Sai V. Yalla

A growing troubling triad: diabetes, aging, and falls.

There is a significant and troubling link between diabetes (DM) and falls in the elderly. Individuals with DM are prone to fall for reasons such as decreased sensorimotor function, musculoskeletal/neuromuscular deficits, foot and body pain, pharmacological complications, and specialty (offloading) footwear devices. Additionally, there is some concern that DM patients are prone to have more severe problems with falls than non-DM individuals. Fractures, poorer rehabilitation, and increased number of falls are all concerns. Fortunately, efforts to mitigate falls by DM patients show promise. A number of studies have shown that balance, strength, and gait training may be utilized to successfully reduce fall risk in this population. Furthermore, new technologies such as virtual reality proprioceptive training may be able to provide this reduced risk within a safe training environment.

Fear of Falling Is Prevalent in Older Adults with Diabetes Mellitus But Is Unrelated to Level of Neuropathy

BACKGROUND Patients with diabetic peripheral neuropathy (DPN) demonstrate gait alterations compared with their nonneuropathic counterparts, which may place them at increased risk for falling. However, it is uncertain whether patients with DPN also have a greater fear of falling. METHODS A voluntary group of older adults with diabetes was asked to complete a validated fear of falling questionnaire (Falls Efficacy Scale International [FES-I]) and instructed to walk 20 m in their habitual shoes at their habitual speed. Spatiotemporal parameters of gait (eg, stride velocity and gait speed variability) were collected using a validated body-worn sensor technology. Balance during walking was also assessed using sacral motion in the mediolateral and anteroposterior directions. The level of DPN was quantified using vibration perception threshold from the great toe. RESULTS Thirty-four diabetic patients (mean ± SD: age, 67.6 ± 9.2 years; body mass index, 30.9 ± 5.7; hemoglobin A1c, 7.9% ± 2.3%) with varying levels of neuropathy (mean ± SD vibration perception threshold, 34.6 ± 22.9 V) were recruited. Most participants (28 of 34, 82%) demonstrated moderate to high concern about falling based on their FES-I score. Age (r = 0.6), hemoglobin A1c level (r = 0.39), number of steps required to reach steady-state walking (ie, gait initiation) (r = 0.4), and duration of double support (r = 0.44) were each positively correlated with neuropathy severity (P < .05). Participants with a greater fear of falling also walked with slower stride velocities and shorter stride lengths (r = -0.3 for both, P < .05). However, no correlation was observed between level of DPN and the participants actual concern about falling. CONCLUSIONS Fear of falling is prevalent in older adults with diabetes mellitus but is unrelated to level of neuropathy.

Physiological and psychological challenges of increasing physical activity and exercise in patients at risk of diabetic foot ulcers: a critical review

Obesity and a sedentary lifestyle are common challenges among individuals at risk of diabetic foot ulcers. While substantial research exists on physical activity interventions in adults with diabetes, those at greatest risk for foot ulceration were often excluded or not well represented. Both at‐risk patients and their clinicians may be hesitant to increase physical activity because of their perception of diabetic foot ulcer risks. Physical activity is not contraindicated for those at risk of diabetic foot ulcer, yet patients at risk present with unique barriers to initiating increases in physical activity. This review focuses upon the physiological and psychological challenges of increasing physical activity and exercise in patients at risk of diabetic foot ulcers. Offloading, diabetic peripheral neuropathy, depression, pain, self‐efficacy and social support, diabetic foot ulcer risk‐specific beliefs and emotions, and research to date on exercise interventions in this population are all discussed. Additionally, recommendations for implementing and researching physical activity interventions for individuals at risk for diabetic foot ulcer are provided. Copyright

Segmenting human trajectory data by movement states while addressing signal loss and signal noise

ABSTRACT This paper considers the problem of partitioning an individual GPS trajectory data into homogeneous, meaningful segments such as stops and trips. Signal loss and signal noise are highly prevalent in human trajectory data, and it is challenging to deal with uncertainties in segmentation algorithms. We propose a new trajectory segmentation algorithm that detects stop segments in a noise-robust manner from GPS data with time gaps. The algorithm consists of three steps that impute time gaps, split data into base segments and estimate states over a base segment. The state-dependent path interpolation was proposed as a framework for gap imputation to deal with locational and temporal uncertainties associated with signal loss. A spatiotemporal clustering-based trajectory segmentation was proposed to detect spatiotemporal clusters of any shape regardless of density to cut a trajectory into internally similar base segments. Fuzzy inference was employed to deal with borderline cases in determining states over base segments based on input features. The proposed algorithm was applied to detect stop/move episodes from raw GPS trajectories that were collected from 20 urban and 19 suburban participants. Sensitivity analysis was conducted to guide the choice of parameters such as the temporal and spatial definitions of a stop. Experimentation results show that the proposed method correctly identified 92% of stop/move episodes, and correctly estimated 98% of episode duration. This study indicates that a sequence of state-dependent gap imputation, clustering-based data segmentation and fuzzy-set-based state estimation can satisfactorily deal with uncertainty in processing human GPS trajectory data.

Monitoring Location-Specific Physical Activity via Integration of Accelerometry and Geotechnology Within Patients With or At Risk of Diabetic Foot Ulcers A Technological Report

Objective: Physical activity variability is a risk factor for diabetic foot ulcers (DFU). Geographic context may influence variability. This study developed initial methods for monitoring location-specific physical activity in this population. Secondarily, preliminary comparisons in location-specific physical activity were made between patients at risk versus patients with active DFU. Methods: Five at-risk and 5 actively ulcerated patients were monitored continuously for 72 hours with physical activity and GPS monitors. A custom algorithm time synchronized the 2 devices’ data. Results: On average for all 10 subjects, 1.5 ± 2.1% of activity lacked a corresponding GPS location. 80 ± 11% of self-reported activity events per subject had a GPS identified location. The GPS identified locations were in agreement with the self-reported locations 98 ± 6% of the time. DFU participants’ weight-bearing activity was 188% higher at home than away from home. At-risk participants showed similar weight-bearing activity at home as active DFU participants, however, at-risk participants had 132% more weight-bearing activity away-from-home. Conclusions: Objectively monitoring location-specific physical activity proved feasible. Future studies using such methodology may enhance understanding of pathomechanics and treatment of DFU.

Recent Advances and Future Opportunities to Address Challenges in Offloading Diabetic Feet: A Mini-Review

Diabetic foot ulcers (DFU) are a substantial dilemma for geriatric individuals with diabetes. The breakdown in tissue associated with DFU is typically a result of repetitive cycles of physical stress placed on the feet during weight-bearing activity. Accordingly, a key tenet in healing as well as preventing DFU is the use of offloading footwear to redistribute physical stress away from high stress locations such as bony prominences. Over the last several years there has been a substantial amount of effort directed at better understanding and implementing the practice of offloading. A review of this work as well as relevant technological advances is presented in this paper. Specifically, we will discuss the following topics in association with offloading diabetic feet: achieving optimal offloading, dosing activity/physical stress, thermal monitoring to detect preulcerative tissue damage, adherence with offloading devices, and optimizing the user experience. In addition to presenting progress to date, potential directions for further advancement are discussed.

Effects of Commercial Exergames on Motivation in Brian Injury Therapy

Brain injuries (BI) are a major public health concern. Many therapists who focus on BI use commercial video-exergames (CVEs) to motivate patients to perform the repetitive exercises required for rehabilitation. However, there is relatively little work examining the effects of CVE use on BI patient motivation to perform rehabilitation exercises. In this paper, we report on a randomized controlled study with 35 outpatients; we examined how including CVEs was associated with intrinsic motivation using Self-Determination Theory as a framework. We found using CVEs was associated with an increased perceived competence over a four-week study period when compared to a control group receiving only standard care. However, there was very little indication that games were more intrinsically motivating than standard care. Our work represents a much-needed study to investigate motivational aspects of CVE use in therapies for people who have had a BI.

Preliminary Evaluation of a Cycling Cleat Designed for Diabetic Foot Ulcers

BACKGROUND Offloading devices for diabetic foot ulcers (DFU) generally restrict exercise. In addition to traditional health benefits, exercise could benefit DFU by increasing blood flow and acting as thermotherapy. This study functionally evaluated a cycling cleat designed for forefoot DFU. METHODS Fifteen individuals at risk of developing a DFU used a recumbent stationary bicycle to complete one 5-minute cycling bout with the DFU cleat on their study foot and one 5-minute bout without it. Foot stress was evaluated by plantar pressure insoles during cycling. Laser Doppler perfusion monitored blood flow to the hallux. Infrared photographs measured foot temperature before and after each cycling bout. RESULTS The specialized cleat significantly reduced forefoot plantar pressure (9.9 kPa versus 62.6 kPa, P < .05) and pressure time integral (15.4 versus 76.4 kPa*sec, P < .05). Irrespective of footwear condition, perfusion to the hallux increased (3.97 ± 1.2 versus 6.9 ± 1.4 tissue perfusion units, P < .05) after exercise. Infrared images revealed no changes in foot temperature. CONCLUSIONS The specialized cleat allowed participants to exercise with minimal forefoot stress. The observed increase in perfusion suggests that healing might improve if patients with active DFU were to use the cleat. Potential thermotherapy for DFU was not supported by this study. Evaluation of the device among individuals with active DFU is now warranted.

Control of lower extremity edema in patients with diabetes: double blind randomized controlled trial assessing the efficacy of mild compression diabetic socks

AIMS Persons with diabetes frequently present with lower extremity (LE) edema; however, compression therapy is generally avoided for fear of compromising arterial circulation in a population with a high prevalence of peripheral arterial disease. This double blind randomized controlled trial (RCT) assessed whether diabetic socks with mild compression could reduce LE edema in patients with diabetes without negatively impacting vascularity. METHODS Eighty subjects with LE edema and diabetes were randomized to receive either mild-compression knee high diabetic socks (18-25mmHg) or non-compression knee high diabetic socks. Subjects were instructed to wear the socks during all waking hours. Follow-up visits occurred weekly for four consecutive weeks. Edema was quantified through midfoot, ankle, and calf circumferences and cutaneous fluid measurements. Vascular status was tracked via ankle brachial index (ABI), toe brachial index (TBI), and skin perfusion pressure (SPP). RESULTS Seventy-seven subjects (39 controls and 38 mild-compression subjects) successfully completed the study. No statistical differences between the two groups in terms of age, body mass index, gender, and ethnicity. Repeated measures analysis of variance and Sidak corrections for multiple comparisons were used for data analyses. Subjects randomized to mild-compression diabetic socks demonstrated significant decreases in calf and ankle circumferences at the end of treatment as compared to baseline. LE circulation did not diminish throughout the study with no significant decreases in ABI, TBI or SPP for either group. CONCLUSIONS Results of this RCT suggest that mild compression diabetic socks may be effectively and safely used in patients with diabetes and LE edema.

Motion-based gaming to improve balance and physical activity in patients with mild traumatic brain injury (mTBI)

Motion based gaming was used in combination with standard therapy in 17 mild traumatic brain injury participants when compared to 20 controls to study the effectiveness of motion based gaming on physical activity level and postural stability measured by using body worn sensors. Significant improvements in number of steps, stability, and perceived motivation suggest promising use of motion based gaming in combination with physical therapy for improved rehabilitation outcomes in this population.