Hamstring injury is the leading cause of loss of game time in rugby players. It is a common injury and can be caused by several factors. Recent research on hamstrings injury in rugby players is helping guide an important component of return to play. How much strength you have is unsurprisingly one of the most important factors guiding our rehabilitation of these important injuries.
How are hamstrings injured?
This can be from a number of causes like over training, sudden over stretching or high-speed running to name a few. The hamstring exerts force to decelerate the leg while swinging through the running stride. Such movement is known as eccentric loading, or the contraction of the muscle to control lengthening of a joint. Let me explain further. The hamstring primary role is to bend the knee, contraction of the hamstrings bends the knee. However, the hamstring muscles also act as a brake when the knee is straightened by the quadriceps. When the knee is straightening, and the hamstrings are active we call this eccentric activation of the hamstring, contraction of the muscle as it lengthens rather than shortens. The quadriceps are straightening the knee while the hamstrings is coordinating the speed this happens to help control the movement. This action at high velocity can sometimes lead to overloading of the hamstring and the muscle tearing.
Why is eccentric load on the hamstring important?
Studies have identified increased injury risk in hamstrings when there is an imbalance between one side and the other. This can be the result of a previous injury, previous surgery to surrounding structures (like an ACL injury for example), over loading or through under activity. We can measure this eccentric strength and compare one side against the other side through various exercises like Nordic curls, using theraband, gym machines or bridge variations.
How much is at risk with asymmetrical hamstring?
A recent study of 178 rugby players from the Queensland Reds and lower grades revealed there is increased risk of injury with increasing imbalance. The research showed you are 2.4 times more likely to be injured if your hamstring was 15% weaker than the other side. This increased to 3.4 times if the imbalance was 20%. Fortunately, this study did not find any correlation with older players and injury risk, phew!
So how do we rehabilitate these injuries?
This is the important part. There are many aspects to rehabilitation which help you return to what is important to you. Our role as therapists is to ensure you are in the best condition to reduce your chances of re-injury. We tailor your rehabilitation to suit your sport and lifestyle demands.
If you would like to discuss a hamstring injury, or any other sports injury, come in and see us here at Bend + Mend at one of our four Sydney city locations.