‘The Perfect Storm’
Much like the millennial BAFTA award winning film, the table below depicts just how numerous ever-changing factors throughout the maturation process can brew ‘the perfect storm’ for injuries to develop. Resulting in a 6 out of 10 chance of injury for youth athletes (1). these distinguished bounds provide clarity of an individual’s maturity status but also, the distinctive factors within each category offer crucial information that will or at least should govern our coaching and training decisions. To emphasise this further, injury trends have previously been shown to have a linear increase from the ages of 9 – 15 years of age with more aggressive spikes occurring at 13 years corresponding with anthropometric changes that occur at this stage (2). There is a greater presence of overuse injuries during these stages of development, with Osgood Schlatter’s and Severs Disease being two of the most common types we tend to see. These pathologies bear the medical name traction apophysitis’s, apophysitis being the inflammation that presents at and surrounding the insertion point of the Patella (Osgood Schlatter) and Achilles (sever’s) tendon which is also happens to be the site at which the growth plate (Epiphysis) is located. Whereas ‘Traction’ is more indicative of the mechanism’s causing the inflammatory responses to the stresses inflicted on the tissue. Therefore, it becomes intuitive to us that the youth athletes taking part in running, sprinting, and jumping based sports are the ones most impacted by these overuse injuries, because of the repetitive traction forces these movements impart on the Calcaneus (sever’s) and Tibial Tuberosity (Osgood’s).
Table 1. Differences between biological categorisations. (3–7)
So why do we not witness a continued profound presence of these injuries after growth spurt (Post PHV) and into adulthood you ask? – As cliché as it sounds its multifactorial, however there is one big reason at the core of it all. The larger proportions of immature bone (mainly at the growth plate) in those that are in or yet to reach their growth spurts mean that these areas of the bone lack the density and strength to tolerate and withstand the traction forces that accompany the sporting demands. Nonetheless, disproportional limb lengths, increasing body mass, high training loads decreases in flexibility, neuromuscular control and co-ordination must take responsibility for vulnerability of the growth plate.
Reactive or Proactive?
With a total average of 3.9 weeks of the year injury burden/time loss in these cases, it’s clear to see the threat these injuries pose to a child’s sports participation, talent development, motivation, self-confidence, and social development, albeit for a diminishing period until immature bone is replaced. With this at stake the management and mitigation before, during and thereafter overuse injuries become of increased importance, commonly falling into the hands of the physiotherapists and strength & conditioning practitioners. Strategies to manage and mitigate, largely revolve around reducing symptoms / pain management and addressing modifiable risk factors. Cryotherapy (ICE protocols) and movement based (predominately mixed static & dynamic stretching) methods dominate the practitioners toolbox which accounts for 50 – 55% of treatment choices, to reduce sensitivity at the apophysitis, reduce/minimise inflammatory responses and finally increase flexibility of connecting muscles to reduce traction and tension at the tendon and thus the apophysitis (8). On the other hand, there is an astounding 73.8% of practitioners strongly against prolonged activity restriction (excluding cases of avulsion) in these case’s and in addition to strategies aforementioned, load management (within the sport) and education are a more effective and preferred options for the holistic development of the child including matters of psychology and social inclusion (6,9).
Despite the experimental and experiential validity these methods have in managing and mitigating growth-related issues, there is still a continued unwavering presence/prevalence in youth sport impacting sporting experience and participation. However, if we step back and truly scrutinize our strategies, it may be ambitious to expect a decline in these cases. Although controversial. I say this because of the REACTIVE pattern of application they follow (injury incidence / increase symptoms first, treatment next), particularly ICE, taping. On other hand the same cannot be said for load management and educational strategies, they can have a positive influence in reducing injury incidence and severity, however how PROACTIVE this is all generally dependant upon whether all influencing factors are governed and employed before injury incidence not after, a task not so easy to administer in the real world. Ultimately the purpose of these strategies is either to influencing an individual’s capacity or load to ensure load does not exceed an individual capacity to tolerant this and thus increasing risk of injury.
Figure 1. Mechanisms of Injury
So here is where I’d like to propose the use of isolated strength training as a PROACTIVE strategy to raise’s ones the capacity instead of just maintaining it!
Train Muscle NOT Movements (Just this once)
Contrary to the evolution of physical preparation in sports the concept of training muscles not movement may have a place in the modern day! So, how can isolated or targeted strength training joint support or even reduce the prevalence and severity of growth-related overuse injuries? – In order to answer this question, the discussion must begin with the mechanism of injury and what is being asked of the tissues involved.
As previously mentioned, it is well established that running, sprinting, and jumping make up the core mechanisms of growth-related overuse injury, which all share a common denominator being that all can be categorised into fast stretch shortening cycle (SSC) movements (relative to age of course). Moreover, because of the temporal constraints of the sport during these movements, our youth athletes are subject to large ground reaction forces that are up to 8 times bodyweight, which paints a clear picture of the high demand on the muscles, tendons, and body as whole. Achieving this, as we know requires strength, stiffness, and co-ordination to name a few (irrespective of age), from which many youth athletes are likely to be redundant in, during their physical development journey (10–12). Nonetheless there are clear and consistent behaviours adopted by the muscular tendon unit of lower limb that facilitate these movements to take place 1) producing propulsive forces with length changes 2) storing and returning elastic energy 3) significant force with minimal length change – a strut 4) controlled eccentric lengthening to dampen and absorb energy. The latter two behaviours have significant and direct implications for the apophysitis and growth plate due to the contractile contributions to the dissipation / distribution of the ground reaction forces that are in play. In other words, an inability to “share the load” between muscle and tendon, will inevitably leave non-contractile structures of tendon and bone vulnerable to burden the load. Thus, with respect to Osgood Schlatter’s and Severs conditions the spotlight falls on the quadriceps and triceps square group to assist both Patella tendon and Tibia, Achilles tendon and Calcaneus, respectively. Consequently, not only does exposure to the growth plate and apophysitis create greater risk of trauma, injury incidence and severity but also negate any performance or athletic benefits within the energy return of these fast stretch-shortening cycle actions.
With this evidence in mind, it becomes intuitive that training targeted muscular strength (Quadriceps and Triceps Surae Group) and not just movements (in the case of growth related apophyseal injuries) to improve force production can only facilitate the pertinent behaviours that could positively influence load distributions and thus growth related apophyseal injuries. Although further research is needed to rigorously challenge this bid for target strength training specific to the management and mitigation of growth-related injuries, this presents a truly governable and PROACTIVE strategy amongst both the symptomatic and asymptomatic athletes (if administered appropriately). However, in our attempts to introduce this with youth athletes we must continuously consider the contextual factors of low training age as well as those outlined above, when employing these interventions. Whilst also ensuring that principles of training and progressive overload are central to our programming decisions, there are numerous options available to us and isometric training presents itself as a very fitting option in the case of the growth-related injuries that have been discussed thus far.
Isometric training has picked up considerable traction in recent years in both a strength & conditioning and rehabilitation setting for reason beyond the lack of DOM’s and ease of application. Despite the difficulties or assessment without appropriate technology, isometric has seen profound benefits such as
- Analgesia
- Tendon Adaptations
- Neuromuscular Adaptations
- Safer methods of Maximal Strength Assessment
Figure 1 & 3. Examples of Isometric Exercises - Photo by Sergio Pedemonte & Tyler Nix on Unsplash
“Bang for your buck” comes to mind when looking at this list particularly in relation to the introduction of targeted strength training with PRE or CIRCA PHV youth athletes. The primary focus of this intervention in this context is to enhance the force production capabilities of the quadriceps and triceps surae group. Therefore, the ability to develop strength through Neuromuscular adaptions without the associated soreness present from more traditional strength training methods ensures opportunities for increased frequency / volume and more importantly considerable improvements in strength in quick succession (4 – 6 Weeks). Yet, to truly develop the dampening and strut like behaviours of the muscle, isometric exercise can be divided into yielding and overcoming types which yield (no pun intended) strength benefits of greater specificity to the mechanism of force/load distributions in these sporting actions (13). Finally, with pain and antalgic gait being a key driver behind time loss in these injuries the analgesic benefits of isometric exercises approve its use in symptomatic as well as the asymptomatic individuals.
Irrespective of the favourable elements that isometric training offers us as a means of increasing capacity safely and effectively in youth athletes, the holistic components that contribute to these growth-related injuries cannot and should not be neglected. Therefore, training muscles and NOT just movements could form part of our armoury alongside load monitoring, cryotherapy, education, and movement in our attempts to tackle Osgood Schlatter and Severs incidence and burden in our youth.
References
Display Cover Image Credit - Photo by Yogendra Singh on Unsplash
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