Flexibility
From Wikipedia, the free encyclopedia
Flexibility is the popular term for the ability to easily bend an object or the ability to adapt to different circumstances. However, in various professional fields, more precise terms are used.
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[edit] Materials
In materials science, the amount of deformation an object can be bent, twisted, lengthened or compressed due to a force or stress is called the strain.
- Plasticity is a property of a material to undergo a non-reversible change of shape in response to an applied force.
- Elasticity is the ability to deform under stress (e.g., external forces), but then return to its original shape when the stress is removed.
- Ductility is the physical property of being capable of sustaining large plastic deformations without fracture (in metals, such as being drawn into a wire).
- Malleability means the material can easily be deformed, especially by hammering or rolling, without cracking or breaking.
[edit] Systems theory
In systems theory, which has applications in diverse fields including biology, ecology, psychology, economics, and management, the flexibility of a system is related to its adaptation to a new environment or its resilience in recovering from a shock or disturbance. Individuals within an organization also demonstrate flexibility with their ability to adapt to the environment or troubleshoot while in the field.
One example is the attribute of flexibility in engineering.
[edit] Physiology
In the physiology of vertebrates, including humans, the measurement of the achievable distance between the flexed position and the extended position of a particular joint or muscle group is called its "flexibility", but this is more properly called its range of motion or range of movement. In this sense, the flexibility of a joint depends on many factors, particularly the length and looseness of the muscles and ligaments due to normal human variation, and the shape of the bones and cartilage that make up the joint.
Flexibility, or suppleness, is also a more generalized term used to compare the relative range of motion of all joints of an individual with a standard. The ability to achieve a full range of movements – to turn, stretch, twist and bend – without any stiffness, aching or suffering a spine or joint injury is defined as suppleness.
Medical conditions such as arthritis can decrease flexibility, while Ehlers-Danlos Syndrome can increase flexibility. Exercise increases the amount of flexibility in a joint, while decreasing the amount of resistance. Different sports have different flexibility requirements, which can be increased further through training and practice of the sport. A person training for gymnastics would develop more flexibility than a shot put thrower.
Those who practice gymnastics (especially rhythmic gymnastics), dance, figure skating, martial arts, body toning, yoga, cheerleading and contortion rely on functional flexibility (increased range of motion with strength and control) to perform their actions.
[edit] Relative flexibility
Since muscles which go through growth in size but not in length, when one muscle grows through hypertrophy its opposite side muscle (the antagonist) will have to lengthen, and absolute flexibility is the term to describe a muscle's length, in and of itself, where relative flexibility is the flexibility of a joint, as compared to its antagonistic movement[1].
For example, the calf muscle extends the foot towards the ground (plantarflexion) and the shin muscle flexes the foot in the opposite direction (dorsiflexion). If a person's calf is overly strong it will not be as flexible as the opposite shin muscle, and plantarflexion will be exhibit relatively inflexible as compared to dorsiflexion using the person's weaker, but more flexible shin muscle.
[edit] References
- ^ "Back to the Basics for the New Year", by Paul Chek
