A Move to Improve - 7: Stretching
As a Physio I often prescribed stretching specific muscles to overcome imbalance and improve comfort or performance. As an active adult unfortunately I do not practice what I preach and rarely stretch pre/post exercise. Despite participating in yoga for 5 years I felt no real benefit in comfort, flexibility or injury prevention so turned my back yoga studio. There is a good reason for this, not all stretches work for everyone but, it is important to maintain appropriate muscle length, so I am going to take you through a few different options for you to try yourself.
One of the main reasons why some stretches work and others don't is the structure you are stretching. An example of this is after a total knee replacement. If the quad muscles are stopping the knee from bending I will have the patient do a few strong bends of their knee with not much hold time. This is because the muscle is partially contracted (therefore shorter) and so all I need to do is pull the actin and myosin apart to create a the same sarcomere length as relaxed muscle. If the same patient is having trouble straightening their leg this is often a connective tissue issue. Connective tissue is very difficult to stretch if at all and some research says ligament length won't be affected just our tolerance to the stretch. For this reason I prescribe 1x long (20min) stretch of the back of their knee; usually with their foot on a chair. So, as you can see for the same person there are 2x different stretching techniques based on what the tissue is you want to stretch.
Stretching is mainly prescribed to help with an issue of inappropriate muscle length. So, if your muscles are even left and right and not shortened there is little benefit to be made from a quick 5-10min stretch before a run as this does not even reduce risk of injury. However, there are benefits to doing longer sessions (>45min) of stretching such as hatha yoga. As mentioned above the longer stretching sessions help reduce the 'fear' of tension on connective tissue and so you can move further without reactive restriction by over protective muscles. This however takes time and need to be done regularly. Yoga also helps with other parts of your life such as stress, anxiety and productivity by assisting with relaxing the body. So, if you are comfortable with your movements through life, don't stiffen up from sitting at a desk all day, don't need to do a downward dog as part of your work and you are relaxed with minimal anxiety then yoga is only good for socialising.
In terms of injury prevention the standard static stretches you would do at school have not been shown to help. I different type of stretching, called dynamic stretching is better. This is because there are very few times in a rugby match where you stop, sit on the ground in the figure 4 position leaning forward. At no time in a swimming race does a competitor reach their arm across their body. Despite this we are taught these stretches and religiously taken through them before doing anything active. The difference with dynamic stretching ( as the name suggests) is the movement involved with these stretches. How many times in a soccer game would a player stretch their hamstring by kicking a ball compared to sitting down and leaning forward? The stretch needs to mimic the movement.
The reason for this is during a static stretch we are taught to relax the muscles so we have less tension on the joint - this also means less control. However, when we go to kick a ball, all the muscles in the body are contributing in some way to make sure the foot goes where we want and with the right amount of force and we stay balanced while completing the task.
So, with dynamic stretching it is not just about putting the target muscle under tension (which as discussed above may or may not make a difference) but allowing the other muscle to co-ordinate themselves to provide the correct amount of support to make the action happen in a controlled way, stopping the limb from going too far and causing injury.
So, take home messages:
1. static stretches for tension or discomfort eg prolonged sitting
2. Static stretch don't prevent injury
3. Sports specific dynamic stretches eg leg swings for soccer players are best for injury prevention
Life is too short to worry about pain