Noise-Enhanced Sensory Function in Elders at Risk for Falls

Study Overview
=================
Brief Summary
-----------------
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.

Detailed Description
-----------------
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.

Official Title
-----------------
Noise-Enhanced Sensory Function in Elders at Risk for Falls

Conditions
-----------------
Aging, Somatosensory Deficit

Intervention / Treatment
-----------------
* Device: Vibrating Insoles


Participation Criteria
=================
Eligibility Criteria
-----------------
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)

Ages Eligible for Study
-----------------
Minimum Age: 70 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1<br>85 elderly individuals with somatosensory deficits | Device: Vibrating Insoles<br>* Participants wear vibrating sandals for 3 trials of 6 minutes, during a single lab visit. The sandal vibration is on during either first or second 3 minutes of the 6 minute trial, as they walk. Also, participants wear the sandals for 2 hours while sitting, with vibrations on for one visit and off for the other.<br>|
| Experimental: 2<br>85 elderly individuals with recurrent falls | Device: Vibrating Insoles<br>* Participants wear vibrating sandals for 3 trials of 6 minutes, during a single lab visit. The sandal vibration is on during either first or second 3 minutes of the 6 minute trial, as they walk. Also, participants wear the sandals for 2 hours while sitting, with vibrations on for one visit and off for the other.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Area ellipse of sway |  | Three 6-minute trials in one visit, repeated one week later | 
| Berg Functional Balance Scales |  | Three 6-minute trials in one visit, repeated one week later | 
| Timed Up and Go (TUG)Test |  | Three 6-minute trials in one visit, repeated one week later | 
| Timed one-legged stance test |  | Three 6-minute trials in one visit, repeated one week later | 
| Gait timing variability |  | Three 6-minute trials in one visit, repeated one week later | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in: stabilogram-diffusion analysis (SDA) |  | Three 6-minute trials in one visit, repeated one week later | 
| Neurological risk factors related to falls |  | Three 6-minute trials in one visit, repeated one week later | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Sensory loss, psychomotor function, balance, gait