Pre-participation screening is a key role of many sports therapists working with recreational club, sub-elite or top-flight athletes, so it is useful from time to time to remind ourselves of the rationale, principles, the dilemmas and the practicalities involved. Here we explain how one aspect of the process – musculoskeletal screening – is carried out with the Queensland Academy of Sport’s men’s water polo squad.
Currently most of the water polo coaches at the QAS will budget for musculoskeletal screening by a sports physiotherapist at least once a season. This is in addition to a thorough medical questionnaire, video analysis by a biomechanist, physiological, psychological, nutritional and strength and conditioning tests.
All screening will address one or other of these fundamental aspects of athlete support. Currently the debate is on across the Queensland Academy of Sport as to which side of the line the physiotherapy musculoskeletal screening falls. But it is probably more useful to think in terms of a continuum of athlete testing procedures, with injury prevention at one extreme (where, arguably, the science of medical screening by a doctor would come) and pure performance enhancement at the other (screening by a strength and conditioning specialist). In this continuum, musculoskeletal screening surely comes somewhere midway – if for no other reason than the fact that an injured athlete always performs poorly! Therefore if you manage to prevent even one injury during the season by correcting a biomechanical problem highlighted during screening, that athlete will have performed better.
A small number of sports use a screening programme to help predict performance – such as in dance, where discovery of osseo-ligamentous movement limitations may preclude a young dancer from entering certain academies – but generally the goal is to find ways of improving body mechanics to enable an athlete with potential to maximise it.
At a more technical level, musculoskeletal screening is invaluable for revealing deficits in muscle/ joint flexibility and in muscular stability/control that might lead to overuse injuries. And while the link between correcting these deficits and improved performance can be hard to prove, the growth in popularity of musculoskeletal screening among professionals over the last few decades lends a heavy weight of anecdotal and clinical evidence to support its efficacy.
The more research that is done, the more evidence we have to confirm which tests are useful – and of late physio-philosophers have been debating how to upgrade the scientific validity of screening(1,2). Peter Blanch(1), sports physiotherapist to the AIS, makes the all-important point that while ‘clinical intuition and experience are important factors in the development of our knowledge (as it pertains to screening)’, it is when we cease to be critical of our tests and procedures that we are at risk of relying on ‘faith rather than science’.
Why is it hard to prove the link between screening and improved performance? In essence it is because improved performance is such a multifactorial business. There could be numerous reasons why a top goal shooter in water polo seems to be nailing more balls in the back of the net. It is possible that just one of those reasons is the fact that he can get higher out of the water because his right hip joint has an increased range of flexion, allowing his hip extensors (glut muscles) to work better during his maximal egg-beater kick (see panel above). Hard to prove – but it is certainly a good possibility.
While the scientific evidence for screening is somewhat thin on the ground, there does seem to be a good correlation between certain factors, eg flexibility and:
Physiotherapists are not alone in facing this problem of how valid screening is. It seems that the assessors of strength and power(2) face the same difficulties. Isometric muscle testing and isokinetic dynamometry are believed these days to reveal less than we used to think about an athlete’s proficiency in the dynamic requirements of a given sport. Instead, in the early 1990s, the principle of sports specificity(2) required a shift in strength and power test protocols towards isoinertial (loaded repetitive functional movement) testing.
A second core aim of screening is to record the details of significant past injuries, and to assess for any ongoing effects on the mechanics of the injured and non-injured parts of the body. A classic example is how a serious ankle injury, even one that’s 10 years old, may have set a knee problem in motion. The assessment and correction of an ankle joint with reduced gliding motion, proprioception deficits and compensatory subtalar joint pronation should prevent the knee from gradually breaking down.
Recording of injury rates and areas of injury across the whole QAS squad should enable us to identify and correct patterns of injury which may arise from any number of external factors, such as weather, water temperature, intensity of training or competition, etc.
This type of information helps the sporting bodies to understand the importance of screening, and enhances athletes’ willingness to adhere to their exercise regimes.
Thankfully the challenge within the QAS water polo squad is not to convince the coaches and people in authority of the efficacy of musculoskeletal screening, but rather to persuade the athletes, who are often faced with competing demands on time, energy and finances. The best weapon a physiotherapist has, faced with athletes who consider the whole screening process a waste of time, is a professional and enthusiastic approach(1).
For an effective musculoskeletal screening you will need:
We conduct a post-report interview with athlete and coach together (plus the QAS strength and conditioning specialist and biomechanist, if deemed necessary). We develop a time-framed set of goals, an exercise regime and a monitoring plan. This will always include a reassessment of the athlete, where we can confirm progress and work out any implications for their technique in the pool.
You will need to consider:
Tests should be generic ones that have been subjected to research, and/or tests used clinically and validated anecdotally (ie, they have not been subjected to the rigours of research, but are sourced from the general body of knowledge and experience of the profession).
The need to follow the logic of sport-specificity is unquestionable, yet it seems to me to be potentially at odds with the need to use tests that are scientifically validated, because in reality only a handful of appropriate tests may fall into the latter category(2).
For water polo, the major jobs that the body has to do (with corresponding biomechanical requirements) are:
Sport profiling also tells us that water polo players mainly suffer shoulder injuries (24.1% of all injuries), facial injuries (15.5%) and hand injuries (14.7%). So the shoulder comes high on our priority scale for assessment(1,6-8).
In 2002 and 2003 our water polo screening was done at the beginning of the training season in September, with a view to preparing the players for their competitive season (November to April/May).
While the literature has suggested that the ideal time for a pre-season screen should be four to six weeks ahead of season’s start(9), I believe this is not long enough to allow athletes to make real positive changes to faulty mechanics.
Recently the case has successfully been put for QAS’s water polo screening to be moved to early in the off-season (six to eight weeks before season’s start) for the following reasons: