Balance (ability)

There are environmental factors that can affect balance such as light conditions, floor surface changes, alcohol, drugs, and ear infection.

Age-related decline in the ability of the above systems to receive and integrate sensory information contributes to poor balance in older adults.

[5] 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.

There is strong evidence in research showing that deficits in postural balance is related to the control of medial-lateral stability and an increased risk of falling.

To remain balanced, a person standing must be able to keep the vertical projection of their center of mass within their base of support, resulting in little medial-lateral or anterior-posterior sway.

A study done by Nardone and Schieppati (2006) showed that individuals with Parkinson's disease problems in balance have been related to a reduced limit of stability and an impaired production of anticipatory motor strategies and abnormal calibration.

Studies have found, however, that muscle fatigue around the hips (gluteals and lumbar extensors) and knees have a greater effect on postural stability (sway).

[9] Another method to improve balance is perturbation training, which is an external force applied to a person's center of mass in an attempt to move it from the base of support.

[12][13] Studies have suggested, higher level of physical activity have shown to reduce the morbidity and mortality along with risk of fall up to 30% to 50%.

Some functional balance tests that are available are: [23][24] Concussion (or mild traumatic brain injury) have been associated with imbalance among sports participants and military personnel.

Other inexpensive, custom-built force plates are being integrated into this new dynamic to create a growing field of research and clinical assessment that will benefit many populations.

Fatigue, causing central nervous system (CNS) dysfunction, can indirectly result in the inability to remain upright.

So far, researchers have only been able to estimate that athletes need anywhere from 8–20 minutes of rest before testing balance[28][29][30] That can be a huge difference depending on the circumstances.

[31] Tests have shown that older adults demonstrate shorter functional reach and larger body sway path lengths.

However, there was no or limited evidence on the effectiveness of general physical activities, such as walking and cycling, computer-based balance games and vibration plates.

"[33] Supra-postural tasks are those activities that rely on postural control while completing another behavioral goal, such as walking or creating a text message while standing upright.

[35] Adopting an external focus of attention subsequently improves the performance of supra-postural tasks, while increasing postural stability.