Nima Toosizadeh

Interests

Research

Wearable sensors, Gait and Balance, Aging, Frailty, Cognitive impairments

Teaching

Biomechanics

Courses

Scholarly Contributions

Journals/Publications

• Laksari, K., Wendel, C. S., Toosizadeh, N., Mohler, J., Laksari, K., & Kumar, D. P. (2021). Between-day repeatability of sensor-based in-home gait assessment among older adults: assessing the effect of frailty.. Aging clinical and experimental research, 33(6), 1529-1537. doi:10.1007/s40520-020-01686-x
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  While sensor-based daily physical activity (DPA) gait assessment has been demonstrated to be an effective measure of physical frailty and fall-risk, the repeatability of DPA gait parameters between different days of measurement is not clear..To evaluate test-retest reliability (repeatability) of DPA gait performance parameters, representing the quality of walking, and quantitative gait measures (e.g. number of steps) between two separate days of assessment among older adults..DPA was acquired for 48-h from older adults (age ≥ 65 years) using a tri-axial accelerometer. Continuous walking bouts (≥ 60 s) were identified from acceleration data and used to extract gait performance parameters, including time- and frequency-domain gait parameters, representing walking speed, variability, and irregularity. To assess repeatability, intraclass correlation coefficient (ICC) was calculated using two-way mixed effects F-test models for day-1 vs. day-2 as the independent random effect. Repeatability tests were performed for all participants and also within frailty groups (non-frail and pre-frail/frail identified using Fried phenotype)..Data was analyzed from 63 older adults (29 non-frail and 34 pre-frail/frail). Most of the time- and frequency-domain gait performance parameters showed good to excellent repeatability (ICC ≥ 0.70), while quantitative parameters, including number of steps and walking duration showed poor repeatability (ICC < 0.30). Among majority of the gait performance parameters, we observed higher repeatability among the pre-frail/frail group (ICC > 0.78) compared to non-frail individuals (0.39 < ICC < 0.55)..Gait performance parameters, showed higher repeatability compared to quantitative measures. Higher repeatability among pre-frail/frail individuals may be attributed to a reduced functional capacity for performing more intense and variable physical tasks..The clinical trial was retrospectively registered on June 18th, 2013 with ClinicalTrials.gov, identifier NCT01880229.
• Parthasarathy, S., Toosizadeh, N., Ruberto, K., Parvaneh, S., Parthasarathy, S., Mohler, J., Ehsani, H., & Carpenter, B. (2021). Frailty and heart response to physical activity.. Archives of gerontology and geriatrics, 93, 104323. doi:10.1016/j.archger.2020.104323
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  Although previous studies showed that frail older adults are more susceptible to develop cardiovascular diseases, the underlying effect of frailty on heart rate dynamics is still unclear. The goal of the current study was to measure heart rate changes due to normal speed and rapid walking among non-frail and pre-frail/frail older adults, and to implement heart rate dynamic measures to identify frailty status..Eighty-eight older adults (≥65 years) were recruited and stratified into frailty groups based on the five-component Fried frailty phenotype. While performing gait tests, heart rate was recorded using a wearable ECG and accelerometer sensors. Groups consisted of 27 non-frail (age = 78.70 ± 7.32) and 61 pre-frail/frail individuals (age = 81.00 ± 8.14). The parameters of interest included baseline heart rate measures (mean heart rate and heart rate variability), and heart rate dynamics due to walking (percentage change in heart rate and required time to reach the maximum heart rate)..Respectively for normal and rapid walking conditions, pre-frail/frail participants had 46% and 44% less increase in heart rate, and 49% and 27% slower occurrence of heart rate peak, when compared to non-frail older adults (p < 0.04, effect size = 0.71 ± 0.12). Measures of heart rate dynamics showed stronger associations with frailty status compared to baseline resting-state measures (sensitivity = 0.75 and specificity = 0.65 using heart rate dynamics measures, compared to sensitivity = 0.64 and specificity = 0.62 using baseline parameters)..These findings suggest that measures of heart rate dynamics in response to daily activities may provide meaningful markers for frailty screening.
• Toosizadeh, N., Ruiz, M., Pena, M., Mohler, J., Joseph, B., Fain, M., Ehsani, H., & Cohen, A. (2021). Physical and Cognitive Function Assessment to Predict Postoperative Outcomes of Abdominal Surgery.. The Journal of surgical research, 267, 495-505. doi:10.1016/j.jss.2021.05.018
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  Current evaluation methods to assess physical and cognitive function are limited and often not feasible in emergency settings. The upper-extremity function (UEF) test to assess physical and cognitive performance using wearable sensors. The purpose of this study was to examine the (1) relationship between preoperative UEF scores with in-hospital outcomes; and (2) association between postoperative UEF scores with 30-d adverse outcomes among adults undergoing emergent abdominal surgery..We performed an observational, longitudinal study among adults older than 40 y who presented with intra-abdominal symptoms. The UEF tests included a 20-sec rapid repetitive elbow flexion (physical function), and a 60-sec repetitive elbow flexion at a self-selected pace while counting backwards by threes (cognitive function), administered within 24-h of admission and within 24-h prior to discharge. Multiple logistic regression models assessed the association between UEF and outcomes. Each model consisted of the in-hospital or 30-d post-discharge outcome as the dependent variable, preoperative UEF physical and cognitive scores as hypothesis covariates, and age and sex as adjuster covariates..Using UEF physical and cognitive scores to predict in-hospital outcomes, an area under curve (AUC) of 0.76 was achieved, which was 17% more sensitive when compared to age independently. For 30-d outcomes, the AUC increased to 0.89 when UEF physical and cognitive scores were included in the model with age and sex..Sensor-based measures of physical and cognitive function enhance outcome prediction providing an objective practicable tool for risk stratification in emergency surgery settings among aging adults presenting with intra-abdominal symptoms.
• Toosizadeh, N., Tax, T., Mohler, J., Ehsani, H., Cohen, A. T., & Asghari, M. (2021). Nonlinear analysis of the movement variability structure can detect aging-related differences among cognitively healthy individuals.. Human movement science, 78, 102807. doi:10.1016/j.humov.2021.102807
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  Studying the dynamics of nonlinear systems can provide additional information about the variability structure of the system. Within the current study, we examined the application of regularity and local stability measures to capture motor function alterations due to dual-tasking using a previously validated upper-extremity function (UEF). We targeted young (ages 18 and 30 years) and older adults (65 years or older) with normal cognition based on clinical screening. UEF involved repetitive elbow flexion without counting (ST) and while counting backward by one (DT1) or three (DT3). We measured the regularity (measured by sample entropy (SE)), local stability (measured by the largest Lyapunov exponent (LyE)), as well as conventional peak-dependent variability measures (coefficient of variation of kinematics parameters) to capture motor dynamic alterations due to dual-tasking. Within both groups, only SE showed significant differences between all pairs of UEF condition comparisons, even ST vs DT1 (p = 0.007, effect size = 0.507), for which no peak-dependent parameter showed significant difference. Among all measures, the only parameter that showed a significant difference between young and older adults was LyE (p < 0.001, effect size = 0.453). Current findings highlight the potential of nonlinear analysis to detect aging-related alterations among cognitively healthy participants.
• Arrué, P., Toosizadeh, N., Babaee, H., & Laksari, K. (2020). Low-Rank Representation of Head Impact Kinematics: A Data-Driven Emulator. Frontiers in bioengineering and biotechnology, 8, 555493.
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  Head motion induced by impacts has been deemed as one of the most important measures in brain injury prediction, given that the vast majority of brain injury metrics use head kinematics as input. Recently, researchers have focused on using fast approaches, such as machine learning, to approximate brain deformation in real time for early brain injury diagnosis. However, training such models requires large number of kinematic measurements, and therefore data augmentation is required given the limited on-field measured data available. In this study we present a principal component analysis-based method that emulates an empirical low-rank substitution for head impact kinematics, while requiring low computational cost. In characterizing our existing data set of 537 head impacts, each consisting of 6 degrees of freedom measurements, we found that only a few modes, e.g., 15 in the case of angular velocity, is sufficient for accurate reconstruction of the entire data set. Furthermore, these modes are predominantly low frequency since over 70% of the angular velocity response can be captured by modes that have frequencies under 40 Hz. We compared our proposed method against existing impact parametrization methods and showed significantly better performance in injury prediction using a range of kinematic-based metrics-such as head injury criterion (HIC), rotational injury criterion (RIC), and brain injury metric (BrIC)-and brain tissue deformation-based metrics-such as brain angle metric (BAM), maximum principal strain (MPS), and axonal fiber strains (FS). In all cases, our approach reproduced injury metrics similar to the ground truth measurements with no significant difference, whereas the existing methods obtained significantly different ( < 0.01) values as well as substantial differences in injury classification sensitivity and specificity. This emulator will enable us to provide the necessary data augmentation to build a head impact kinematic data set of any size. The emulator and corresponding examples are available on our website.
• Ehsani, H., Parvaneh, S., Mohler, J., Wendel, C., Zamrini, E., O'Connor, K., & Toosizadeh, N. (2020). Can motor function uncertainty and local instability within upper-extremity dual-tasking predict amnestic mild cognitive impairment and early-stage Alzheimer's disease?. Computers in biology and medicine, 120, 103705.
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  In this study, we examined the uncertainty and local instability of motor function for cognitive impairment screening using a previously validated upper-extremity function (UEF). This approach was established based upon the fact that elders with an impaired executive function have trouble in the simultaneous execution of a motor and a cognitive task (dual-tasking). Older adults aged 65 years and older were recruited and stratified into 1) cognitive normal (CN), 2) amnestic MCI of the Alzheimer's type (aMCI), and 3) early-stage Alzheimer's Disease (AD). Participants performed normal-paced repetitive elbow flexion without counting and while counting backward by ones and threes. The influence of cognitive task on motor function was measured using uncertainty (measured by Shannon entropy), and local instability (measured by the largest Lyapunov exponent) of elbow flexion and compared between cognitive groups using ANOVAs, while adjusting for age, sex, and BMI. We developed logistic ordinal regression models for predicting cognitive groups based on these nonlinear measures. A total of 81 participants were recruited, including 35 CN (age = 83.8 ± 6.9), 30 aMCI (age = 83.9 ± 6.9), and 16 early AD (age = 83.2 ± 6.6). Uncertainty of motor function demonstrated the strongest associations with cognitive impairment, with an effect size of 0.52, 0.88, and 0.51 for CN vs. aMCI, CN vs. AD, and aMCI vs. AD comparisons, respectively. Ordinal logistic models predicted cognitive impairment (aMCI and AD combined) with a sensitivity and specificity of 0.82. The findings accentuate the potential of employing nonlinear dynamical features of motor functions during dual-tasking, especially uncertainty, in detecting cognitive impairment.
• Follis, S., Chen, Z., Mishra, S., Howe, C. L., Toosizadeh, N., & Dohm, M. (2020). Comparison of wearable sensor to traditional methods in functional outcome measures: A systematic review. Journal of orthopaedic research : official publication of the Orthopaedic Research Society.
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  Traditional methods of collecting functional outcome measures are widely used for lower extremity arthroplasty outcome assessment. Wearable sensors are emerging as viable tools for functional outcome measures in monitoring of postarthroplasty recovery. The objective of this review was to compare the efficacy of wearable sensors with traditional methods for monitoring postarthroplasty functional recovery. Articles were searched for inclusion in this review that used both traditional and wearable sensor functional outcome measures to assess lower extremity function before and after lower extremity arthroplasty. Two independent screeners reviewed all articles, and resolved differences through consensus and consultation with the senior author. Studies that met inclusion criteria were evaluated for methodologic quality using performed risk of bias assessments. Results from several traditional and wearable sensor functional outcome measures from baseline through follow-up were normalized across studies. Fourteen articles met the inclusion criteria. Six studies used statistical methods to directly compare functional outcome measures and eight studies used qualitative description of comparisons. This review found evidence that wearable sensors detected nuanced functional outcome information on the specific biomechanics and timing of recovery, which were unaccounted for using traditional methods. Wearable sensors have shown promising utility in providing additional recovery information from lower extremity arthroplasty compared with traditional functional outcome measures, but future research is needed to assess the clinical significance of this additional information. Wearable sensor technology is an emerging clinical tool providing advanced and determinative data with the potential for advancing the assessment of lower extremity arthroplasty outcomes.
• Pradeep Kumar, D., Toosizadeh, N., Mohler, J., Ehsani, H., Mannier, C., & Laksari, K. (2020). Sensor-based characterization of daily walking: a new paradigm in pre-frailty/frailty assessment. BMC geriatrics, 20(1), 164.
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  Frailty is a highly recognized geriatric syndrome resulting in decline in reserve across multiple physiological systems. Impaired physical function is one of the major indicators of frailty. The goal of this study was to evaluate an algorithm that discriminates between frailty groups (non-frail and pre-frail/frail) based on gait performance parameters derived from unsupervised daily physical activity (DPA).
• Pradeep Kumar, D., Wendel, C., Mohler, J., Laksari, K., & Toosizadeh, N. (2020). Between-day repeatability of sensor-based in-home gait assessment among older adults: assessing the effect of frailty. Aging clinical and experimental research.
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  While sensor-based daily physical activity (DPA) gait assessment has been demonstrated to be an effective measure of physical frailty and fall-risk, the repeatability of DPA gait parameters between different days of measurement is not clear.
• Toosizadeh, N., Ehsani, H., Parthasarathy, S., Carpenter, B., Ruberto, K., Mohler, J., & Parvaneh, S. (2020). Frailty and heart response to physical activity. Archives of gerontology and geriatrics, 93, 104323.
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  Although previous studies showed that frail older adults are more susceptible to develop cardiovascular diseases, the underlying effect of frailty on heart rate dynamics is still unclear. The goal of the current study was to measure heart rate changes due to normal speed and rapid walking among non-frail and pre-frail/frail older adults, and to implement heart rate dynamic measures to identify frailty status.
• Vahdat, I., Toosizadeh, N., Tanbakoosaz, A., Parnianpour, M., & Ghomsheh, F. T. (2020). COMPARING METHODS FOR 3D INVERSE DYNAMICS ANALYSIS OF SQUAT LIFTING USING A FULL BODY LINKED SEGMENT MODEL. Journal of Mechanics in Medicine and Biology, 20(03), 2031001. doi:10.1142/s0219519420310016
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  Objective: The main objective of this study was to assess the accuracy of bottom-up solution for three-dimensional (3D) inverse dynamics analysis of squat lifting using a 3D full body linked segmen...
• Wahlert, G., Fain, M. J., Wahlert, G., Toosizadeh, N., Mohler, J., & Fain, M. (2020). The effect of vibratory stimulation on the timed-up-and-go mobility test: a pilot study for sensory-related fall risk assessment.. Physiological research, 69(4), 721-730. doi:10.33549/physiolres.934451
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  Effects of localized lower-extremity vibration on postural balance have been reported. The purpose of the current study was to investigate the effect of low-frequency vibration of calf muscles on the instrumented Timed-Up-and-Go (iTUG) test among older adults. Older adults were recruited and classified to low (n=10, age=72.9±2.8 years) and high fall risk (n=10, age=83.6±9.6) using STEADI. Vibratory system (30Hz or 40Hz), was positioned on calves along with wearable motion sensors. Participants performed the iTUG test three times, under conditions of no-vibration, 30Hz, and 40Hz vibration. Percentage differences in duration of iTUG components were calculated comparing vibration vs no-vibration conditions. Significant between-group differences were observed in iTUG (p=0.03); high fall risk participants showed reduction in the duration of turning (-10 % with 30Hz; p=0.15 and -15 % with 40Hz; p=0.03) and turning and sitting (-18 % with 30Hz; p=0.02 and -10 % with 40Hz; p=0.08). However, vibration increased turning (+18 % with 30Hz; p=0.20 and +27 % with 40Hz; p=0.12) and turning and sitting duration (+27 % with 30Hz; p=0.11 and +47 % with 40Hz; p=0.12) in low fall risk participants. Findings suggest that lower-extremity vibration affects dynamic balance; however, the level of this influence may differ between low and high fall risk older adults, which can potentially be used for assessing aging-related sensory deficits.
• Yanquez, F. J., Peterson, A., Weinkauf, C., Goshima, K. R., Zhou, W., Mohler, J., Ehsani, H., & Toosizadeh, N. (2020). Sensor-Based Upper-Extremity Frailty Assessment for the Vascular Surgery Risk Stratification. The Journal of surgical research, 246, 403-410.
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  Available methods for determining outcomes in vascular surgery patients are often subjective or not applicable in nonambulatory patients. The purpose of the present study was to assess the association between vascular surgery outcomes and a previously validated upper-extremity function (UEF) method, which incorporates wearable motion sensors for the physical frailty assessment.
• Ehsani, H., Mohler, M. J., Golden, T., & Toosizadeh, N. (2019). Upper-extremity function prospectively predicts adverse discharge and all-cause COPD readmissions: a pilot study. International journal of chronic obstructive pulmonary disease, 14, 39.
• Ehsani, H., Mohler, M. J., O'Connor, K., Zamrini, E., Tirambulo, C., & Toosizadeh, N. (2019). The association between cognition and dual-tasking among older adults: the effect of motor function type and cognition task difficulty. Clinical interventions in aging, 14, 659-669.
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  Dual-task actions challenge cognitive processing. The usefulness of objective methods based on dual-task actions to identify the cognitive status of older adults has been previously demonstrated. However, the properties of select motor and cognitive tasks are still debatable. We investigated the effect of cognitive task difficulty and motor task type (walking versus an upper-extremity function [UEF]) in identifying cognitive impairment in older adults.
• Jansen, C. P., Toosizadeh, N., Mohler, M. J., Najafi, B., Wendel, C., & Schwenk, M. (2019). The association between motor capacity and mobility performance: frailty as a moderator. European review of aging and physical activity : official journal of the European Group for Research into Elderly and Physical Activity, 16, 16.
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  In older adults, the linkage between laboratory-assessed 'motor capacity' and 'mobility performance' during daily routine is controversial. Understanding factors moderating this relationship could help developing more valid assessment as well as intervention approaches. We investigated whether the association between capacity and performance becomes evident with transition into frailty, that is, whether frailty status moderates their association.
• Laksari, K., Toosizadeh, N., Mohler, J., Laksari, K., & Kumar, D. P. (2019). FRAILTY ASSESSMENT BASED ON THE QUALITY OF DAILY WALKING. Innovation in Aging, 3(Supplement_1), S85-S85. doi:10.1093/geroni/igz038.328
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  Abstract Frailty is an increasingly recognized geriatric syndrome resulting in age-related decline in reserve across multiple physiologic systems. An impaired physical function is a prime indicator of frailty. In this study, we aim to implement a body-worn sensor to characterize the quantity and quality of everyday walking, and establish associations between gait impairment and frailty. Daily physical activity was acquired for 48 hours from 125 older adults (≥65 years; 44 non-frail, 60 pre-frail, and 21 frail based on the Fried gold standard) using a tri-axial accelerometer motion-sensor. Continuous purposeful walks (≥60s) without pauses were identified from time-domain acceleration data. Power spectral density (PSD) analysis was performed to define higher gait variability, which was identified by a shorter and wider PSD peak. Association between frailty and gait parameters was assessed using multivariable nominal logistic models with frailty as the dependent variable, and demographic parameters along with the gait parameters as the independent variables. Stride times, PSD gait variability, and total and maximum continuous purposeful walking duration were significantly different between non-frail and pre-frail/frail groups (p
• Mohler, M. J., Toosizadeh, N., Hsu, C., & Taylor-Piliae, R. E. (2019). A Novel Dual-Task Balance Challenge to Prevent Falls in Older Adults: A Randomized Pilot Study. Journal of Geriatric Medicine and Gerontology, 5, 075. doi:Doi:10.23937/2469-5858/1510075
• Muslim, K., Hendershot, B., Toosizadeh, N., Nussbaum, M. A., Bazrgari, B., & Madigan, M. L. (2019). DISTURBANCES TO INTRINSIC STIFFNESS AND REFLEXIVE MUSCLE RESPONSES FOLLOWING REPEATED STATIC TRUNK FLEXION.
• Taylor-piliae, R. E., Toosizadeh, N., Taylor-piliae, R. E., Mohler, J., & Hsu, C. H. (2019). Abstract P258: Novel Dual-task Balance Challenge to Prevent Falls in Older Adults With Cardiovascular Disease Risk Factors. Circulation, 139(Suppl_1). doi:10.1161/circ.139.suppl_1.p258
• Tirambulo, C. G., Toosizadeh, N., Tirambulo, C. V., Sween, A., Stipho, F., Mohler, J., & Hindosh, Z. (2019). P2-591: THE EFFECT OF INTENSITY AND DURATION OF PHYSICAL ACTIVITY ON COGNITION. Alzheimers & Dementia, 15, P849-P849. doi:10.1016/j.jalz.2019.06.3000
• Tirambulo, C. G., Toosizadeh, N., Tirambulo, C. V., Sween, A., Stipho, F., Mohler, J., Mills, C. S., Hindosh, Z., & Ehsani, H. (2019). P1-593: ASSESSING THE ASSOCIATION OF FEAR OF FALLING AND DEPRESSION IN OLDER ADULTS. Alzheimers & Dementia, 15, P503-P504. doi:10.1016/j.jalz.2019.06.1198
• Toosizadeh, N., Ehsani, H., Wendel, C., Zamrini, E., Connor, K. O., & Mohler, J. (2019). Screening older adults for amnestic mild cognitive impairment and early-stage Alzheimer's disease using upper-extremity dual-tasking. Scientific reports, 9(1), 10911.
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  The purpose of the current study was to develop an objective tool based on dual-task performance for screening early-stage Alzheimer's disease (AD) and mild cognitive impairment (MCI of the Alzheimer's type). Dual-task involved a simultaneous execution of a sensor-based upper-extremity function (UEF) motor task (normal or rapid speed) and a cognitive task of counting numbers backward (by ones or threes). Motor function speed and variability were recorded and compared between cognitive groups using ANOVAs, adjusted for age, gender, and body mass index. Cognitive indexes were developed using multivariable ordinal logistic models to predict the cognitive status using UEF parameters. Ninety-one participants were recruited; 35 cognitive normal (CN, age = 83.8 ± 6.9), 34 MCI (age = 83.9 ± 6.6), and 22 AD (age = 84.1 ± 6.1). Flexion number and sensor-based motion variability parameters, within the normal pace elbow flexion, showed significant between-group differences (maximum effect size of 1.10 for CN versus MCI and 1.39 for CN versus AD, p 
• Toosizadeh, N., Nussbaum, M. A., & Madigan, M. L. (2019). VISCOELASTIC MODELING OF THE LUMBAR SPINE: THE EFFECT OF PROLONGED FLEXION ON INTERNAL LOADS.
• Chuan Yen, T., Mohler, J., Dohm, M., Laksari, K., Najafi, B., & Toosizadeh, N. (2018). The Effect of Pain Relief on Daily Physical Activity: In-Home Objective Physical Activity Assessment in Chronic Low Back Pain Patients after Paravertebral Spinal Block. Sensors (Basel, Switzerland), 18(9).
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  This study evaluates the effect of paravertebral spinal injection (PSI), utilizing both subjective and objective assessments in chronic low back pain (LBP) associated with facet joint arthrosis over a one-month duration. Subjective questionnaires included the visual analogue scale (VAS) for pain, the Oswestry Disability Index, the Health Survey SF-12, and the short Falls Efficacy Scale International (FES-I). Objective assessments included in-clinic gait and Timed Up and Go (TUG) tests using wearable sensors, as well as 48 h daily physical activity (DPA) monitored using a chest-worn triaxial accelerometer. Subjective and objective measures were performed prior to treatment, immediately after the treatment, and one month after the treatment. Eight LBP patients were recruited for this study (mean age = 54 ± 13 years, body mass index = 31.41 ± 6.52 kg/m², 50% males). Results show significant decrease in pain (~55%, < 0.05) and disability (Oswestry scores, ~21%, < 0.05). In-clinic gait and TUG were also significantly improved (~16% and ~18% faster walking and shorter TUG, < 0.05); however, DPA, including the percentage of physical activities (walking and standing) and the number of steps, showed no significant change after PSI ( 0.25; effect size ≤ 0.44). We hypothesize that DPA may continue to be truncated to an extent by conditioned fear-avoidance, a psychological state that may prevent increase in daily physical activity to avoid pain.
• Chuan, Y. T., Mohler, J., Dohm, M., Laksari, K., Najafi, B., & Toosizadeh, N. (2018). The Effect of Pain Relief on Daily Physical Activity: In-Home Objective Physical Activity Assessment in Chronic Low Back Pain Patients after Paravertebral Spinal Block. Sensors, 18(9), 3048.
• Ehsani, H., Mohler, J., Marlinski, V., Rashedi, E., & Toosizadeh, N. (2018). The influence of mechanical vibration on local and central balance control. Journal of Biomechanics, 71, 59--66.
• Ehsani, H., Tirambulo, C., Mills, C. S., Zamrini, E. d., Mohler, J., & Toosizadeh, N. (2018). ASSESSING COGNITION USING DUAL-TASK MOTOR FUNCTION: THE INFLUENCE OF COGNITIVE TASK TYPE. Alzheimer's & Dementia: The Journal of the Alzheimer's Association, 14(7), P1444.
• Fakhoury, S., Gaytan-Jenkins, D., Lopez, A., Ehsani, H., O'Connor, K., Zamrini, E. d., Mohler, J., & Toosizadeh, N. (2018). ASSESSMENT OF DUAL-TASK MOTOR FUNCTION DETERIORATION FOR DETECTING COGNITIVE IMPAIRMENT. Alzheimer's & Dementia: The Journal of the Alzheimer's Association, 14(7), P191.
• Hindosh, Z., Stipho, F., Tirambulo, C., Mills, C. S., Sween, A., Golden, T. R., Mohler, J., & Toosizadeh, N. (2018). THE ASSOCIATION OF PHYSICAL ACTIVITY WITH COGNITIVE IMPAIRMENT. Alzheimer's & Dementia: The Journal of the Alzheimer's Association, 14(7), P586.
• Junna, S., Golden, T. R., Ghazala, S., Wadeea, R., Gonzalez, M., Tirambulo, C., Toosizadeh, N., Mohler, J., & Taleban, S. (2018). Mo1629-Frailty Predicts Colonoscopy Outcomes in Patients Undergoing Screening. Gastroenterology, 154(6), S--775.
• Mousavi-Khatir, R., Talebian, S., Toosizadeh, N., Olyaei, G. R., & Maroufi, N. (2018). Disturbance of neck proprioception and feed-forward motor control following static neck flexion in healthy young adults. Journal of Electromyography and Kinesiology, 41, 160--167.
• Mousavi-Khatir, R., Talebian, S., Toosizadeh, N., Olyaei, G. R., & Maroufi, N. (2018). The effect of static neck flexion on mechanical and neuromuscular behaviors of the cervical spine. Journal of Biomechanics, 72, 152--158.
• Taleban, S., Toosizadeh, N., Junna, S., Golden, T., Ghazala, S., Wadeea, R., Tirambulo, C., & Mohler, J. (2018). Frailty assessment predicts acute outcomes in patients undergoing screening colonoscopy. Digestive Diseases and Sciences, 63(12), 3272--3280.
• Taylor-Piliae, R., Sutherland-Mills, C., Tirambulo, C., Toosizadeh, N., Hsu, P., & Mohler, J. (2018). ENHANCING A MATTER OF BALANCE FALL INTERVENTION WITH A PILOT DUAL TASK BALANCE CHALLENGE. Innovation in Aging, 2(suppl_1), 517--517.
• Toosizadeh, N., Ehsani, H., Miramonte, M., & Mohler, J. (2018). Proprioceptive impairments in high fall risk older adults: the effect of mechanical calf vibration on postural balance. Biomedical engineering online, 17(1), 51.
• Toosizadeh, N., Ehsani, H., Taleban, S., Golden, T., Mohler, J., & Tirambulo, C. V. (2018). Screening Colonoscopy Adverse Events in Aging Adults: Does Frailty Matter?. Journal of Geriatric Medicine and Gerontology, 4(4). doi:10.23937/2469-5858/1510055
• Toosizadeh, N., Mohler, J., & Marlinski, V. (2018). Low intensity vibration of ankle muscles improves balance in elderly persons at high risk of falling. PLoS one, 13(3), e0194720.
• Zamrini, E., Fakhoury, S., Gaytan-Jenkins, D., Lopez, A., Ehsani, H., Belden, C., O'Connor, K., Mohler, J., & Toosizadeh, N. (2018). CORRELATIONS BETWEEN REY AUDITORY VERBAL LEARNING TEST (AVLT) AND UPPER EXTREMITY DUAL TASK FUNCTION IN DETECTING COGNITIVE IMPAIRMENT. Alzheimer's & Dementia: The Journal of the Alzheimer's Association, 14(7), P530--P531.
• Bruton, M., Hosking, D. E., Hollan, I., Sargent-Cox, K. A., Anstey, K. J., Xiao, J., Jiang, D. a., Lindroos, E., Mohler, J., Mikkelsen, K., Toosizadeh, N., Rynning, S. E., Grewal, G. S., Saatvedt, K., Najafi, B., Almdahl, S. M., Parvaneh, S., Harris, H. E., Robinson, S. A., , Lundberg, I. E., et al. (2017). Front & Back Matter. Gerontology, 63(5).
• Golden, T., Toosizadeh, N., Berry, C. E., Mei, Y., Miramontes, M., Zaldizar, C., Mohler, J., & Ghazala, L. (2017). A103 COPD: DISEASE PROGRESSION AND PROGNOSIS: Frailty Assessment For Predicting Readmission And Discharge Disposition Among Patients Hospitalized For Chronic Obstructive Pulmonary Disease Exacerbation. American Journal of Respiratory and Critical Care Medicine, 195.
• Joseph, B., Toosizadeh, N., Orouji Jokar, T., Heusser, M. R., Mohler, J., & Najafi, B. (2017). Upper-Extremity Function Predicts Adverse Health Outcomes among Older Adults Hospitalized for Ground-Level Falls. Gerontology, 63(4), 299-307.
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  Despite National Surgical Quality Improvement guidelines to integrate frailty into surgical elder assessments, a quick, accurate, and simple frailty assessment tool suitable for busy clinical settings is still not available. Recently, we have demonstrated that a simple upper-extremity function (UEF) test based on wearable sensors could identify frailty with high agreement with conventional assessments by testing 20-s repetitive elbow flexion and extension.
• Parvaneh, S., Mohler, J., Toosizadeh, N., Grewal, G. S., & Najafi, B. (2017). Postural Transitions during Activities of Daily Living Could Identify Frailty Status: Application of Wearable Technology to Identify Frailty during Unsupervised Condition. Gerontology, 63(5), 479-487.
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  Impairment of physical function is a major indicator of frailty. Functional performance tests have been shown to be useful for identification of frailty in older adults. However, these tests are often not translatable into unsupervised and remote monitoring of frailty status at home and/or community settings.
• Peterson, R., Stocker, H. R., Toosizadeh, N., Wendel, C., Fain, M., & Mohler, J. J. (2017). BALANCE CHANGES ASSOCIATED WITH SIX-MONTH FRAILTY STATUS CHANGES. Innovation in Aging, 1(Suppl 1), 1128.
• Stocker, H. R., Peterson, R., Toosizadeh, N., Wendel, C., Fain, M., & Mohler, J. J. (2017). FRAILTY TRANSITIONS AMONG OLDER ADULTS. Innovation in aging, 1(suppl_1), 195--196.
• Toosizadeh, N., Berry, C. E., Mei, Y., Miramontes, M., Zaldizar, C., Mohler, J., Ghazala, L., & Golden, T. (2017). Frailty Assessment For Predicting Readmission And Discharge Disposition Among Patients Hospitalized For Chronic Obstructive Pulmonary Disease Exacerbation. Am J Respir Crit Care Med, 195, A2723.
• Toosizadeh, N., Berry, C., Bime, C., Najafi, B., Kraft, M., & Mohler, J. (2017). Assessing upper-extremity motion: An innovative method to quantify functional capacity in patients with chronic obstructive pulmonary disease. PloS one, 12(2), e0172766.
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  Assessment of functional capacity is important in directing chronic obstructive pulmonary disease (COPD) care (e.g., rehabilitation and discharge readiness), and in predicting outcomes (e.g., exacerbation, hospitalization, and mortality). The 6-minute walk distance (6MWD) test for functional capacity assessment, may be time-consuming and burdensome.
• Toosizadeh, N., Mei, Y., Golden, T. R., Miramontes, M., Zaldizar, C., Mohler, J., & others, . (2017). Frailty and age may not Adequately Predict Colonoscopy Outcomes in Adults. Gastroenterology, 152(5), S530.
• Toosizadeh, N., Wendel, C., Hsu, C. H., Zamrini, E., & Mohler, J. (2017). Frailty assessment in older adults using upper-extremity function: index development. BMC geriatrics, 17(1), 117.
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  Numerous multidimensional assessment tools have been developed to measure frailty; however, the clinical feasibility of these tools is limited. We previously developed and validated an upper-extremity function (UEF) assessment method that incorporates wearable motion sensors. The purpose of the current study was to: 1) cross-sectionally validate the UEF method in a larger sample in comparison with the Fried index; 2) develop a UEF frailty index to predict frailty categories including non-frail, pre-frail, and frail based on UEF parameters and demographic information, using the Fried index as the gold standard; and 3) develop a UEF continuous score (points scores for each UEF parameter and a total frailty score) based on UEF parameters and demographic information, using the Fried index as the gold standard.
• Gary, M., Toosizadeh, N., Mager, R., Veldhuizen, J., O'connor, K., Mohler, J., & Najafi, B. (2016). student Presentation Upper-extremity function testing as an alternative to gait performance measures in older adults: d68. Journal of the American Geriatrics Society, 64, S241.
• Gill, S. V., Walsh, M. K., Pratt, J. A., Toosizadeh, N., Najafi, B., & Travison, T. G. (2016). Changes in spatiotemporal gait patterns during flat ground walking and obstacle crossing 1 year after bariatric surgery. Surgery for obesity and related diseases : official journal of the American Society for Bariatric Surgery, 12(5), 1080-5.
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  Obesity has a negative impact on motor function, leading to an increase in fall risk. Massive weight loss improves some aspects of gait on flat ground. However, we have little information about whether gait changes during flat-ground walking and during more complex motor tasks beyond flat-ground walking.
• Jokar, T. O., Najafi, B., Rhee, P. M., Mohler, J., Toosizadeh, N., Heusser, M. R., Kulvatunyou, N., Hassan, A., Gries, L. M., & Joseph, B. (2016). Motion Sensors Estimated Upper Extremity Frailty Score: A Practical Method to Identify 30-Day Recurrent Fall and Hospital Readmission in Elderly Trauma Patients. Journal of the American College of Surgeons, 223(4), S42.
• Lei, H., Toosizadeh, N., Schwenk, M., Sherman, S., Karp, S., Sternberg, E., & Najafi, B. (2016). A Pilot Clinical Trial to Objectively Assess the Efficacy of Electroacupuncture on Gait in Patients with Parkinson's Disease Using Body Worn Sensors. PloS one, 11(5), e0155613.
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  Gait disorder, a key contributor to fall and poor quality of life, represents a major therapeutic challenge in Parkinson's disease (PD). The efficacy of acupuncture for PD remains unclear, largely due to methodological flaws and lack of studies using objective outcome measures.
• Mohler, M. J., Wendel, C. S., Taylor-Piliae, R. E., Toosizadeh, N., & Najafi, B. (2016). Motor Performance and Physical Activity as Predictors of Prospective Falls in Community-Dwelling Older Adults by Frailty Level: Application of Wearable Technology. Gerontology, 62(6), 654-664.
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  Few studies of the association between prospective falls and sensor-based measures of motor performance and physical activity (PA) have evaluated subgroups of frailty status separately.
• Thiede, R., Toosizadeh, N., Mills, J. L., Zaky, M., Mohler, J., & Najafi, B. (2016). Gait and balance assessments as early indicators of frailty in patients with known peripheral artery disease. Clinical biomechanics (Bristol, Avon), 32, 1-7.
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  Peripheral artery disease is associated with increased morbidity and mortality, and frailty syndrome may mediate the risk of these adverse health outcomes to predict intervention results. The aim of this study was to determine the association between motor performance impairments based on in-clinic gait and balance measurements with frailty at intermediate stages (pre-frailty) in peripheral artery disease patients.
• Toosizadeh, N., Harati, H., Yen, T. C., Fastje, C., Mohler, J., Najafi, B., & Dohm, M. (2016). Paravertebral spinal injection for the treatment of patients with degenerative facet osteoarthropathy: Evidence of motor performance improvements based on objective assessments. Clinical biomechanics (Bristol, Avon), 39, 100-108.
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  This study examined short- and long-term improvements in motor performance, quantified using wearable sensors, in response to facet spine injection in degenerative facet osteoarthropathy patients.
• Toosizadeh, N., Joseph, B., Heusser, M. R., Jokar, T. O., Mohler, J., Phelan, H. A., & Najafi, B. (2016). Assessing Upper-Extremity Motion: An Innovative, Objective Method to Identify Frailty in Older Bed-Bound Trauma Patients. Journal of the American College of Surgeons.
• Toosizadeh, N., Joseph, B., Heusser, M. R., Orouji Jokar, T., Mohler, J., Phelan, H. A., & Najafi, B. (2016). Assessing Upper-Extremity Motion: An Innovative, Objective Method to Identify Frailty in Older Bed-Bound Trauma Patients. Journal of the American College of Surgeons, 223(2), 240-8.
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  Despite increasing evidence that assessing frailty facilitates medical decision-making, a quick and clinically simple frailty assessment tool is not available for trauma settings.
• Toosizadeh, N., Najafi, B., Reiman, E. M., Mager, R. M., Veldhuizen, J. K., O'Connor, K., Zamrini, E., & Mohler, J. (2016). Upper-Extremity Dual-Task Function: An Innovative Method to Assess Cognitive Impairment in Older Adults. Frontiers in aging neuroscience, 8, 167.
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  Difficulties in orchestrating simultaneous tasks (i.e., dual-tasking) have been associated with cognitive impairments in older adults. Gait tests have been commonly used as the motor task component for dual-task assessments; however, many older adults have mobility impairments or there is a lack of space in busy clinical settings. We assessed an upper-extremity function (UEF) test as an alternative motor task to study the dual-task motor performance in older adults.
• Toosizadeh, N., Stocker, H., Thiede, R., Mohler, J., Mills, J. L., & Najafi, B. (2016). Alterations in gait parameters with peripheral artery disease: The importance of pre-frailty as a confounding variable. Vascular medicine (London, England), 21(6), 520-527.
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  Although poor walking is the most common symptom of peripheral artery disease (PAD), reported results are inconsistent when comparing gait parameters between PAD patients and healthy controls. This inconsistency may be due to frailty, which is highly prevalent among PAD patients. To address this hypothesis, 41 participants, 17 PAD (74±8 years) and 24 aged-matched controls (76±7 years), were recruited. Gait was objectively assessed using validated wearable sensors. Analysis of covariate (ANCOVA) tests were used to compare gait parameters between PAD and non-PAD groups, considering age, gender, and body mass index as covariates, while stratified based on frailty status. According to the Fried frailty index, 47% of PAD and 50% of control participants were non-frail and the rest were classified as pre-frail. Within non-frail participants, gait speed, body sway during walking, stride length, gait cycle time, double-support, knee range of motion, speed variability, mid-swing speed, and gait initiation were significantly different between PAD and control groups (effect size d = 0.75±0.43). In the pre-frail group, however, most of the gait differences were diminished except for gait initiation and gait variability. Results suggest that gait initiation is the most sensitive parameter for detecting gait impairment in PAD participants when compared to controls, regardless of frailty status (d = 1.30-1.41; p
• Waanders, J., Beijersbergen, C., Hortob'agyi, T., Murgia, A., Helbostad, J. L., Bergland, A., Fr"andin, K., Gr"onstedt, H., Andresen, M., Puggaard, L., & others, . (2016). Contents Vol. 62, 2016. Gerontology, 62(6), I--VI.
• Waanders, J., Beijersbergen, C., Hortob'agyi, T., Murgia, A., Helbostad, J. L., Bergland, A., Fr"andin, K., Gr"onstedt, H., Andresen, M., Puggaard, L., & others, . (2016). Front & Back Matter. Gerontology, 62(6).
• Yen, T. C., Toosizadeh, N., Howe, C., Dohm, M., Mohler, J., & Najafi, B. (2016). Postural Balance Parameters as Objective Surgical Assessments in Low Back Disorders: A Systematic Review. Journal of applied biomechanics, 32(3), 316-23.
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  Balance assessments could render useful objective performance measures to evaluate the efficacy of low back surgeries, yet these assessments have not been collectively examined to determine longitudinal sensitivity across surgical interventions. The purpose of this review was to determine sensitivity of balance measurements for disparate spinal disorders after surgical intervention. We searched PubMed, Embase, Scopus, the Cochrane Library, Web of Science, and CINAHL. Articles were selected based on: (1) sample consisted of low back disorder individuals and (2) balance measurements were obtained both pre- and postsurgery. Most of the articles addressed 2 specific low back disorders: (1) adolescent idiopathic scoliosis/spinal fusion and (2) disc herniation/decompression surgery. For scoliosis patients, body sway increased (14-97%) immediately following surgery but gradually reduced (1-33%) approaching the 1-year post spinal fusion assessment. For patients with disc herniation, sway range, sway velocity, sway area, and sway variability all decreased (19-42%) immediately postsurgery. Balance assessments for adolescents with idiopathic scoliosis who underwent surgical intervention should be performed with visual occlusion, focus on time domain parameters, and evaluated with longer follow-up times. Patients with disc herniation who underwent decompression surgery should have balance assessments with visual deprivation, test conditions specifically addressing hip strategy, and correlation with pain.
• Parvaneh, S., Howe, C. L., Toosizadeh, N., Honarvar, B., Slepian, M. J., Fain, M., Mohler, J., & Najafi, B. (2015). Regulation of Cardiac Autonomic Nervous System Control across Frailty Statuses: A Systematic Review. Gerontology, 62(1), 3-15.
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  Frailty is a geriatric syndrome that leads to impairment in interrelated physiological systems and progressive homeostatic dysregulation in physiological systems.
• Toosizadeh, N., Lei, H., Schwenk, M., Sherman, S. J., Sternberg, E., Mohler, J., & Najafi, B. (2015). Does integrative medicine enhance balance in aging adults? Proof of concept for the benefit of electroacupuncture therapy in Parkinson's disease. Gerontology, 61(1), 3-14.
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  Postural balance and potentially fall risk increases among older adults living with neurological diseases, especially Parkinson's disease (PD). Since conventional therapies such as levodopa or deep brain stimulation may fail to alleviate or may even worsen balance, interest is growing in evaluating alternative PD therapies.
• Toosizadeh, N., Mohler, J., & Najafi, B. (2015). Assessing Upper Extremity Motion: An Innovative Method to Identify Frailty. Journal of the American Geriatrics Society, 63(6), 1181-6.
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  To objectively identify frailty using wireless sensors and an innovative upper extremity motion assessment routine that does not rely on gait.
• Toosizadeh, N., Mohler, J., Armstrong, D. G., Talal, T. K., & Najafi, B. (2015). The influence of diabetic peripheral neuropathy on local postural muscle and central sensory feedback balance control. PloS one, 10(8), e0135255.
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  Poor balance control and increased fall risk have been reported in people with diabetic peripheral neuropathy (DPN). Traditional body sway measures are unable to describe underlying postural control mechanism. In the current study, we used stabilogram diffusion analysis to examine the mechanism under which balance is altered in DPN patients under local-control (postural muscle control) and central-control (postural control using sensory cueing). DPN patients and healthy age-matched adults over 55 years performed two 15-second Romberg balance trials. Center of gravity sway was measured using a motion tracker system based on wearable inertial sensors, and used to derive body sway and local/central control balance parameters. Eighteen DPN patients (age = 65.4±7.6 years; BMI = 29.3±5.3 kg/m2) and 18 age-matched healthy controls (age = 69.8±2.9; BMI = 27.0±4.1 kg/m2) with no major mobility disorder were recruited. The rate of sway within local-control was significantly higher in the DPN group by 49% (healthy local-controlslope = 1.23±1.06×10-2 cm2/sec, P
• Toosizadeh, N., Mohler, J., Lei, H., Parvaneh, S., Sherman, S., & Najafi, B. (2015). Motor Performance Assessment in Parkinson's Disease: Association between Objective In-Clinic, Objective In-Home, and Subjective/Semi-Objective Measures. PloS one, 10(4), e0124763.
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  Advances in wearable technology allow for the objective assessment of motor performance in both in-home and in-clinic environments and were used to explore motor impairments in Parkinson's disease (PD). The aims of this study were to: 1) assess differences between in-clinic and in-home gait speed, and sit-to-stand and stand-to-sit duration in PD patients (in comparison with healthy controls); and 2) determine the objective physical activity measures, including gait, postural balance, instrumented Timed-up-and-go (iTUG), and in-home spontaneous physical activity (SPA), with the highest correlation with subjective/semi-objective measures, including health survey, fall history (fallers vs. non-fallers), fear of falling, pain, Unified Parkinson's Disease Rating Scale, and PD stage (Hoehn and Yahr). Objective assessments of motor performance were made by measuring physical activities in the same sample of PD patients (n = 15, Age: 71.2±6.3 years) and age-matched healthy controls (n = 35, Age: 71.9±3.8 years). The association between in-clinic and in-home parameters, and between objective parameters and subjective/semi-objective evaluations in the PD group was assessed using linear regression-analysis of variance models and reported as Pearson correlations (R). Both in-home SPA and in-clinic assessments demonstrated strong discriminatory power in detecting impaired motor function in PD. However, mean effect size (0.94±0.37) for in-home measures was smaller compared to in-clinic assessments (1.30±0.34) for parameters that were significantly different between PD and healthy groups. No significant correlation was observed between identical in-clinic and in-home parameters in the PD group (R = 0.10-0.25; p>0.40), while the healthy showed stronger correlation in gait speed, sit-to-stand duration, and stand-to-sit duration (R = 0.36-0.56; p
• Toosizadeh, N., Mohler, J., Wendel, C., & Najafi, B. (2015). Influences of frailty syndrome on open-loop and closed-loop postural control strategy. Gerontology, 61(1), 51-60.
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  As the population of older adults quickly increases, the incidence of frailty syndrome, a reduction in physiological reserve across multiple physiological systems, likewise increases. To date, impaired balance has been associated with frailty; however, the underlying frailty-related postural balance mechanisms remain unclear.
• Toosizadeh, N., Yen, T. C., Howe, C., Dohm, M., Mohler, J., & Najafi, B. (2015). Gait behaviors as an objective surgical outcome in low back disorders: A systematic review. Clinical biomechanics (Bristol, Avon), 30(6), 528-36.
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  Objective motor performance measures, especially gait assessment, could improve evaluation of low back disorder surgeries. However, no study has compared the relative effectiveness of gait parameters for assessing motor performance in low back disorders after surgery. The purpose of the current review was to determine the sensitive gait parameters that address physical improvements in each specific spinal disorder after surgical intervention.
• Toosizadeh, N., Yen, T., Dohm, M., Fastje, C., & Najafi, B. (2015). Can paravertebral facet injection improve motor performance in patients with degenerative facet osteoarthropathy?. pain, 2(0001).
• Toosizadeh, N., & Nussbaum, M. A. (2014). PROLONGED TRUNK FLEXION CAN INCREASE SPINE LOADS DURING A SUBSEQUENT LIFTING TASK: AN INVESTIGATION OF THE EFFECTS OF TRUNK FLEXION DURATION AND ANGLE USING A SAGITTALLY SYMMETRIC, VISCOELASTIC SPINE MODEL. Journal of Musculoskeletal Research, 16(4), 1350022.
• Toosizadeh, N., & Nussbaum, M. A. (2014). Trunk Tissue Creep Can Increase Spine Forces During a Subsequent Lifting Task. IIE Transactions on Occupational Ergonomics and Human Factors, 2(2), 71--82.
• Toosizadeh, N., Bunting, M., Howe, C., Mohler, J., Sprinkle, J., & Najafi, B. (2014). Motorized mobility scooters: the use of training/intervention and technology for improving driving skills in aging adults - a mini-review. Gerontology, 60(4), 357-65.
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  Motorized mobility scooters (MMS) have become the most acceptable powered assistive device for those with impaired mobility, who have sufficient upper body strength and dexterity, and postural stability. Although several benefits have been attributed to MMS usage, there are likewise risks of use, including injuries and even deaths.
• Toosizadeh, N., Lei, H., Schwenk, M., Sherman, S., Esternberg, E., & Najafi, B. (2014). Effectiveness of Electro-Acupuncture Therapy in Improving Gait and Balance in People with Parkinson's Disease. The Journal of Alternative and Complementary Medicine, 20(5), A45--A45.
• Toosizadeh, N., Mohler, J., & Najafi, B. (2014). a Novel Upper Limb Kinematics Assessment Using Wearable Sensors to Identify Frailty: b88. Journal of the American Geriatrics Society, 62, S121.
• Toosizadeh, N., Sherman, S. J., Schwenk, M., Parvaneh, S., Najafi, B., Lei, H., Karp, S., & Esternberg, E. (2014). Objective Assessment of Electro-acupuncture Benefit for Improving Balance and Gait in Patients with Parkinson’s Disease (P3.074). Neurology, 82.
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  OBJECTIVE: Assessing effectiveness of a standardized electro-acupuncture (EA) regimen for improving balance and gait in patients with idiopathic Parkinson’s Disease (PD) using objective modalities employing innovative body-worn sensor technology. BACKGROUND: Balance and gait disturbances, predictors of falling risk and impaired quality of life, have emerged as major therapeutic concerns in PD. While acupuncture is increasingly used as a complementary PD therapy, objective measures of its effectiveness in improving clinically relevant ambulatory performance in PD are lacking. DESIGN/METHODS: Thirteen PD patients were randomly assigned to an intervention group (n=10) or a control group (n=3). All patients underwent either real or sham acupuncture for 3 weeks in once-weekly, 30-minute sessions. Outcomes were assessed in an off-medication state at baseline prior to and at the end of therapy. Measurements included balance (assessed by ratio of mediolateral center of mass sway to anteroposterior sway during eyes open, eyes closed, and eyes open dual-task), gait (assessed during single-task vs. dual-task habitual or fast walking), postural transitions (assessed by Timed Up and Go, TUG), quality of life (SF12) and UPDRS. RESULTS: Significant improvement occurred in the intervention group compared to baseline for balance, gait, TUG, SF12, UPDRS II on fall and UPDRS III. Overall balance improved by 31% (reduction in ML/AP sway); gait speed increased by 10%, and stride length increased by 5% among all participants in active group for all different conditions of testing. No improvement for any measurement was found in the control group compared to baseline. No between group difference was observed for baseline assessments and demographic information (P>0.11). After treatment, between groups comparison revealed that balance, gait speed and stride length during all conditions was significantly better in the intervention group compared to control group (p
• Hendershot, B. D., Toosizadeh, N., Muslim, K., Madigan, M. L., & Nussbaum, M. A. (2013). Evidence for an exposure-response relationship between trunk flexion and impairments in trunk postural control. Journal of biomechanics, 46(14), 2554-7.
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  Prolonged trunk flexion alters passive and active trunk tissue behaviors, and exposure-response relationships between the magnitude of trunk flexion exposure and changes in these behaviors have been reported. This study assessed whether similar exposure-response relationships exist between such exposures and impairments in trunk postural control. Twelve participants (6 M, 6 F) were exposed to three distinct trunk flexion conditions (and a no-flexion control condition), involving different flexion durations with/without an external load, and which induced differing levels of passive tissue creep. Trunk postural control was assessed prior to and immediately following trunk flexion exposures, and during 10 min of standing recovery, by tracking center of pressure (COP) movements during a seated balance task. All COP-based sway measures increased following each flexion exposure. In the anteroposterior direction, these increases were larger with increasing exposure magnitude, whereas such a relationship was not evident for mediolateral sway measures. All measures were fully recovered following 10 min of standing. The present results provide evidence for an exposure-response relationship between trunk flexion exposures and impairments in trunk postural control; specifically, larger impairments following increased exposures (i.e., longer flexion duration and presence of external load). Such impairments in trunk postural control may result from some combination of reduced passive trunk stiffness and altered/delayed trunk reflex responses, and are generally consistent with prior evidence of exposure-dependent alterations in trunk mechanical and neuromuscular behaviors assessed using positional trunk perturbations. Such evidence suggests potential mechanistic pathways through which trunk flexion exposures may contribute to low-back injury risk.
• Muslim, K., Bazrgari, B., Hendershot, B., Toosizadeh, N., Nussbaum, M. A., & Madigan, M. L. (2013). Disturbance and recovery of trunk mechanical and neuromuscular behaviors following repeated static trunk flexion: influences of duration and duty cycle on creep-induced effects. Applied ergonomics, 44(4), 643-51.
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  Occupations involving frequent trunk flexion are associated with a higher incidence of low back pain. To investigate the effects of repeated static flexion on trunk behaviors, 12 participants completed six combinations of three static flexion durations (1, 2, and 4 min), and two flexion duty cycles (33% and 50%). Trunk mechanical and neuromuscular behaviors were obtained pre- and post-exposure and during recovery using sudden perturbations. A longer duration of static flexion and a higher duty cycle increased the magnitude of decrements in intrinsic stiffness. Increasing duty cycle caused larger decreases in reflexive muscle responses, and females had substantially larger decreases in reflexive responses following exposure. Patterns of recovery for intrinsic trunk stiffness and reflexive responses were consistent across conditions and genders, and none of these measures returned to pre-exposure values after 20 min of recovery. Reflexive responses may not provide a compensatory mechanism to offset decreases in intrinsic trunk stiffness following repetitive static trunk flexion. A prolonged recovery duration may lead to trunk instability and a higher risk of low back injury.
• Toosizadeh, N. (2013). Time-dependent assessment of the human lumbar spine in response to flexion exposures: in vivo measurement and modeling. VT Library.
• Toosizadeh, N., & Nussbaum, M. A. (2013). 5 Trunk Tissue Creep Can Increase Spine Forces During a Subsequent Lifting Task: An Investigation of the Effects of Trunk Flexion on Spine Mechanical Behaviors Using Experimental and Viscoelastic Modeling Approaches. Time-dependent Assessment of the Human Lumbar Spine in Response to Flexion Exposures: In Vivo Measurement and Modeling, 1001, 93.
• Toosizadeh, N., & Nussbaum, M. A. (2013). Creep deformation of the human trunk in response to prolonged and repetitive flexion: measuring and modeling the effect of external moment and flexion rate. Annals of biomedical engineering, 41(6), 1150-61.
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  While viscoelastic responses of isolated trunk soft tissues have been characterized in earlier studies, the effects of external loading and flexion rate on these responses in the intact human trunk are largely unknown. Two experiments were conducted to measure trunk viscoelastic behaviors, one involving prolonged flexion with several extra loads (attached to the wrists) and the other repetitive trunk flexion with different extra loads and flexion rates. Direct outcome measures included initial trunk angle, creep angle, and residual/cumulative creep. Viscoelastic behaviors in both experiments were characterized using different Kelvin-solid models. For prolonged flexion, extra load significantly affected initial angle, creep angle, and viscoelastic model parameters, while residual creep remained unchanged. For repetitive flexion, cumulative creep angle significantly increased with both extra load and flexion rate. Nonlinear viscoelastic behavior of the trunk was evident in both experiments, which also indicated better predictive performance using Kelvin-solid models with ≥2 retardation time constants. Understanding trunk viscoelastic behaviors in response to flexion exposures can help in future modeling and in assessing how such exposures alter the synergy between active and passive trunk tissues.
• Toosizadeh, N., & Nussbaum, M. A. (2013). PROLONGED TRUNK FLEXION CAN INCREASE SPINE LOADS DURING A SUBSEQUENT LIFTING TASK: AN INVESTIGATION OF THE EFFECTS OF TRUNK FLEXION DURATION AND ANGLE USING A SAGITTALLY SYMMETRIC, VISCOELASTIC SPINE MODEL. Journal of Musculoskeletal Research, 16(04), 1350022. doi:10.1142/s021895771350022x
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  Load-relaxation of the human trunk following prolonged flexion has been observed earlier, yet the adverse effects of such viscoelastic behaviors on performing demanding tasks (e.g. lifting) remain poorly understood. Theoretically, trunk stiffness reduces following flexion exposures and requires a compensatory increase in paraspinal muscle activation and spine loads. Here, a multi-segment model with nonlinear viscoelastic properties was developed. After evaluating the model, it was used to predict changes, due to a range of trunk flexion exposures, in several outcome measures (i.e. peak spine load, peak axial stiffness and absorbed energy) at L5/S1 during simulated lifting. All three measures increased during lifting following flexion exposures, including a ~ 9% (~ 284 N) increase in spine loads, and these changes were magnified by increasing flexion duration and angle. These results support prior epidemiological evidence that occupational low back injury risk is elevated when prolonged trunk flexion along with lifting are required. Further, the dependency of spine loads on loading conditions was determined in response to several flexion angles and loading durations. The current modeling approach is considered as an initial step toward implementing Kelvin-solid models in future viscoelastic spine models.
• Toosizadeh, N., Bazrgari, B., Hendershot, B., Muslim, K., Nussbaum, M. A., & Madigan, M. L. (2013). Disturbance and recovery of trunk mechanical and neuromuscular behaviours following repetitive lifting: influences of flexion angle and lift rate on creep-induced effects. Ergonomics, 56(6), 954-63.
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  Repetitive lifting is associated with an increased risk of occupational low back disorders, yet potential adverse effects of such exposure on trunk mechanical and neuromuscular behaviours were not well described. Here, 12 participants, gender balanced, completed 40 min of repetitive lifting in all combinations of three flexion angles (33, 66, and 100% of each participant's full flexion angle) and two lift rates (2 and 4 lifts/min). Trunk behaviours were obtained pre- and post-exposure and during recovery using sudden perturbations. Intrinsic trunk stiffness and reflexive responses were compromised after lifting exposures, with larger decreases in stiffness and reflexive force caused by larger flexion angles, which also delayed reflexive responses. Consistent effects of lift rate were not found. Except for reflex delay no measures returned to pre-exposure values after 20 min of recovery. Simultaneous changes in both trunk stiffness and neuromuscular behaviours may impose an increased risk of trunk instability and low back injury.
• Toosizadeh, N., Nussbaum, M. A., Bazrgari, B., & Madigan, M. L. (2012). Load-Relaxation Properties of the Human Trunk in Response to Prolonged Flexion.
• Toosizadeh, N., Nussbaum, M. A., Bazrgari, B., & Madigan, M. L. (2012). Load-relaxation properties of the human trunk in response to prolonged flexion: measuring and modeling the effect of flexion angle. PloS one, 7(11), e48625.
• Bazrgari, B., Hendershot, B., Muslim, K., Toosizadeh, N., Nussbaum, M. A., & Madigan, M. L. (2011). Disturbance and recovery of trunk mechanical and neuromuscular behaviours following prolonged trunk flexion: influences of duration and external load on creep-induced effects. Ergonomics, 54(11), 1043--1052.
• Hendershot, B., Bazrgari, B., Muslim, K., Toosizadeh, N., Nussbaum, M. A., & Madigan, M. L. (2011). Disturbance and recovery of trunk stiffness and reflexive muscle responses following prolonged trunk flexion: influences of flexion angle and duration. Clinical Biomechanics, 26(3), 250--256.
• Toosizadeh, N., & Haghpanahi, M. (2011). Generating a finite element model of the cervical spine: Estimating muscle forces and internal loads. Scientia Iranica, 18(6), 1237--1245.

Proceedings Publications

• Golden, T., Junna, S., Wadeea, R., Ghazala, S., Tirambulo, C., Toosizadeh, N., Taleban, S., & Mohler, J. (2018). Frailty Status Predicts Screening Colonoscopy Adverse Events. In JOURNAL OF THE AMERICAN GERIATRICS SOCIETY, 66.
• Sayre, M. K., Pike, I. L., Bunkley, E. N., Odera, D. A., Reeves, C. A., Toosizadeh, N., Mohler, J., Alexander, G. E., & Raichlen, D. A. (2018). Assessing age-related differences in frailty measurements among Pokot agro-pastoralists of Kenya. In AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, 165.
• Tirambulo, C., Sutherland-Mills, C., Ehsani, H., Golden, T., Toosizadeh, N., & Mohler, J. (2018). Frailty and Depression in Older Adults: A Cross Sectional Study. In JOURNAL OF THE AMERICAN GERIATRICS SOCIETY, 66.
• Parvaneh, S., Dabanloo, N. J., Rezaei, S., Moharreri, S., & Toosizadeh, N. (2017). Heart rate asymmetry in response to colored light. In 2017 Computing in Cardiology (CinC).
• Parvaneh, S., Najafi, B., Toosizadeh, N., Riaz, I. B., & Mohler, J. (2016). Is there any association between ventricular ectopy and falls in community-dwelling older adults?. In 2016 Computing in Cardiology Conference (CinC).
• Veldhuizen, J., Mager, R., Toosizadeh, N., Mohler, J., Reiman, E., O'Connor, K., & Najafi, B. (2016). Association between cognitive impairment and upper-extremity performance under a dual task condition. In JOURNAL OF THE AMERICAN GERIATRICS SOCIETY, 64.
• Parvaneh, S., Toosizadeh, N., & Moharreri, S. (2015). Impact of mental stress on heart rate asymmetry. In 2015 Computing in Cardiology Conference (CinC).
• Hendershot, B., Bazrgari, B., Muslim, K., Toosizadeh, N., Nussbaum, M. A., & Madigan, M. L. (2010). Disturbances to intrinsic stiffness and reflexive muscle responses following prolonged trunk flexion. In Proceedings of the 34th Annual Meeting of the American Society of Biomechanics, Providence, Rhode Island, USA./http://www. asbweb. org/conferences/2010/abstracts/72. pdfS.
• Haghpanahi, M., & Toosizadeh, N. (2008). Generating exact finite element model of lower cervical spine (C3-C7). In Proceedings of the Sixth IASTED International Conference on Biomedical Engineering.
• Haghpanahi, M., & Toosizadeh, N. (2008). Generating finite element model of the cervical spine, investigating the role of the muscle forces in flexion/extension. In Proceedings of the 1st WSEAS international conference on Biomedical electronics and biomedical informatics.

Poster Presentations

• Mohler, M. J., Toosizadeh, N., Hsu, C., & Taylor-Piliae, R. E. (2019, March). Novel Dual-Task Balance Challenge to Prevent Falls in Older Adults with Cardiovascular Disease Risk Factors. American Heart Association's 2019 EPI/Lifestyle Scientific Sessions. Houston, TX: American Heart Association.
  More info

  accepted for presentation

Others

• Najafi, B., Mohler, M. J., & Toosizadeh, N. (2015). Method and system to identify frailty using body movement.
• Lei, H., Toosizadeh, N., Schwenk, M., Sherman, S., Karp, S., Parvaneh, S., Esternberg, E., & Najafi, B. (2014). Objective assessment of electro-acupuncture benefit for improving balance and gait in patients with Parkinson’s disease (P3. 074).