An Introduction to Movement and Functions of Skeletal Muscle:



Knowledge of the muscular system is essential to massage
therapists because skeletal muscles and their related fascia
are a primary focus in the application of effective massage
therapy treatments. The thought of being alive brings to the
forefront the idea of movement-- the heartbeat, fascial
expressions, and the rise and fall of the chest with each breath. 
These visible signs of life are all created by muscle
contractions.

Muscle cells are referred to as muscle fibers. Each fiber is
surrounded and protected by fibrous bands of connective tissue
which is known as fascia. Superficial fascia is immediately deep to
the skin, and deep fascia surrounds the muscles, holding them
together, yet also separating them into functioning groups.
The term myofascial refers to the skeletal muscles and related fascia
in the muscular system. It is important to understand that all fascial
structures are continuous with one another; that is their fibers
blend together, hence the saying "everything is connected".

Shortening or lengthening of any particular muscle is the result of
change in the relative positions of one muscle fiber to another.
Generally speaking most skeletal muscles are attached to bones by
tendons (another type of connective tissue) that can span joints.
The attachment of a muscle to the bone that moves when the muscle
contracts is referred to as the insertion, whereas the end of a muscle that
is attached to the bone that does not move during contraction is called the .
origin. When the muscle contracts, one bone (the insertion) moves relative to
the other bone (the origin). The insertion end of a muscle always moves towards
the origin.Sometimes muscles work in groups to perform a particular movement.
When a muscle has a primary role in providing a movement, it is called the agonist.
Syngerist muscles work with, or assist, the agonist to cause a movement. Often
muscles span more than one joint, and a synergist will stabilize one joint while
the agonist acts to create movement on the other joint. For example, the fingers
can be flexed to make a fist without bending the wrist because certain muscles fix
the wrist in a stabilized position.

Antagonists are the muscles that oppose, or reverse, a particular movement. For
example, when you bend or flex your elbow, your biceps brachii muscle acts as
the chief agonist and your triceps brachii muscle relaxes. When straightening the elbow
, the biceps brachii muscle relaxes and the triceps brachii muscle on the opposite
side contracts. The two muscles are on opposite sides of the humerus bone and have
contrasting functions in terms of movement.

Every muscle in the body requires and relies on its counterpart. Agonistic muscles
can only exist if the antagonistic muscles are there to oppose and the synergists
are there to support. Overuse and repetitive stress injuries from poor postural habits
can force muscles and intertwining fascial connections into imbalance, therefore
causing discomfort and or dis-ease--to each individual body unique in its own way.
Through becoming more aware of the dynamics associated with the intricate ways our
skeletal muscle moves our bodies, we can become more in-tune with ourselves as a whole,
further facilitating structural healing and balance.  Come visit any one of the wonderful
therapists at the Pittsburgh Center for Complimentary Health and Healing for a truly
customized therapeutic massage session and experience how various modalities of
bodywork can help relax, realign and rejuvenate those overworked muscles.

References:

“Applied Kinesiology: A Training Manual and Reference Book of Basic Principles and Practices” by Robert

Frost

“The Anatomy and Physiology Learning System” by Edith Applegate, MS.

“Massage Therapy Principles and Practices” by Susan G. Salvo

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