A Mobile Tai Chi Platform for Fall Prevention and Cognition in Older Adults

The percentage of Tele-Tai-Chi practice sessions completed by participants.

The percentage of participants who complete the study.

The scale is based on a 10-item questionnaire with five response options (from Strongly agree to Strongly disagree) in which participants rate the usability of the system. The scale ranges from 0 to 100, with higher scores indicating greater usability.

Qualitative interview about ease of use of the Tele-Tai Chi platform.

This is 16-item self-report measure in which participants rate their balance confidence to perform motor activities. The minimum score is 0. The maximum score is 100. Positive changes (i.e., higher scores post-intervention) would represent a positive outcome.

The PROMIS 29 instrument is a 29-item questionnaire assessing each of the following domains: anxiety, depression, fatigue, physical function, pain interference, pain intensity, sleep disturbance, and ability to participate in social roles and activities. The minimum score is 4 per domain, except for pain intensity for which the minimum score is 0. The maximum score per domain is 20, except for pain intensity for which the maximum score is 10. For the physical function and the ability to participate in social roles and activities domains a high score is indicative of positive outcome. For the anxiety, depression, fatigue, sleep disturbance, pain interference, and pain intensity a low score is indicative of positive outcome.

Self-reported level of physical activity in individuals aged 65 years or older during the previous 7 days. The score accounts for the type of activities performed and the time of performance of each activity. The minimum score is 0. The scale has theoretical maximum value of 864, if subjects spent 24 hours per day over 7 days engaged in vigorous activities. However, as this is not possible, a maximum value of 400 is typically considered as that would correspond to being engage in vigorous activities for 8 hours per day + more moderate activities for 4.5 hours per day.

The test to assess executive cognitive function. It has two parts: TMT A (number sequence only) considers visual search, and TMT B (alternating numbers and letters) evaluates executive control. The participant is asked to draw a line between 24 circles randomly arranged on a page that have to be linked in consecutive order. The TMT is scored by how long it takes to complete the test.

9-item questionnaire that focuses on the self-efficacy expectations for exercise for older adults. The minimum score is 0. The maximum score is 90. Positive changes (i.e., higher scores post-intervention) would represent a positive outcome.

Tai Chi experts will use video recordings to score proficiency using a developed instrument to score each of the six Tai Chi movements performed by participants. The minimum score is 6. The maximum score is 30 per Tai Chi exercise. Positive changes (i.e., higher scores post-intervention) would represent a positive outcome. The change in Tai Chi proficiency score ranges from -24 to +24. A change equal to 0 represents no change in proficiency.

Test routinely used in clinical practice to determine fall risk. The participant is asked to stand up from a chair, walk 3 meters, turns 180°, walk 3 meters back, and sits back down with back resting against the chair.

Test routinely used in clinical practice to determine fall risk and ambulation status. The participant is asked to stand up from a chair, walk 3 meters, turns 180°, walk 3 meters back, and sits back down with back resting against the chair while counting backwards by three.

Measured with a motion capture system. Balance on each leg (two trials): The participant is asked to stand on one leg for as long as they can up to a maximum of 30 seconds.

Measure of fall risks. The participant is asked to stand up from a chair while keeping their arms crossed across their chest and repeat the task as many times as possible during a period of 30 seconds.

Participants are instructed to perform two tasks: 1) stand on both legs with feet shoulder-width apart for approximately 20 seconds, and 2) stand on both legs with feet close to each other again for approximately 20 seconds. A sensor positioned at the waist is used to track the displacement of the center of mass during the 20 second data collection (for each task). The root mean square (RMS) value of the acceleration data collected using the sensor positioned at the waist is estimated in the antero-posterior (AP) and medio-lateral (ML) directions for the middle 15 seconds of each experiment. Data is gathered at baseline and post-intervention and derived for each condition for a total of 8 variables.

Study participants undergo an instrumented gait evaluation. Stride length is defined as the distance from ipsilateral foot contact to the next ipsilateral foot contact during gait. Normalized-to-height stride length is derived by computing the stride length and dividing such value by the height of the study participant.

Physical activity (e.g. number of steps per day) derived using a wrist-worn activity monitor.

MiniBEST Test: Test to assess dynamic balance. It is a 14-item test scored using a three-level ordinal scale. This test will be performed only in individuals who are willing to be tested in the laboratory (as opposed to via a remote visit). The minimum score is 0. The maximum score is 28. Positive changes (i.e., higher scores post-intervention) would represent a positive outcome.

The test examines working memory span. COWAT requires the participant to produce as many words as possible that begin with a given letter of the alphabet (F,A,S). There is 1 minute allowed for each of the three letters. The score is the sum of all acceptable words produced in the three trials.

The test assesses short-term memory by asking participants to memorize and recall in correct serial order a number of digits (i.e., numerals from 0 to 9). The test start asking participants to memorize fewer digits and then the number of digits is increased. The number sequences get progressively more difficult. Scores are based on the number of sequences correctly recalled (i.e., until the participant consecutively fails two trials of the same digit span length).

Investigators measure the grip strength of both upper limbs using a hand grip dynamometer. They repeat the measure three times (per side) for a total of six trials. The average value of the six trials is derived. Measures are gather at baseline and post-intervention. The difference in mean values (post-intervention minus baseline) is reported.

Study participants undergo an instrumented gait evaluation. Stride time is measured as the time from foot contact to the next foot contact of the same leg. Stride time variability is defined as the standard deviation of the stride time values estimated for a session.