Muscle contractions are classified according to the movements they cause
Any contraction where the muscle shortens under load or tension is known as a concentric contraction. For example, the quadriceps muscles in the thigh contract concentrically (shorten) during the upward phase of the squat movement.
Muscles not only ‘shorten’ but can also lengthen under load or tension. An eccentric contraction refers to any contraction where the muscle lengthens under load or tension. In the squat exercise, the quadriceps muscles will contract eccentrically (lengthen) in the downward phase of the movement.
Muscles don’t actually need to move (shorten or lengthen) at all to contract or develop tension. An isometric contraction refers to any contraction of muscles where little or no movement occurs, i.e. a Planck position. The abdominal muscles would be contracting isometrically, it would still be under load/tension but no movement would occur.
Why we lose flexibility as they grow older?
We lose flexibility as they grow older because of diminishing elasticity in our muscle tissue.
A lifetime of activity has build up micro trauma in our muscles, tendons and fascia. Micro trauma is the general term given to small injuries that can include the micro tearing of muscle fibres, the sheath around the muscle and the connective tissue. When it heals, a scar is formed. It pulls the wound together, making the muscle shorter. Stretching the muscle after exercise helps to reset muscles, but cannot really prevent the muscle from healing at a shorter length. Even if you could prevent the muscle from shortening a stiffening of the tendons and ligaments is certain. Ligaments and tendons are made of collagen, which gives them strength, and elastin, which, as its name implies, provides elasticity. As you age, the elastin/collagen ratio changes in favour of collagen, or scar tissue. There isn’t an exercise that can prevent the aging of connective tissues. If you still try to literally stretch yourself, change the mechanical properties of your muscles, tendons and ligaments, your desperate attempts can even bring more injuries than flexibility.
What prevents us from lengthening our muscles?
Fear and Tension!
The muscles tighten up and resist lengthening. Based on our daily habits and exercise routines our nervous system has picked the preferred length of our muscles and want to keep it this way. Whenever we reach passed this standard, the stretch reflex kicks in and reins the muscle in. Not short muscles and connective tissues that make you tight; it is your nervous system. It refuses to let your muscles to slide out to their true full length! A muscle with pre-depression connective tissues and plenty scars is still long enough to display as much flexibility as allowed by its associated joints. Once you master the muscular tension, you will be as flexible as you want to be, at any age.
– muscles habitually kept in a shortened position lose their strength in the stretched position.
When you become stronger in the extreme range of motion through contract-relax stretching, you send the message to your body that you will not be stuck in that position because you now have the strength to recover from it.
Your muscles do not undergo a reflexive contraction since your nervous system perceives the stretch as safe and your flexibility increases.
How do we reclaim our youthful flexibility?
Before we move on, let us examine the muscle roles and contraction types. Antagonist and agonist muscles often occur in pairs, called antagonistic pairs. As one muscle contracts, the other relaxes. An example of an antagonistic pair is the biceps and triceps; during an arm curl – the triceps relaxes while the biceps contracts to lift the lower arm.
For stunning results, stretching exercises must be performed slowly and carefully, with a fixation of the stretched position for a minute or so. While holding the stretch all your intentions should be on relaxation and a reduction of tension in the stretched muscles.
• Relax Stretching – Waiting out the Tension and visualisation techniques work well only in select stretches. Relaxed stretching develops flexibility without strength. This is unnatural. Normally your body does not allow a range of motion it cannot control.
• PNF and Isometric Stretching – Fooling the stretch reflex to gain a few inches in flexibility and more strength. Extreme flexibility through tension and breathing.