We are delighted to introduce a guest blog from Jonny King (@Jonny_King_PT), a sports physiotherapist based at Aspetar, Qatar. Jonny has experience working in professional football in the UK with both Norwich City FC and AFC Bournemouth before he made the big move East to Doha. A prevalent voice on twitter and definetely worth a follow, he provkes some intriguing questions regarding our current understanding of hamstring injuries. We hope you enjoy… P&P
Hamstring strain injury (HSI) continues to present as a huge challenge for those of us working within the sport and exercise medicine field – whether that be in a research or clinical setting. Disappointing figures have recently shown that despite an increasing body of publications over recent years and a perceived improvement in understanding of underlying causes, the epidemiology for HSI in elite sport has not changed over the past 10 years (Ekstrand, Hagglund & Walden, 2009) A worrying reality.
Some will argue that WE HAVE improved our understanding and management of hamstring injuries but the evidence base is not being applied effectively into clinical practice. (Bahr, Thornborg, EKstrand, 2015). Others will state that our ability to influence epidemiological data at elite level, has been affected by the evolution of sporting competition including increased physical application. Take professional football for example, both sprint distance (35%) and high intensity running distance (30%) have significantly increased over the past 7 years, alongside a reduction in recovery times as a result of increased fixture congestion (Barnes et al, 2014) These can all be seen as restraints to our drive for better data around HSI.
These are all factors we should appreciate, however are we missing something else?
In brief, we know those at highest risk are those with history of previous strain, weak eccentric strength and those in a fatigued state (Opar, Williams and Shield, 2012). Flexibility, neuromuscular inhibition, biomechanics and H:Q ratios have all been flirted with, but with no real hard conclusion as to their influence on HSI. Identifying those at risk is relatively straight forward these days, given increased accessibility to advanced monitoring technology, helping to identify fatigue or strength reduction. We can thank systems such as GPS and The Nordboard for this. These are for sure all very important considerations as we take a multifactorial approach to injury management and prevention. But, Is there anything else we need to consider?
One area that I feel needs further investigation with regards to HSI is the psychological harmony of the athlete. It may be difficult to account for the primary injury, but are negative beliefs, anxiety and apprehension contributing factors to high rates of re-injury?
Cognitive functioning and therapy has been discussed at length in the treatment and management of many other musculoskeletal conditions, notably chronic LBP (O’Sullivan 2012) and ACL Reconstruction , with methods such as CBT proving an effective intervention in many cases. I wonder therefore if this needs more consideration when it comes to hamstring injury treatment? Poor psychological readiness has been associated with hamstring strain re-injury (Glazer, 2009) and this would also provide a feasible explanation as to why completion of Carl Askling’s H-Test appears a strong indicator for RTP. Maybe it’s something we are missing, or not considering enough? By more thorough monitoring of anxiety and apprehension can we mitigate ‘previous HSI’ as a risk factor? Food for thought..
What about fatigue and eccentric weakness?
- We know HSI is more likely to occur towards end of 1st half & throughout the 2nd half (Ekstrand 2011) and that optimal time for full physiological recovery is 72 hours (Dellal et al 2013).
We also know..
- The widely documented success of the Nordic Curl programme and other eccentric lengthening programmes in reducing HSI in some populations (Arnason, 2008 and Askling 2013).
Throughout the competitive season, the clinical challenge is to address both fatigue and eccentric strength, because for me, the 2 are counterintuitive to one another. You cannot perform regular, effective eccentric strength training without inducing fatigue, therefore it becomes very difficult to address both variables during a season of heavy fixture congestion.
I do wonder if we spend too much time in-season, prescribing injury prevention programmes and exercises. I feel there is a strong argument that we are only exposing our athletes to a greater risk of injury by adding to the overall accumulative training load and fatigue.
Why are we not reducing hamstring strain injuries?
Are we trying too hard in search for that holy grail of HSI prevention? Do we just need to ease off these guys?
Ultimately, and realistically I think there has to be a fine balance between the 2 . Windows of opportunity, such as the international breaks and pre-season, should be fully utilized for specific strength training and the remainder of the season used to ensure players have adequate time to recover and prepare physiologically for upcoming competition.
No answers here, just some food for thought. Enjoy your sport =)