Intervention of muscle strength training combined with neuromuscular electrical stimulation on lower limb function and biomechanical changes in patients with patellofemoral pain / 中国组织工程研究

BACKGROUND:Lower limb peri-knee muscle strength training and neuromuscular electrical stimulation are generally safe and effective rehabilitation methods for patellofemoral joint pain,but the mechanism of their intervention is still unclear. OBJECTIVE:To determine the effect of muscle strength training combined with neuromuscular electrical stimulation on pain,lower extremity function and biomechanical characteristics in patients with patellofemoral pain. METHODS:Thirty-seven patients with patellofemoral pain were randomly divided into muscle strength training combined with electrical stimulation group(trial group,n=19)and muscle strength training group(control group,n=18).Both groups underwent intervention training for 6 weeks,three times a week.The visual analog scale and anterior knee pain scale were used to evaluate the pain level and functional level of the knee.Kinematic and kinetics data during running were collected by using an infrared motion capture system and a three-dimensional force platform simultaneously.A two-way analysis of variance with repeated measures(group*time)was applied to analyze the data. RESULTS AND CONCLUSION:(1)After the intervention,the visual analog scale scores of the trial group and the control group were significantly decreased(P<0.001),and the anterior knee pain scale scores were significantly increased(Ptrial group<0.001,Pcontrol group=0.001)in the trial group and control group.The anterior knee pain scale scores of the trial group were significantly higher compared to the control group after the intervention(P=0.001).(2)The peak knee flexion angle(P=0.011),peak knee extension moment(P<0.001),the peak knee internal rotation moment(P=0.008),the peak patellofemoral stress(P<0.001)and the peak patellofemoral contact force(P<0.001)were significantly decreased in the trial and control groups during running after the intervention compared with those before the intervention.(3)In conclusion,both muscle strength training and muscle strength training combined with electrical stimulation training are helpful to improve the subjective pain and lower limb function of patellofemoral pain patients,enhance the movement pattern during running and reduce the stress of the patellofemoral joint.Compared with muscle strength training alone,muscle strength training combined with electrical stimulation can improve lower limb function more significantly.

Biomechanics characteristics during sitting up in knee osteoarthritis patients of different ages:a systematic review and meta-analysis / 中国组织工程研究

OBJECTIVE:There is no consensus on which sit-up strategy to adopt in knee osteoarthritis patients of different ages.Therefore,this study evaluated the biomechanical characteristics of sit-ups in knee osteoarthritis patients of different ages compared with healthy individuals by meta-analysis system and analyzed the sit-up movement patterns of patients of different ages to provide a reference for improving the sit-up function of patients. METHODS:By March 2023,observational studies of biomechanical characteristics of sitting up in patients with knee osteoarthritis and healthy population were retrieved on PubMed,Web of Science and CNKI.Subjects were required to be patients over 50 years of age with knee osteoarthritis who had Kellgren-Lawrence severity grading≥Ⅰ on knee imaging and who had regular knee pain.Subjects were analyzed by age(50-60 years vs.over 60 years)and severity(mild to moderate patients vs.severe patients)subgroups according to inclusion and exclusion criteria.Quality assessment was performed using the modified Down and black scale.Stata 16.0 software was used to perform subgroup analysis to determine the biomechanical characteristics of sitting up in patients with knee osteoarthritis of different ages and severities. RESULTS:A total of 14 randomized controlled trials(824 subjects)were included in the meta-analysis.The mean quality score of all included literature was 76.2,with a range of 66.7 to 86.7,all of which were of medium to high quality and representative.The included studies were of moderate to high quality and representative.Meta-analysis results found that(1)compared to healthy individuals,patients with knee osteoarthritis had longer total sitting up time(SMD=0.92,95%CI:0.76-1.09),P<0.001)and longer extension phase time(SMD=0.46,95%CI:0.18-0.74,P=0.001).Compared to mild to moderate patients,the total duration increased more significantly in severe patients(P<0.001)and the duration of the extension phase increased more significantly in patients over 60 years of age than in patients 50-60 years of age(P=0.001).(2)Compared to healthy individuals,patients with knee osteoarthritis had greater sitting-up trunk flexion motion range(SMD=0.64,95%CI:0.37-0.91,P<0.001);knee flexion motion range(SMD=-0.47,95%CI:-0.70 to-0.24,P<0.001)and ankle dorsiflexion motion range(SMD=-0.32,95%CI:-0.56 to-0.08,P=0.01)were smaller.And knee flexion motion range decreased more significantly in patients over 60 years of age than in patients 50-60 years of age(P<0.001).(3)The peak hip flexion moment(SMD=-0.57,95%CI:-0.83 to-0.31,P<0.001)and peak knee extension moment(SMD=-0.83,95%CI:-1.08 to-0.59,P<0.001)were smaller in patients with knee osteoarthritis. CONCLUSION:(1)Patients with knee osteoarthritis over the age of 60 years have a longer sit-up cushion and extension phase than patients aged 50 to 60 years.The increase in total sit-up duration was also more pronounced in patients with higher severity grades.The increased length of sitting up in patients with advanced age and knee osteoarthritis severity may increase the duration of cartilage loading,exacerbate knee pain symptoms,and increase the difficulty of sitting up in this population.(2)Patients with knee osteoarthritis exhibit limited knee and ankle flexion motion range.Knee mobility is more limited in patients over 60 years of age.(3)Patients with knee osteoarthritis have reduced peak hip flexion and knee extension moments,which may be a compensatory strategy for pain relief.

Effects of kinesio taping on the biomechanical characteristics of the lower limbs during side-step cutting / 中国组织工程研究

BACKGROUND:Kinesio taping has been widely used as a means of sports protection,but its role as a means to correct abnormal biomechanical changes of the lower limbs during side-step cutting remains unclear. OBJECTIVE:To analyze and compare the changes in lower limb kinematics and dynamics when the subjects complete the side-step cutting of the knee joint under the conditions of kinesio taping,placebo taping and blank control. METHODS:Thirty-nine male college students majoring in basketball were recruited as subjects.Each subject was tested with kinesio taping,placebo taping or no taping.The mechanical correction method was used to patch the dominant knee joint of each subject.The run-up speed of 4.5-5.5 m/s was selected to complete the 45° side-step cutting motion,and the kinematics and kinetics data were collected synchronously by the three-dimensional dynamic capture system and the force measuring platform.The kinematics and kinetics parameters at the moment of initial touchdown and peak ground reaction force were selected for data analysis.SPSS 27.0 software was used for statistical analysis of the test data. RESULTS AND CONCLUSION:Kinematic indexes:compared with no taping and placebo taping,the hip abduction and knee valgus angles at the initial touchdown moment were significantly decreased when kinesio taping was used(P<0.05);at the moment of peak lateral ground reaction force,the angles of hip abduction,knee valgus and ankle plantar flexion decreased significantly(P<0.05),and the knee flexion angle was significantly increased(P<0.05).Kinetic indexes:Compared with no taping,both kinesio taping and placebo taping significantly reduced hip abduction and external rotation torque,knee valgus and external rotation torque at the moment of initial touchdown(P<0.05),and significantly reduced peak vertical ground reaction force and peak horizontal backward ground reaction force(P<0.05);in addition,kinesio taping significantly reduced peak lateral ground reaction force compared with no taping and placebo taping(P<0.05).These results indicate that kinesio taping of the knee joint may improve some kinematic and kinetic indexes associated with lower limb injury risk factors during the completion of the side-step cutting in basketball specialized college students to some extent,and may have a positive effect on the prevention of injury during the side-step cutting.In addition,the trends in the effects of placebo taping and kinesio taping on the knee joint are more consistent in terms of changes in some indexes,suggesting that there may be a placebo effect on the mechanism of action of kinesio taping.

Assessing the effect of prophylactic ankle taping on ankle and knee biomechanics during landing tasks in healthy individuals: A cross-sectional observational study

ABSTRACT BACKGROUND: Current research supports the fact that prophylactic ankle taping (AT) is effective in preventing ankle injuries in amateur and elite sports athletes. OBJECTIVE: This study aimed to investigate the effect of AT on balance, knee valgus during drop jump and single-leg countermovement jump (SL-CMJ) landings, and ankle range of motion (ROM) restriction in healthy participants. DESIGN AND SETTING: A cross-sectional observational study was conducted at the Universidad Europea de Madrid, Madrid, Spain. METHODS: Participants: Thirty-nine healthy individuals participated in this study and performed the movements under two conditions (with and without tape). Outcome measurements: ankle ROM, balance, SL-CMJ height, flight time, ground time, and knee valgus. Before any intervention, a random process was developed with a 1:1 allocation ratio, and the participants were assigned to groups A (tape-no tape) and B (no tape-tape). RESULTS: Significant differences between tape and no-tape moments were observed for drop jump knee valgus flexion (P = 0.007), with an increase in knee valgus in participants with ankle taping. Similarly, the Y-balance testshowed a significant decrease in all variables (P = 0.001 and), ankle dorsiflexion (P = 0.001) in participants with ankle taping. CONCLUSIONS: AT is effective for immediate ankle ROM restriction. However, an increase in knee valgus during drop jump task and a decrease in lower limb balance were observed during drop jump task. Based on these results, it can be concluded that AT application in healthy individuals should not be recommended as it results in increase in injury risk factors.

Effects of Different Trunk-Restraint Squatting Postures on Human Lower Limb Kinematics and Dynamics / 医用生物力学

Objective To investigate the effect of trunk control on the biomechanical characteristics of lower limb movements during Asian squats(AS)and Western squats(WS)in young adults to provide empirical support for the application and promotion of deep squat training.Methods Twenty-four healthy young male collegiate students performed AS and WS with and without bar control,and their lower limb kinematic and kinetic characteristics were collected using an infrared light-point motion capture system and a three-dimensional(3D)dynamometer.The 3D angles of the lower limbs were obtained using Cortex-642.6.2 software,based on the calculation of Euler angles,and the 3D moments were obtained by applying the inverse dynamics method.The effects of trunk control and deep squatting posture on the lower limb kinematic characteristics were examined using a two-factor analysis of variance with a 2×2 repeated design.Results There was no significant interaction between trunk control and the deep squatting posture for either kinematic or kinetic parameters(P>0.05).The WS group had a large knee flexion angle,peak patellofemoral contact force,and ratio of peak hip and knee extension moments,and small ankle dorsiflexion and hip flexion angles(P<0.05).The deep squat with a bar had a large ankle dorsiflexion angle,peak patellofemoral contact force,and hip flexion angle as well as a small knee flexion angle and ratio of peak hip and knee extension moments(P<0.05).Conclusions WS is helpful for training hip extension muscle groups,whereas AS is helpful for training knee extension muscle strength.The peak patellofemoral joint contact force of the WS is significantly greater than that of the AS;therefore,it is recommended that patients with patellofemoral joint pain use the AS.A squat with a bar can compensate for the body's balance;thus,people with limited ankle dorsiflexion range of motion or anterior tibial muscle weakness may consider trunk control training,such as a deep squat with a bar.This may help improve lower limb stability during squats.

Standard Value of Three-dimensional Joint Kinematics during Gait in Healthy People Collected Using an Inertial Sensor-based Motion Capture System / The Japanese Journal of Rehabilitation Medicine

Objective：An inertial sensor-based motion capture system for rehabilitation therapy is feasible due to its simple measurement methods. However, a standard value must be used to evaluate or diagnose pathological gait kinematically. This study aimed to set a standard value by determining the averaged spatial-temporal parameter (STP) and range of motion (ROM) during gait in healthy participants.Methods：This study included 177 healthy individuals, who were grouped into six groups according to gender (male and female) and age (young, middle, and old). All participants walked under two speed conditions (NORMAL or FAST) and the gait was captured with an inertial sensor-based motion capture system. Eight types of STP and fourteen types of ROM were calculated.Results：Of the 132 variables (22 variables × 2 sexes × 3 ages), 123 variables for NORMAL and 112 variables for FAST followed the normal distribution. A main effect of age on walking velocity for FAST was noted but not for NORMAL. The middle and old ages depended on an increased cadence for maintaining walking velocity. Ankle and hip ROMs in the old were smaller than that in the young, and these differences were demonstrated more so during the FAST condition. There were gender differences in hip ROMs (men had greater internal-external rotation and women had greater flexion-extension).Conclusion：The standard value can be determined from variables in gait assessment, for young to elderly, and gender-specific.

Videofluoroscopic measures of swallowing in people with stable COPD compared to healthy aging

ABSTRACT Purpose Swallowing impairment is a serious extra-pulmonary manifestation of Chronic Obstructive Pulmonary Disease (COPD). Previous studies suggest that individuals with stable COPD show atypical values for several videofluoroscopy measures of swallowing, compared to healthy adults under age 60. However, it is unclear to what degree these changes are attributable to healthy aging. In this study, we aimed to clarify how swallowing in people with stable COPD differs from age-matched healthy controls. Methods We performed a retrospective analysis of videofluoroscopy data from two previously-collected datasets: a) a sample of 28 adults with stable COPD (18 male); b) a sample of 76 healthy adults, from which 28 adults were selected, matched for sex and age to participants in the COPD cohort. In both prior studies, participants swallowed 20% w/v liquid barium prepared in different consistencies (thin; mildly, moderately, and extremely thick). Blinded duplicate ratings were performed according to a standard procedure, yielding measures of laryngeal vestibule closure (LVC) integrity and timing, swallow timing, upper esophageal sphincter (UES) opening, pharyngeal constriction and pharyngeal residue. Mann-Whitney U tests and odds ratios were performed to determine significant group differences (p<.05). Results Across the consistencies tested, participants with COPD showed significantly shorter durations of LVC, earlier onsets and shorter durations of UES opening, and reduced pharyngeal constriction. No significant differences were seen in other measures. Conclusion These results point to features of swallowing in people with stable COPD that differ from changes seen with healthy aging, and which represent risks for potential aspiration.

Running intralimb coordination patterns after a foot core exercise program in recreational runners

This study investigated the effects of a foot core intervention on the coordination of foot joints in recreational runners. This was a secondary analysis from a randomized controlled trial conducted with 87 recreational runners allocated to the control group (CG), which followed a placebo lower limb stretching protocol, or the intervention group (IG), which underwent an 8-week (3 times/week) foot core training. The participants ran on a force-instrumented treadmill at a self-selected speed (9.5-10.5 km/h) while the foot segment motion was captured. The vector coding technique was used to assess inter-joint coordination for four selected coupled segment and joint angles. The coordination patterns of the calcaneus and midfoot (CalMid) and midfoot and metatarsus (MidMet) joint pairs were affected. In the frontal plane, IG showed an in-phase with proximal dominancy coordination at heel strike, with a decrease in its frequency after the training (P=0.018), suggesting a longer foot supination. Additionally, IG showed an anti-phase with distal dominancy pattern at early stance compared to CG due to a smaller but earlier inversion of the CalMid-MidMet pair (P=0.020). The intervention also had an effect on the transverse plane of the CalMid-MidMet pair, with IG showing a significantly greater frequency of anti-phase coordination with proximal dominancy during propulsion than CG (P=0.013), probably due to a reduction in the CalMid abduction. Overall, the results suggested that the foot core intervention reduces the occurrence of running-related injuries by increasing the resistance to calcaneus pronation and building a more rigid and efficient lever during push-off.

A novel validation approach shows new, solid reasons why vertical jump height should not be used to predict leg power / Uma nova abordagem de validação acrescenta fortes razões para não usar a altura do salto vertical como um indicador de potência das pernas / Un novedoso enfoque de validación añade sólidas razones para no utilizar la altura del salto vertical como predictor de la potencia de piernas

Abstract Jump height continues to be widely used to predict power in humans. Individual progress is often monitored on the basis of estimated power, but prediction equations are based on group data. The objective of the study was to show that vertical jump performance (vJP) and mechanical power are poorly associated, particularly within individuals. Two experiments are presented. First, 52 physically active male college students performed five maximal vertical jumps each. Second, three young male participants performed 50 maximal jumps each. Participants rested for 1 minute between jumps. vJP was calculated from kinematic data as peak body center of mass (BCOM) minus standing BCOM; peak power (PEAKPWR) was calculated from the vertical ground reaction force registered by a force plate, and average power (MEANPWR) during propulsion from the change in potential energy of BCOM. Regression analyses were performed using standardized vJP scores as the predictor variable and standardized power scores as the resulting variables, expecting an identity function of y = x (intercept = 0, slope = 1) and R2 = 1. In experiment 1, the model for zPEAKPWR R2 = 0.9707 (p < 0.0001) but slope (0.3452) ≠ 1 (p < 0.0001). The model for zMEANPWR R2 = 0.9239 (p < 0.0001); nevertheless, slope (0.4257) ≠ 1 (p < 0.0001). In experiment 2, all individual models for zPEAKPWR and zMEANPWR resulted in poor associations (R2 ≤ 0.21) and slopes ≠ 1 (p≤0.001). In conclusion, regression analysis for individuals, and even for groups, confirms that vJP is a poor predictor of mechanical power.

Resumo A altura do salto ainda é amplamente usada para prever a potência em humanos. O progresso individual é frequentemente monitorado usando a estimativa de potência, mas as equações de previsão são baseadas em dados de grupo. O objetivo do estudo é demonstrar que a altura do salto vertical (ASv) e a potência mecânica têm uma correlação débil, principalmente em um mesmo indivíduo. São apresentados dois experimentos: primeiro, 52 estudantes universitários fisicamente ativos realizaram cinco saltos verticais máximos cada um; segundo, três participantes do sexo masculino realizaram 50 saltos máximos cada um. Os participantes descansaram por 1 minuto entre os saltos. A ASv foi calculada a partir de dados cinemáticos como a posição mais alta do centro de massa corporal (CMC) menos o CMC em pé; a potência de pico (PEAKPWR) foi calculada a partir da força de reação vertical registrada por uma plataforma de força e a potência média (MEANPWR) durante a propulsão a partir da mudança na energia potencial do CMC. As análises de regressão foram realizadas usando os escores da ASv padronizados como variável preditora e os escores de potência padronizados como variáveis de resultado, com a expectativa de obter uma função de identidade y = x (interceptação = 0, inclinação = 1) e R2 = 1. No experimento 1, o modelo para zPEAKPWR produziu R2 = 0,9707(p < 0,0001), mas a inclinação (0,3452) ≠ 1 (p = 8,7x10-15). O modelo para zMEANPWR apresentou R2 = 0,9239 (p < 0,0001); no entanto, a inclinação (0,4257) ≠ 1 (p = 1,15x10-5). No experimento 2, todos os modelos individuais para zPEAKPWR e zMEANPWR apresentaram associações débeis (R2 ≤ 0,21) e inclinações ≠ 1(p ≤ 0,001). Em conclusão, a análise de regressão para indivíduos e até mesmo para grupos confirma que a ASv é um indicador débil da potência mecânica.

Resumen La altura del salto se sigue usando ampliamente para predecir la potencia en seres humanos. El progreso individual, a menudo, se monitorea usando una estimación de la potencia, pero las ecuaciones de predicción se basan en datos grupales. El estudio pretende demostrar que la altura del salto vertical (ASv) y la potencia mecánica tienen una pobre correlación, particularmente en un mismo individuo. Se presentan dos experimentos; primero, 52 estudiantes universitarios físicamente activos ejecutaron cinco saltos verticales máximos cada uno; segundo, tres participantes masculinos ejecutaron 50 saltos máximos cada uno. Los participantes descansaron 1 minuto entre saltos. ASv se calculó a partir de los datos cinemáticos como posición más alta del centro de masa corporal (CDM) menos CDM de pie; la potencia pico (PEAKPWR) se calculó a partir de la fuerza vertical de reacción registrada por una plataforma de fuerza y la potencia promedio (MEANPWR) durante la propulsión a partir del cambio en la energía potencial del CDM. Se realizaron análisis de regresión usando puntajes estandarizados de ASv como la variable predictora y puntajes estandarizados de potencia como las variables resultantes, con la expectativa de obtener una función de identidad y = x (intercepto = 0, pendiente = 1) y R2 = 1. En el experimento 1, el modelo para zPEAKPWR arrojó R2 = 0.9707 (p <.0001) pero la pendiente (0.3452) ≠ 1 (p = 8.7x10-15). El modelo para zMEANPWR dio R2 = 0.9239 (p < .0001); sin embargo, la pendiente (0.4257) ≠ 1 (p = 1.15x10-5). En el experimento 2, todos los modelos individuales para zPEAKPWR y zMEANPWR arrojaron asociaciones débiles (R2 ≤ 0.21) y pendientes ≠ 1 (p ≤ .001). En conclusión, el análisis de regresión para individuos y aún para grupos confirma que la ASv es un pobre predictor de la potencia mecánica.

Evaluation of the rotary kinematics between actual and set speeds of X-Smart Plus, VDW.Silver and iRoot motors

Abstract The present study evaluated the actual rotational speed of three different endodontic motors compared to the values provided by the manufacturers. A total of three endodontic motors (X-Smart Plus, VDW.Silver, and iRoot) were tested at 400 rpm and 800 rpm and 2 N/cm2 torque. The kinematics of the devices was recorded by using a custom angle-measuring disc with a 50-mm diameter attached to the handpiece provided by the manufacturer, whereas their movement was captured by a high-speed camera at 2,400 frames per second, 800 x 800 pixel-resolution and distance of 0.3 m from the target object. Statistical analysis was performed at a significance level of 5%. At 400 rpm, the iRoot motor had a value of 17.94 rpm above that indicated by the manufacturer, which was significantly different from those of X-Smart Plus (5.20 rpm below that indicated by the manufacturer) and VDW.Silver (0.62 rpm above that indicated by the manufacturer) motors (P < 0.05). At 800 rpm, the iRoot motor had a value of 51.34 rpm below that indicated by the manufacturer, whereas the X-Smart Plus motor had a value of 13.00 rpm below that indicated by the manufacturer (P > 0.05). The VDW.Silver motor statistically differed from the iRoot and X-Smart Plus ones, showing a value of 1.68 rpm above that indicated by the manufacturer. In conclusion, the X-Smart Plus, VDW.Silver, and iRoot motors showed lower variations in the rotational speed values compared to those reported by their manufacturers. The endodontic motors presented different behaviors between them, with the VDW.Silver motor presents the most accurate values and the iRoot presents the most divergent values.

Resumo O presente estudo avaliou a real velocidade rotacional de três diferentes motores endodônticos comparados aos valores fornecidos pelos fabricantes. Um total de três motores endodônticos (X-Smart Plus, VDW.Silver e iRoot) foram testados a 400 rpm e 800 rpm e torque de 2 N/cm2. A cinemática dos dispositivos foi verificada utilizando-se um disco customizado de 50 mm de diâmetro acoplado ao contra ângulo fornecido pelo fabricante e o movimento foi capturado através de uma câmera ajustada em 2400 quadros por segundo com resolução de 800 x 800 pixels distante 0,3 m do objeto alvo. A análise estatística foi realizada com nível de significância de 5%. A 400 rpm, o motor iRoot apresentou 17,94 rpm acima do indicado pelo fabricante, sendo o valor significativamente diferente do X-Smart Plus (5,20 rpm abaixo do indicado pelo fabricante) e VDW.Silver (0.62 rpm acima do indicado pelo fabricante) (P > 0,05). A 800 rpm, iRoot apresentou 51.34 rpm abaixo do indicado pelo fabricante e X-Smart Plus 13,00 rpm abaixo do indicado pelo fabricante (P > 0,05). VDW.Silver foi estatisticamente diferente de iRoot e X-Smart Plus, apresentando 1,68 rpm acima do indicado pelo fabricante. Concluiu-se que os motores X-Smart Plus, VDW.Silver e iRoot apresentaram baixa variação na velocidade rotacional quando comparada ao fornecido pelo fabricante. Os motores endodônticos apresentaram diferentes comportamentos entre eles, sendo que o motor VDW.Silver apresentou valores mais acurados enquanto o iRoot foi o mais divergente.

Taping can relieve chronic ankle instability among basketball players / 中华物理医学与康复杂志

Objective:To observe the effect of taping on the kinematic characteristics of the ankle joint during forward and lateral jumps by male basketball players with chronic ankle instability (CAI).Methods:A Vicon 3D motion capture system and a Kistler 3D ergometer were used to collect data describing the landing data with or without taping from forward and lateral jumps of 29 male basketball players with CAI. The landing data included the dorsiflexion and plantarflexion angles, valgus and inversion angles and external and internal rotation angles. Dorsiflexion or plantarflexion angular velocity was also recorded along with valgus or inversion angular velocity and external or internal rotation angular velocity 200ms, 150ms, 100ms and 50ms before and after touchdown. The data obtained were modeled using three-dimensional motion analysis software, and then analyzed.Results:Taping reduced the ankle plantarflexion in landing from a forward jump by 3.27° 50ms before landing and by 2.70° at touchdown. The ankle inversion angle was reduced 2.13° 50ms before touchdown, while the angle of external rotation decreased by 2.59° 200ms before touchdown and 2.17° 150ms before. Moreover, the angle of external rotation 100ms after landing was reduced by a significant 1.59° compared with that without taping. In lateral jumps taping reduced the average ankle plantarflexion angle by 1.94° 50ms before landing and 3.23° at touchdown compared with no taping. Ankle inversion was reduced significantly by 2.86° 50ms before landing and by 2.87° at touchdown. External rotation was a significant 0.93° less 200ms before landing and 2.36° smaller 150ms before touchdown. In the forward jump landing, taping reduced the average angular velocity of ankle dorsiflexion on landing by a significant 58.5°/s and by 28.39°/s 100ms later. In the lateral jump landings the average ankle dorsiflexion velocity decreased by significant 20.5°/s with taping, but the valgus velocity increased by 49.7°/s compared with no taping. However, 50ms after touchdown the speed of external rotation with taping was 30.3°/s slower than without taping.Conclusions:Ankle taping can modify ankle rotation angles and angular velocities during landing from jumps. This is particularly helpful for basketball players with CAI.

Kinematic and Dynamic Study on Traditional Chinese Cervical Manipulation / 医用生物力学

Objective To simultaneously collect and analyze the kinematic and dynamic parameters for two techniques of traditional Chinese cervical manipulation ( TCCM), and quantitatively describe its biomechanical characteristics. Methods A senior practitioner completed the TCCM (positioning and directional rotation pulling, lateral flexion, respectively) on 10 healthy subjects, and the fluorescent marker balls were pasted on the operator to capture manipulation movements. The dynamic parameters and the surface electromyography ( sEMG) signals were collected by pressure-sensitive gloves and wireless sEMG acquisition system. Results The upper arm muscle was the main force muscle during TCCM, and biceps brachii had the highest contribution rate. The range of motion (ROM), speed, pulling force, and time during cervical spine positioning and directional rotation pulling were all greater than those during cervical spine lateral flexion. The integrate electromyography ( iEMG) and root mean square (RMS) for each muscle of the operator during cervical spine positioning and directional rotation pulling were higher than those during cervical spine lateral flexion. Conclusions The overall ROM, three-dimensional (3D) motion angle, load intensity and time during CCTM have the characteristics of high speed, low amplitude and strong force, reflecting the biomechanical characteristics of ‘ cunjin ’ ( one-inch punch ) in traditional Chinese medicine. This study provides references for further standardizing manual teaching and training and improving clinical safety.

Analysis of Knee Joint Stress During Drop Jump Landing in Females with Generalised Joint Hypermobility / 医用生物力学

Objective To analyze the differences of von Mises stress distribution in knee cartilage and meniscus in female with generalised joint hypermobility (GJH) and healthy female during drop jump landing. Methods The kinematic and ground reaction force (GRF) characteristics of knee joint in female with GJH and healthy female at the moment of peak vertical GRF (VGRF) during loading phase of drop jump landing were collected. The knee joint reaction force was calculated via inverse dynamics, and the combined force of knee joint along long axis of the femur was applied as the load. Based on three-dimensional (3D) finite element model of a female knee joint, numerical simulations were performed separately during drop jump landing of subjects in two groups, and von Mises stresses and stress distribution of knee cartilage and meniscus were calculated. Results At the moment of peak VGRF during drop jump landing, knee flexion and valgus angles in GJH group and control group showed a statistical significance (P<0. 05). Compared with control group, knee flexion angle decreased and valgus angle increased in GJH group. During drop jump landing, GJH group bore larger stress inside the knee joint, and stress distribution in weight-bearing areas of the medial and lateral tibiofemoral compartments was uneven, while the lateral femoral cartilage lateral condyle, the anterior and middle lateral of lateral tibial cartilage, the anterior angle and body lateral margin of lateral meniscus were stress concentration sites. Conclusions For females with GJH, the stability of knee joint decreases and force lines change in jumping events, due to the increased range of motion of knee joint and relaxation of joint capsule, which increases the risk of cartilage and meniscal injury in lateral knee joint. During jumping sports, females with GJH should especially prevent knee joint injury caused by altered force lines in frontal plane of knee joint.

Puncture and Needle Picking Action of Venipuncture Manipulator / 医用生物力学

Objective To propose a new multi-joint series venipuncture system, explore the mechanics and kinematics-based related control problems involved in needle insertion and needle picking during the puncture process, and verify feasibility of this system. Methods A puncture manipulator was built, and needle displacement control algorithm was proposed by combing with the puncture mechanics model. The the forward kinematics was calculated by using DH method, so as to obtain the tip coordinates. Then the inverse kinematics was calculated by using the geometric method. The forward and inverse processes were closely connected. The position error of the end coordinates before and after needle picking was compared by using the method of kinematics positive solution-inverse solution-re-positive solution. Finally, experimental verification and simulation were conducted by combining with the physical object. Results Through simulation and experiments, accuracy of the theoretical model was verified. The needle insertion algorithm could be used to achieve success with only one needle insertion, which provided theoretical basis for the control of robot arm. The position error before and after needle picking could be controlled within 1 mm from the end trajectory. The end needle tip of robot arm was almost kept fixed during the needle picking process. Therefore, this needle picking scheme was feasible and could basically verify that the needle picking action of robot arm met the accuracy and safety requirements. Conclusions The venipuncture manipulator truly simulates the needle insertion and needle picking action during the puncture process, and can safely and accurately realize the needle insertion and needle picking action with needle tip as the fixed point, indicating that it has certain clinical value.

Kinematics and Plantar Pressure Analysis of Varus Femur and Varus Tibia / 医用生物力学

Objective To compare the differences in kinematic parameters and plantar pressures for two types of knee varus with tibial and femoral origins in gait analysis, so as to provide biomechanical theoretical basis for different types of genu varus. Methods Twenty-six patients with unilateral knee osteoarthritis (KOA) varus genu were enrolled, with 13 from femoral and 13 from tibial sources. Using Noraxon MyoMotion three-dimensional (3D) motion capture system and Footscan plantar pressure test system, the gait of the subjects during natural walking was measured, the temporal and spatial parameters of the gait, the kinematics parameters of lower limb joints and plantar pressures were collected, to make comparative analysis between the two groups. Results The range of knee flexion and extension of tibial varus, the peak of hip abduction, the range of motion (ROM) of hip adduction and abduction and the peak of ankle pronation were larger than those of femoral lateral genu varus. The peak of knee flexion and hip adduction was smaller than that of femoral lateral genu varus. Compared with femoral varus, subjects with tibial varus had increased stress time and peak pressure on the plantar of the 4th and 5th metatarsals (P<0.05). In the 3rd metatarsal region, the impulse of healthy femoral limb was greater than that of healthy limb with tibial deformity. While in the medial calcaneal region, the impulse of healthy femoral limb was smaller (P<0.05). Conclusions There are some differences in kinematic parameters and plantar pressures between two different types of unilateral genu varus patients. The results of this study are helpful to understand the abnormal gait caused by genu varus, and provide reliable reference for postoperative rehabilitation and limb exercise for different types of genu varus.

Effects of Backpack Types on Kinematics and Plantar Pressure in College Students During Stairs Walking / 医用生物力学

Objective To analyze the influence of different backpack types and loads on kinematics and plantar pressure of college students during stair climbing, so as to provide references for choosing the appropriate backpack and carrying mode. Methods The Nokov infrared light point motion capture system and Podome plantar pressure system were used to analyze the differences in the range of motion ( ROM) of the trunk and lower limb joints, the kinematic parameters at the peak time, the peak pressure of each plantar partition, the contact time, the maximum pressure of the whole foot, the average pressure and the maximum contact area for 15 male college students during the support period of stair climbing. Results The 5% BW and 10% BW backpack loads reduced ROM of trunk rotation, increased ROM of ankle flexion/ extension and varus / valgus. The 10% BW backpack loads increased the peak pressure of the 1st and 3rd metatarsals bones and the maximum pressure of the whole foot ( P < 0. 05). Single-shoulder bag and handbag reduced ROM of trunk tilting and rotation, and increased ROM of ankle flexion and extension, hip flexion angle, peak pressure of foot arch and medial heel (P<0. 05). The double-shoulder bag loads increased peak pressure in the toe area (P<0. 05). Conclusions During walking on the stairs, the 5% BW and 10% BW backpack loads limited trunk rotation and increased ankle ROM. The 10% BW loads also increased the load in metatarsal area. The unilateral weight-bearing mode would make the trunk tilt to the unload side and rotate to the weight-bearing side. The pressure in toe area was higher when carrying double-shoulder bag, while single-shoulder bag and handbag mainly increased the pressure of arch foot and medial heel. It is suggested that college students choose symmetrical backpack scheme, and wisely allocate back weight to avoid the injury of foot area.

Structure Design of Hip Joint Parallel Rehabilitation Exoskeleton / 中国医疗器械杂志

At present, most of the research on hip exoskeleton robots adopts the method of decoupling analysis of hip joint motion, decoupling the ball pair motion of hip joint into rotational motion on sagittal plane, coronal plane and cross section, and designing it into series mechanism. Aiming at the problems of error accumulation and man-machine coupling in series mechanism, a parallel hip rehabilitation exoskeleton structure is proposed based on the bionic analysis of human hip joint. The structure model is established and the kinematics analysis is carried out. Through the OpenSim software, the curve of hip flexion and extension, adduction and abduction angle in a gait cycle is obtained. The inverse solution of the structure is obtained by the D-H coordinate system method. The gait data points are selected and compared with the inverse solution obtained by ADAMS software simulation. The results show that the inverse solution expression is correct. The parallel hip exoskeleton structure can meet the requirements of the rotation angle of the hip joint of the human body, and can basically achieve the movement of the hip joint, which is helpful to improve the human-computer interaction performance of the exoskeleton.

Upper limb movement characteristics in volleyball athletes / Características do movimento dos membros superiores em atletas de voleibol / Características del movimiento de las extremidades superiores en atletas de voleibol

ABSTRACT Introduction Passing and serving are the most direct and efficient tactics for scoring points in volleyball. The recoil of the upper limbs in dominating the ball requires strength and muscular explosion, where the effect of the body's angular momentum accompanies a joint and rhythmic action. Objective This study aims to analyze muscle strength in upper limb movements in volleyball athletes. Methods Several volleyball players volunteered for the research. The movement when the athlete hits the ball was analyzed using kinematic analysis. The relationship between muscle strength and ball movement was also analyzed. Results Body muscle tissue can be effectively trained during volleyball practice. The compound movements also help in the elasticity of the abdominal muscles. The stimulation of other muscle groups was observed in the participation of the movements. Conclusion In modern volleyball training, athletes should strengthen their training with rapid trunk muscle swing exercises to improve the coordination ability of the sets of muscle groups. The protocols presented can assist in improving players' skills and performance. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução Passar e servir são as táticas mais diretas e eficientes de marcar pontos no voleibol. O recuo dos membros superiores no domínio da bola requer força e explosão muscular onde o efeito do momento angular do corpo acompanha uma ação conjunta e rítmica. Objetivo O objetivo deste estudo é analisar a força muscular no movimento dos membros superiores em atletas de voleibol. Métodos Vários jogadores de voleibol voluntariaram-se para a pesquisa. Foi analisado o movimento quando o atleta acerta a bola utilizando o recurso de análise cinemática. Também foi analisada a relação entre a força muscular e o movimento da bola. Resultados O tecido muscular corporal pode ser efetivamente treinado durante a prática do voleibol. Os movimentos compostos também auxiliam na elasticidade da musculatura abdominal. O estímulo de outros grupos musculares foi observado na participação dos movimentos. Conclusão No treinamento moderno de voleibol, os atletas devem fortalecer o treinamento com exercício rápido de balanço dos músculos do tronco para melhorar a capacidade de coordenação dos conjuntos de grupos musculares. Os protocolos apresentados podem auxiliar na melhoria das habilidades e no desempenho dos jogadores. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción El pase y el saque son las tácticas más directas y eficaces para conseguir puntos en el voleibol. El retroceso de los miembros superiores en el dominio del balón requiere fuerza y explosión muscular donde el efecto del momento angular del cuerpo acompaña una acción conjunta y rítmica. Objetivo El objetivo de este estudio es analizar la fuerza muscular en el movimiento de las extremidades superiores en atletas de voleibol. Métodos Varios jugadores de voleibol se ofrecieron como voluntarios para la investigación. El movimiento cuando el atleta golpea la pelota se analizó mediante la función de análisis cinemático. También se analizó la relación entre la fuerza muscular y el movimiento del balón. Resultados El tejido muscular del cuerpo puede entrenarse eficazmente durante la práctica del voleibol. Los movimientos compuestos también ayudan a la elasticidad de los músculos abdominales. Se observó la estimulación de otros grupos musculares en la participación de los movimientos. Conclusión En el entrenamiento moderno de voleibol, los atletas deben reforzar su entrenamiento con ejercicios de balanceo rápido de los músculos del tronco para mejorar la capacidad de coordinación de los conjuntos de grupos musculares. Los protocolos presentados pueden ayudar a mejorar las habilidades y el rendimiento de los jugadores. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Kinematic analysis of lower extremity movement techniques in soccer training / Análise cinemática das técnicas de movimento dos membros inferiores no treinamento de futebol / Análisis cinemático de las técnicas de movimiento de los miembros inferiores en el entrenamiento de fútbol

ABSTRACT Introduction The improvement of soccer sports skills depends on many training efforts and is closely related to intrinsic scientific methods. Attention to the integral quality of the lower limb muscles and the performance of specific exercises of technical movements is essential to reach the optimal state of physical performance in players. Objective Analyze the kinematic effect of lower limb movement techniques in soccer training. Methods 10 athletes were marked with reflective spheres and submitted to the kinematic training method of the lower limbs designed by the coaches in 60 minutes, three times a week, for six weeks. Before and after the experiment, data captured by reflective spheres were captured, compared, classified, and analyzed. Results Kinematic training can effectively optimize movement time, swing amplitude, swing angle, and other aspects of lower limb mechanical structure, thus improving energy expenditure and making the movement concise, conveying strength and precision. Conclusion Trainers should seriously study the principles of applied kinematic analysis and optimize the training program from a scientific point of view because the athletic level of athletes is significantly improved with this real-time feedback. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução O aprimoramento das habilidades esportivas do futebol depende de muitos esforços de treinamento e está intimamente relacionado com métodos científicos intrínsecos. Atenção na qualidade integral dos músculos dos membros inferiores e a realização de exercícios específicos de movimentos técnicos é essencial para atingir o estado ótimo da performance física nos jogadores. Objetivo Analisar o efeito cinemático das técnicas de movimento dos membros inferiores no treinamento de futebol. Métodos 10 atletas foram marcados com esferas reflexivas e submetidos ao método de treinamento cinemático dos membros inferiores desenhado pelos treinadores num período de 60 minutos, três vezes por semana, durante 6 semanas. Antes e depois do experimento, os dados capturados por esferas reflexivas foram capturados, comparados, classificados e analisados. Resultados O treinamento cinemático pode otimizar efetivamente o tempo de movimento, amplitude de balanço, ângulo de balanço e outros aspectos da estrutura mecânica dos membros inferiores, melhorando assim o dispêndio energético e tornando o movimento conciso, transmitindo força e precisão. Conclusão Os treinadores devem estudar seriamente os princípios da análise cinemática aplicada, otimizar o programa de treinamento do ponto de vista científico, pois o nível esportivo dos atletas é melhorado significativamente com a adição desse feedback em tempo real. Nível de evidência II; Estudos terapêuticos - investigação dos desfechos do tratamento.

RESUMEN Introducción La mejora de las capacidades deportivas en el fútbol depende de muchos esfuerzos de entrenamiento y está estrechamente relacionada con métodos científicos intrínsecos. La atención sobre la calidad integral de los músculos de los miembros inferiores y la realización de ejercicios específicos de movimientos técnicos es esencial para alcanzar el estado óptimo del rendimiento físico en los jugadores. Objetivo Analizar el efecto cinemático de las técnicas de movimiento del miembro inferior en el entrenamiento de fútbol. Métodos 10 atletas fueron marcados con esferas reflectantes y sometidos al método de entrenamiento cinemático de los miembros inferiores diseñado por los entrenadores en un período de 60 minutos, tres veces por semana, durante 6 semanas. Antes y después del experimento, se capturaron, compararon, clasificaron y analizaron los datos captados por las esferas reflectantes. Resultados El entrenamiento cinemático puede optimizar eficazmente el tiempo de movimiento, la amplitud del balanceo, el ángulo de balanceo y otros aspectos de la estructura mecánica de las extremidades inferiores, mejorando así el gasto de energía y haciendo que el movimiento sea conciso, transmitiendo fuerza y precisión. Conclusión Los entrenadores deberían estudiar seriamente los principios del análisis cinemático aplicado, optimizar el programa de entrenamiento desde un punto de vista científico, ya que el nivel atlético de los deportistas mejora significativamente con la incorporación de esta información en tiempo real. Nivel de evidencia II; Estudios terapêuticos - investigación de los resultados del tratamiento.

The video assistant referee (var) in soccer: where is the biomechanics? / árbitro assistente de vídeo (var) no futebol: onde está a biomecânica?

ABSTRACT The aim of this article is to explore the basic principles of Biomechanics in relation to the objective measurements carried out by the Video Assistant Referee (VAR) operators and systems in soccer. It was presented an overall framework about the determination of kinematical variables, the definition and the sources of error, the understanding of factors contributing to errors in VAR decisions, and prospects for future solutions. To exemplify these concepts, the offside rule was chosen as it offers numerous instances of tools aiding for accurate measurements. Based on consolidated procedures of literature, a discussion about the actual challenges and an suggestions for a fully comprehension and improvement of VAR were provided.

RESUMO O objetivo deste artigo foi explorar os princípios básicos da Biomecânica em relação às medições objetivas realizadas pelos operadores e sistemas do Árbitro Assistente de Vídeo (VAR) no futebol. Foi apresentado uma estrutura geral sobre a determinação das variáveis ​​cinemáticas, a definição e as fontes de erro, a compreensão dos fatores que contribuem para os erros nas decisões do VAR e as perspectivas de soluções futuras. Para exemplificar esses conceitos, a regra do impedimento foi escolhida, pois oferece inúmeras instâncias de ferramentas que requerem medições acuradas. Com base em procedimentos consolidados da literatura, foram apresentadas discussões sobre os atuais desafios e sugestões para compreensão e aprimoramento completos do VAR.