BY CATHY LASSE
The investigation studies the effects of flooring conditions on balance in young and older people and its interaction with visual cues. The prediction was that standing stability in older adults would decrease as flooring compliance increased, especially when participants were subject to a moving visual environment. Balance was measured by center of pressure recordings which computed postural sway.
Seven flooring conditions created the compliant surfaces. Three visual conditions were used: eyes open, eyes closed, and a moving visual surround. Posture control is a result of interactions of sensory input from three systems, the visual system, the vestibular system and the proprioceptive system (Redfern et al.,1997). Sensory conflict can arise when inputs from the systems are incongruent, at which time the sensory integration process employs spacial orientation to produce proper posture. The sensory conflict creates sway, especially in older adults, therefor influences on the sensory system integration process will affect stability. This indicates flooring conditions could effect postural control. Softer floors may reduce inputs to the postural control system and may add to sensory conflict by contributing false proprioceptive cues from ankles and feet. Alternately, hard floors may create a stable reference for the proprioceptive system and positively effect stability (Redfern et al.,1997).
Sway was found to be greater in older adults than younger adults, particularly in the moving visual surround condition. Floor compliance was found to have an effect on sway, again particularly in the moving surround condition with the largest effect on the older subjects. Overall, as predicted, floor compliance has an influence on standing postural stability in older people, especially in a moving visual environment. The study suggests that less compliant flooring may decrease incidence of falling for older adults.
The study is limited in that the older participants were healthy. Larger effects may be found with a more disabled group of older adults. Furthermore, this study viewed effects from a standing position, whereas a more complicated condition such as walking may show greater effects. Walking and a moving visual experience would lend ecological validity to further research in this worthwhile investigation. It may also be of value to study the effects of implements such as canes or walkers in relation to flooring compliance and balance. The consequences of falling for older people can be disabling and even lead to death. Consequently, it seems the practicality of harder floor conditions would override the aesthetic of plush carpet.
REFERENCE
Redfern,M.,Moore,P.,& Yarsky,C.(1997). The influence of flooring on standing balance among older persons. Human Factors, 39(3), 445-455.