Flexibility is defined as the ability to move a joint through its full range of motion. Stretching is used by physiotherapists and others to realign muscle fibres and correct unnatural shortness in muscles, improving the function of joints. Stretching before or after exercise is also used to increase movement at joints but opinion is divided on the value of this method, especially in the case of static stretching, when various parts of the body are placed in specific positions and held there, for example, Hanumanasana, Samankonasana, Kurmasana.
There are a few problems associated with this kind of stretching, apart from outright muscle tearing:
- Muscles are damaged if intense stretching is started without the body being warmed up properly. Warming up muscles means increasing the flow of blood to them, usually by doing some form of exercise that raises the heart-rate and by gradually increasing the ranges of motion at joints. Sun Salutations perform this function and as such are very important. Some people complain that they are boring and repetitive, but there are many different salutes out there, taking the trouble to learn a variety of established forms, or being innovative and creating your own will ensure that you are not bored, or boring, as a teacher.
- Muscles don’t lengthen beyond the Stabilisers ability to support them, or the strength and flexibility of the Antagonists involved. If they are forced to stretch, they are damaged at a microscopic level and weakened, and always feel tight and sore- this is especially true of hamstrings and hip muscles. These relationships will be explored in Hip and Leg flexibility.
- Asanas which stretch intensely are held for too long: if asanas like Hanumanasana feel comfortable, then they can be held for long periods, but if they don’t, holding them longer than 15-20 seconds (5 breaths) can be damaging. Most health professionals consider 15-20 seconds an optimum period for effective stretching, beyond that, there is very little positive value in stretching, muscles are weakened and have slower responses.
- Static stretching occurs in fixed positions and planes, so muscles are always stretched in a particular way, whereas dynamic flexibility is what the body needs to safely perform movements, all muscles need to be a similar length, thus Hanumanasana needs to be practised together with Kapotasana, Titthibhasana, Samankonasana, Parighasana, Vasistasana, Crescent lunges and Kurmasana, or variants of these asanas, and a similar level of flexibility should be found in all these asanas, if not, this points to a muscle imbalance.
Muscle imbalance is a basic cause of many yoga injuries, especially stretching related injury. Assisted stretching, whether with partners or straps, should be approached with great caution – it frequently causes more harm than anything else in yoga.
Flexibility must be tied to strength – joints need support, to move safely. Strength does not limit flexibility, but enhances it: ask any dancer, gymnast or martial artist, they all move in ways that require high levels of both.
Sharkey, 2008, The Concise book of Neuromuscular Therapy
Franklin, 2004, Conditioning for Dance
Kim, 2004, Ultimate Flexibility