The Influence of Morphological Characteristics on the Ball Throwing Velocity in the Professional Handball Players / Influencia de las Características Morfológicas en la Velocidad de Lanzamiento del Balón en los Jugadores Profesionales de Balonmano

SUMMARY: The aim of this study was to determine influence of upper limbs on the ball throwing velocity. A total of 10 professional handball players (25.74±4.84 years) participated in this study. All of them were playing in the top Montenegrin professional handball league. The results obtained in this study shows that upper limbs have high influence on ball throwing velocity. This study provides normative data and performance standards for professional handball. Coaches can use this information to determine the type of anthropometric characteristics that are needed for handball. Anthropometric parameters such as arm length, wrist diameter, hand length and arm span are the most relevant aspects related to ball throwing speed, given that these parameters cannot be changed through training, they should be taken into account when discovering talents.

El objetivo de este estudio fue determinar la influencia de los miembros superiores sobre la velocidad de lanzamiento de la pelota. En el estudio participaron un total de 10 jugadores profesionales de balonmano (25,74±4,84 años). Todos ellos jugaban en la principal liga profesional de balonmano de Montenegro. Los resultados obtenidos mostraron que los miembros superiores tienen una alta influencia en la velocidad de lanzamiento de la pelota. Este estudio proporciona datos normativos y estándares de rendimiento para el balonmano profesional. Los entrenadores pueden utilizar esta información para determinar el tipo de características antropométricas necesarias para el balonmano. Los parámetros antropométricos como la longitud del brazo, el diámetro de la muñeca, la longitud de la mano y la envergadura del brazo son los aspectos más relevantes relacionados con la velocidad de lanzamiento de la pelota, dado que estos parámetros no se pueden cambiar mediante el entrenamiento, deben tenerse en consideración a la hora de descubrir talentos.

The application of restricted kinematic alignment in total knee arthroplasty / 中华骨科杂志

Objective:To investigate the feasibility and therapeutic effect of total knee arthroplasty (TKA) with cruciate-retaining (CR) prosthesis by using FEM-X1 femoral extramedullary positioning instrument based on the theory of restricted kinematic alignment (rKA).Methods:Thirty five cases who underwent total knee arthroplasty in Nanjing Drum Tower Hospital from November 2019 to December 2020 were retrospectively analyzed, including 7 males and 28 females with an average age of 71± 8 years (ranging from 55 to 85 years) Following the guidance of rKA alignment, the FEM-X1 femoral extramedullary positioning instrument was used for TKA with CR prosthesis. Before the operation, the full-length lower limb radiographs of both anteroposterior and lateral views were taken in a standing position for preoperative assessment of lateral distal femoral angle (LDFA), the medial proximal tibial angle (MPTA) and hip-knee-ankle angle (HKA). According to the principle of rKA alignment, the target LDFA, MPTA and HKA were calculated. The proximal end of tibia and distal end of femur were cut using extramedullary positioning instrument respectively. The posterior femoral condyle was cut according to the tibial plateau and mediolateral soft tissue tension. The prosthesis was installed after osteotomy. The release of collateral ligaments, PCL function, release of PCL, patellofemoral trajectory, release of patellofemoral support band, the amount of blood loss and time of operation were recorded. Postoperative LDFA, MPTA, HKA, and posterior slope angle of tibial prosthesis were measured on X-ray images. The Knee Society Score (KSS) was used for functional evaluation.Results:Thirty five cases of TKA with CR prosthesis following rKA alignment were successfully completed. The operation time was 100 (90, 110) min, and the blood loss was 100 (100, 200) ml. 30 of them were followed up for 12.5±0.7 months (ranging from 12 to 14 months). The pre-operative and post-operative LDFA were 1.0°(-2.0°, 4.0°), 0°(-2.0°, 2.0°), MPTA were -4.0°(-5.0°, -1.0°), -2.0°(-3.0°, -1.0°), HKA were -3.0°(-3.0°, -1.0°), -2.0°(-3.0°, -1.0°). There was no significant difference between the three angles before and after operation ( Z=-0.89, P=0.372; Z=1.87, P=0.061; Z=1.03, P=0.302). The average posterior tibial slope was 5°(3°, 7°). At the follow-up of one year, the KSS clinical score was 94(92, 97) and functional score was 80(70, 90) in 30 cases. During the operation, PCL was released in 1 case because of excessive tension; and lateral retinacular release was performed in 1 case because of poor patellofemoral track. Conclusion:ITKA with CR prosthesis by using the extramedullary positioning instrument on the theory of rKA alignment showed a good clinical outcome at a short follow up.

Biomechanics Assessment of Kinematic Parameters of Low-Sprint Start in High-Performance Athletes Using Three Dimensional Motion Capture System

ABSTRACT In a sprint start, the athlete takes up a position with their hands just behind a line, arms vertical, feet generally placed about a shoe length apart, and the hips rising above the line of the head. Mistakes in this position influence the execution of the low-sprint start, and can drastically influence the initial running speed and acceleration achieved by the athlete. Common mistakes occur due to the misconception that athletes must also lean forward, bringing the shoulders ahead of their hands and putting pressure on them. A standard approach to identify sprint start mistakes is to use a stick or weighted string to drop down from the shoulders. The effective implementation of this approach depends on the coach's experience and remains a significant challenge. In this study, a three-dimensional motion capture system with the Vicon® Plug-in-Gait model was used to characterize the kinematic parameters that influence the execution of low-sprint start in six high-performance athletes. The main kinematic parameters are reaction time, stride length, and stride time. The obtained results demonstrate the potential utility of a three-dimensional motion capture system to assess the kinematic parameters of low-sprint start in high-performance athletes.

Assessment of Postoperative Surface Electromyography and Joint Angle in Children with Spastic Cerebral Palsy / 医用生物力学

Objective To analyze and assess the postoperative motor function in children with spastic cerebral palsy (SCP) by surface electromyography (sEMG) and joint angle. Methods Sixteen children with SCP were involved in this study. The sEMG of rectus femoris, biceps femoris, semitendinosus, tibialis anterior, lateral gastrocnemius and medial gastrocnemius muscles and joint angles of the hip, knee and ankle during straight walking were collected preoperatively and postoperatively. In every gait phase, the mean values of joint angles, root mean square and integrated electromyography of sEMG were calculated, to evaluate muscle strength and muscular tension quantitatively. Results The muscle tension of lower limbs was significantly decreased (P<0.05). The muscle strength of rectus femoris and biceps femoris was decreased in the swing phase. At the midswing and terminal swing phase, the strength of tibialis anterior increased significantly (P<0.05). The flexion angle of hip and knee decreased significantly (P<0.05). The dorsiflexion angle of ankle increased significantly (P<0.05), and the varus angle decreased significantly (P<0.05). Conclusions After operation, the crouching gait and clubfoot were improved positively. Therefore, the motor function of children was improved. Combining sEMG and joint angle can evaluate the muscle function of patients quantitatively, and it also can provide references for clinical diagnosis.

Effects of kinematic alignment on range of motion after total knee arthroplasty / 中国康复理论与实践

ObjectiveTo explore the effect of kinematic alignment on postoperative knee function for patients after total knee arthroplasty (TKA). MethodsFrom June, 2020 to October, 2021, 200 patients undergoing primary TKA in Beijing Chaoyang Hospital were divided into mechanical alignment (MA) group (n = 100) and kinematic alignment (KA) group (n = 100). All the patients accepted comprehensive rehabilitation after operation. They were assessed with Keen Society Score (KSS) before and three months after operation, with Visual Analogue Scale for pain (VAS) before, and three days and three months after operation. The time of first standing, the time of first straight-leg raising more than 30°, and the active range of motion (AROM) of knee before, and one, two and three days, and one and three months after operation were recorded, as well as where to go after discharge. ResultsA total of 96 patients in MA group and 98 in KA group finished the research. The AROM of knee improved more in the KA group than in the MA group after operation (Fgroup = 8.816, P = 0.017), and the incidence going to the rehabilitation institutes was less (χ2 = 6.542, P = 0.011). ConclusionKA may promote the rapid recovery of AROM of knee for patients after TKA, and reduce the needs of institute-based rehabilitation after discharge, to save medical costs.

Quantitative Study on Kinematics of Ankle Rotating-Traction-Poking Manipulation for Treating Acute Lateral Ankle Sprain / 医用生物力学

Objective To quantify operation characteristics of the ankle rotating-traction-poking manipulation (RTPM) for treating acute lateral ankle sprain by using motion capture technology, so as to provide objective references for standardized operation of RTPM and its education inheritance. Methods A professional physiotherapist performed the RTPM on 60 volunteers with acute lateral ankle sprain. Motion capture system was used to acquire effective kinematic data during the RTPM, so as to make analysis and summarize rules. Results The average time of ankle rotating for six circles was 11.36 s and the average time of ankle traction and poking was 3.42 s. The average displacement of ankle traction was 36.94 mm and the average displacement of ankle poking was 22.44 mm. The average angle of ankle traction was 23.27°, and the average angle of ankle poking was 22.76°. During the RTPM for treating acute lateral ankle sprain, the average linear velocity of ankle rotating was 58.28 mm/s, and the average linear velocity of ankle traction and poking was 23.81 mm/s. The linear acceleration of ankle rotating was 0.43 mm/s2, and the linear acceleration of ankle traction and poking was 0.54 mm/s2. Conclusions The RTPM can be applied in clinical practice. During the RTMP, the principle of gentleness, rhythmicity and continuity should be followed. Under the premise of following physiological characteristics of ankle joint, treatment of the sprained ankle should be carried out with slow and uniform speed continuously.

Demandas físicas de jugadores profesionales costarricenses de fútbol: Influencia de la posición de juego y nivel competitivo / Physical Demands of Costa Rican Professional Soccer Players: Influence of the Playing Position and the Competitive Level

Resumen La monitorización de las demandas físicas durante partidos de fútbol con tecnologías GPS proporciona información valiosa que puede ser utilizada para potenciar el rendimiento deportivo. Por tanto, el objetivo de este estudio fue conocer las demandas físicas de jugadores profesionales costarricenses de fútbol, así como analizar la influencia de la posición de juego y el nivel competitivo durante partidos. Sesenta futbolistas masculinos, 50 de la primera división del fútbol costarricense y 10 de una selección nacional absoluta de CONCACAF (SAC), fueron monitoreados con un Sistema de Posicionamiento Global (GPS) para cuantificar variables cinemáticas como la distancia recorrida (m), total y a diferentes intensidades (Z 1-5), velocidad máxima (km/h), impactos totales (g), aceleraciones (m/s) y desaceleraciones (m/s). Las posiciones de juego se categorizaron en: defensas (Def), mediocampistas (Med) y delanteros (Del), y el nivel competitivo en: a) SAC, b) Equipos de nivel élite (ENE) y c) Equipos de nivel sub-élite (ENS). Los resultados reflejaron diferencias significativas respecto al nivel competitivo en la distancia recorrida a diferentes intensidades Z1 (SAC >ENS >ENE), Z2 (ENE >SAC >ENS) y Z4 (ENE >SAC >ENS), aceleraciones (SAC >ENE >ENS) y en desaceleraciones (SAC >ENS >ENE). Por posiciones de juego, las diferencias estuvieron en la distancia total (Med >Def >Del), en la distancia recorrida en Z2 (Med >Def >Del) y Z3 (Med >Def >Del), así como en impactos totales (Med >Def >Del). Se concluye que el nivel competitivo influye sobre las demandas físicas. SAC registró más aceleraciones y desaceleraciones y, ENE recorrió mayor distancia a esfuerzos moderados e intensos. Existen diferencias en las posiciones de juego, los mediocampistas recorrieron mayores distancias y registraron más impactos.

Abstract Monitoring physical demands during soccer matches with GPS technologies provides valuable information that can be used to enhance sports performance. Therefore, this study aimed to know Costa Rican professional soccer players' physical demands and analyze the influence of the playing position and the competitive level during matches. Sixty male soccer players, 50 from the first division of Costa Rican soccer and 10 from an absolute national CONCACAF (SAC) team were monitored with a Global Positioning System (GPS) to quantify kinematic variables such as distance traveled (m), total and different intensities (Z 1-5), maximum speed (km/h), total impacts (g), accelerations (m / s) and decelerations (m/s). The game positions were categorized into defenses (Def), midfielders (Mid) and forward (For), and the competitive level in a) SAC, b) Elite level teams (ENE), and c) Sub-elite level teams (ENS). The results reflected significant differences regarding the competitive level in the distance traveled at different intensities Z1 (SAC >ENS >ENE), Z2 (ENE >SAC >ENS) and Z4 (ENE >SAC >ENS), in accelerations (SAC >ENE >ENS), and in decelerations (SAC >ENS >ENE). By game positions, the differences were in the total distance (Mid >Def >For), in the distance traveled in Z2 (Mid >Def >For) and Z3 (Mid >Def >For), as well as in total impacts (Mid >Def >For). It is concluded that the competitive level influences the physical demands. SAC registered more accelerations and decelerations, and ENE traveled a greater distance with moderate and intense efforts. There were differences between playing positions; midfielder traveled longer distances and recorded more impacts.

Resumo O monitoramento das demandas físicas durante partidas de futebol com tecnologias GPS fornece informações valiosas que podem ser usadas para aprimorar o desempenho atlético. Portanto, o objetivo deste estudo foi conhecer as demandas físicas dos jogadores de futebol profissional da Costa Rica, bem como analisar a influência da posição de jogo e do nível competitivo durante os jogos. Sessenta jogadores de futebol masculino, 50 da primeira divisão do futebol costarriquenho e 10 da seleção nacional absoluta da CONCACAF (SAC), foram monitorados com um Sistema de Posicionamento Global (GPS) para quantificar variáveis cinemáticas como distância percorrida (m), total já diferentes intensidades (Z 1-5), velocidade máxima (km / h), impactos totais (g), acelerações (m / s) e desacelerações (m / s). As posições de jogo foram categorizadas em: defensores (Def), meio-campistas (Med) e atacantes (Del), e o nível competitivo em: a) SAC, b) Times de elite (ENE) e c) times de nível pré-elite (ENS). Os resultados refletiram diferenças significativas em relação ao nível competitivo na distância percorrida em diferentes intensidades Z1 (SAC> ENS> ENE), Z2 (ENE> SAC> ENS) e Z4 (ENE> SAC> ENS), acelerações (SAC> ENE> ENS) e em desacelerações (SAC> ENS> ENE). Por posições de jogo, as diferenças foram na distância total (Med> Def> Del), na distância percorrida em Z2 (Med> Def> Del) e Z3 (Med> Def> Del), bem como nos impactos totais (Med > Def> Del). Conclui-se que o nível competitivo influencia as demandas físicas. O SAC registrou mais acelerações e desacelerações, e a ENE percorreu uma distância maior com esforços moderados e intensos. Existem diferenças nas posições de jogo, os meio-campistas percorreram distâncias maiores e registraram mais impactos.

Análisis cinemático de la masticación de una granola prototipo en contraste con la masticación de maní / Kinematic analysis of chewing by using a granola prototype and peanut

La masticación se ha estudiado desde diferentes puntos de vista, utilizando alimentos de prueba naturales y artificiales. La evidencia es escasa cuando se analizan alimentos a base de cereales, que van desde cereales para el desayuno hasta barras de granola. El investigar este tipo de alimentos, se vuelve importante para entender el comportamiento de la masticación frente a alimentos con diferentes composiciones y texturas, y como estas características pueden influir en el proceso masticatorio. Se analizó la masticación desde un punto de vista cinemático, en sujetos jóvenes dentados. El alimento de prueba utilizado fue granola prototipo y maní, este último se ha estudiado en sujetos con rehabilitación protésica y su consumo se recomienda en esta población. Se analizaron las características cinemáticas de la masticación como numero de ciclos, frecuencia masticatoria, velocidad de masticación de ascenso y descenso, y el área de masticación en los tres planos del espacio. Se relacionaron los movimientos masticatorios con los movimientos mandibulares bordeantes que conformaron el polígono de Posselt, este también se analizó en los tres planos espaciales. En todas las variables analizadas la granola presento valores mayores, excepto en el número de ciclos masticatorios, sólo se encontraron diferencias estadísticamente significativas (p= 0,03) al comparar la velocidad (ascenso y descenso) y el área de masticación en el plano horizontal.

Chewing has been studied from different points of view, using natural and artificial foods test. When analyzing cereal-based foods, from breakfast cereals to granola bars, the evidence is scarce. Investigate this type of food is important to understand the behavior of chewing, with foods of different compositions and textures, and how these characteristics can influence the chewing process. Chewing was analyzed from a cinematic point of view, in young subjects complete dental. The test food used was prototype granola and peanuts, last one has been studied in subjects with prosthetic rehabilitation and its consumption is recommended in this population. The kinematic characteristics of chewing were analyzed: number of cycles, chewing frequency, ascent and descent chewing speed, and the chewing area in the three planes of space. The masticatory movements were related to the bordering mandibular movements, that formed the Posselt polygon, which was also analyzed in the three spatial planes. In all the variables analyzed, granola showed higher values, except in the number of chewing cycles, only statistically significant differences (p = 0.03) were found when comparing speed (ascent and descent) and the chewing area in the horizontal plane.

Power hop in agricultural tractors / O power hop em tratores agrícolas

ABSTRACT: The objective of this research was to develop concepts, possibilities of occurrence, and ways to solve the vibratory phenomenon of power hop, which is quite common in tractors with auxiliary front-wheel drive or all-wheel drive, in particular conditions of field work. First, the phenomenon is defined, and context is given for the practical situations in which the phenomenon can occur. Subsequently, actions are proposed to solve and minimize the problems arising from power hop. The subject of this study has been insufficiently analyzed in the literature, with mentions (some detailed) in scientific articles and theses developed to diagnose and propose ways to solve the problem. Equally, there has been almost no mention of the problem in agricultural tractor operation manuals, despite the frequent occurrence of the phenomenon.

RESUMO: O objetivo deste trabalho foi desenvolver conceitos, possibilidades de ocorrência e modos de solucionar o fenômeno vibratório do power hop, bastante frequente em tratores com tração dianteira auxiliar ou tração integral, em condições particulares de trabalho em campo. Em um primeiro momento, o trabalho preocupa-se em definir o fenômeno e contextualizar as situações em que ele pode produzir-se em situações práticas. Posteriormente, são propostas ações para solucionar e minimizar os problemas decorrentes do galope, como também é conhecido, em língua portuguesa e espanhola. A temática que envolve este estudo é analisada de forma insuficiente pela bibliografia, encontrando-se menções, algumas detalhadas, em artigos científicos e teses desenvolvidas com objetivo de diagnosticar e propor maneiras para solucionar o problema. Igualmente, é quase inexistente a menção do problema em manuais de operação de tratores agrícolas, em contradição com a frequente ocorrência do fenômeno.

Meta-analysis of total knee arthroplasty guided by kinematic alignment and mechanical alignment / 中国组织工程研究

BACKGROUND: Although mechanical alignment technique ensures the long-term survival rate of knee arthrosis, some patients are still not satisfied with the effect of total knee arthroplasty and the function of knee joint after operation. OBJECTIVE: Meta-analysis was used to evaluate the effect of kinematic alignment technique and mechanical alignment technique in the guidance of total knee arthroplasty. METHODS: The literature of clinical controlled study of kinematic alignment and mechanical alignment in the guidance of total knee arthroplasty published from the date of establishment to July 2019 was searched in Chinese Biomedical Literature Database, Wanfang data, CNKI, VIP data, PubMed, Cochrane Library, and Embase. The literature was screened, and evaluated; data were extracted. Review Manager 5.3 software was used for statistical analysis. RESULTS AND CONCLUSION: (1) A total of 945 cases were included in 12 articles, including 470 cases in kinematic alignment group and 475 cases in mechanical alignment group. (2) The results of meta-analysis showed that the operation time was shorter in the kinematic alignment group than in the mechanical alignment group [MD=-15.44, 95%C/(-27.16, -3.71)]. Western Ontario and McMaster University Osteoarthritis Index was better in the kinematic alignment group than in the mechanical alignment group [MD=-8.40, 95%C/(-15.39, -1.40)]. Oxford knee score was better in the kinematic alignment group than in the mechanical alignment group [M7=4.72, 95%C/(0.24, 9.21)]. Distal angle of mechanical lateral femur and proximal angle of mechanical medial tibia were significantly larger in the mechanical alignment group than in the kinematic alignment group (all P 0.05). (4) The function of knee joint after kinematic alignment for guiding total knee arthroplasty was better than that in mechanical alignment group. However, the imaging and perioperative results were similar, and the incidence of complications was not increased after operation. It is suggested that kinematic alignment may be a lower extremity force alignment method to guide total knee arthroplasty.

Effect of body mass index on the early-term hip functional recovery after total hip arthroplasty by three-dimensional gait analysis / 中国组织工程研究

BACKGROUND: The impact of obesity on total hip arthroplasty has been discussed. However, there is a lack of follow-up study on the patients with different body mass indexes using three-dimensional gait analysis. OBJECTIVE: To investigate the effect of body mass index on the early-term functional recovery after total hip arthroplasty by three-dimensional gait analysis. METHODS: Sixty patients who underwent total hip arthroplasty at Department of Joint Surgery of Affiliated Zhongshan Hospital of Dalian University from January 2017 to June 2018 were enrolled. According to the body mass index at admission, they were divided into overweight group (body mass index ≥ 25 kg/m2) and normal group (body mass index 0.05). The operation time in the overweight group was significantly longer than that in the normal group (P=0.000). (2) In terms of time-distance parameters, there was no significant difference in the stride length, stride frequency and mean velocity between two groups. The stride length in the overweight group was smaller than that in the normal group (1.08±0.18 vs. 1.35±1.45 m). (3) The range of motion of each planes of hip joint in the overweight group was significantly less than that in the normal group (P < 0.05). (4) In terms of kinetic parameters, the peak torque of hip flexion in the overweight group was significantly less than in the normal group (P=0.011). There was no significant difference in the peak torque of hip extension between two groups (P=1.000). (5) To conclude, obesity has certain effect on the early functional recovery after total hip arthroplasty.

Equivalent modeling and evaluation of molars using point-contact higher kinematic pair based on occlusal dynamic analysis / 生物医学工程学杂志

As a representative part of the oral system and masticatory robot system, the modeling method of the dental model is an important factor influencing the accuracy of the multi-body dynamic model. Taking the right first molars of the masticatory robot as the research object, an equivalent model, point-contact higher kinematic pair composed of v-shaped surface and sphere surface, was proposed. Firstly, the finite element method was used to analyze the occlusal dynamics of the original model in three static contact cases (intrusive contact, centric occlusion, and extrusive contact) and one dynamic chewing case, and the expected bite force was obtained. Secondly, the Hertz contact model was adopted to establish the analytical expression of the bite force of the equivalent model in three static contact cases. The normal vectors and contact stiffness in the expression were designed according to the expected bite force. Finally, the bite force performance of the equivalent model in three static contact cases and one dynamic chewing case was evaluated. The results showed that the equivalent model could achieve the equivalent bite force of 8 expected items in the static contact cases. Meanwhile, the bite force in the early and late stages of the dynamic chewing case coincides well with the original model. In the middle stage, a certain degree of impact is introduced, but it can be weakened by subsequent trajectory planning. The equivalent modeling scheme of the dental model proposed in this paper further improves the accuracy of the dynamic model of the multi-body system. It provides a new idea for the dynamic modeling of other complex human contacts.

Therapeutic effect on post-stroke spastic paralysis of upper extremity treated with combination of kinematic-acupuncture therapy and rehabilitation training / 中国针灸

OBJECTIVE@#To compare the clinical therapeutic effect on post-stroke spastic paralysis of the upper extremity between the combination of kinematic-acupuncture therapy and rehabilitation training and the combined treatment of the conventional acupuncture with rehabilitation training.@*METHODS@#A total of 60 patients of post-stroke spastic paralysis of the upper extremity at the non-acute stage were randomized into an observation group (30 cases) and a control group (30 cases, 1 case dropped off). On the base of the routine western medication and rehabilitation treatment, the kinematic-acupuncture therapy was added in the observation group and the conventional acupuncture was used in the control group. Baihui (GV 20), Dazhui (GV 14), Jiaji (EX-B 2) from T to T, Tianzong (SI 11), Jianzhen (SI 9), Jianyu (LI 15) and Quyuan (SI 13) were selected in both groups. The treatment was given once daily and the treatment for 14 days was as one course. The one course of treatment was required in this research. Separately, before treatment and in 7 and 14 days of treatment, the score of simplified Fugl-Meyer scale of the upper extremity (FMA-UE), the grade of the modified Ashworth scale (MAS) and the score of the modified Barthel index scale (MBI) were compared between the two groups.@*RESULTS@#Compared before treatment, in 7 and 14 days of treatment, FMA-UE score was increased obviously in either group (<0.01). In 14 days of treatment, FMA-UE score in the observation group was higher than that in the control group (<0.05). In 7 and 14 days of treatment, MAS grades of shoulder joint, elbow joint, wrist joint and metacarpophalangeal joint were all improved markedly in the two groups (<0.05). Compared with the grades in 7 days of treatment, MAS grades of elbow joint and metacarpophalangeal joint were improved markedly in 14 days of treatment in the two groups (<0.05). Compared with the control group, MAS grades of elbow joint and metacarpophalangeal joint were improved more markedly in the observation group in 14 days of treatment (<0.05). Compared with the score before treatment, MBI score was increased in 7 and 14 days of treatment respectively in the observation group (<0.05, <0.01). In 14 days of treatment, MBI score was increased in the control group (<0.01).@*CONCLUSION@#For the patients with post-stroke spastic paralysis of the upper extremity at the non-acute stage, the combined treatment with kinematic-acupuncture therapy and rehabilitation training obviously improves the motor function of the upper extremity and the muscle tone of elbow joint and metacarpophalangeal joint. The therapeutic effect of this combination is better than that of the combined treatment of the conventional acupuncture with rehabilitation training. Additionally, this combined therapy improves the ability of daily life activity.

Kinematically Aligned Total Knee Arthroplasty with Patient-Specific Instrument

Kinematically aligned total knee arthroplasty (TKA) is a new alignment technique. Kinematic alignment corrects arthritic deformity to the patient's constitutional alignment in order to position the femoral and tibial components, as well as to restore the knee's natural tibial-femoral articular surface, alignment, and natural laxity. Kinematic knee motion moves around a single flexion-extension axis of the distal femur, passing through the center of cylindrically shaped posterior femoral condyles. Since it can be difficult to locate cylindrical axis with conventional instrument, patient-specific instrument (PSI) is used to align the kinematic axes. PSI was recently introduced as a new technology with the goal of improving the accuracy of operative technique, avoiding practical issues related to the complexity of navigation and robotic system, such as the costs and higher number of personnel required. There are several limitations to implement the kinematically aligned TKA with the implant for mechanical alignment. Therefore, it is important to design an implant with the optimal shape for restoring natural knee kinematics that might improve patient-reported satisfaction and function.

Are cursorial birds good kinematic models of non-avian theropods? / ¿Son los pájaros corredores buenos modelos cinemáticos de terópodos no aviares?

Determining kinematics of hindlimbs of theropod dinosaurs has been a challenge. Since cursorial birds are phylogenetically closest to theropod dinosaurs they are commonly used as a kinematic model of theropod dinosaur locomotion. Using a comparative biomechanical approach, we found that cursorial birds have a different morphology of legs than non avian theropodos and that appears to be that felines and ungulates share more morphological properties in the hindlimbs with theropod dinosaurs than cursorial birds. We calculated the ratio between the lower leg and the femur, and the relative length of the tibia and the metatarsus with respect to the length of the femur in cursorial birds, as well as felines, ungulates and non-avian theropods. We found that as the length of the femur increases, the length of the lower leg increases similarly in felines, ungulates and non-avian theropods. On the other hand, existing and extinct cursorial birds did not follow this pattern. This observation suggests that the hindlimb of cursorial birds are not well suited to serve as kinematic models for hindlimb of extinct theropod dinosaur locomotion.

Determinar la cinemática de los miembros pelvianos de los dinosaurios terópodos ha sido un desafío. Dado que las aves corredoras son filogenéticamente más cercanas a los dinosaurios terópodos, son comúnmente utilizadas como modelo cinemático de la locomoción del dinosaurio terópodo. Usando un enfoque biomecánico comparativo, encontramos que las aves corredoras tienen una morfología de pies diferente a la de los terópodos no aviares y parece ser que los felinos y los ungulados comparten más propiedades morfológicas en los pies con los dinosaurios terópodos que las aves corredoras. Calculamos la proporción entre la parte inferior de la pierna y el fémur, y la longitud relativa de la tibia y el metatarso con respecto a la longitud del fémur en aves corredoras, así como en los terópodos no aviares y ungulados. Encontramos que a medida que aumenta la longitud del fémur, la longitud de la parte inferior de la pierna aumenta de manera similar en los terópodos, los ungulados y los terópodos no aviares. Por otro lado, las aves corredoras existentes y extintas no siguieron este patrón. Esta observación sugiere que el miembro pelviano de las aves corredoras no es adecuada para servir como modelos cinemáticos de locomoción del miembro pelviano del dinosaurio terópodo extinto.

Kinematic and electromyographic analysis of school children gait with and without load in the backpack

AbstractIntroduction: Excessive load on the backpacks can lead to musculoskeletal injuries and gait alterations. The objective of this study was to analyze the electromyographic (EMG) activity in association to the kinematic during the stance and balance phases of gait performed with and without the use of the backpack. Methods Twelve volunteers have executed a gait cycle in 3 tasks: without the school backpack (SM), with a backpack with load equivalent to 10% (M10) and 20% (M20) of the body weight (BW). It was evaluated the ankle, knee and hip angular excursion (AE), linear displacement (LD) of the toe and ankle, knee, hip, shoulder, head and EMG activity of the tibialis anterior (TA), vastus medialis (VM), rectus abdominis (RA), gastrocnemius lateral (GL), biceps femoris (BF) and spinal erector (EE) muscles. Results In the LD in the stance phase there was an AP increase for the toe and ankle, hip and head (p<0.043). In the balance phase for VT (vertical) direction, the shoulder presented a smaller displacement as well as the toe, ankle, knee, hip, shoulder and head in the ML direction. In the AP direction, the toe displacement was smaller as well as the ankle (p < 0.038). The AE in both phases was smaller for the hip (p <0.006). In the balance phase the IEMG was higher for the RA (p = 0.034). Conclusion These results suggest that the transport of school backpacks with loads of more than 10%BW causes changes in the kinematic and in the muscular recruitment pattern.

Normative Temporal Data of Hyolaryngeal Movements during Swallowing / 대한연하장애학회지

OBJECTIVE: This study evaluated the temporal variables of hyolaryngeal movements during normal swallowing using kinematic analysis of the video fluoroscopic swallowing study (VFSS) to present the normal cut-off values of those variables. METHODS: Seventy-five healthy volunteers (17 men, 58 women) without swallowing dysfunctions were recruited to examine the swallowing of 2-ml diluted barium by a VFSS. Kinematic analysis was conducted by digitization of video files for movements of hyolaryngeal structures, including the vocal cords, hyoid bone, and epiglottis during normal swallowing. The time points and duration of hyolaryngeal movements were measured. The time points were the start point, maximal point, and the end point of the LE (Laryngeal Elevation), HE (Hyoid Excursion), and EF (Epiglottic Folding). The durations of LE, HE, and EF were obtained by subtracting the time of the start point from the time of the maximal point. The onset time of LE was defined as the reference time point (0 sec). The upper and lower limits of the 95% confidence interval were adopted as the normal cut-off values for the temporal variables of hyolaryngeal movements after transformation to a normal distribution. If a transformation formula to a normal distribution was not found in a variable, the values of the 2.5–97.5 percentile were adopted. RESULTS: The cut-off values of the maximal and end points of the LE were 0.281 to 0.916 sec, and 0.830 to 2.205 sec, respectively. The cut-off values of the start, maximal and end points of the HE were −0.233 to 0.400 sec, 0.320 to 0.874 sec, and 0.889 to 2.055 sec, respectively. The cut-off values of the start, maximal, and end points of the EF were 0.017 to 0.483 sec, 0.364 to 1.055 sec, and 0.774 to 1.773 sec, respectively. The cut-off values of the duration of LE, HE, and EF were 0.281 to 0.916 sec, 0.258 to 0.767 sec, and 0.255 to 0.787 sec, respectively. CONCLUSION: This study presented the normal cut-off values of temporal variables of hyolaryngeal movements during normal swallowing. This study can serve as a basis for classifying and analyzing the patterns of patients with dysphagia.

Acute effect of uphill running: current scenario and future hypotheses / Efeito agudo da corrida ascendente: cenário atual e futuras hipóteses

Strategies for metabolic adjustments are often considered by athletes throughout a running event. Planning for such events during training does not always include variations from level training, even though up/downhill exertion should definitely be a part of such planning. The differentiation of training stimuli, under adverse conditions of intensity and inclination, can generate differentiated benefits. However, uphill running raises expectations of deleterious effects. The imposition of different slope gradients throughout running could generate increased metabolic demands for sports performance. Thus, the present study aimed to answer questions mainly about the acute effects of uphill running, its relationship with aerobic performance, allowing us to introduce new hypotheses for future studies in the area on the subject. Gaps still need to be filled concerning the relevance of uphill running, and its determinants. Many of the points presently under scrutiny only lead to speculative explanations; for logical reasons, more studies should focus on the prescription of training at different slopes. This is the point at which specific conditioning is required, because the regulation of the effort and the energy cost resulting from the imposition of uphill running during competitive races depends heavily on previous experiences. This review will cover recently published research on the subject.

RESUMO Estratégias para ajustes metabólicos são frequentemente consideradas por atletas ao longo de um evento de corrida. O planejamento de tais eventos durante o treinamento nem sempre inclui treinamento em planos inclinados, que deveriam compor esse planejamento. Adiferenciação dos estímulos de treinamento, em condições adversas de intensidade e inclinação, pode gerar benefíciosdiferenciados. No entanto, a corrida ascendente aumenta as expectativas de efeitos deletérios. Portanto, a imposição de diferentes gradientes de inclinação ao longo da corrida poderia gerar demandas metabólicas aumentadas paradesempenho esportivo. Assim, o presente estudo tevecomo objetivo responder questões principalmente sobre os efeitos agudos da corrida ascendente, sua relação com o desempenho aeróbio e a proposição de novas possíveis hipóteses para estudos futuros sobre o assunto. Muitaslacunas ainda precisam ser preenchidas sobre a relevância da corrida ascendente e seus determinantes. Muitas das questões apresentadas apenas levam a explicaçõesespeculativas; por razões lógicas, mais estudos devemse concentrar na prescrição de treinamento em face dediferentes porcentagens de inclinação. Este é o ponto em que o condicionamento específico é necessário, porquea regulação do esforço e do custo de energia resultanteda imposição de corrida ascendente durante corridascompetitivas depende fortemente das experiênciasanteriores.

Kinematic Characteristics of Gait for Children with Spastic Cerebral Palsy / 医用生物力学

Objective To analyze kinematic characteristics of children with spastic cerebral palsy during walking based on the method of gait analysis. Methods The gait of 14 children with spastic cerebral palsy and 16 healthy children, who were required to walk back and forth on level ground at normal speed, was tested using portable gait analyzer. The gait differences between diseased side and healthy side of lower limbs for children with spastic cerebral palsy, as well as the gait differences between children with spastic cerebral palsy children and healthy children were compared. Results For children with spastic cerebral palsy, single step time, swing time and toe-off time of diseased side were significantly longer than those of healthy side (P＜0.05), while step frequency, velocity and terminal stance were significantly shorter than those of healthy side (P＜0.05). Compared with healthy children, gait cycle time, single step time, stance time, swing time, percentage of stance phase, mid stance phase, pre-swing stage and toe-off time for diseased side of children with spastic cerebral palsy were significantly longer (P＜0.05). Stride, velocity, step frequency and terminal stance of the children with spastic cerebral palsy were significantly lower than those of healthy children (P＜0.05). Pulling acceleration for children with spastic cerebral palsy also decreased compared with healthy children (P=0.05). Conclusions The stability of children with spastic cerebral palsy decreased during walking, and their single step time, swing time, toe-off time and pulling acceleration might be considered as the sensitive indicators.

Coronal lower limb alignment in total knee arthroplasty / 中华外科杂志

Many factors contribute to a successful total knee arthroplasty, and postoperative coronal lower limb alignment has always been a focus of joint surgeons. Previous researches have suggested that neutral alignment can bring higher prosthesis survival rate and better knee function. However, the theory has been challenged in recent years.In this article, the author introduces the axis, alignment and osteotomy of total knee arthroplasty briefly and reviews the studies on the neutral alignment and kinematic alignment of recent years in order to provide some advice for the clinical operation.