This document contains the results of an experiment conducted in the Biomechanics Research Laboratory at the University of Miami. Vicon motion capture data are used as a baseline for comparing values generated by an innovative motion capture technique using digital video analysis and other software packages. Marker locations, knee angle, ankle angle, knee moment and ankle moment values were produced by each system. The values show statistically significant differences, however if used as an estimator, digital analysis can be of great value. Possible applications for the use of the innovative video analysis technique are discussed. Methods for improving the accuracy and precision of the digital video motion analysis technique are outlined.

The main objective of this study was to determine differences, if any, in three-dimensional (3D) kinematic characteristics of the three principal punches (the jab, hook and uppercut) executed by novice, intermediate and elite level amateur boxers. Specifically, the kinematic variables related to the displacement, linear velocity and acceleration of the upper body segments, translational hand acceleration and vertical ground reaction force generated by boxers were analyzed. The subjects of this study composed of 10 novice, 9 intermediate, and 11 elite level amateur boxers. Ages of the subjects ranged from 18 to 34 years old. All subjects executed their punches toward a head-high target on a standard practice bag. The motions were captured with PhaseSpace real time optical tracking system with 8 high speed cameras at 240 fps. Then, the motions captured were analyzed to quantify the kinematic factors associated with each punch. The results showed that the uppercut punch generated larger linear shoulder, elbow and wrist velocity compared to the jab punch. Similarly, the uppercut punch generated larger linear shoulder, elbow and wrist acceleration compared to the hook and jab punches. Moreover, the uppercut and hook punches generated larger translational hand acceleration compared to the jab punch. As a conclusion, the results for all kinematic variables demonstrated that the type of punch executed was the major determinant of the magnitude of each factor studied. Moreover, the technique employed can significantly affect the resulting displacement, linear velocity and acceleration, and translational hand acceleration of the fist.

Dancers spend many years practicing repetitive movements in order for their bodies to gain flexibility, strength and muscle memory. This thesis investigated the biomechanics of a dance student's knee motion during a tendu to the front in first, third, and fifth positions. A dancer will often perform 75 or more tendu closing actions during one technique class - particularly in ballet technique. During a tendu the moving foot moves along the floor but the toes never leave the floor. The tendu is used to strengthen the leg muscles, particularly the quadriceps and gluteal muscles. Flexion/extension, abduction/adduction, and rotation angles of the knees during a traditional flat footed closing were compared to the knee angles during pli#233; and relev#233; closing. These movements were performed by 10 healthy dance students from USF. The dancers' movements were tracked using the VICON Nexus motion analysis system and 27 passive reflective markers placed on bony landmarks. Visual 3D software was used to calculate the knee angles. There were statistically significant the differences between knee angles during the traditional and pli#233; closings and between the relev#233; and pli#233; closings for all positions. There were only 4 conditions in which there was statistical significance between traditional and relev#233; closings. Knee flexion difference between the traditional and relev#233; closings was unanticipated, as the expectation of the tendu movement is to maintain a fully straight knee throughout the full range. This result suggests that the students may be bending the knees to achieve greater outward rotation, particularly in the third and fifth positions. The pli#233; had the largest range of motion (ROM) for all of the angles tested including abduction/adduction in which the subjects used the abduction at the knee to hold the feet in a turned out position. The collected data gives better insight into the biomechanics of the knee movement and will be used as feedback for improving muscular strength and preventing injuries in dancers.

The purpose of this dissertation was to analyze shoulder joint kinematics and electromyographic activities of wheelchair propulsion between two stroke patterns. Twenty physical therapy students (14 females and 6 males, age 27.4 ± 5.9 years, body mass 64.41 ± 9.37 Kg and body height 169.32 ± 9.12 cm) participated. Eleven reflective markers were placed on thorax and right scapula, humerus, third metacarpophalangeal joint and wheelchair axle. Surface electrodes were placed on right pectoralis major, anterior and posterior deltoids, infraspinatus, middle trapezius, biceps brachialis long head and triceps brachialis. Participants propelled a standard wheelchair on a stationary roller system at 0.9 m/s and 1.8 m/s with semicircular (SC) and single loop (SL) stroke patterns for 20 seconds. Three-dimensional body movement and muscle activities were recorded at 100 and 1000 Hz, respectively. All data were compared for differences between two patterns and two speeds using 2-way repeated measures ANOVA (α < .05). Results showed longer drive phase and shorter recovery phase in SC when compared to SL, with no difference found on cycle time. Smaller release angles in SC caused longer angle ranges of hand contact on the pushrim while initial contact angles did not change. During drive phase, smaller scapular protraction range of motion (ROM) was found in SC. Shoulder abduction in drive phase was larger in terms of the maximal angle and ROM. In the recovery phase, minimal scapular tilting, protraction, and shoulder abduction and internal rotation were larger in SC when compared to SL pattern. Shoulder linear velocities and accelerations were higher in both phases for abduction/adduction and flexion/extension in SC. For SC pattern, pectorals major and middle trapezius showed lower activities during drive phase while posterior deltoid and triceps showed higher activities during both phases when compared to SL. Although posterior deltoid and triceps muscles work harder in SC pattern, longer drive phase and lower muscle activities in pectorals major and middle trapezius during the drive phase may make SC the better stroke pattern in wheelchair propulsion when compared to SL.

A testing framework was developed to address system spatial and temporal performance characteristics in a two-dimensional (2D) human motion analysis system using commercially available digital video capture. The first testing protocol involved developing a method to evaluate system spatial performance characteristics with respect to accuracy, precision, and resolution. A physical model comprising a calibration frame was constructed with phantom postures selected to represent joint angles and off-plane movement typical of the activities of interest. This provided reference angles to which angles measured from digitally captured images were compared using the Bland and Altman method. Validation experiments confirmed that the principal sources of error were due to off-plane motion and pixel resolution in the video capture and analysis systems. In these analyses, it was verified that simulated experimental conditions could be corrected using the direct linear transform (DLT); however, the removal of parallax still resulted in 2 degrees of error in measured joint angles. The main source of error was resolution of the data acquisition system verified through Monte Carlo simulations. The second testing protocol involved developing a simple method to determine the temporal accuracy of motion analysis systems incorporating digital video cameras and a pendulum. A planar column pendulum with a natural frequency of 0.872 Hz was used to analyse five systems incorporating commercially available cameras and a single codec. The frame rate for each camera was measured to be within 3% of the US National Television Systems Committee (NTSC) broadcasting digital video standard of 29.97 fps.; however some cameras produced a frame duplication artefact. Least squares curve-fitting using a sinusoidal function revealed RMS differences between 3-5% for angular position and 5-15% for angular speed compared to the captured motion data. It was shown that some digital-video cameras and computer playback software contain data compression technology that may produce substantial temporal frame inaccuracies in recovered video sequences and that temporal accuracy should be evaluated in digital-based human motion analysis systems prior to their use in experimentation. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2009-08-14 10:54:58.685

The way surgical trainees acquire technical skills is changing in modern surgical training programmes: simulation is proposed as a key part of those changes. Arthroscopy is a surgical technique that is increasing in both incidence and technical complexity; where simulation is becoming common, but evidence is limited. Real-world performance improvements can be measured following simulation training in other fields, but equivalent measures of intra-operative performance are inadequate. Thus, although surgical simulation is popular and improves simulated performance, there is little objective evidence that it improves intra-operative performance. The original contribution of this thesis is to objectively demonstrate the transfer of simulation training into improved intra-operative technical skills. To achieve this, a systematic literature review investigated the quantitative metrics currently used to measure arthroscopic performance, identifying wireless motion analysis as a potential method to assess performance intra-operatively. Motion analysis is a recognised objective method to measure surgical activity which correlates with surgical experience, so wireless motion analysis was validated against a wired motion analysis method commonly used in simulation but not feasible for intra-operative use. Wireless motion analysis metrics were further validated with a simulated arthroscopy list: this environment allowed deliberate practice of arthroscopic sub-skills with proximate feedback for independent practice. This simulated arthroscopy list with wireless motion analysis was used in two randomised studies: the penultimate study of this thesis investigated the impact of simulated practice on the arthroscopic learning curve and showed that performance improved rapidly with independent practice but was not modified by feedback, while the final study investigated additional simulation practice during early surgical training, and objectively demonstrated that additional simulation training improved intra-operative performance compared to traditional training alone. This thesis is the first to objectively show that simulation affects intra-operative behaviour. It sets the groundwork for further investigations into efficient, cost-effective simulation and the impact of simulation training on patient outcomes.

Detection of events and actions in video entails substantial processing of very large, even open-ended, video streams. Video data presents a unique challenge for the information retrieval community because properly representing video events is challenging. We propose a novel approach to analyze temporal aspects of video data. We consider video data as a sequence of images that form a 3-dimensional spatiotemporal structure, and perform multiview orthographic projection to transform the video data into 2-dimensional representations. The projected views allow a unique way to rep- resent video events and capture the temporal aspect of video data. We extract local salient points from 2D projection views and perform detection-via-similarity approach on a wide range of events against real-world surveillance data. We demonstrate our example-based detection framework is competitive and robust. We also investigate the synthetic example driven retrieval as a basis for query-by-example.

Human motion analysis is an important tool for assessing movement, rehabilitation progress, fall risk, progression of neurodegenerative diseases, and classifying gait patterns. Advancements in artificial intelligence models and high-performance computing technologies have given rise to marker-less human motion analysis that determine point correspondences between an array of cameras and estimate 3D joint coordinates using triangulation. However, existing methods have not considered the physical setup and design of a marker-less human motion analysis tool that could be deployed in an institutional environment for active use, such as an institutional hallway where individuals pass regularly on a daily basis (i.e., Smart Hallway). In this thesis, camera locations were modelled, four machine vision grade cameras connected to an NVIDIA Jetson AGX were set up in a simulated institutional hallway environment, and custom software was written to capture synchronized 60 frame per second video of a participant walking through the Smart Hallway capture volume. Software was also written to calculate 3D joint coordinates and extract outcome measures for various test conditions. These outcome measures were compared to ground truth body segment length measurements obtained from direct measurement and ground truth foot event timings obtained from direct observation. Body segment length measurements were within 1.56 (SD=2.77) cm of ground truth values. AI-based stride parameters were comparable with ground truth foot event timings and the implemented foot event detection algorithm was within 4 frames (67 ms), with an absolute error of 3 frames (50 ms) on the ground truth foot event labels. The Smart Hallway can be deployed in an unobtrusive manner and be temporally and spatially calibrated with ease. This multi-camera marker-less approach is viable for calculating useful outcome measures for clinical decision making. With these findings, marker-less motion capture is viable for non-invasive human motion analysis and compares well with marker-based systems. With future research and innovations, marker-less motion analysis will be the ideal approach for human motion analysis that requires minimal human resource to collect meaningful information.

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Des méthodes efficaces s'appuyant sur des outils statistiques pour réaliser dela reconnaissance de mouvement ont été développé. Ces méthodes reposent surl'apprentissage de primitives situé dans des espaces approprié, par exemplel'espace latent de l'espace articulaire et/ou d'espace de tâches adéquat. Lesprimitives apprises sont souvent séquentielle: un mouvement est segmenté selonl'axe des temps. Dans le cas d'un robot humanoïde, le mouvement peut êtredécomposé en plusieurs sous-tâches simultanées. Par exemple dans un scénario deserveur, le robot doit placer une assiette sur la table avec une main tout enmaintenant son plateau horizontal avec son autre main. La reconnaissance nepeut donc pas se limiter à une seule et unique tâche par segment de tempsconsécutif. La méthode présenté dans ces travaux utilise la connaissance destâches que le robot est capable d'accomplir, ainsi que des contrôleurs quigénèreront les mouvements pour réaliser une rétro ingénierie sur un mouvementobservé. Cette analyse est destinée à reconnaître des tâches qui ont été exécutéde manière simultanées. La méthode repose sur la fonction de tâche et lesprojections dans l'espace nul des tâches afin de découpler les contrôleurs.L'approche a été appliqué avec succès sur un vrai robot pour distinguer desmouvements visuellement très proches, mais sémantiquement différents / Efficient methods to perform motion recognition have been developed usingstatistical tools. Those methods rely on primitives learning in a suitablespace, for example the latent space of the joint angle and/or adequate taskspaces. The learned primitives are often sequential : a motion is segmentedaccording to the time axis. When working with a humanoid robot, a motion can bedecomposed into simultaneous sub-tasks. For example in a waiter scenario, therobot has to keep some plates horizontal with one of his arms, while placing aplate on the table with its free hand. Recognition can thus not be limited toone task per consecutive segment of time. The method presented in this worktakes advantage of the knowledge of what tasks the robot is able to do and howthe motion is generated from this set of known controllers to perform a reverseengineering of an observed motion. This analysis is intended to recognizesimultaneous tasks that have been used to generate a motion. The method relieson the task-function formalism and the projection operation into the null spaceof a task to decouple the controllers. The approach is successfully applied ona real robot to disambiguate motion in different scenarios where two motionslook similar but have different purposes