The somatosensory nervous system (providing touch and position sense) deteriorates with age, and is associated with the impairment of physical balance. James J Collins from Boston University, USA, and colleagues investigated whether stimulating the sensory system with vibrating insoles could improve postural control.
15 young people (average age 23 years) and 12 older people (average age 73 years) took part in the study. They received low-frequency subsensory (undetectable) mechanical stimulation via insoles, or no stimulation (the control measure), during a series of 30-second trials where participants had to stand quietly with their eyes closed.
The investigators measured the degree of sway from each participant during the trials; use of the vibrating insoles substantially improved balance (by a reduction in sway) among the elderly participants; younger participants also had reduced sway. The balance of younger people without stimulation was achieved by elderly participants when they had received stimulation from the vibrating insoles.
James J Collins comments: "Elderly people gain more in motor control performance than do young people with the application of noise to the feet. Noise-based devices, such as randomly vibrating shoe insoles, might be effective in enhancing the performance of dynamic balance activities (eg, walking), and could enable older adults to overcome postural instability caused by age-related sensory loss."