Introduction, Physiology and Application

Stretching is a form of exercise applied to skeletal muscles. Represents
pressure in the direction of the muscle attachment points in order to
distance them. Stretching stretches both, muscles and adjacent tissues
(tendons, connective tissue, peripheral nerves, muscle fascia). Stretching refers to the optimal range of motion of a joint.

Stretching is often performed by abducting the target muscle group
relative to the torso. Its main task is to improve muscle elasticity,
lengthen muscle fibers, and improve overall tone.

Physiology of stretching

The biomechanics of skeletal muscle is under our conscious control and
work on the principle of opposites, for example: when we want to
straighten the knee, the brain sends signals to the quadriceps, it
tightens, and its opposing back thigh muscle relaxes and stretches.
This action, in turn, triggers a sequence of physiological reactions that
remain beyond our logical awareness and are known as the stretching
reflex.
In essence, it is a protective mechanism that protects the joints from
injury.

Receptors located in the joints, muscles, and tendons detect movement
and signal the central nervous system, which response to the stimulus
by regulating the momentary contractility of the muscle and its length.
This in turn affects the range of motion of the working joint.
Thus, conscious biomechanical actions cause unconscious physiological
reactions.
The main sensory organs involved in controlling the length of muscle
fibers are the muscular spindle and the Golgi apparatus.
Moving the body in a given position initiates a chain reaction of
biomechanical and physiological events.

• Stretchability – Stretching refers to muscles, tendons, andligaments, ie. this is the ability of the fibers to increase their lengthunder the influence of applied pressure. This concept should not beconfused with “elasticity”.
• Elasticity – Elasticity is a quality of muscles that allows them toregain their original shape after deformation – under the influenceof weight or after stretching. When a muscle is shortened, itselasticity increases at the expense of extensibility; in case ofmuscle fatigue, the extensibility increases.
• Mobility – Mobility is a quality of joints that depends on severalfactors and relates to their range of motion.

Mobility and stability of the joints

Mobility and stability in the joints exist on the principle of opposites -the greater the mobility, the less stability. Feedback is also valid. Threefactors determine the range of motion of each joint:

1. The shape of the bone;

2. The structure of the joint fossa/cavity and surrounding tissues;

3. The muscles located around the joint.

The structure of the bones involved in the formation of joint connections
contributes to the range of motion in a given joint.
Large and deep, the hip joint has a limited range of motion on the three
surfaces (frontal, vertical, and sagittal), but it has a stability that takes
almost all the weight of the body.
A shallower joint structure, such as the shoulder, has significantly
greater mobility, but finds it difficult to stabilize more weight.

The capsule and ligaments surrounding the joint are made up of fibrous
connective tissue. This whole structure tightens the bones together and
also affects joint mobility and stability.
The bones that form strong and stable joints (as in the case of the
sacroiliac joint) are associated with extremely strong ligaments that
limit the mobility of the “joint”.
On the other hand, the bones that make up the shoulder joint are joined
by much looser and more stretchable ligaments, allowing a wide range
of motion.
Near the joint are located muscles or the so-called joint stabilizers.

Muscle contraction not only serves to move but also to stabilize the
joint. The degree of muscle contraction affects the mobility of the
joint.
Stretching lengthens the muscles that stabilize a joint, allowing greater
freedom in the movement of the joint.
Regular stretching exercises gradually relieve tension in the muscles
that stabilize the joints and provide more comfortable movement in all
joints.

When should you strech?

As mentioned at the beginning, stretching, increasing the length of
muscle fibers should not be used as a form of pre-workout warm-up.
It requires good training and warm muscles to be performed safely and
to get the most out of its application.

So therefore to get the best results in long-term strech after your workout.