by Adriano A-S
I dislike the term 'prevention' (hence why it is in quotation marks) because of the simple fact that you can't know that you prevented something that did not occur. Also, I am of the thought that the best form of injury prevention is appropriate training. However, someone can definitely take action to decrease the likelihood of something happening. In light of this, in this post I will outline some of the strategies a physical performance coach may implement in the football codes (football-soccer, AFL, rugby union/league/sevens, etc.) to decrease the chances of hamstring injuries occurring by looking at and addressing different facets of an athlete's preparation.
Hamstring injuries represent the most common injury in professional football (soccer) and AFL (Ekstrand et al., 2009; Orchard et al., 2013). Further, hamstring injuries come with significant burden where sport participation may be limited anywhere from 48 to 83 days lost/ 1000 hours (Whalan et al., 2018). Therefore, sports performance practitioners spend much of their efforts and energy in fighting hamstring muscle injuries in these sports.
In football (soccer), the most common type of hamstring injury are muscle tears (Incidence [95% CI] 0.27 (0.18–0.37)) followed by muscle strains (0.20 (0.14–0.30)) (Raya-González et al., 2020). The most widely documented location of injury is the long head of the biceps femoris, which originates from the lower and inner impression on the posterior part of the ischium tuberosity (hip). The long head of the biceps femoris is a weaker knee flexor when the hip is extended and a weaker hip extender when the knee is flexed.
Over time, studies have demonstrated that the most common mechanism of hamstring muscle strain/ tear in football is an excessive strain in eccentric contraction (lengthening), instead of force production per se. Moreover, the elongation speed and duration of activation before the eccentric contraction is thought to affect the severity of the injury (Best et al., 1998), and therefore the rehabilitation required. It has also been proposed that in sports like AFL, rugby, American football, and football (soccer), hamstring strain injuries tend to occur during the late swing phase and late stance phase of sprinting (Liu et al., 2012). Schuermans et al. (2014) proposed that, under fatigue, the biceps femoris muscles must compensate for the lack of endurance of the semitendinosus muscles, increasing the hamstring injury risk; and that therefore, improving fatigue tolerance with gradually greater chronic high-speed running (HSR) loads is important.
As physical performance practitioners, in order to use our practice to minimise the likelihood of hamstring injuries, it is central to examine the factors that are under our control (i.e., modifiable). Some of the modifiable risk factors, for hamstring injuries and muscle injuries in general, that have been identified in the scientific literature include:
Previous injury and/ or inappropriate rehabilitation of this one
Unprecedented spikes in high-speed or sprint running loads
Sub-optimal hamstring conditioning
Sub-optimal eccentric hamstring strength and/ or strength imbalances
Shortened optimum muscle length / lack of hamstring flexibility
Inappropriate/ insufficient warm-up
Fatigue and/ or sub-optimal sleep
Sub-optimal running mechanics (grey area)
Lower back injury and/ or poor lumbar posture
Poor trunk muscle strength and/ or endurance
Increased muscle neural tension
There is also some more novel and ecological research proposing that in football (soccer), playing position, timepoint during the competitive year, and time period during the match are also pertinent risk factors that may be addressed with practice to better our chances. Specifically, a longitudinal injury surveillance study by Raya-González et al. (2018) in Spanish footballers reported:
Playing positions that demand greater distances running at high intensity or sprinting (i.e., fullbacks, wide midfielders and forwards) present the highest hamstring injury rates than other playing positions (i.e., centre-midfielders and centre backs).
Hamstring injuries occur most frequently toward the end of each half (i.e., 30–45 minute and 75–90 minute intervals), probably due to fatigue-related effects.
Hamstring injury incidence also showed a seasonal variation, where most (peak incidence) occurred in the pre-season (August), likely due to the accumulation of fatigue from intensive periods of soccer-specific training (Gabbett & Ullah, 2012); and after the start of the in-season period (October), likely due to physical stress from competitive matches, where young players may be at the highest risk (Jayanthi et al., 2015).
A physical performance coach may be involved in multiple areas of a football athlete's preparation, including: strength and conditioning training, nutrition, recovery, load monitoring and injury management. Therefore, here I have created a mind-map with some of the potential areas to intervene to reduce the risk of hamstring injuries in a footballer's preparation.
Key: HSR: High-Speed Running
To follow, I present a Table with three columns.
Column 1 (red) displays a list of risk factors that physical performance and medical practitioners may wish to address in reducing the likelihood of their athletes experiencing a hamstring injury.
Column 2 (blue) represents the logical course of action to take.
Finally, Column 3 (green) displays a list of strategies (and objective parameters), that may be applied in practice to address the risk factor. The list is not exhaustive.
Key: HSR: High-Speed Running, VHSR: Very High-Speed Running
Link 3: https://link.springer.com/content/pdf/10.1007/s10865-006-9047-6.pdf (see Appendix for Sleep Hygiene Index)
Clearly, both injuries and fatigue in sports are complex phenomena, inter-linked by physiological, biomechanical and psychological factors, and are often impossible to reduce to one sole causal factor. It is true that appropriate physical training strategies may reduce an athlete's risk of injury, delay fatigue onset, and when they do occur, accelerate the injury rehabilitation process. Likewise, identifiable factors including sleep, nutrition, genetics and psychological stress, may play a role in protecting or pre-disposing an athlete to injury and/ or higher levels of performance.
With this post hopefully I outlined some practical strategies that will help hamstring injury risk mitigation. However, as physical performance specialists will be aware, no one strategy is a guarantee, or will fix the problem, and context will often determine the efficacy of each strategy. With that said, by implementing these strategies you will certainly be putting some chances in your athletes favour...
Thanks for taking the time to read.
Whalan, M., Lovell, R., McCunn, R., & Sampson, J. A. (2018). The incidence and burden of time loss injury in Australian men’s sub-elite football (soccer): a single season prospective cohort study.
Raya-González, J., de Ste Croix, M., Read, P., & Castillo, D. (2020). A Longitudinal Investigation of muscle injuries in an elite spanish male academy soccer club: A hamstring injuries approach. Applied Sciences, 10(5), 1610.
Best, T. M., McElhaney, J. H., Garrett Jr, W. E., & Myers, B. S. (1995). Axial strain measurements in skeletal muscle at various strain rates.
Liu, H., Garrett, W. E., Moorman, C. T., & Yu, B. (2012). Injury rate, mechanism, and risk factors of hamstring strain injuries in sports: A review of the literature. Journal of Sport and Health Science, 1, 92e101.
Schuermans, J., Van Tiggelen, D., Danneels, L., & Witvrouw, E. (2014). Biceps femoris and semitendinosus—teammates or competitors? New insights into hamstring injury mechanisms in male football players: a muscle functional MRI study. British journal of sports medicine, 48(22), 1599-1606.
Gabbett, T. J., & Ullah, S. (2012). Relationship between running loads and soft-tissue injury in elite team sport athletes. The Journal of Strength & Conditioning Research, 26(4), 953-960.
Jayanthi, N. A., LaBella, C. R., Fischer, D., Pasulka, J., & Dugas, L. R. (2015). Sports-specialized intensive training and the risk of injury in young athletes: a clinical case-control study. The American journal of sports medicine, 43(4), 794-801.
Strand, S. L., Hjelm,