Balance (ability)
Encyclopedia
Biomechanics
Biomechanics is the application of mechanical principles to biological systems, such as humans, animals, plants, organs, and cells. Perhaps one of the best definitions was provided by Herbert Hatze in 1974: "Biomechanics is the study of the structure and function of biological systems by means of...
, balance is an ability to maintain the center of gravity
Center of gravity
In physics, a center of gravity of a material body is a point that may be used for a summary description of gravitational interactions. In a uniform gravitational field, the center of mass serves as the center of gravity...
of a body within the base of support with minimal postural sway. When exercising the ability to balance, one is said to be balancing.
Balancing requires concurrent processing of inputs from multiple sense
Sense
Senses are physiological capacities of organisms that provide inputs for perception. The senses and their operation, classification, and theory are overlapping topics studied by a variety of fields, most notably neuroscience, cognitive psychology , and philosophy of perception...
s, including equilibrioception
Equilibrioception
Equilibrioception or sense of balance is one of the physiological senses. It helps prevent humans and animals from falling over when walking or standing still. Balance is the result of a number of body systems working together: the eyes , ears and the body's sense of where it is in space ideally...
(from the vestibular system
Vestibular system
The vestibular system, which contributes to balance in most mammals and to the sense of spatial orientation, is the sensory system that provides the leading contribution about movement and sense of balance. Together with the cochlea, a part of the auditory system, it constitutes the labyrinth of...
), vision
Visual perception
Visual perception is the ability to interpret information and surroundings from the effects of visible light reaching the eye. The resulting perception is also known as eyesight, sight, or vision...
, and perception of pressure and proprioception
Proprioception
Proprioception , from Latin proprius, meaning "one's own" and perception, is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement...
(from the somatosensory system
Somatosensory system
The somatosensory system is a diverse sensory system composed of the receptors and processing centres to produce the sensory modalities such as touch, temperature, proprioception , and nociception . The sensory receptors cover the skin and epithelia, skeletal muscles, bones and joints, internal...
), while the motor system
Motor system
The motor system is the part of the central nervous system that is involved with movement. It consists of the pyramidal and extrapyramidal system....
simultaneously controls muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
actions. The senses must detect changes of body position with respect to the base, regardless of whether the body moves or the base moves.
Age-related decline in the ability of the above systems to receive and integrate sensory
Sense
Senses are physiological capacities of organisms that provide inputs for perception. The senses and their operation, classification, and theory are overlapping topics studied by a variety of fields, most notably neuroscience, cognitive psychology , and philosophy of perception...
information contributes to poor balance in older adults. As a result, the elderly are at an increased risk of falls
Falling (accident)
Falling is a major cause of personal injury, especially for the elderly. Builders, electricians, miners, and painters represent worker categories representing high rates of fall injuries. The WHO estimate that 392,000 people die in falls every year...
. In fact, one in three adults aged 65 and over will fall each year.
In the case of an individual standing quietly upright, the limit of stability is defined as the amount of postural sway at which balance is lost and corrective action is required. The limit of stability may be described by an irregular conical
Cone (geometry)
A cone is an n-dimensional geometric shape that tapers smoothly from a base to a point called the apex or vertex. Formally, it is the solid figure formed by the locus of all straight line segments that join the apex to the base...
envelope above the support base.
Balance can be severely affected in individuals with neurological conditions. Patients who suffer a stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
or a spinal cord injury
Spinal cord injury
A spinal cord injury refers to any injury to the spinal cord that is caused by trauma instead of disease. Depending on where the spinal cord and nerve roots are damaged, the symptoms can vary widely, from pain to paralysis to incontinence...
for example, can struggle with this ability. It has also been determined that impaired balance is strongly associated with future function and recovery in some cases, particularly in stroke patients. Additionally, balance problems have been identified as the strongest predictor of falls.
Balance Training
Since balance is a key predictor of recovery and is required in so many of our activities of daily livingActivities of daily living
Activities of Daily Living is a term used in healthcare to refer to daily self-care activities within an individual's place of residence, in outdoor environments, or both...
, it is often introduced into treatment plans by physiotherapists and occupational therapists when dealing with geriatrics, patients with neurological conditions, or others whom they have determined it to be beneficial.
Balance training in stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
patients has been supported in the literature. Methods commonly used and proven to be effective for this population include sitting or standing balance practice with various progressions including reaching, variations in base of support, use of tilt boards, gait training varying speed, and stair climbing exercises. The type of training should be determined by a physiotherapist and will depend on the nature and severity of the stroke, stage of recovery, and the patient’s abilities and impairments after the stroke.
Functional Balance Tests
Functional tests of balance focus on maintenance of static balance, balance during weight shifting or voluntary movement (dynamic balance), balance responses to manual perturbations, and functional mobility. Standardized tests of balance are available to allow physiotherapists and other health care professionals to assess an individual’s functional performance. Some functional balance tests that are available are:- The Romberg TestRomberg's testRomberg's test or the Romberg maneuver is a test used by doctors in a neurological examination, and also as a test for drunken driving. The exam is based on the premise that a person requires at least two of the three following senses to maintain balanced while standing:Proprioception ; Vestibular...
: used to determine proprioceptive contributions to upright balance. - Functional Reach Test: measures the maximal distance one can reach forward beyond arm’s length while maintaining feet planted in a standing position.
- The Berg Balance Scale: measures static and dynamic balance abilities using functional tasks commonly performed in everyday life. One study reports that the Berg Balance Scale is the most commonly used assessment tool throughout stroke rehabilitationStroke rehabilitationThe primary goals of stroke management are to reduce brain injury and promote maximum patient recovery. Rapid detection and appropriate emergency medical care are essential for optimizing health outcomes. When available, patients are admitted to an acute stroke unit for treatment. These units...
, and found it to be a sound measure of balance impairment in patients following a stroke. - Performance-Oriented Mobility Assessment (POMA): measures both static and dynamic balance using tasks testing balance and gaitGaitGait is the pattern of movement of the limbs of animals, including humans, during locomotion over a solid substrate. Most animals use a variety of gaits, selecting gait based on speed, terrain, the need to maneuver, and energetic efficiency...
. - Timed Get Up and Go Test: measures dynamic balance and mobility.
- The Balance Efficacy Scale: self-report measure that examines an individual’s confidence while performing daily tasks with or without assistance.
External links
- McCredie, Scott (2007). Balance: In search of the lost sense. New York: Little, Brown. 296 pp.