Mechanisms of gait speed changes in middle-aged adults: Simultaneous analysis of magnitude and temporal effects.

Background: Middle-aged adults represent the transition between younger and older adults, where some of the characteristic gait differences due to aging begins to surface. However, the gait characteristics of middle-aged adults across the whole gait cycle remains an understudied topic. As speed is a sensitive indicator of health, characterizing the effects of speed on the gait of middle-aged adults and differentiating it from the response of young adults will provide insights into the effects of aging on gait speed modulation mechanisms.

Characterization of Upper Extremity Kinematics Using Virtual Reality Movement Tasks and Wearable IMU Technology.

Task-specific training has been shown to be an effective neuromotor rehabilitation intervention, however, this repetitive approach is not always very engaging. Virtual reality (VR) systems are becoming increasingly popular in therapy due to their ability to encourage movement through customizable and immersive environments. Additionally, VR can allow for a standardization of tasks that is often lacking in upper extremity research.

Effects of Walking Speed and Added Mass on Hip Joint Quasi-Stiffness in Healthy Young and Middle-Aged Adults.

Joint quasi-stiffness has been often used to inform exoskeleton design. Further understanding of hip quasi-stiffness is needed to design hip exoskeletons. Of interest are wearer responses to walking speed changes with added mass of the exoskeleton.

How Do Joint Kinematics and Kinetics Change When Walking Overground with Added Mass on the Lower Body?

Lower-limb exoskeletons, regardless of their control strategies, have been shown to alter a user's gait just by the exoskeleton's own mass and inertia. The characterization of these differences in joint kinematics and kinetics under exoskeleton-like added mass is important for the design of such devices and their control strategies. In this study, 19 young, healthy participants walked overground at self-selected speeds with six added mass conditions and one zero-added-mass condition.

How Does Added Mass Affect the Gait of Middle-Aged Adults? An Assessment Using Statistical Parametric Mapping.

To improve exoskeleton designs, it is crucial to understand the effects of the placement of such added mass on a broad spectrum of users. Most prior studies on the effects of added mass on gait have analyzed young adults using discrete point analysis. This study quantifies the changes in gait characteristics of young and middle-aged adults in response to added mass across the whole gait cycle using statistical parametric mapping.

Spatiotemporal and muscle activation adaptations during overground walking in response to lower body added mass.

Background: Lower-extremity exoskeletons have been used in rehabilitation and performance augmentation for the past two decades. An exoskeleton adds a significant load to certain segments of the user's body and the underlying science about the effects of adding mass to the different lower-body segments is limited.

Research Question: What are the adaptive changes that occur when mass is placed on three lower body segments (pelvis, thigh, and shank)?

Methods: Healthy adults (n = 24) completed 5 overground walking trials for 7 added mass conditions.

Impact of an ankle foot orthosis on reactive stepping in young adults.

Background: Ankle-foot orthoses (AFOs) have been shown to improve gait and static balance in individuals with lower extremity weakness and instability. However, the effects of AFOs on dynamic balance reactions including reactive stepping responses are not well known. Therefore, the purpose of this study was to determine the effects of an AFO on reactive stepping responses in healthy young adults.

Influence of musculoskeletal model parameter values on prediction of accurate knee contact forces during walking.

Treatment design for musculoskeletal disorders using in silico patient-specific dynamic simulations is becoming a clinical possibility. However, these simulations are sensitive to model parameter values that are difficult to measure experimentally, and the influence of uncertainties in these parameter values on the accuracy of estimated knee contact forces remains unknown. This study evaluates which musculoskeletal model parameters have the greatest influence on estimating accurate knee contact forces during walking.

Multi-segment foot model reveals distal joint kinematic differences between habitual heel-toe walking and non-habitual toe walking.

Toe walking is observed in pathological populations including cerebral palsy, stroke, and autism spectrum disorder. To understand pathological toe walking, previous studies have analyzed non-habitual toe walking. These studies found sagittal plane deviations between heel-toe and toe walking at the hip, knee, and ankle.

Surface Electromyography of the Internal and External Oblique Muscles During Isometric Tasks Targeting the Lateral Trunk.

Context: Tasks that activate the lateral trunk muscles are clinically relevant in athletic and rehabilitation programs. However, no electromyography studies have compared tasks aimed at lateral trunk muscle activation.

Objective: To compare the activation magnitudes of the internal and external obliques between 4 tasks targeting recruitment of the lateral trunk muscles, including the proposal of a novel assessment.

Simulation on the Effect of Gait Variability, Delays, and Inertia with Respect to Wearer Energy Savings with Exoskeleton Assistance.

Exoskeletons are human-robot interfaces that have enormous potential to assist people with everyday tasks. To improve the design of exoskeletons for use in clinical populations, it is important to further our understanding of how exoskeleton design and control parameters lead to sub-optimal effectiveness. Here we simulated the effect of three factors, gait variability, wearer-exoskeleton delays, and exoskeleton inertia, have on the predicted energy assistance provided by an exoskeleton with a finite-state controller trained on a set of stroke survivors' free walking gait data.

A virtual learning collaborative to implement health promotion in routine mental health settings: Protocol for a cluster randomized trial.

Background: Despite widespread use of learning collaboratives in health care, few randomized trials have evaluated their effectiveness. The primary aim of this cluster randomized implementation trial is to evaluate the effectiveness of a virtual learning collaborative (VLC) in the implementation of a lifestyle intervention for persons with serious mental illness (SMI) in routine mental health settings, compared to standard individual technical assistance.

Methods: Forty-eight mental health provider organizations from across the United States will be recruited to participate in the trial.

Adolescents' Use of Digital Technologies and Preferences for Mobile Health Coaching in Public Mental Health Settings.

Youth with mental illnesses often engage in unhealthy behaviors associated with early mortality from physical diseases in adulthood, but interventions to support positive health behaviors are rarely offered as part of routine mental health care for this group. Digital health technology that is desirable, accessible, and affordable has the potential to address health behaviors in public mental health settings where many adolescents with severe mental health problems receive care. The aims of this study were to examine how adolescents receiving public mental health services use digital technology and social media and to explore their preferences using technology to support health and wellness.

Peer support and mobile health technology targeting obesity-related cardiovascular risk in young adults with serious mental illness: Protocol for a randomized controlled trial.

Background: Individuals with serious mental illness (SMI) such as schizophrenia and bipolar disorder face a higher risk of early death due to cardiovascular disease and other preventable chronic illnesses. Young adulthood is a critical window of development for lifestyle interventions to improve the long-term health and quality of life in this population. Fit Forward is an NIH-funded randomized clinical trial examining the effectiveness of a group lifestyle intervention (PeerFIT) enhanced with mobile health technology compared to one-on-one mobile lifestyle coaching with Basic Education in fitness and nutrition supported by a wearable Activity Tracking device (BEAT) in achieving clinically significant weight loss and improved cardiorespiratory fitness in young adults with SMI.

Identification of key outcome measures when using the instrumented timed up and go and/or posturography for fall screening.

The Timed Up and Go (TUG) has been commonly used for fall risk assessment. The instrumented Timed Up and Go (iTUG) adds wearable sensors to capture sub-movements and may be more sensitive. Posturography assessments have also been used for determining fall risk.

Age Stratification and Sample Entropy Analysis Enhance the Limits of Stability Tests for Older Adults.

The objective of this study was to determine if a foam testing condition and/or nonlinear analysis methods can be used to identify differences between age stratified subgroups of older adults when conducting the Limits of Stability assessment. Ninety older adults participated in this study. A force plate was used to record center of pressure data during Limits of Stability testing on a firm and foam surface.

Facilitating Partner Support for Lifestyle Change Among Adults with Serious Mental Illness: A Feasibility Pilot Study.

The purpose of this pilot study was to explore the feasibility of an intervention designed to facilitate partner support for lifestyle change among overweight and obese adults with serious mental illness (SMI). Fifteen adults with SMI enrolled in a lifestyle intervention at community mental health centers participated with a self-selected partner in an additional 12-week intervention component designed to facilitate social support for health behavior change. Participants reported that the program was useful, convenient, and helped them reach their goals.

Feasibility Study of Increasing Social Support to Enhance a Healthy Lifestyle Intervention for Individuals with Serious Mental Illness.

Objective: Healthy lifestyle interventions addressing obesity in people with serious mental illness (SMI) lead to modest weight losses that tend not to be sustained over time. By augmenting lifestyle interventions with family and peer support targeting health behavior change, greater weight loss might be obtained and sustained in this population. The purpose of this study was to assess the feasibility of increasing support from family and friends to enhance a healthy lifestyle intervention (In SHAPE) adapted for individuals with SMI.

Manual and Cognitive Dual Tasks Contribute to Fall-Risk Differentiation in Posturography Measures.

Falls occur in 33% of older adults each year, some leading to moderate to severe injuries. To reduce falls and fall-related injuries, it is important to identify individuals with subtle risk factors elevating their likelihood of falling. The objective of this study was to determine how postural sway measures differed between fallers and nonfallers under standard and dual-task conditions.

Neuromusculoskeletal Model Calibration Significantly Affects Predicted Knee Contact Forces for Walking.

Though walking impairments are prevalent in society, clinical treatments are often ineffective at restoring lost function. For this reason, researchers have begun to explore the use of patient-specific computational walking models to develop more effective treatments. However, the accuracy with which models can predict internal body forces in muscles and across joints depends on how well relevant model parameter values can be calibrated for the patient.

Evaluation of Direct Collocation Optimal Control Problem Formulations for Solving the Muscle Redundancy Problem.

Estimation of muscle forces during motion involves solving an indeterminate problem (more unknown muscle forces than joint moment constraints), frequently via optimization methods. When the dynamics of muscle activation and contraction are modeled for consistency with muscle physiology, the resulting optimization problem is dynamic and challenging to solve. This study sought to identify a robust and computationally efficient formulation for solving these dynamic optimization problems using direct collocation optimal control methods.

How sensitive is the deltoid moment arm to humeral offset changes with reverse total shoulder arthroplasty?

Background: Reverse total shoulder arthroplasty commonly treats cuff-deficient or osteoarthritic shoulders not amenable to rotator cuff repair. This study investigates deltoid moment arm sensitivity to variations in the joint center and humeral offset of 3 representative reverse total shoulder arthroplasty subjects. We hypothesized that a superior joint implant placement may exist, indicated by muscle moment arms, compared with the current actual surgical implant configuration.

Peer health coaching for overweight and obese individuals with serious mental illness: intervention development and initial feasibility study.

Effective and scalable interventions are needed to reach a greater proportion of individuals with serious mental illness (SMI) who experience alarmingly high rates of obesity. This pilot study evaluated the feasibility of translating an evidenced-based professional health coach model (In SHAPE) to peer health coaching for overweight and obese individuals with SMI. Key stakeholders collaborated to modify In SHAPE to include a transition from professional health coaching to individual and group-based peer health coaching enhanced by mobile health technology.

The other 23 hours: a qualitative study of fitness provider perspectives on social support for health promotion for adults with mental illness.

Current efforts to reduce the increased risk of premature death from preventable cardiovascular disease among adults with serious mental illness (SMI) through lifestyle change have had limited success. Engaging informal support systems to promote healthy behaviors in everyday life may increase the effectiveness of health promotion interventions targeting this at-risk population. In-depth semistructured interviews were conducted with 10 fitness trainers serving adults with SMI in a health promotion program at community mental health centers to explore their perspectives on the potential of enlisting support from significant others for health behavior change.

Muscle synergies may improve optimization prediction of knee contact forces during walking.

The ability to predict patient-specific joint contact and muscle forces accurately could improve the treatment of walking-related disorders. Muscle synergy analysis, which decomposes a large number of muscle electromyographic (EMG) signals into a small number of synergy control signals, could reduce the dimensionality and thus redundancy of the muscle and contact force prediction process. This study investigated whether use of subject-specific synergy controls can improve optimization prediction of knee contact forces during walking.