Body Mechanism
Mobility: the ability to move freely, easily, rhythmically, and purposefully in the
environment, is an essential part of living.
Normal movement:
Normal movement and stability are the result of an intact musculoskeletal
system, an intact nervous system, and intact inner ear structures which
responsible for equilibrium.
Normal body movement involves four basic elements: body alignment and (posture),
joint mobility, balance, and coordinated movement.
1- Alignment and posture: proper body alignment and posture bring body parts
in to position in a manner that promotes optimal balance and function whether
the client is standing, sitting, or lying down.
Line of gravity: an imaginary vertical line drawn through the body s center
gravity pass through the point at which all of the body mass is centered.
Base of support: the foundation on which the body rests.
2- Joint Mobility: when a person is inactive, the joints are pulled into a flexed
position, if the tendency is not counteracted with exercise and position changes, the
muscle permanently shorten, and the joint becomes fixed in a flexed
position. Types of joint movement are:
Flexion : decreasing the angle of the joint .
Extension: increasing the angle of the joint.
Hyperextension: further extension of the joint.
Abduction: movement of the bone away from the midline of the body.
Adduction: movement of the bone toward the midline of the body.
Rotation: movement of the bone around its center axis
Circumduction : movement of the distal part of the bone in a circle while the
proximal end remain fixed .
Eversion : turning the sole of the foot outward by moving the ankle joint .
Inversion: turning the sole of the foot inward by moving the ankle joint.
Pronation : moving of the bones of the forearm so that the palm of the hand face
the body .
Supination : moving of the bones of the forearm so that the palm of the hand
faces upward when held in front of the body .
Range of motion (ROM): is the maximum movement that is possible for that
joint. It varies from one person to other by genetic makeup, developmental
patterns, presence and absence of disease and the amount of physical activities in
which the person normally engages.
3- Balance: mechanisms of equilibrium (sense of balance) .
4- Coordination: balance, smooth, purposeful movement, it’s the result of the
proper functioning of the nerves system