Detection of Real-World Trips in At-Fall Risk Community Dwelling Older Adults Using Wearable Sensors.

Background: Near-falls such as a trip, slip, stumble, or misstep involve a loss of balance (LOB) that does not result in a fall, occur more frequently than actual falls, and are associated with an increased fall risk. To date, studies have largely involved detection of simulated laboratory LOBs using wearable devices in young adults. Data on the detection of and kinematics of naturally occurring LOBs in people at high risk of falling are lacking. This may provide a new way to identify older adults at high risk for falls. We aimed to explore key body kinematics underlying real-world trips in at-fall risk community dwelling older adults wearing inertial measurement units (IMU). Methods: Five community-dwelling older adults with a history of falls who reported trips during the study period participated. They wore a voice recorder and 4 IMUs mounted on feet, lower back and wrist for two consecutive weeks to provide a record of the context and timing of LOB events. Sensor data prior to time-stamped voice recording of a trip were processed in order to visually identify unusual foot trajectories and lower back and arm orientations. Then, data of feet, lower back and wrist position and orientation were combined to create a three-dimensional animation representing the estimated body motion during the noted time segments in order to corroborate the occurrence of a trip. Events reported as a trip by the participant and identified as a trip by a researcher, blinded to voice recordings description, were included in the final analysis. Results: A total of 18 trips obtained from five participants were analyzed. Twelve trips occurred at home, three outside and for three the location was not reported. Trips were identified in the sensor data by observing (1) additional peaks to the typical foot velocity signal during swing phase; (2) increased velocity of the contralateral foot and (3) sharp changes in lower back pitch angles. Conclusions: Our approach demonstrates the feasibility of identifying and studying the mechanisms and context underlying trip-related LOBs in at-fall risk older adults during real world activities.

Reconstruction of body motion during self-reported losses of balance in community-dwelling older adults.

Older adults experience slips, trips, stumbles, and other losses of balance (LOBs). LOBs are more common than falls and are closely linked to falls and fall-injuries. Data about real-world LOBs is limited, particularly information quantifying the prevalence, frequency, and intrinsic and extrinsic circumstances in which they occur. This paper describes a new method to identify and analyze LOBs through long-term recording of community-dwelling older adults. The approach uses wearable inertial measurement units (IMUs) on the feet, trunk and one wrist, together with a voice recorder for immediate, time-stamped self-reporting of the type, context and description of LOBs. Following identification of an LOB in the voice recording, concurrent IMU data is used to estimate foot paths and body motions, and to create body animations to analyze the event. In this pilot study, three older adults performed a long-term monitoring study, with four weeks recording LOBs by voice and two concurrent weeks wearing IMUs. This report presents a series of LOB cases to illustrate the proposed method, and how it can contribute to interpretation of the causes and contexts of the LOBs. The context and timing information from the voice records was critical to the process of finding and analyzing LOB events within the voluminous sensor data record, and included much greater detail, specificity, and nuance than past diary or smartphone reporting.

Effects of activity strategy training on pain and physical activity in older adults with knee or hip osteoarthritis: a pilot study.

OBJECTIVE: To examine effects of activity strategy training (AST), a structured rehabilitation program taught by occupational therapists and designed to teach adaptive strategies for symptom control and engagement in physical activity (PA). METHODS: A randomized controlled pilot trial was conducted at 4 sites (3 senior housing facilities and 1 senior center) in southeastern, lower Michigan. Fifty-four older adults with hip or knee osteoarthritis (mean +/- SD age 75.3+/-7.1 years) participated. At each site, older adults were randomly assigned to 1 of 2 programs: exercise plus AST (Ex + AST) or exercise plus health education (Ex + Ed). The programs involved 8 sessions over 4 weeks with 2 followup sessions over a 6-month period, and were conducted concurrently within each site. Pain, total PA and PA intensity (measured objectively by actigraphy and subjectively by the Community Healthy Activities Model Program for Seniors questionnaire), arthritis self-efficacy, and physical function were assessed at baseline and posttest. RESULTS: At posttest, participants who received Ex + AST had significantly higher levels of objective peak PA (P=0.02) compared with participants who received Ex + Ed. Although not statistically significant, participants in Ex + AST tended to have larger pain decreases, increased total objective and subjective PA, and increased physical function. No effects were found for arthritis self-efficacy. CONCLUSION: Although participants were involved in identical exercise programs, participants who received AST tended to have larger increases in PA at posttest compared with participants who received health education. Future studies will be needed to examine larger samples and long-term effects of AST.

Bath transfers in older adult congregate housing residents: assessing the person-environment interaction.

OBJECTIVES: To examine environmental feature utilization (EFU) and the types and prevalence of performance difficulties during a videotaped bath transfer and to determine the personal characteristics associated with total EFU and performance difficulties. DESIGN: Cross-sectional analysis. SETTING: Two congregate housing facilities in southeastern Michigan. PARTICIPANTS: Eighty-nine older adults who reported independence in bathing. MEASUREMENTS: Trained video coders recorded EFU (defined as upper extremity contact with features in the environment) and rated performance difficulties (defined as lack of fluid movement or difficulty negotiating the environment). EFU was measured by determining whether features used were safe (i.e., designed for use as a transfer support) or unsafe and by total EFU (i.e., number of environmental features used during the transfer). Personal characteristics included self-reported medical conditions, bath transfer difficulty, functional mobility, lower extremity strength, range of motion functional impairment, and falls efficacy. RESULTS: For participants with a tub-shower, safe EFU was higher than unsafe EFU (85% vs 19%; P<.001). Participants with shower stalls had the same rate of safe and unsafe EFU (71%). In multiple regression analysis, self-reported bath transfer difficulty was associated with total EFU (P=.01). One-third of the sample had performance difficulties. In multivariate analysis, range of motion functional impairment (odds ratio (OR)=13.49, 95% confidence interval (CI)=1.11-163.53) and lowest quartile in falls efficacy scores (OR=5.81, 95% CI=1.24-27.41) were associated with performance difficulties. CONCLUSION: Unsafe EFU and performance difficulties were common in independently bathing older adults. Self-reported bath transfer difficulty appears to be a good indicator of high total EFU and may be used as a screening question for clinicians. Important strategies to reduce unsafe EFU and to increase falls efficacy include removing shower sliding glass doors and training older adults in safe transfer techniques.