Center of the Gravity

Republic of the Philippines

CAMARINES NORTE STATE COLLEGE

Daet, Camarines Norte

INTRODUCTION: When the body is in equilibrium, an even adjustment exist among all opposing forces, and the body is in balance. The state of balance may be secure. And when it is secure, the body is said to possess a high degree of stability.

* Stability is firmness of balance, or the ability to resist forces by which may destroy balance.

CENTER OF THE GRAVITY

Can be defined as:

* The point of exact center, around w/c the body may rotate freely in all direction.

* The point around which the weight is equal on all opposite side.

* The point of intersection of the tree cardinal (primary) body plains-sagittal, frontal, and transvers.

Important factors on understanding how the center of gravity and itseffects on its performances:

1. Because the differences in the body structure b/w men and women, the center of gravity is usually proportionately lower in women than in man.

2. On the average. The center of the gravity is proportionately higher in children than in adults as a result in change in the body.

3. The center of gravity is affected by amputation and other structural changes w/c cause the body to deviate from normal.

4. The center of gravity is influence by specific body position.

5. The addition for external weight, such a backpack, will relocate the center of gravity.

PRINCIPLE OF BALANCE

* For a balance to be maintained in any stationary position, the center of the gravity must remain over the base of the support.

* For a balance to be maintained in standing position, continuous forward body lean is necessary.

Type of balancing skills in performing effectively

1. Adequate strength to support the body in a given position.

2. Ability to shift the body weight quickly into the correct position at the right time.

Quality of STRENGTH

* Contractile force of the mover muscle.

* Ability to coordinate all the muscle involved in the act.

* Mechanical ratio of the different levers.

Quality of SHIFTING BODY WEIGHT

* Kinesthetic perception and visual perception.

* Function of the balance center of the inner ear.

* Quick reaction, good neuromuscular coordination, agility, and passively flexibility.

RECOVERY OF THE BALANCE

Principle: if the center of the gravity moves outside the base of support, a quickly adjustment must be made in order to regain balance the base of the support may be move or enlarge, or the body part may be adjust in order to return the center of the gravity to a position over the base of the support.

SENSORY- RECEPTOR ADJUSTMENTS

Principle: the reduction of unfamiliar sensation associated with the balance receptor often reduces dizziness w/c may lead to a loss of balance. Also, fast-twirling head movements produced movements of fluids in the inner ear w/c give rise to the sensation of dizziness.

CARRYING POSTURE

Principle: when external weight is applied to the body, as in lifts and carries, the body must be shifted in order to maintain balance around the line of the gravity.

PRINCIPLE OF STABILITY

* Stability is a firmness of balance, the stable the body is less to be disturbed by any upsetting influences.

* The physical makeup of a person exerts strong influence on his stability.

POSITION OF THE CENTER OF THE GRAVITY

Principle: for maximum stability in all direction the center of the gravity of the body should be placed over the center of the base of support or as near to as it's possible.

LOWERED CENTER OF GRAVITY

Principle: stability may be increase by lowering the center of gravity.

ENLARGE BASE OF SUPPORT

Principle: stability is enhancing by increasing the area of the base of support.

* As the base becomes larger the center of the gravity must be moved through a greater distance in order to disrupt the balance.

BODY SIZE AND PROPORTION

Principle: all else being equal, the greater the weight the greater the stable the objects is against external forces

FRICTION

Principle: the greater the friction b/w the supporting surface and the body parts in contact with that surface, the greater the stability.

Moving the center of the gravity toward the force

Principle: if a known fore is approaching, and the performer wishes to maintain balance. The center of the gravity should be very near the edge of the base of support on the side nearest