Getting Back to Sport After Hamstring Injury
The following write up will outline everything you need to know about hamstrings – including what they are, what their role is in sports, how injuries happen, how to come back from them and how to prevent them from happening again.
For those of you who’ve had a hamstring injury, you’ll agree that they can be one of the most frustrating and difficult sporting injuries to get on top of. You’re not alone – Hamstring injuries are the single most common injury in elite football and AFL (Ekstrand J, 2011). The risk of reinjury is also high. Up to one-third of hamstring injuries will recur, with the greatest risk being during the initial 2 weeks following return to sport (Orchard J, 2005). As a result, they account for a lot of days rest and a lot of money and resources to rehabilitate them. Thus, an abundance of money is currently going in to sports science/medicine in an attempt to figure out how we can best treat, manage and prevent hamstring injuries from having such a burden on amateur and elite athletes.
Anatomy & Function
The hamstrings comprise of three muscles:
- Biceps Femoris
- Short Head
- Long Head
All three hamstring muscles (excluding the short head of BF) connect from the pelvis and insert onto the shin bone. These muscles cross two joints (hip and knee) and are therefore termed ‘bi-articular’.
This anatomical information is important as it means that the hamstrings have two actions – 1) flex the knee and 2) extend the hip. Thus, it is essential that hamstring exercises are prescribed that act both at the hip and at the knee (we’ll get into exercise details a bit further down).
When performing hamstring exercises, externally rotate your foot (outwards) to bias biceps femoris activation. Internally rotate your foot (inwards) to bias semitendinosus and semimembranosus activation.
The ability to rapidly and forcefully extend the hip and flex the knee is integral to sprinting. When the hamstring group concentrically contracts (muscle getting shorter in length), in unison with the gluteus maximus and the calf muscles, the leg is moved backwards and the body is propelled forward through space. Injuries to the hamstring muscles during sprinting are referred to as type I muscle strains (see below).
Aside from concentrically contracting to bring the leg backwards while sprinting, the hamstring muscles also eccentrically contract (muscle getting longer in length) at the end of a swing, stretch or kick to bring the leg back to the ground. Injuries during stretching movements are referred to as type II muscle strains.
Types of Injury
There are two distinctly different types of hamstring injuries that can be distinguished by different mechanisms of injury – type I and type II strains.
It’s important to note that the severity of hamstring strain is an important prognostic factor with respect to return to play. This is commonly done through an MRI machine and will be diagnosed as either grade I, II or III.
It is very difficult to determine how long an athlete may be out for based on their MRI report (Chumanov, 2007). For example, athlete A may have a minor grade I type I hamstring strain and require 6 weeks of rehab, while athlete B may have a moderate grade II type II hamstring strain and return to sport within 3 weeks. Other prognostic factors are considered when determining an athletes prognosis (Brukner et al, 2017)
- Days to walk pain free (>1 day = 4 times more likely to take >3 weeks)
- The more proximal the site of injury to the pelvis = the longer the return to play
- Involvement of the tendon = longer return to play
- Larger tenderness area with palpation = longer return to play
- Less self-confidence = longer return to play
Rehabilitation & Prevention
As mentioned earlier, a lot of money has gone into researching how we can best rehabilitate athletes returning from hamstring injuries so that they can 1) return to sport faster and 2) reduce the risk of reinjury.
In 2013, Carl M Askling proposed three exercises that would achieve these outcomes more consistently and reliably than any other method of rehabilitating hamstrings.
Carl and his team recruited seventy-five elite swedish footballers with varying severities of acute type I or type II hamstring strains. These seventy-five athletes were randomly assigned to carry out one of two rehabilitation protocols (lengthening vs conventional) which consisted of three hamstring exercises each.
Average time to return to play for the athletes in the L-Protocol was 28 days when compared to the C-Protocol which was 51 days. At a 12 month follow up, none of the athletes in the L-protocol had reinjured their hamstring (Askling C, 2013)
You can find video tutorials on how to complete these exercises here
The authors of this paper concluded that a rehabilitation protocol consisting of mainly lengthening type exercises is more effective than a conventional protocol in promoting return to elite football after acute hamstring strain. On this basis, rehab should be based on strength and flexibility exercises with high loads at long muscle-tendon lengths (Askling C, 2013). This exercise protocol has also demonstrated that if adhered to strictly, can significantly reduce the risk of reinjury.
Now it’s important to note that this is just one randomised control trial within a sea of evidence for treating hamstring injuries. The take home message from this paper is that exercises that load the hamstrings in a lengthened position should be implemented in protocol. Recommend these evidence based exercises to your physiotherapist when rehabilitating your hamstring injury so you can get back to your physical best!
George Dooley (APAM)
Askling, C. M., Tengvar, M., & Thorstensson, A. (2013). Acute hamstring injuries in Swedish elite football: a prospective randomised controlled clinical trial comparing two rehabilitation protocols. Br J Sports Med, bjsports-2013.
Askling, C. M., Tengvar, M., Saartok, T., & Thorstensson, A. (2007). Acute first-time hamstring strains during high-speed running: a longitudinal study including clinical and magnetic resonance imaging findings. The American journal of sports medicine, 35(2), 197-206.
Brukner, P. (2012). Brukner & Khan’s clinical sports medicine. Chapter 34, Posterior Thigh Pain North Ryde: McGraw-Hill
Chumanov, E. S., Heiderscheit, B. C., & Thelen, D. G. (2007). The effect of speed and influence of individual muscles on hamstring mechanics during the swing phase of sprinting. Journal of biomechanics, 40(16), 3555-3562.
Ekstrand, J., Hägglund, M., & Waldén, M. (2011). Epidemiology of muscle injuries in professional football (soccer). The American journal of sports medicine, 39(6), 1226-1232.
Orchard, J., Best, T. M., & Verrall, G. M. (2005). Return to play following muscle strains. Clinical Journal of Sport Medicine, 15(6), 436-441.