Markerless motion capture provides repeatable gait outcomes in patients with knee osteoarthritis.

Motion analysis has seen minimal adoption for orthopaedic clinical assessments. Markerless motion capture solutions, namely Theia3D, address limitations of previous methods and provide gait outcomes that are robust to clothing choice and repeatable in healthy adults. Repeatability in orthopaedic populations has not been investigated and is important for clinical utility and adoption.

Comparison of Concurrent and Asynchronous Running Kinematics and Kinetics From Marker-Based and Markerless Motion Capture Under Varying Clothing Conditions.

As markerless motion capture is increasingly used to measure 3-dimensional human pose, it is important to understand how markerless results can be interpreted alongside historical marker-based data and how they are impacted by clothing. We compared concurrent running kinematics and kinetics between marker-based and markerless motion capture, and between 2 markerless clothing conditions. Thirty adults ran on an instrumented treadmill wearing motion capture clothing while concurrent marker-based and markerless data were recorded, and ran a second time wearing athletic clothing (shorts and t-shirt) while markerless data were recorded.

Prediction of Model Generated Patellofemoral Joint Contact Forces Using Principal Component Prediction and Reconstruction.

It is not currently possible to directly and noninvasively measure in vivo patellofemoral joint contact force during dynamic movement; therefore, indirect methods are required. Simple models may be inaccurate because patellofemoral contact forces vary for the same knee flexion angle, and the patellofemoral joint has substantial out-of-plane motion. More sophisticated models use 3-dimensional kinematics and kinetics coupled to a subject-specific anatomical model to predict contact forces; however, these models are time consuming and expensive.

Principal component analysis of whole-body kinematics using markerless motion capture during static balance tasks.

Balance tests have clinical utility in identifying balance deficits and supporting recommendations for appropriate treatments. Motion capture technology can be used to measure whole-body kinematics during balance tasks, but to date the high technical and financial costs have limited uptake of traditional marker-based motion capture systems for clinical applications. Markerless motion capture technology using standard video cameras has the potential to provide whole-body kinematic assessments with clinically accessible technology.

Clothing condition does not affect meaningful clinical interpretation in markerless motion capture.

Markerless motion capture allows whole-body movements to be captured without the need for physical markers to be placed on the body. This enables motion capture analyses to be conducted in more ecologically valid environments. However, the influences of varied clothing on video-based markerless motion capture assessments remain largely unexplored.

Influence of Articular Geometry and Tibial Tubercle Location on Patellofemoral Kinematics and Contact Mechanics.

Trochlear groove geometry and the location of the tibial tubercle, where the patellar tendon inserts, have both been associated with patellofemoral instability and can be modified surgically. Although their effects on patellofemoral biomechanics have been investigated individually, the interaction between the two is unclear. The authors' aim was to use statistical shape modeling and musculoskeletal simulation to examine the effect of patellofemoral geometry on the relationship between tibial tubercle location and patellofemoral function.

Knee extension moment arm variations relate to mechanical function in walking and running.

The patellofemoral joint plays a crucial mechanical role during walking and running. It increases the knee extensor mechanism's moment arm and reduces the knee extension muscle forces required to generate the extension moment that supports body weight, prevents knee buckling and propels the centre of mass. However, the mechanical implications of moment arm variation caused by patellofemoral and tibiofemoral motion remain unclear.

Concurrent assessment of gait kinematics using marker-based and markerless motion capture.

Kinematic analysis is a useful and widespread tool used in research and clinical biomechanics for the quantification of human movement. Common marker-based optical motion capture systems are time intensive and require highly trained operators to obtain kinematic data. Markerless motion capture systems offer an alternative method for the measurement of kinematic data with several practical benefits.

Assessment of spatiotemporal gait parameters using a deep learning algorithm-based markerless motion capture system.

Spatiotemporal parameters can characterize the gait patterns of individuals, allowing assessment of their health status and detection of clinically meaningful changes in their gait. Video-based markerless motion capture is a user-friendly, inexpensive, and widely applicable technology that could reduce the barriers to measuring spatiotemporal gait parameters in clinical and more diverse settings. Two studies were performed to determine whether gait parameters measured using markerless motion capture demonstrate concurrent validity with those measured using marker-based motion capture and a pressure-sensitive gait mat.

Inter-session repeatability of markerless motion capture gait kinematics.

The clinical uptake and influence of gait analysis has been hindered by inherent limitations of marker-based motion capture systems, which have long been the standard method for the collection of gait data including kinematics. Markerless motion capture offers an alternative method for the collection of gait kinematics that presents several practical benefits over marker-based systems. This work aimed to determine the reliability of lower limb gait kinematics from video based markerless motion capture using an established experimental protocol for testing reliability.

Measures of movement and mobility used in clinical practice and research: a scoping review.

Objective: The first objective of this scoping review was to identify all the tools designed to measure movement or mobility in adults. The second objective was to compare the tools to the conceptual definitions of movement and mobility by mapping them to the International Classification of Functioning, Disability and Health (ICF).

Introduction: The concepts of movement and mobility are distinct concepts that are often conflated, and the differences are important to patient care.

A comparison of centre of pressure behaviour and ground reaction force magnitudes when individuals walk overground and on an instrumented treadmill.

Background: Instrumented treadmills facilitate analysis of consecutive strides in ways that typical overground gait data collections cannot. Researchers have quantified differences between joint kinetic measures whilst walking on an instrumented treadmill compared to those walking overground. The reason for such differences has not yet been established.

The Effect of Ankle Brace Use on a 3-Step Volleyball Spike Jump Height.

Purpose: The purpose of this study was to determine whether ankle brace use in university-level varsity volleyball athletes affected their 3-step spike jump height and whether certain types of ankle braces have a greater effect on jump height.

Methods: Nine male university-level varsity volleyball athletes participated in a repeated-measures design study in which each athlete performed three 3-step volleyball spike jumps in 3 ankle brace conditions (soft, rigid, and no brace). Vertical jump height was measured by the Vertec device and video motion analysis at a university biomechanics research laboratory.

Relationship Between Lateral Patellar Stability and Tibial Tubercle Location for Varying Patellofemoral Geometries.

The geometry of the patellofemoral joint affects function and pathology. However, the impact of trochlear groove depth on treatments for patellar instability and pain is not clear. Tibial tubercle osteotomy is a common surgical intervention for patellar instability where the tibial insertion of the patellar tendon (PT) is translated to align the extensor mechanism and stabilize the joint.

Contributions of muscles and external forces to medial knee load reduction due to osteoarthritis braces.

Background: Braces for medial knee osteoarthritis can reduce medial joint loads through a combination of three mechanisms: application of an external brace abduction moment, alteration of gait dynamics, and reduced activation of antagonistic muscles. Although the effect of knee bracing has been reported independently for each of these parameters, no previous study has quantified their relative contributions to reducing medial knee loads.

Methods: In this study, we used a detailed musculoskeletal model to investigate immediate changes in medial and lateral loads caused by two different knee braces: OA Assist and OA Adjuster 3 (DJO Global).

Movement and Mobility: A Concept Analysis.

This article provides an analysis of the concepts of movement and mobility within the context of the International Classification of Functioning, Disability, and Health (ICF) for patients' functioning, disability, and health. The methodology developed by Walker and Avant was used to clarify definitions, components, and relationships relevant to the 2 concepts and to the elements of the ICF framework. Definitions and the relationship between concepts are key information that clinicians and researchers need to measure the correct concept when they are assessing the effectiveness of interventions in nursing practice.

The effect of articular geometry features identified using statistical shape modelling on knee biomechanics.

Articular geometry in the knee varies widely among people which has implications for risk of injury and pathology. The goals of this work were to develop a framework to systematically vary geometry in a multibody knee model and to use this framework to investigate the effect of morphological features on dynamic knee kinematics and contact mechanics. A statistical shape model of the tibiofemoral and patellofemoral joints was created from magnetic resonance images of 14 asymptomatic knees.

Measures of movement and mobility used in clinical practice and research: a scoping review protocol.

The first objective of this scoping review is to identify all tools designed to measure movement or mobility in adults. The second objective is to compare the tools to the conceptual definitions of movement and mobility by mapping them against the International Classification of Functioning, Disability and Health (ICF).The specific questions that will be answered for each tool by the mapping are.

Self-Selected walking speed increases when individuals are aware of being recorded.

Background: Typical gait data collections consist of discrete walking trials where participants are aware when data are being recorded. Anecdotally, some investigators have reported that participants often walk differently between trials or before or after data collection compared to when they know they are being recorded. In addition, walking speed, which affects a number of gait variables, is known to be different when individuals complete discrete and continuous walking trials.

Validation of method for analysing mechanics of unloader brace for medial knee osteoarthritis.

Unloader braces are one non-invasive treatment of knee osteoarthritis, which primarily function by applying an external abduction moment to the joint to reduce loads in the medial compartment of the knee. We developed a novel method using brace deflection to estimate the mechanical effect of valgus braces and validated this model using strain gauge instrumentation. Three subjects performed static and walking trials, in which the moment applied by an instrumented brace was calculated using the deflection and strain methods.

Prediction of Knee Joint Contact Forces From External Measures Using Principal Component Prediction and Reconstruction.

Abnormal loading of the knee joint contributes to the pathogenesis of knee osteoarthritis. Gait retraining is a noninvasive intervention that aims to reduce knee loads by providing audible, visual, or haptic feedback of gait parameters. The computational expense of joint contact force prediction has limited real-time feedback to surrogate measures of the contact force, such as the knee adduction moment.

Operator Bias Errors Are Reduced Using Standing Marker Alignment Device for Repeated Visit Studies.

When optical motion capture is used for motion analysis, reflective markers or a digitizer are typically used to record the location of anatomical landmarks identified through palpation. The landmarks are then used to construct anatomical coordinate systems. Failure to consistently identify landmarks through palpation over repeat tests creates artifacts in the kinematic waveforms.

Identification of good candidates for valgus bracing as a treatment for medial knee osteoarthritis.

Unlabelled: Valgus unloader braces are a conservative treatment option for medial compartment knee osteoarthritis that aim to unload the damaged medial compartment through application of an external abduction moment. Patient response to bracing is highly variable, however. While some experience improvements in pain, function, and joint loading, others receive little to no benefit.