Construction and Simulation of Athlete’s Wrong Action Recognition Model in Sports Training Based on Embedded Wireless Communication and Computer Vision

Embedded networking has a broad prospect. Because of the Internet and the rapid development of PC skills, computer vision technology has a wide range of applications in many fields, especially the importance of identifying wrong movements in sports training. To study the computer vision technology to identify the wrong movement of athletes in sports training, in this paper, a hidden Markov model based on computer vision technology is constructed to collect video and identify the landing and take-off movements and badminton serving movements of a team of athletes under the condition of sports training, Bayesian classification algorithm to analyze the acquired sports training action data, obtain the error frequency, and the number of errors of the landing jump action, and the three characteristic data of the displacement, velocity, and acceleration of the body’s center of gravity of the athlete in the two cases of successful and incorrect badminton serve actions and compared and analyzed the accuracy of the action recognition method used in this article, the action recognition method based on deep learning and the action recognition method based on EMG signal under 30 experiments. The training process of deep learning is specifically split into two stages: 1st, a monolayer neuron is built layer by layer so that the network is trained one layer at a time; when all layers are fully trained, a tuning is performed using a wake-sleep operation. The final result shows that the frequency of the wrong actions of the athletes on the landing jump is concentrated in the knee valgus, the total frequency of error has reached 58%, and the frequency of personal error has reached 45%; the problem of the landing distance of the two feet of the team athletes also appeared more frequently, the total frequency reached 50%, and the personal frequency reached 30%. Therefore, athletes should pay more attention to the problems of knee valgus and the distance between feet when performing landing jumps; the difference in the displacement, speed, and acceleration of the body’s center of gravity during the badminton serve will affect the error of the action. And the action recognition method used in this study has certain advantages compared with the other two action recognition methods, and the accuracy of action recognition is higher.

Lower extremity kinematic coupling during single and double leg landing and gait in female junior athletes with dynamic knee valgus

Background Dynamic knee valgus (DKV) is a common lower extremity movement disorder among females. This study aimed to investigate kinematic couplings between lower extremity joints in female junior athletes with DKV during single and double-leg landing and gait. Methods Twenty-six physically active female junior athletes (10–14 years old) with DKV were recruited. Kinematic couplings between rearfoot, tibia, knee, and hip were extracted using eight Vicon motion capture cameras and two force plates. Zero-lag cross-correlation coefficient and vector coding were used to calculate kinematic couplings between joints during physical tasks. Paired t-test and Wilcoxon tests were run to find significant couplings between joint motions and coupling strengths. Bonferroni posthoc was used to determine significance with α ≤ 0.05. Results The results showed that the strongest kinematic relationship existed between rearfoot eversion/inversion and tibial internal/external rotation during all three tasks. Correlations of the rearfoot supination/pronation with tibial rotations, knee, and hip motions in sagittal, frontal, and transverse planes were very strong to strong during double-leg landing and moderate to weak during gait. A weak correlation was observed between rearfoot supination/pronation and hip adduction/abduction during single-leg landing. Conclusions Coupling relationships between rearfoot, knee, and hip vary by the task intensity and alignment profiles in female juniors with DKV.

Dynamic knee valgus alignment in healthy young adults and its association with single leg triple hop distance and athletic single leg stability

Objective The purpose of the current study was to determine the dynamic knee valgus angulation (DKVA) among sedentary young adults and the relationship of DKVA with triple hop distance and athletic single leg stability. Methods A cross sectional study was conducted on a sample of 72 healthy sedentary young adults aged 18-26 years out of which 29 (38.33%) were males and 43 (61.76%) were females. DKVA, single leg triple hop distance and athletic single leg stability were the outcome measurements for the study. Shapiro-Wilk and Kolmogorov Smirnov tests were used to determine normality of data. Independent t-test and Mann Whitney-U test were used for gender based comparison, paired t-test and Wilcoxon signed-rank test for comparing values of right and left leg, Freidman test for comparing the values of DKVA in different tasks and Pearson and Spearman correlation was used to determine relationship between two variables. Confidence interval was kept at 95% and p<0.05 was considered significant. Results DKVA was found to be lower for dominant leg in all tasks, and higher for single leg tasks as compared to drop jump screening test for both legs. Greater values of DKVA were observed in females in all tasks. Single leg triple hop distance and athletic single leg stability scores were higher in males as compared to females. No significant correlation of DKVA was observed with single leg triple hop distance and athletic single leg stability. Continuous...

The Effects of the Functional Garment on the Biomechanics During the Single Leg Drop Landing.

Background: Female athletes with an anterior cruciate ligament (ACL) injury should decrease both dynamic valgus of the knee and related kinematics of the lower limb during single leg drop landing (SLDL). A functional biomechanics garment (FBG) may help prevent injury by improved kinematics during motion. The purpose of this study was to investigate the effects of the FBG on the biomechanics of SLDL.Methods: Seventeen female university basketball players participated in this study. Characteristics of the FBG were designed based on biomechanics during weight-loaded performance of human movement such as gait, running, and jumping. Lower limb kinematic and kinetic data were calculated using a three-dimensional motion analysis system during a SLDL task with and without the FBG. The hip, knee, and ankle angles and joint moments were automatically calculated from the standard plug-in gait lower body model. The average values of lower limb kinematics and kinetics in the sagittal and frontal planes from 3 SLDL with and without FBG were measured and compared.Results: The maximum varus angle of the knee showed a significant difference between with FBG (15.3±15.1 degrees) and without FBG (5.9±15.4 degrees). (p<0.01; effect size 0.6) Conclusion: Use of the FBG decreases dynamic knee valgus, which reduces risk of knee injury. The FBG can reduce dynamic knee valgus during SLDL in athletic rehabilitation and to play a role in the prevention of knee injury.

Factors influencing knee valgus alignment in Crowe type IV hip dysplasia after total hip arthroplasty

Background Valgus deformity of the knee remains a complaint after total hip arthroplasty (THA) among some patients with Crowe type IV hip dysplasia. We aimed to identify the knee alignment in these patients before and after surgery, and to explore the factors contributing to postoperative knee valgus alignment. Materials and methods We retrospectively reviewed a series of Crowe type IV patients who received THA between February 2010 and May 2019 in our hospital. The patients’ medical data were collected from the hospital information system. On both preoperative and postoperative full limb length standing radiographs, the following parameters were measured: hip–knee–ankle angle (HKA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle, anatomical tibiofemoral angle, anatomical lateral distal femoral angle, femoral neck-shaft angle, pelvic obliquity, limb length, height and lateral distance of hip center, and femoral offset. Univariate and multivariate binary logistic regression were used to identify the factors influencing postoperative knee valgus alignment. Results A total of 64 Crowe type IV patients (87 hips) were included in the study. Overall, HKA improved from 176.54 ± 3.52° preoperatively to 179.45 ± 4.31° at the last follow-up. Those hips were subdivided into non-valgus group (≥ 177.0°, n = 65) and valgus group (< 177.0°, n = 22) according to postoperative HKA. Only postoperative mLDFA was a significant factor in the multivariate regression model. Conclusions The postoperative mLDFA is a major factor related to knee valgus alignment after THA, which combines the preoperative anatomy and surgical reconstruction. Other factors previously published were found to have no significance. Level of evidence III.

Detección de déficits neuromusculares a través del análisis del patrón de salto y aterrizaje en deportistas adolescentes

El objetivo principal del presente estudio fue analizar el rendimiento de la técnica del salto y aterrizaje en deportistas adolescentes mediante la versión modificada del Tuck Jump Assessment (TJA). Como objetivo secundario se compararon los resultados obtenidos, según sexo. Se puntuó cada variable de la herramienta mediante el análisis en video de la prueba de los 75 participantes incluidos en el estudio. Las variables contempladas fueron la puntuación global del TJA y cada criterio del instrumento: 1) Valgo de la extremidad inferior en el aterrizaje; 2) Muslos no paralelos (punto máximo de salto); 3) Muslos no alineados durante la fase de vuelo; 4) Mala alineación de los pies con los hombros; 5) Posición de los pies no paralela (de la punta al talón); 6) Contacto desigual de los pies (aterrizaje asimétrico); 7) Demasiado ruido en el aterrizaje; 8) Pausa entre saltos; 9) La técnica empeora antes de los 10 segundos; 10) No aterriza en el mismo punto (salto consistente). Los valores promedios de la puntuación global de la versión modificada del TJA fueron 8,85±2,31 en el total de la muestra (8,85±2,63 hombres vs. 8,86±2,14 mujeres). Los resultados de la comparación según sexo indicaron diferencias significativas en el criterio 1 (χ2=10,288; p< 0,01), en el criterio 2 (χ2=20,788; p< 0,01), en el criterio 4 (χ2=22,587; p< 0,01) y en el criterio 10 (χ2=8,883; p< 0,01). En consecuencia, el análisis del patrón de salto y aterrizaje permite identificar alteraciones neuromusculares y biomecánicas del patrón de salto-aterrizaje. The main objective of the present study was to analyze the performance of the jump and landing technique in adolescent team sports athletes through the modified version of the Tuck Jump Assessment, (TJA). As a secondary objective, the results obtained were compared, according to sex. Each outcome measure of the tool was scored through video analysis of the test of the 75 participants included in the study. The main outcome measures were the total score of TJA and each of the ten items: Knee valgus at landing (1), thighs do not reach parallel (2), thighs not equal side-to-side (3), foot placement not shoulder width apart (4), foot placement not parallel (5), foot contact timing not equal (6), excessive landing contact noise (7), pause between jumps (8), technique declines prior to ten seconds (9), and does not land in the same footprint (10). The variables contemplated were the global score of the TJA and the ten criteria of the instrument. The average values of the global score of the modified version of the TJA were 8.85±2.31 in the total sample (8.85±2.63 men vs. 8.86±2.14 women). The results of the gender comparison indicated significant differences in item 1 (χ2=10,288; p< 0,01), item 2 (χ2=20,788; p<0,01), item 4 (χ2=22,587; p<0,01) and item 10 (χ2=8,883; p< 0,01). Consequently, the analysis of the jump and landing pattern makes it possible to identify neuromuscular and biomechanical alterations of the jump-landing pattern. O objetivo principal do presente estúdio fue analisar o rendimiento da técnica do salto e aterrissagem em deportistas adolescentes mediante a versão modificada do Tuck Jump Assessment (TJA). Como objetivo secundário se comparar os resultados obtidos, según sexo. Se puntuó cada variável do herramienta mediante a análise no vídeo da prueba dos 75 participantes incluidos no estudio. As variáveis contempladas na versão global do TJA e cada critério do instrumento: 1) Valgo de la extremidad inferior en el aterrizaje; 2) Muslos no paralelos (ponto máximo de salto); 3) Muslos no alineados durante la fase de vuelo; 4) Mala alineación de los pies con los hombros; 5) Posición de los pies no paralela (de la punta al talón); 6) Contacto desigual de los pies (aterrizaje asimétrico); 7) Demasiado ruido en el aterrizaje; 8) Pausa entre saltos; 9) La técnica empeora antes de los 10 segundos; 10) No aterriza en el mismo punto (salto consistente). Os valores prometidos da versão global modificada do TJA fueron 8,85 ± 2,31 no total da muestra (8,85 ± 2,63 hombres vs. 8,86 ± 2,14 mujeres). Os resultados da comparação segundo sexo indicaron diferencias relevantes no critério 1 (χ2 = 10.288; p <0,01), no critério 2 (χ2 = 20.788; p <0,01), no critério 4 (χ2 = 22.587 ; p <0,01) e o critério 10 (χ2 = 8.883; p <0,01). Na sequência, a análise do patrón de salto y aterrizaje permite identificar alterações neuromusculares y biomecánicas del patrón de salto-aterrizaje.

Effect of Six Weeks of Progressive Jump-Landing Training on Jump Shooting Accuracy and Knee Valgus Angle in Male Basketball Players with Dynamic Knee Valgus

Objective: Dynamic Knee Valgus (DKV) causes many acute and chronic knee injuries during deceleration and landing in sports activities and can affect the athletes’ specific skills. This study aims to investigate the effect of 6 weeks of progressive jump-landing training on jump shooting accuracy and knee valgus angle in male basketball players with DKV. Methods: This is a quasi-experimental study conducted on 24 male basketball players with DKV in Mazandaran, who were selected purposefully. They were randomly divided into training and control groups. Their jump shooting accuracy was assessed by Boddington’s Basketball Jump Shooting Accuracy Test, and their DKV angle was measured by a two-dimensional evaluation method in Quinoa software. In addition to their routine exercises, the training group performed the jump-landing training for 6 weeks at 3 sessions per week, while the control group performed their usual exercises only. In order to compare the two study groups, ANCOVA was used. Results: The progressive jump-landing program had a significant effect on jump shooting accuracy (P=0.001) and DKV angle (P=0.001). Conclusion: Six weeks of progressive jump-landing training can improve the jump shooting accuracy and knee valgus angle in basketball players with DKV. Therefore, jump landing exercises are recommended for improving the jump shooting skill and knee alignment in these athletes.