Balance4Mobilität: Auswirkungen von Walkasinen bei Personen mit peripherer Neuropathie und Gleichgewichtsprobleme

Participants randomized to the user group will receive Walkasins, consisting of two parts for each leg: the Haptic Module and the Receptor Sole. They will use the device for one year (52 weeks). In addition, the user group participants will receive the fall prevention information provided to the control group.

Walkasins® is an external, lower limb sensory prosthesis intended to replace part of the nerve function used for detection and signaling of foot pressure sensation during standing and walking activities. Walkasins consist of two parts for each leg: the Haptic Module and the Receptor Sole. The Haptic Module wraps around the lower leg of the user and contains electronics for reading Receptor Sole pressure signals, a microprocessor, and four vibrating motors that provide gentle tactile sensory cues to the front, back, medial, and lateral surfaces of the user's leg. These cues reflect real-time foot pressure information at a location above the ankle where skin sensation is still present.

Participants will watch "6 Steps to Prevent a Fall," a short (2 minute) educational video from the National Council on Aging, which describes simple steps to reduce fall risk. To improve their access to the education provided, participants will also receive three handouts, produced by the Center for Disease Control and Prevention (CDC) STEADI initiative (Stopping Elderly Accidents, Deaths, and Injuries), to review after the study visit. The STEADI Initiative is a coordinated approach for healthcare providers to implement the American and British Geriatrics Societies' Clinical Practice Guideline for fall prevention (https://www.cdc.gov/steadi/index.html).

Participants randomized to the control group will receive fall prevention information during the baseline visit. After six months, they will receive Walkasins for use during the final six months of the trial.

Participants will watch "6 Steps to Prevent a Fall," a short (2 minute) educational video from the National Council on Aging, which describes simple steps to reduce fall risk. To improve their access to the education provided, participants will also receive three handouts, produced by the Center for Disease Control and Prevention (CDC) STEADI initiative (Stopping Elderly Accidents, Deaths, and Injuries), to review after the study visit. The STEADI Initiative is a coordinated approach for healthcare providers to implement the American and British Geriatrics Societies' Clinical Practice Guideline for fall prevention (https://www.cdc.gov/steadi/index.html).

The Functional Gait Assessment (FGA) is a 10-item scale that measures postural stability while individuals perform walking tasks that are scored from 0 to 3 (3 = normal, 2 = mild impairment, 1 = moderate impairment, 0 = severe impairment). Scores range from a minimum of 0 to a maximum of 30. Higher scores indicate better postural stability.

The PSFS asks patients to define up to five specific tasks that they have difficulty with or are unable to perform because of their physical injury or disability. Some research studies adapt the PSFS by asking participants to list three tasks rather than five, which is the plan for this study. The patients then rate their difficulty in performing those tasks on a scale of 0 to 10 with 0 meaning "unable to perform activity" to 10 meaning "able to perform activity at the same level as before injury or problem." The ratings for the three activities are averaged. Higher scores indicate greater ability to perform the activity.

Eight items that have the most relevance for measuring change in individuals who have received Walkasins were selected from the 165 items comprising the PROMIS Item Bank v2.0 - Physical Function. Specifically, the selected items measure an individual's ability to perform various activities that involve upright mobility (balance, standing, and walking). Participants rate the eight items on a scale of 1 to 5; the raw scores are converted to T-scores for comparison to national norms.

Gait speed will be measured through the 10-Meter Walk Test, timing only the middle 6 meters to allow for acceleration and deceleration. Participants will be instructed to walk at normal speed. Higher numbers indicate faster speeds (i.e., more meters per second).

The 4-Stage Balance Test is part of the Centers for Disease Control's recommended test protocol for balance function. It includes four gradually more challenging postures the subject is exposed to: (1) Stand with feet side by side. (2) Stand with feet in semi-tandem stance. (3) Stand with feet in tandem stance. (4) Stand on one leg. Participants pass each level if they can hold the stance for 10 seconds and then move on to the next stance. If they cannot hold the stance, the test ends. Higher times indicate better balance than lower times.

The Multidirectional Reach Test is a quick screening tool for fall risk to indirectly measure the limits of stability. The participant outstretches his/her arm to shoulder height next to a yardstick mounted on the wall; then he/she reaches as far as possible in the instructed direction without taking a step. The test administrator records the start and end position of the index finger of the outstretched hand, and the difference represents the total reach for that direction. Higher differences indicate better stability.

The Modified Multidirectional Reach Test used in this clinical trial will include only forward and backwards reaching that is completed and recorded with eyes closed. It will omit the left and right reaches.

The Single Leg Stance Test (also called the unipedal stance test) "is a simple test for measuring static aspects of balance." It "is related to conditions such as peripheral neuropathy and intermittent claudication" and "is also associated with an increased risk for falls" (Spring et al., 2007) Participants stand unassisted on one leg with their hands on their hips. Timing begins when they lift one leg off the floor and ends when it touches the ground or the standing leg or an arm leaves the hips

The Timed Up and Go Test is part of the Centers for Disease Control (CDC)-recommended STEADI test protocol for balance function. From a seated position in a standard armchair, the participant is asked to stand up from the chair, walk to a line on the floor 10 feet away at normal pace, turn, walk back to the chair at normal pace, and sit down again. The tester records the time taken from the command "Go" until the subject sits down again. Lower times indicate better/faster performance.

The TUG-Cog is performed as described above; in addition, the participant is asked to count backwards by threes from a randomly selected number between 20 and 100. Lower times indicate better/faster performance.

Powell and Myers developed the 16-item Activities-specific Balance Confidence (ABC) Scale to detect levels of balance confidence in older adults. Schepens et al. (2009) validated a 6-item version of the ABC, using the six most challenging activities from the 16-item scale. The six tasks are rated on a scale of 0 to 100; a score of 0 indicates no confidence and a score of 100 indicates complete confidence when performing the task. The overall score is calculated by adding the individual items then dividing by the total number of items (6). The higher the score, the greater the person's balance confidence; thus, higher scores indicate that subjects are more confident of their balance.

The EQ-5D-5L consists of five questions, one each on "mobility," "self-care," "usual activities," "pain / discomfort," and "anxiety / depression." Participants rate themselves according to statements reflecting five levels ranging from no problems with the activity or construct to inability to perform the activity or having an extreme amount of difficulty with the construct.

The PROMIS Pain Intensity assessment measures "how much a person hurts" (https://www.healthmeasures.net/images/PROMIS/manuals/PROMIS_Pain_Intensity_Scoring_Manual.pdf). The three questions are not disease specific. Two items address pain experienced in the past seven days; the other, pain at present. In addition, we will ask participants to rate the neuropathic pain in their feet on scale of 0-10 (0 = No Pain, 10 = Worst Pain Imaginable).

The Rapid Assessment of Physical Activity (RAPA) is a measure of physical activity, designed for use with older adults. The researchers will administer the RAPA during in-person visits and the TAPA, a telephone-based assessment of physical activity based on the RAPA, during the Weeks 18 and 36 telephone visits. The assessments consist of seven questions on light, moderate, and vigorous physical (aerobic) activities to which the participants respond "yes" or "no," depending on whether or not the question is true of them. Scoring is based on the number of the item to which the participants report the highest positive response (e.g., if the participant answered "Yes" to question 4 and "No" to 5, 6, and 7, then "4" is the participant's score). Higher scores indicate more physical activity. The final two items address strength and flexibility and are scored separately.

At the follow-up visits, the study team will ask the participants assigned to the Walkasins user group specific questions about their experience with Walkasins. Control group participants will complete the survey at Weeks 36 and 52.

Participants will report details regarding falls they experience during their enrollment in the study.

The Centers for Medicare & Medicaid Services (CMS) identifies the monofilament test as the means of diagnosing loss of protective sensation (https://www.cms.gov/medicare-coverage-database/view/ncd.aspx?NCDId=171). To conduct the test, a clinician applies pressure with various sizes of monofilament to selected parts of the foot and asks the participant to indicate when he/she feels the filament. Including catch trials helps to ensure accurate test results. Per CMS, inability to feel a 10-gram monofilament on at least two of five test sites on either foot indicates loss of protective sensation (LOPS).

Vibration is one of several types of sensation encompassed within the somatosensory system, and it is often diminished in individuals with neuropathy. To examine vibration sense, a clinician applies a low-frequency (128 Hz) tuning fork to bony prominences and asks the participant (with closed eyes) to report when the vibration starts and stops. For this study, site personnel will employ the Rydel-Seiffer tuning fork, which provides a more quantitative assessment of vibratory sensation ranging from 2 to 8.