Two-step deep-learning identification of heel keypoints from video-recorded gait.

Accurate and fast extraction of step parameters from video recordings of gait allows for richer information to be obtained from clinical tests such as Timed Up and Go. Current deep-learning methods are promising, but lack in accuracy for many clinical use cases. Extracting step parameters will often depend on extracted landmarks (keypoints) on the feet.

Machine Learning Approaches for Dementia Detection Through Speech and Gait Analysis: A Systematic Literature Review.

Background: Dementia is a general term for several progressive neurodegenerative disorders including Alzheimer's disease. Timely and accurate detection is crucial for early intervention. Advancements in artificial intelligence present significant potential for using machine learning to aid in early detection.

Prediction of conversion to dementia disorders based on timed up and go dual-task test verbal and motor outcomes: a five-year prospective memory-clinic-based study.

Background: While assessment tools can increase the detection of cognitive impairment, there is currently insufficient evidence regarding clinical outcomes based on screening for cognitive impairment in older adults.

Methods: The study purpose was to investigate whether Timed Up and Go dual-task test (TUGdt) results, based on TUG combined with two different verbal tasks (name different animals, TUGdt-NA, and recite months in reverse order, TUGdt-MB), predicted dementia incidence over a period of five years among patients (N = 186, mean = 70.7 years; 45.

Dual-Task Interference of Gait Parameters During Different Conditions of the Timed Up-and-Go Test Performed by Community-Dwelling Older Adults.

The Timed Up-and-Go (TUG) test has been combined with different verbal/cognitive tasks (i.e., TUG dual task [TUGdt]) as a form of motor-cognitive testing.

Metabolic Demands and Kinematics During Level Walking in Darkness With No Vision or With Visual Aid.

Introduction: Uniformed services commonly perform foot-borne operations at night, while using visual aid in terms of night vision goggles (NVG). During slow-level walking, complete lack of visual input alters kinematics and markedly increases the metabolic demand, whereas the effect on kinematics and energy expenditure of restricting the peripheral visual field by wearing NVG is still unknown. The purpose was to evaluate whether metabolic demands and kinematics during level walking are affected by complete darkness with and without visual aid.

Extraction of gait parameters from marker-free video recordings of Timed Up-and-Go tests: Validity, inter- and intra-rater reliability.

Background: We study dual-task performance with marker-free video recordings of Timed Up-and-Go tests (TUG) and TUG combined with a cognitive/verbal task (TUG dual-task, TUGdt).

Research Question: Can gait parameters be accurately estimated from video-recorded TUG tests by a new semi-automatic method aided by a technique for human 2D pose estimation based on deep learning?

Methods: Thirty persons aged 60-85 years participated in the study, conducted in a laboratory environment. Data were collected by two synchronous video-cameras and a marker-based optoelectronic motion capture system as gold standard, to evaluate the gait parameters step length (SL), step width (SW), step duration (SD), single-stance duration (SSD) and double-stance duration (DSD).

Neuromuscular Controller Models for Quantifying Standing Balance in Older People: A Systematic Review.

Objective quantification of the balancing mechanisms in humans is strongly needed in health care of older people, yet is largely missing among current clinical balance assessment methods. Hence, the main goal of this literature review is to identify methods that have the potential to meet that need. We searched in the PubMed and IEEE Xplore databases using predefined criteria, screened 1064 articles, and systematically reviewed and categorized methods from 73 studies that deal with identification of neuromuscular controller models of human upright standing from empirical data.

Robust Plug-and-Play Joint Axis Estimation Using Inertial Sensors.

Inertial motion capture relies on accurate sensor-to-segment calibration. When two segments are connected by a hinge joint, for example in human knee or finger joints as well as in many robotic limbs, then the joint axis vector must be identified in the intrinsic sensor coordinate systems. Methods for estimating the joint axis using accelerations and angular rates of arbitrary motion have been proposed, but the user must perform sufficiently informative motion in a predefined initial time window to accomplish complete identifiability.

Timed Up-and-Go Dual-Task Testing in the Assessment of Cognitive Function: A Mixed Methods Observational Study for Development of the UDDGait Protocol.

New methods to screen for and identify early-stage dementia disorders are highly sought after. The purpose of this pilot study is to develop a study protocol for a dual-task test aimed at aiding the early detection of dementia disorders. We used the Timed Up-and-Go (TUG) test, which is a mobility task involving starting in a sitting position, standing up, walking three meters to cross a line on the floor, turning around, walking back and sitting down again.

A Study Protocol for Applying User Participation and Co-Learning-Lessons Learned from the eBalance Project.

The eBalance project is based on the idea that serious exergames-i.e., computer gaming systems with an interface that requires physical exertion to play-that are well adapted to users, can become a substantial part of a solution to recognized problems of insufficient engagement in fall-prevention exercise and the high levels of fall-related injuries among older people.

The concept of mobility in single- and double handed manipulation.

The concept of mobility describes an important property of the human body when performing manipulation tasks. It describes, in a sense, how easy it is to accelerate a link or a point on the manipulator. Most often it is calculated for the end-link or end-point of the manipulator, since these are important for the control objective of the manipulator.

A longitudinal study of gait function and characteristics of gait disturbance in individuals with Alzheimer's disease.

Walking in daily life places high demands on the interplay between cognitive and motor functions. A well-functioning dual-tasking ability is thus essential for walking safely. The aims were to study longitudinal changes in gait function during single- and dual-tasking over a period of two years among people with initially mild AD (n=21).

Kinematic, kinetic and electromyographic adaptation to speed and resistance in double poling cross country skiing.

This study incorporated variations in speed and the horizontal resistance acting upon elite female skiers during double poling (DP) on a treadmill and specifically analyzed biomechanical adaptations to these variations. Whole body kinematics and pole force data were recorded and used to calculate the moment of force acting on the shoulder and elbow joints. Data were obtained with a 3D optoelectronic system using reflective markers at given anatomical landmarks.

Acute effects of reducing vertical displacement and step frequency on running economy.

This work studies the immediate effects of altering the vertical displacement of the center of mass (VD) and step frequency (SF) on the metabolic cost of level treadmill running at 16 km · h(-1) on 16 male runners. Alterations of VD, SF, and the product VD × SF was induced using a novel feedback system, which presents target and current values to the runner by visual or auditory display. Target values were set to 5 and 10% reductions from individual baseline values.

Impact of stroke on anterior-posterior force generation prior to seat-off during sit-to-walk.

Force generation during sit-to-walk (STW) post-stroke is a poorly studied area, although STW is a common daily transfer giving rise to a risk of falling in persons with disability. The purpose of this study was to describe and compare strategies for anterior-posterior (AP) force generation prior to seat-off during the STW transfer in both subjects with stroke and in matched controls. During STW at self-selected speed, AP force data were collected by 4 force plates, beneath the buttocks and feet from eight subjects with stroke (>6 months after onset) and 8 matched controls.

Elite golfers' kinematic sequence in full-swing and partial-swing shots.

The aim of this study was to investigate whether kinematic proximal-to-distal sequencing (PDS) and speed-summation are common characteristics of both partial and full-swing shots in golf players of different skill levels and genders. A total of 45 golfers participated, 11 male tournament professionals, 21 male and 13 female elite amateurs. They performed partial shots with a wedge to targets at three submaximal distances, 40, 55 and 70 m, and full-swing shots with a 5 iron and a driver for maximal distance.

Immediate effect of visual and auditory feedback to control the running mechanics of well-trained athletes.

The correlation between mechanical factors of running and running economy as measured by metabolic cost is a subject of much interest in the study of locomotion. However, no change in running technique has been shown to result in an immediate improvement in running economy on an intra-individual basis. To evaluate the effect of a modified running technique, it is probably necessary that the individual trains with the new technique for a longer period using a feedback system to control the new kinematics.

Medio-lateral stability of sit-to-walk performance in older individuals with and without fear of falling.

Most falls in older people are due to loss of balance during everyday locomotion, e.g., when initiating walking from sitting; sit-to-walk (STW).

Minimal marker set for center of mass estimation in running.

The purpose was to study the validity of a recently proposed method [Forsell C, Halvorsen K. A method for determining minimal sets of markers for the estimation of center of mass, linear and angular momentum. Journal of Biomechanics 2009;42(3):361-5] for estimating the trajectory of the whole-body center of mass (CoM) in the case of running at velocities ranging from 10 to 22 km h(-1).

Temporal coordination of the sit-to-walk task in subjects with stroke and in controls.

Objectives: To explore events and describe phases for temporal coordination of the sit-to-walk (STW) task, within a semistandardized set up, in subjects with stroke and matched controls. In addition, to assess variability of STW phase duration and to compare the relative duration of STW phases between the 2 groups.

Design: Cross-sectional.

Measurements of vertical displacement in running, a methodological comparison.

The aim was (1) to evaluate measurements of vertical displacements (V(disp)) of a single point on sacrum as an estimate of the whole body centre of mass (CoM) V(disp) during treadmill running and (2) to compare three methods for measuring this single point. These methods were based on a position transducer (PT), accelerometers (AMs) and an optoelectronic motion capture system. Criterion method was V(disp) of the whole body CoM measured with the motion capture system.

A method for determining minimal sets of markers for the estimation of center of mass, linear and angular momentum.

A new method is proposed for finding small sets of points on the body giving sufficient information for estimating the whole body center of mass (CoM), as well as the linear momenta (LM) and angular momenta (AM). In the underlying model each point (whose trajectory is tracked by a marker) is a point mass: Hence the body is represented by a simple system of point masses. The first step is to determine the appropriate set of points and the mass of each point, which is assumed to be specific for the movement performed.