Stretching should feel wonderful, but be careful to ensure you know what you should stretch when you stretch. Stretching the wrong tissues may cause irreparable damage to your body.
Bones and joints
Don’t put pressure on your bone and joints when you stretch. There are no positive changes from attempting to alter the shape of joints by stretching. Some sports rely on flexibility as an indicator for performance, and can put enormous pressure on bones and joints. This can damage the growth plates of a child or adolescent, causing growth problems, or cause deterioration in the structure of the bone leading to chronic joint injuries of an adult.
Don’t put too much stretch on the muscle tendons. They are made up mainly of the strong, inelastic connective tissue called “collagen“, rather than the supple connective tissue called “elastin“. Tendons are like rubbery plastic that are designed to transmit force from the muscles to the bones. Tendons are designed to stretch by about 5 percent, so they only have enough elasticity to be able to absorb sudden forces without snapping, rather than have an extended range of movement.
Stretching tendons often causes micro-tearing of the inelastic collagen fibers (which is that hot burning sensation you get when you stretch too far), the formation of scar tissue, and ultimately a loss of flexibility and an increase in the potential for injury.
If you have a chronic tendon injury, your sports doctor or physiotherapist may prescribe massage, stretching, and associated treatments for the injured tendon, but this is treatment under medical supervision, not everyday stretching. Tendons need to be warmed up and lubricated before exercise, not stretched.
Don’t stretch ligaments or the capsules around your joints. These connective tissues need to be tight to stabilise joints, so if you keep stretching them they’ll eventually weaken and lose the ability to hold your body together.
The main areas where ligaments are over stretched are the knees and the lower back. You need to be under the direction of an experienced, knowledgeable, and trained instructor when stretching these areas.
You’ll know when you’re doing a stretch incorrectly because you’ll feel that hot sensation in the ligaments or joints as you stretch.
Your instructor should be able to advise you on the use of joint mobility exercises to prepare joints and ligaments for the stress and strain of exercise, and to help them recover after exercise. Like tendons, ligaments and joints need to be warmed up and lubricated before exercise, not stretched.
We finally get to the organs in your body that should be regularly stretched – your muscles. Muscle flexibility, mobility, agility, and coordination are all highly trainable through correct stretching.
There are many types of muscle stretching, and here are the three common types of muscle stretching:
The first type is called “double ballistic muscle extension“, or “ballistic stretching” – swinging limbs or torso through repeated bouncing or double action movements at the end of their normal range of movement. This type of stretching is not normally recommended as it can lead to chronic joint and tendon injuries if it is done incorrectly or at the wrong time.
We often see this in the old-style “warm up” where the exerciser flings their arms about a bit, touches their toes a few times, twists their back, then gets into their exercise activity. This abuse of ballistic stretching will lead to long-term decreases in flexibility, and may damage the muscles.
Ballistic extensions activate the stretch reflex. The stretch reflex occurs every time you stretch the muscle fibers too far, for example by bouncing, over-stretching, or stretching a muscle quickly. This reflex is an unconscious nervous signal, designed to protect muscles by activating them to contract. Activating the stretch reflex will cause a muscle to tighten up, not become more flexible! This also leads to microtrauma in the muscle, the formation of scar tissue, and the gradual, loss of muscle flexibility.
The next type of stretching is called “static muscle extension“, or “static stretching“. This is simply where you extend a muscle to the end of its range of movement, and then hold it there for a period of time.
After muscles have been warmed up, static stretching of muscles before exercise can help increase muscle force output. Muscles contract with more force if they are put into a position of slight stretch for five to 10 seconds before activity.
After activity, the stretch reflex is dulled and developmental static stretches held for 20 – 40 seconds can counteract the shortening of muscles associated with activity, and speed up the recovery from exertion. Developmental stretching can give excellent increases in flexibility.
The third major type of stretching is called “proprioceptive neuromuscular facilitation“, or “PNF stretching“, and uses a maximal muscle contraction to do tricky things, such as deaden muscle receptors which usually cause a muscle to contract as a response to stretch.
Finally, as a general rule you should concentrate the center of force of the stretch in the belly of the muscle being stretched. This will maximize flexibility gains, and reduce the chance of injury to associated tissues.