
3. Tackle and bump-pad drills (rather violent drills utilising ‘tackling bags‘ and/or ‘bump pads‘),
4. Opposed drills (team ball work and specific team strategies),
5. Warm-up and cool-down activities (progressing from low- to high-intensity drills during warm-up, easy exertions during cool-down),
6. Power activities (plyometric exercises),
7. Kicking and catching drills (as the name suggests, kicking and catching at low to modest intensities), and
8. Agility drills (game-specific drills involving quick, dexterity-requiring motions over short distances).

How many injuries, and where

Over the course of the season, a total of 168 injuries were recorded during training, creating an overall injury frequency of 26.9 injuries per 1000 training hours (by comparison, injury rates during competitions are often pegged at about 70 injuries per 1000 game hours). 80% of the players sustained more than one injury during the nine-month season.

Injuries to the thigh and calf were the most common by far, accounting for a whopping 40% of all injuries. In comparison, the other regions of the athletes’ bodies were relatively trouble-free, with the ankle and foot checking in with only 16% of total injuries, the knee adding only 12%, and the thorax and abdomen yielding just 11%.

Muscular strains were the most-frequent type of problem, contributing 51% of all injuries categorised by type; joint sprains and contusions – the second- and third-most common injuries – were far back at about 11% each.

Running came out worst!

The activity with the highest rate of injury (38% of the total) was traditional running which involved no skill component, e.g., running aerobically and continuously without the ball. In contrast, tackle and bump-pad drills offered up only 17% of total injuries and had a lower per training-hour incidence of problems. Skill-based conditioning games, feared for their injury potential because of their high intensity, yielded only 11% of all injuries and were associated with a below-average injury rate (when expressed as the number of injuries per 1000 hours of training).

Of the injuries that resulted in lost training time, over half were sustained during traditional running activity (doing laps and attempting to run aerobically), and the only major injury of the season (producing an out-of-action status of five weeks or longer) was incurred during traditional running. Injuries sustained during skill-based games which lead to lost training time were extremely uncommon, occurring at a rate of about 9 such injuries per 1000 hours of training.

So what’s the bottom line for all you rugby enthusiasts? From an injury standpoint, the riskiest thing you can do during your training season appears to be traditional (e.g., aerobic) running – an activity with no likelihood of violent contact! Such training is associated with a high rate of leg injuries, especially those of the thigh and calf areas. These problems are usually muscle strains associated with overtraining, e.g., doing more running than your legs are actually ready for.

Fatigue is the culprit

That would appear to be a potential problem, since fatigue (e.g., a lack of aerobic fitness?) appears to be a major risk factor during competition. The vast majority of rugby injuries occur during the second halves of matches, when rugby athletes’ muscles are more tired and less able to carry out skilful movements – and less likely to provide full protection for associated connective tissues (bones, ligaments, tendons). Yet if rugby athletes scale back on aerobic training in order to reduce the risk of injury during training, won’t they simultaneously raise the risk of getting hurt during games?

Maybe, but not all is lost. The correct approach would not be to eliminate aerobic training altogether, especially since it can help rugby athletes fight fatigue during late stages of matches, but to prepare properly for aerobic running with a deft regimen of running-specific strength training. If traditional running is undertaken with serious intent without an underlying foundation of good, functional, leg-muscle strength, then of course there will be high rates of muscle strains in the quads, hamstrings, and calves. The solution would be to complete several weeks of running-specific strength training utilising resisted movements, which mimic the mechanics of the gait cycle of running. The leg muscles will then be well-prepared for the conventional running taking place during the season, and injury rates will be lower. Naturally, aerobic running should be undertaken sensibly, even when running-specific strength training has preceded it. The amount of aerobic running completed per week should increase only gradually and progressively over time; changes in the intensity and frequency of aerobic work should also be undertaken with care.

Finally, although aerobic running is connected with an unnecessarily high incidence of within-training injury for rugby, skill-based conditioning games are linked with a very low risk of injury and may be pursued by rugby athletes and their coaches without major qualms, especially since such drills seem to enhance a number of important competitive skills.

Jim Bledsoe

References

1. ‘A Prospective Study of Injuries to Élite Australian Rugby Union Players,‘ British Journal of Sports Medicine, Vol. 36, pp. 265-269, 2002
2. ‘Injuries in Professional Rugby League: A Three-Year Prospective Study of the South Sydney Professional Rugby League Football Club,‘ American Journal of Sports Medicine, Vol. 21, pp. 696-700, 1993
3. ‘Training Injuries in Rugby League: An Evaluation of Skill-Based Conditioning Games,‘ Journal of Strength and Conditioning Research, Vol. 16(2), pp. 236-241, 2002
4. ‘Increasing Training Intensity in Country Rugby League Players,‘ Rugby League