The hamstrings – or as they are sometimes referred to – the “hammies”, are the muscles that run down the back of your leg and flex your knee. Unfortunately hamstring injuries are extremely common. They affect people across all sports and, more often than not, they are really tricky to deal with. Most people tear a hamstring when performing explosive activities like sprinting (remember Asafa Powell in the 100 metre final in London 2012?), changing direction, rapidly slowing down, and kicking. Your hamstring can also tear from slower speed movements if done in the right way. Dancers most commonly experience these slow overstretch injuries.
What are the main reasons for you being more at risk of hamstring injuries?
The literature shows that if you’ve injured your hamstring before, you are up to 6 times more likely to get injured again. This is due to a number of reasons. Failing to rehabilitate the injury and rebuild the hamstring strength is considered to be one of the most important. The message here is that prevention of hamstring injury is vital. Once injured, you are probably going to be back on the treatment couch again in the future.
To start with, let’s quickly go through to types of muscle action:
- Concentric hamstring muscle contraction: standing up and bringing your heel to buttock. This shortens the muscle. Stay in this position as you read about the next type of action.
- Eccentric hamstring muscle contraction: Slowly let your foot lower to the floor (take about 10 seconds to do this). You should feel your hamstring muscle work against gravity to keep the movement slow. This is lengthening the hamstring against load.
The most important thing to consider now is the strength ratio between the quad (thigh) muscles and the hamstrings. A CONCENTRIC ratio of 1:0.6 or 66% has been used for a long time for the hamstrings, but this is only for its concentric strength. For example, if your quads can push 100kg, your hamstrings should be able to pull 66kg.
However, a much more useful and important ratio is the ECCENTRIC ratio. For most a ratio of 1:1 is used, (1:1.2 if you’re an elite athlete). For example, for every 100kg your hamstring can pull as the knee bends, it must be able to RESIST 100kg as your knee gets straightened (120kg if you’re an elite athlete).
If you are a dancer, you are more likely to injure a certain part of the hamstring than a sprinter would, as the mechanism of injury will be different. This means that you need to use different preventative exercises to protect different parts of the muscle.
The literature is mixed on the importance of hamstring flexibility. Many studies have found that stretching is not associated with hamstring injury. From a common sense point of view, you need your hamstring to be flexible enough to do the task in hand. So, if you are a dancer, you will need more flexibility than, for example, a wrestler. But, aside from the hamstring itself, it is definitely important to look at the flexibility relationship between the other hip and knee muscles. If your hip flexors and quads are tight, the movement at the hip and knee will be restricted, thus placing more tissue strain on the hamstring.
Core stability or lumbopelvic stability
Recently the literature has linked core stability with hamstring injuries. A secondary role of the hamstrings is to stabilise the lumbopelvis. If the spine and abdominal muscles are doing their job properly, the hamstrings play only a very minor part in this. If those muscles are weak, the hamstrings have to work harder and will be placed under more strain.
Using football as an example, a study looking at the European football leagues found there are more hamstring strains at the end of each half of matches. If you are not properly conditioned for the sport you are taking part in, you will tire earlier. This is when your hamstring will tear. Make sure you’re prepared for your specific sport. Think about your general health too. If you are stressed, ill or have poor nutrition, you are more likely to experience fatigue sooner.
In summary, if you have experienced a hamstring injury, come in and get it properly assessed. We can identify the areas you need to address and help to avoid repetitive injuries and worsening tears. Most of the risk factors above are modifiable. Therefore it is important that you always warm up correctly and prepare yourself well by ensuring your eccentric hamstring strength, core stability and hip and knee flexibility are up to speed. Thanks and happy training!
If you are experiencing hamstring injury problems, make an appointment to see one of our highly qualified Osteopaths and Physiotherapists. You can book appointments online or by calling 020 8789 3881.