Noise-Enhanced Sensory Function in Elders at Risk for Falls

Noise-Enhanced Sensory Function in Elders at Risk for Falls

The long-term goal of this project is to develop a non-invasive, noise-based technique for enhancing somatosensation and thereby improving balance control in elderly fallers and older adults with somatosensory deficits.

Previous studies have shown that sub-sensory mechanical noise (i.e., random vibration with a small intensity) can enhance somatosensory function in healthy individuals and older adults with somatosensory deficits. Moreover, the postural sway of both healthy young and healthy elderly individuals during quiet standing can be significantly reduced by applying sub-sensory mechanical noise to the feet using vibrating shoe insoles.

The specific aims of this project are to determine the effects of noise-enhanced somatosensation at the feet on balance performance in elderly individuals with somatosensory deficits and/or recurrent falls, and to assess whether adaptation occurs in noise-enhanced balance control in these individuals. To accomplish these aims, quiet-standing and dynamic posture studies and clinical balance assessments will be conducted on elderly individuals with somatosensory deficits and elderly individuals with recurrent falls (two or more falls over a 12-month period).

This project could lead to the development of a novel bioengineering technique for improving balance control in older adults and patients with somatosensory deficits. The work could thus serve to reduce the frequency, morbidity and cost of falling, and assist aged individuals in achieving maximal independence in activities of daily living and mobility.

Two groups of participants will be recruited from the RNH Epidemiology Core: 85 elderly individuals with somatosensory deficits, and 85 elderly individuals with recurrent falls. The study consists of three visits--a one-hour neurological exam, and two 6-hour laboratory testing sessions scheduled one week apart.

Inclusion Criteria:

• Participant must (1) have somatosensory deficit (mild to moderate sensory loss on the bottom of both feet) OR (2) be classified as a recurrent faller (two or more incident falls over a twelve-month period not related to syncope, major medical events, or overwhelming external hazards)
• Age 70 and older
• Able to stand unassisted for at least 60 seconds several times over a 30-minute period
• Able to walk without assistance from a walking aid

Exclusion Criteria:

• Known history of seizures or fainting
• Unstable medical condition
• Open lesions or poor skin condition on feet
• Unable to cooperate with or understand the protocol
• Foot size larger or smaller than the constructed vibrating insoles (men's sizes smaller than 3 or larger than 12; women's sizes smaller than 4.5 or larger than 13.5)