AS PE for OCR

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  • Created by: charlotte
  • Created on: 17-01-11 12:12

An analysis of human movement.

The skeleton has 5 basic functions:

Support,

Protection,

Movement,

Blood production,

Mineral storage.

The axial skeleton consists of those bones that provide the greatest support including the skull, the vertebral column and the rib cage.

The appendicular skeleton consists of the bones of the limbs and there respective gurdles.

Bones can be categorised into long, short,flat , irregular or sesamoid.

There are 3 types of cartilage :

Hyaline also known as articular,

white fibrocartilage,

and yellow elastic cartilage.

Bone is a rigid , non elastic tissue, composed of mineral and organic tissue.

There are 2 types of bone :

Compact hard bone.

and Cancellous spongy bone.

Joints are classified according to the degree of movement allowed. There are 3 basic types of joint :

Fixed / fibrous joint.

Cartilaginous joints.

Synovial joints.

Movement at synovial joints can be classified as flexion, extension, abduction, adduction, horizontal flexion, horizontal extension, rotation, pronation, supination, circumduction , plantar flexion , dorsiflexion, inversion and eversion.

The skeletal system can be strengthened through exercise.

Skeletal muscle properties include :

extensibility,

elasticity,

contractility.

Functions include movement , support and posture and heat production.

There are 2 basic types of muscle fibre. Slow twitch (type 1) and Fast twitch (type 2).

Fast twitch fibres can be further subdevided into fast oxidative glycolytic (type 2a) and fast glycolytic (type 2b)

Slow twitch (type 1) can also be known as slow oxidative.

Muscles are attatched to bones via tendons.

The origin of a muscle is the attatchment to a stable bone.

The insertion is the muscle attatchment to the bone that the muscle puts into action.

Muscles often work together to produce coordinated movements. antagonstic muscle action. A muscle directly responsible for the movement is the agonist. The Antagonist often lengthens in order for the agonist to shorten.

 

Muscles can contract in several ways:

Isotonic - (shortening or lengthening)

Concentric (the muscle shortens).

Eccentric ( the muscle lengthens).

A muscle can also contract without any visible movement (isometric).

The analysis of muscle contraction and joint action is called kinesiology.

The benefits of exercise to the skeletal system include increased bone density. Thickening of articular cartilag and a greater range of movement at joints.

The benefits of exercise on the muscular system include increased muscle mass and force of contraction, increased strength of tendons and improved flexibility.

Exercise can prevent and improve skeletal conditions such as osteoporosis and osteoarthritis.

Some high impact activities can lead to growth plate disorders.

Some contact sports can lead to joint instability.

Some activities involving repetitive actions can lead to overuse injuries, such as bursitis, tendonitis or even stress fractures.

All sport relies on the application of force.

force can move a resting body, and cause a body to accelerate, decelerate or change direction and/or shape.

Newtons 3 laws of motion help us understand movement in sporting activities.

Law of inertia states that an object will remain at rest unless acted on by an external force.

law of acceleration -

Comments

Katie

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excellent

adahm jaffer

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very helpful, thanks