Hanging in the Balance: will muscle imbalance move on in elite football (part 1)

Perceptions, Practice and Movement Analysis in Elite Football (Part 1)

This commentary is based on a review of the paper by McCall et al 2015 by Clare Pedersen – McCall et al. Injury risk factors, screening tests and preventative strategies: a systemic review of the evidence that underpins the perceptions and practices of 44 football (soccer) teams from various premier leagues.  British Journal of Sports Medicine, 2013, 49:9 583-589

Cultural practice and the weight of evidence

The article above reflects upon the current state of play in Premier League Football clubs with regards to the validity of current methods of practice. Studies examining the perceived 3 top risk factors related to injury of fatigue, muscle imbalance, and previous injury, were considered alongside the use the use of screening tests and preventative exercises.

  • It stated the overall level of evidence for previous injury, fatigue and muscle imbalance as risk factors were 2++, 4 and ‘inconclusive’, respectively.
  • The graded recommendation for a functional movement screen, psychological questionnaire and isokinetic muscle testing were all ‘D’.
  • Eccentric hamstring work had a weak graded ‘C’ recommendation, whilst eccentric exercise for other body parts was ‘D’.
  • Balance/proprioception exercise to reduce ankle and knee sprain injury was assigned a graded recommendation ‘D’.

The authors opine that although the perceptions and practice of Premier League teams are currently based upon these low levels of evidence and low graded recommendations it does not imply these are not important, rather suggesting practice of this kind is simply yet to be ”sufficiently validated” or refuted.

Andy Franklyn Miller (2015), also commented on this article, stating it as,

” highlighting the lack of investment in finding actual strategies to effectively alter training injury risk which likely lie in modifiable training program design, strategy and coaching. ”

Previous – history predicts the future?

The research for previous injury is well established, as identified in McCalls’ article showing the highest level of evidence was gained in the studies they examined, suggesting that previous injury in the same muscle does play a part in recurrent muscle injury.

A balanced argument?

Muscle imbalance currently lacks an agreed definition, a state leading to difficulties when comparing study methodology, interpretation and outcome. In the literature, the methodological sections often measure very different components – antagonist to agonist, concentric to eccentric action , different agonists working in the same direction yet with stabiliser or mobilser roles, yet all may be placed below the muscle imbalance banner. Such a ‘mezze’ approach to the topic often leaves review articles struggling to produce meaningful data. Of note, the perception amongst health professions is that muscle imbalance does have an important role to play. Yet, just as within academic publications, practitioners also display a lack of consensus as to what muscle imbalance can be defined as. This dual lack of clarity, apparent within the research and the clinic alike leaves the muscle imbalance component of injury risk vague and therefore, often, unsatisfactorily managed.