Three-dimensional Video Analysis Research Articles

Froude Efficiency and Velocity Fluctuation in Forearm-Amputee Front Crawl: Implications for Para Swimming Classification.

The impact of physical impairment on Froude efficiency and intra-cyclic velocity fluctuation in Para swimmers is not well documented. Identification of differences in these variables between disabled and non-disabled swimmers could help develop a more objective system for assigning Para swimmers to classes for competition. This study quantifies Froude efficiency and intra-cyclic velocity fluctuation in unilateral forearm-amputee front crawl swimmers, and evaluates associations between these variables and performance. Ten unilateral forearm-amputee swimmers completed front crawl trials at 50 m and 400 m pace; three-dimensional video analysis provided mass centre, wrist and stump velocities. Intra-cyclic velocity fluctuation was calculated as: 1) maximum - minimum mass centre velocity, expressed as % of mean velocity, and 2) coefficient of variation in mass centre velocity. Froude efficiency was the ratio between mean swimming velocity and wrist plus stump velocity during each segment's respective: 1) underwater phase, and 2) propulsive underwater phase. Forearm-amputees' intra-cyclic velocity fluctuation (400 m: 22 ± 7%; 50 m: 18 ± 5%) was similar to published values for non-disabled swimmers, whilst Froude efficiencies were lower. Froude efficiency was higher at 400 m (0.37 ± 0.04) than 50 m pace (0.35 ± 0.05; p < .05) and higher for the unaffected limb (400 m: 0.52 ± 0.03; 50 m: 0.54 ± 0.04) than the residual limb (400 m: 0.38 ± 0.03; 50 m 0.38 ± 0.02; p < .05). Neither intra-cyclic velocity fluctuation nor Froude efficiency were associated with swimming performance. Froude efficiency may be a valuable measure of activity limitation in swimmers with an upper limb deficiency and a useful metric for comparing swimmers with different types and severity of physical impairment.

Kinematic Diagnosis of Throwing Motion of the Chinese Elite Female Discus Athletes Who Are Preparing for the Tokyo Olympic Games.

The purpose of this study was to examine the difference of kinematic skill characteristics between the Chinese and world elite female discus athletes. We used the methods of literature, three-dimensional video analysis, and mathematical statistics to compare and analyze the differences of some kinematic parameters between the three Chinese female discus athletes and four world female discus athletes. The result shows that the speed of discus release of the Chinese elite female discus athletes is lower (p < 0.05) than that of the world elite female discus athletes. Compared to the world elite female discus athletes, the height of release is higher (p < 0.05). But there was no significant difference in the angle of release (p > 0.05), rotation rhythm (p > 0.05), and discus speed increment (p > 0.05) in different stages during the throwing procedure from double support stage to delivery stage. The results may provide reference for the special technique training of the Chinese female discus throwers, so as to improve the discus throwing level of Chinese women.

Biomechanical analysis of stability of joint depression calcaneal fractures: Fixation with locking compression plate alone compared with addition of supplemental oblique screw

PurposeThe standard treatment of calcaneus fractures is a lateral plate and screw construct. Patients at our institution have been treated with a lateral locking plate combined with one retrograde screw inserted in the oblique plane to allow immediate weight bearing. The purpose of this study was to determine whether addition of a oblique screw to a lateral plate construct increases stability. MethodsA Sanders 2B fracture (AO/OTA 83-C2) was created in 8 pairs (16 total specimens) of cadaveric feet. All were repaired using a lateral locking plate/screws construct. One specimen in each pair was chosen randomly to receive an additional oblique screw. The specimens were tested with cyclic load of up to 800 N. Movement at the fracture sites and subsidence of the talus were tracked with a three-dimensional video analysis system. ResultsTalar subsidence was not significantly affected by the presence of the additional oblique screw (p = 0.22). The sustentaculum fragment in the case of the screw repair moved 0.39 mm while the same fragment without the additional screw repair displaced 0.12 mm (p < 0.01). Two repairs with and one repair without the additional screw failed during longer-term cyclic loading. ConclusionThe two repair types were not statistically different in regards to talar subsidence. While statistical significance resulted in the comparison of sustentaculum fragment movement, the amount of movement did not reach a level of clinical relevance. This study demonstrated immediate stability and durability of the additional screw construct with high volume weight bearing loads.

Prognostic possibilities of evaluation and modeling of barbell squatting technique based on the system-symmetric method of cognition

The process of physical education ensures the implementation of its goals, first of all, by performing various physical exercises, which are aimed at directly solving two main groups of problems. The first task is associated with the development of physical (motor) qualities and the second task is aimed at the formation of human motor actions.The purpose of the study is to build a model of the biomechanical parameters of the technique of squatting with a barbell on the chest in the process of sports training of weightlifters based on the use of the system-symmetric method of cognition of biological systems. The application of this method is based on the idea of studying the biomechanical structure of the technique of squatting with a barbell on the chest as an object of symmetry.Research methods and organization: The experiment is based on the idea of studying the biomechanical structure of the squatting technique with a barbell on the chest as an object of symmetry. Registration of biomechanical characteristics was carried out on the basis of the use of an optical system for three-dimensional video analysis of movements. For the experiment, a group of 15 weightlifters of the CMS and MS levels was selected who were given a building to demonstrate the rational technique of squatting with a barbell on their chest.

Three-dimensional video analysis of helmet-to-ground impacts in North American youth football

This study presents a video analysis of helmet-to-ground impacts in youth football (≤14 years). A total of 21 non-injurious helmet-to-ground impact cases were assessed from game video of two age divisions (9–12 years: n = 9; 13–14 years: n = 12) using a novel multi-camera videogrammetry approach. Descriptive parameters related to the game situation and impact mechanisms were documented. Motion analysis software was used to manually track and compute three-dimensional helmet kinematics and uncertainty of the motion tracking analysis was assessed. Overall, the impact cases primarily followed a body-to-body, body-to-ground, helmet-to-ground contact progression. Impact locations on the helmet were mostly distributed across the rear and side helmet shell. The resultant pre-impact velocities for these cases averaged 4.04 ± 1.24 m/s at an angle of −49.6° to the ground. The average resultant impact-induced change in helmet velocity was 3.32 ± 1.14 m/s; the time interval associated with the duration of helmet-to-ground contact was approximately 0.06 s. The average maximum uncertainty (±) error of the position coordinates from the helmet tracking was 1.5 ± 0.3 cm. In summary, this video-based methodology can effectively be used to quantify helmet impact velocities and locations in youth football games. To date, the acquisition of such information has largely been limited to professional football game footage. Therefore, the data reported here may help inform the development of more representative assessment methods for youth-specific helmet test standards.

Line Hops and Side Hold Rotation Tests Load Both Anterior and Posterior Shoulder: A Biomechanical Study.

BackgroundClinical tests should replicate the stressful positions encountered during sport participation. Evaluating the kinetic and electromyographical demands of clinical tests enables clinicians to choose appropriate tests for specific sports.PurposeTo describe the shoulder forces and muscle activation levels during closed chain functional tests of Line Hops (LH) and Side Hold Rotation (SHR).Study DesignDescriptive biomechanical studyMethodsTen asymptomatic participants were examined in a university laboratory. Two functional tests were evaluated using three-dimensional video analysis and electromyography to measure shoulder forces, moments, and muscular activity levels.ResultsSHR produced a peak average posterior translation force of 4.84 N/kg (CI95 4.32-5.36N/kg) and a peak average anterior translational force of 1.57 N/kg (CI95 1.10-2.01N/kg). High levels of serratus anterior (98% maximum voluntary isometric contraction (MVIC) and infraspinatus (52 %MVIC) were recorded during SHR. LH produced a posterior translational force of 4.25 N/kg (CI95 3.44–5.06N/kg). High levels of serratus anterior (105 %MVIC) and infraspinatus (87 %MVIC) were recorded during the push off phase of this activity.ConclusionsLH and SHR placed large posterior translational forces that approached half of a person’s bodyweight on shoulder structures. SHR produced an anterior translation force at extremes of horizontal abduction placing approximately 18% of bodyweight on shoulder structures. The LH test required the serratus anterior to provide power to push the upper torso of the ground while both the serratus and the infraspinatus provides scapular and humeral stability, respectively.Level of Evidence4: Case series

Personalized rehabilitation assessment of locomotor functions in Parkinson disease using three-dimensional video analysis of motions

Parkinson disease (PD) is one of the most common neurodegenerative diseases. Its main clinical manifestation is movement disorders. The study of innovative objective methods for the diagnosis and rehabilitation of movement disorders in PD is relevant and in demand taking into account the slowly progressive course of the disease and the complex set of symptoms that subsequently forms a characteristic movement pattern. This article provides an example of a personalized rehabilitation assessment of biomechanical manifestations of the gait function of a patient with exacted diagnosis, stage 3.5 PD according to Hoehn and Yahr, by means of the method of three-dimensional motion video analysis using the Vicon Motion Capture Systems soft-hardware complex. The patient has postural and gait disorders. This method was applied after a rehabilitation course based on the activation of lifting the foot from the support surface (“back push”). Changes in the tempo and rhythm parameters of gait in a patient with PD in comparison to a healthy person were revealed: acceleration of walking pace with shortening of the length of single and double step, a decrease in the time of limb advancement, acceleration of the moment of heel rise and a decrease in walking pace. Analysis of the locomotion also revealed a decrease in the amplitude of flexion-extension in the coxofemoral joint, knee joint and tibio-tarsic on the side with more pronounced Parkinsonism. Insufficient knee flexion and hip extension, excessive dorsal flexion of the foot with insufficient plantar flexion were noted. Revealing the last features of locomotion in a particular case allows one to make a plan for a targeted personalized rehabilitation program for a given patient. Thus, the method of three-dimensional video analysis is a valuable diagnostic tool that makes it possible to objectively assess the existing violations of locomotion and identify the targets of rehabilitation.

Comparative Biomechanical Analysis of the Hurdle Clearance Technique of Colin Jackson and Dayron Robles: Key Studies

The purpose of the study was to compare the biomechanical parameters of the hurdle clearance technique of the fifth hurdle in the 110 m hurdle race of Colin Jackson of Great Britain (12.91 s world record was set in 1994) and Dayron Robles of Cuba (12.87 s world record was set in 2008), two world record holders. Despite the athletes having performed at different times, we used comparable biomechanical diagnostic technology for both hurdlers. Biomechanical measurements for both were performed by the Laboratory for Movement Control of the Institute of Sport, Faculty of Sport in Ljubljana. A three-dimensional video analysis of the fifth hurdle clearance technique was used. High standards of biomechanical measurements were taken into account, thus ensuring the high objectivity of the obtained results. The following program was used: the ARIEL kinematic program (Ariel Dynamics Inc., Trabuco Canyon, CA, USA). The results of the comparative analysis found minimal differences between the two athletes, which was expected given their excellence. Dayron Robles’s hurdle clearance was more effective, as it was characterized by a smaller loss of horizontal center of mass (COM) velocity. Robles’s hurdle clearance took 0.50 s: 0.10 s for the take-off, 0.33 s for the flight phase, and 0.07 s for the landing phase. Colin Jackson completed the hurdle clearance slightly slower, as it took him 0.54 s. Jackson’s take-off phase also lasted 0.10 s, his flight phase 0.36 s, and his landing 0.08 s. The two athletes are quite different in their morphological constitution. Dayron Robles is 10 cm taller than Colin Jackson, resulting in a lower flight parabola of CM during hurdle clearance of the Cuban athlete. Dayron Robles has a more effective hurdle clearance technique compared to Jackson’s achievement. It can be considered that their individual techniques of overcoming the hurdle, reached their individual highest efficiency at this time.

RGB-D video-based individual identification of dairy cows using gait and texture analyses

The growth of computer vision technology can enable the automatic assessment of dairy cow health, for instance, the detection of lameness. To monitor the health condition of each cow, it is necessary to identify individual cows automatically. Tags using microchips, which are attached to the cow’s body, have been employed for the automatic identification of cows. However, tagging requires a substantial amount of effort from dairy farmers as well as induces stress on the cows because of the body-mounted devices. A method for cow identification based on three-dimensional video analysis using RGB-D cameras, which capture images with RGB color information as well subject distance from the camera, is proposed. Cameras are mostly maintenance-free, do not contact the cow’s body, and have high compatibility with existing vision-based health monitoring systems. Using RGB-D videos of walking cows, a unified approach using two complementary features for identification, gait (i.e., walking style) and texture (i.e., markings), is developed.

Functional results after facial reanimation in iatrogenic facial palsy.

Iatrogenic facial nerve injury is a common cause of long-standing facial palsy. This study aimed to assess functional results after facial reanimation in iatrogenic facial palsy and to determine correlating patient factors. The data of 128 iatrogenic facial palsy patients were analyzed for this case series. Inclusion criteria for assessment of facial function by three-dimensional video analysis were preoperative and postoperative (>18 months) video sets for facial marker tracking, which were available in 63 patients. Demographic factors and treatment concepts were analyzed and correlations to functional outcomes calculated. One hundred and twenty-eight patients with iatrogenic facial palsy underwent facial reanimation procedures and were included in this study. The mean duration of facial palsy was 7.8 years. The most common procedures leading to iatrogenic facial palsy were acoustic neuroma resection (29.7%), parotidectomy (21.1%), and brainstem/cerebellopontine angle tumor resection (21.1%). Selected functional results were significantly improved after facial reanimation surgery. The mean lagophthalmos during eyelid closure reduced from 7.3 ± 4.1 mm to 5.4 ± 4 mm (p < .001). The function of the mouth was significantly improved, both statically (static asymmetry: 10.3 ± 7.6 mm preoperatively, 0.8 ± 9.5 mm postoperatively; p < .001), and during smile movement ("Dynamic Symmetry Index": 0.16 preoperatively, 0.39 postoperatively; p < .001). The mean duration of facial palsy correlated with postoperative smiling function (r = .358, p = .011). Facial reanimation significantly improves facial function in iatrogenic facial palsy. Early referral to a facial nerve center is crucial as duration of facial palsy influences functional outcomes.

Assessment of walking function in neurological practice

An accurate diagnosis of the existing defect of motor function in patients with neurological pathology is necessary for the optimal formulation of the rehabilitation program, selection of drug therapy and evaluation of the effectiveness of treatment. In current clinical practice, clinical scales such as the Dynamic Gait Index, the Rivermid Mobility Index, the Hauser Walk Index, the Stand Up and Go Test, the MDS-UPDRS III are used most often to assess walking function. Evaluation of walking function using valid scales is very accessible, however, it has such a disadvantage as subjectivity. That's why the study of motor functions by instrumental methods gains more prominence. The most well-known methods of objective walking assessment include an analysis of human movements using accelerometers, three-dimensional video analysis, sub-metric, goniometric and impregnation methods. Each of these methods has both advantages and disadvantages. The main requirement to objective methods of assessing walking functions in neurological pathology is the universality of the complex (the accuracy of measurements, regardless of the type of walking disorder), the ability to determine both temporal and spatial characteristics of the step, the ease of use. Considering these requirements, the use of the 'Induction Analyzer of the kinematic parameters of walking' seems promising in the diagnosis of motor disorders.

Bend sprinting performance: new insights into the effect of running lane

Athletes in inner lanes may be disadvantaged during athletic sprint races containing a bend portion because of the tightness of the bend. We empirically investigated the veracity of modelled estimates of this disadvantage and the effect of running lane on selected kinematic variables. Three-dimensional video analysis was conducted on nine male athletes in lanes 8, 5 and 2 of the bend of an outdoor track (radii: 45.10, 41.41 and 37.72 m, respectively). There was over 2% (p < 0.05) reduction in mean race velocity from lane 8 (left step 9.56 ± 0.43 m/s, right step: 9.49 ± 0.41 m/s) to lane 5 (left step: 9.36 ± 0.51 m/s, right step: 9.30 ± 0.51 m/s), with only slight further reductions from lane 5 to lane 2 (left step: 9.34 ± 0.61 m/s, right step: 9.30 ± 0.63 m/s). Race velocity decreased mainly because of reductions in step frequency as radius decreased. These unique data demonstrate the extent of the disadvantage of inner lane allocation during competition may be greater than previously suspected. Variations in race velocity changes might indicate some athletes are better able to accommodate running at tighter radii than others, which should have implications for athletes’ training.

Kinematic Analysis Guizhou Province Outstanding Young Man Weightlifter Clean and Jerk Technique

Our advantage is weightlifting athletic sports, Guo Linhong Gui Zhou Province outstanding young man weightlifting athlete, but there is still a gap to his clean and jerk motion technology and national elite athletes. In this paper, three-dimensional video analysis method to obtain kinematic parameters of athletes in motion the process of analyzing the operation of the technical characteristics of the athletes, evaluation and diagnosis of the athlete's movement technology to provide a reference for improving the athlete's movement technology to improve athletic performance.

Kinematic analysis on sliding shot put

In this paper, a comprehensive three-dimensional kinematic quantitative analysis has been applied to analyse the movement and biomechanics of throwing technology of a Chinese excellent women's shot. The filming is conducted with a multi-camera 3D imaging system during the championship. A star high titanium 3D signal TEC V1.0C three-dimensional video analysis software system is used for parsing with the RBI web parsing resolution. The human body model applied is Japan Matsui (16, 22 key parameters). The throwing movement is divided into five main stages: the oscillating acceleration phase, the sliding stage, the transition phase and the last stage of throwing. Research analysis for each phase has focused on different biomechanical characteristics and parameters. The key parameters for the throwing movement of the subject in this work is critically compared to other data of related parameters of the domestic and foreign excellent athletes with reference to the general rule of shot put techniques. The key issues associated with the throwing and future biomechanical training is discussed.

Kinematical Analysis on the Throwing Discus Technique of Distinguished Throwing Athlete, Nu Ermaimaiti

It is difficult for many researchers to analyze the technique of throwing discus by some reasonable means because of the fast and complicated process. The paper uses the three-dimensional video analysis technique to obtain the relevant kinematic parameters of each stage and obtains the kinematic characteristics of the excellent Chinese athletes at the present stage. Then, the paper analyzes the advantages and disadvantages of the athletes at all stages, and provides a reasonable theoretical basis for diagnosing the technical movements of the China excellent athletes.

Comparison of Biomechanical Characteristics on Barefoot Running and Shod Running

Background Compared with the rearfoot strike pattern of shod running, barefoot running with a forefoot strike pattern will change the kinematics and kinetic parameters. This paper analyses the biomechanical differences between barefoot running and shod running and aims to provide a reference for barefoot training and the prevention of sports injury. Methods Three-dimensional force plate test and three-dimensional video analysis. Results Kinetic characteristics: The F-t curve by the force plate test shows that barefoot running has a smooth curve with a single peak while the F-t curve of shod running has a double peak on the vertical direction curve. The maximum ground reaction force in the vertical direction of barefoot running is significantly less than shod running. Kinematics characteristics: Compared with shod running, barefoot running has a faster step frequency, a shorter stride length, a shorter foot-to-ground contact time. The smaller stride length means barefoot running has a bigger ankle plantar flexion, which shows barefoot running can reduce sports injuries.

Kinematic Analysis on the Forehand Stroke of ATP Tennis Player Karen Khachanov

By using the three-dimensional video analysis method to kinematic analyze the forehand stroke technique of the ATP professional tennis player, Karen Khachanov. Exploring the action mode and characteristics from him to provide a reference for all tennis learners to improve their forehand stroke. The results show that: (1) At the end of the preparation, Karen Khachanov’s center of gravity was lower, and his body control was steady; (2) After the follow through, each joint of Karen Khachanov’s racquet arm were stretched, so the swing radius is larger. His right leg was like a support point for the next stage---drive leg and rotate hip; (3) At the swing stage, the move of his driving leg and rotating hip was full, so the whole hitting action match the principle whipping technique movement. (4) The “wiper “ style follow through was natural, coordinated, and smooth. After hitting the ball, his body of control was steady, the shoulder movement was obvious, and the hitting was fast and powerful. Conclusion: The forehand stroke of Karen Khachanov was a high quality hitting action, and it’s worthy of tennis players to learn from.

Head motion invariance in three-dimensional video analysis system for the analysis of facial movement

Head motion invariance in three-dimensional video analysis system for the analysis of facial movement

Symmetry and Asymmetry of Kinematic Structure of Natural Human Locomotion

Background/Objectives: Study of symmetry in the structure and functioning of human body does not have a long-term history. In 1848 L. Pasteur discovered symmetric interrelations, thereby laying the groundwork of the molecular asymmetry doctrine, which was the first stage in the intensive study of laterality of organic compounds. References to correlation between symmetry and asymmetry are fragmentary in human physiology. Modern literature does not analyze the study of kinematic structure of a human being motion as a symmetry object. This article is aimed at determining the occurrence of dynamic symmetry and dynamic asymmetry of the kinematic structure of natural locomotions in the course of sports perfection and individual development of a human being in the ontogeny. Methods: Modern methods of registration of kinematic characteristics offer the possibility of objective assessment of the kinematic structure form of natural locomotions. This circumstance enables to apply the systematic and symmetrical method of cognition of biological processes for studying kinematic structure of human motion. Findings: Study of kinematic structure of natural locomotions has been carried out in this article as exemplified by squatting of powerlifters and children aged 5 and 6. Kinematic characteristics were registered on the basis of optical system of three-dimensional video analysis of movements. “Movement Video Analysis” software enables registration of change of angular movements in joints. It was found that spatiotemporal movements in joints during squats done by powerlifters occur in the form of dynamic symmetry and dynamic asymmetry. Dynamic symmetry of joint movement is characterized by kinematic structure, when spatiotemporal angular movement during joint extension is a reverse spatiotemporal angular movement during flexion. Violation of dynamic symmetry reveals in case of increase in poundage by more than 60% of the maximum. In the course of individual development dynamic symmetry of angular movements in ankle, knee and hip joints is formed in a heterotropic mode. Dynamic symmetry of spatiotemporal angular movements in knee joints is formed by six years of age. Dynamic asymmetry is characteristic of this and angular movement in hip and ankle joint. Application: The obtained data will enable to develop methods for assessing quality of realization of human movement skills on the basis of systematic and symmetrical approach.

Kinematic Analysis on the Serve Technique of Elite Tennis Player Grigor•Dimitrov Based on 3D Virtual Reality Technology

By using three-dimensional video analysis, we made a kinematic analysis on Grigor Dimitrov’s Serve technique, aiming at finding the kinematic characteristics of his serve technique during various stages. The results showed that: (1) During the stage of tossing the ball and lifting the racket, the tossing height of the ball was at minimum appropriately, while the elbow extension of the tossing arm was stright, and the angle of his left knee was 95.4°, which is beneficial to making greater kicking power; (2) At the back-swing stage, Dimitrov’s both feet made a great range of pedal and stretch quickly, and the “scratch-back” posture is obvious, and momentum caused by the kicking and coxae-turning was rather large; (3) When hitting the ball, the contact point was accurate and the speed of the racket head was high, which passed a relatively large initial momentum to the ball; (4) Dimitrov’s entire service action was integral and coordinate, smooth and powerful, which was in accordance relatedly with kinematic characteristics