Software AnyBody Research Articles

Research on the mechanism of elbow flexion based on AnyBody

In order to analyze the dynamic characteristics of the upper limbs including the musculoskeletal system in elbow flexion, a human upper limb movement model including the musculoskeletal system was established based on the biomechanical analysis software AnyBody, and the overall model was subjected to inverse dynamics simulation and muscle force analysis to obtain the human body Muscle strength and muscle activity of upper limb muscle groups during elbow flexion exercise. Taking the human biceps as an example for analysis, the muscle strength of the biceps during elbow flexion exercise was obtained. When the loaded load is within a reasonable range, the muscle force will change regularly with the increase and decrease of the load, indicating that the training effect of flexion exercise needs to control the loading load within a certain range, which provides scientific theoretical support for upper limb muscle rehabilitation training.

Guidance for quadriceps rehabilitation based on AnyBody

This paper aims to perform an objective quantitative analysis on quadriceps rehabilitation, and investigate the muscle status in cross-over design under rehabilitation actions. Rehabilitation actions are modeled using the human body modeling software AnyBody, which can analyze the variations in the muscle activity and muscle force of the quadriceps femoris during thigh flexion. In addition, it can experimentally validate the effectiveness of the model in combination with electromyographic (EMG) signals of three quadriceps femoris muscles during different activities. According to the study results, the rehabilitation actions of the quadriceps femoris can be quantified by means of collecting EMG signals.

基于生物力学的驾驶舱坐姿舒适性评价

本文从生物力学角度对飞机驾驶舱坐姿舒适性的评价进行了研究。首先根据飞行员的生理数据进行人体建模，在生物力学仿真软件Anybody中建立“飞行员-座椅”耦合模型，选取肌肉活动、关节扭矩两个评价指标，分别改变座椅高度和椅背倾角，提取仿真数据进行插值处理后得到双变量三维曲面图，从而分析座椅高度和椅背倾角对飞行员主要肌肉活动和关节扭矩的影响。选取肌肉活动的均值、方差和差值平方和这三个参数对坐姿舒适性进行评价，为驾驶舱各设备的总体布局和座椅的几何参数设计提供指导。 In this paper, the sitting comfort evaluation of the cockpit is studied based on biomechanics. Firstly, we establish “pilot seat” model in the biomechanical simulation software Anybody according to the physiological data of pilot and choose two main indexes: the muscle activity and joint torque. We change the seat height and the back angle respectively and the simulation data are obtained after the treatment of double variable 3-D surface chart. We analyze the influence of seat height and back angle changes by the major muscle activity and joint torque of the pilot. The mean value, variance and the square of the muscle activity are selected to evaluate the sitting comfort, providing the guidance for the overall layout of the cockpit and the geometric parameters design for the seat.

Development of a biomechanical model of the wrist joint for patient-specific model guided surgical therapy planning: Part 1.

An enhanced musculoskeletal biomechanical model of the wrist joint is presented in this article. The developed computational model features the two forearm bones radius and ulna, the eight wrist bones, the five metacarpal bones, and a soft tissue apparatus. Validation of the model was based on information taken from the literature as well as own experimental passive in vitro motion analysis of eight cadaver specimens. The computational model is based on the multi-body simulation software AnyBody. A comprehensive ligamentous apparatus was implemented allowing the investigation of ligament function. The model can easily patient specific personalized on the basis of image information. The model enables simulation of individual wrist motion and predicts trends correctly in the case of changing kinematics. Therefore, patient-specific multi-body simulation models are potentially valuable tools for surgeons in pre- and intraoperative planning of implant placement and orientation.

A biomechanical model of the wrist joint for patient-specific model guided surgical therapy: Part 2.

An enhanced musculoskeletal biomechanical model of the wrist joint is presented in this article. The computational model is based on the multi-body simulation software AnyBody. Multi body dynamic musculoskeletal models capable of predicting muscle forces and joint contact pressures simultaneously would be valuable for studying clinical issues related to wrist joint degeneration and restoration. In this study, the simulation model of the wrist joint was used for investigating deeper the biomechanical function of the wrist joint. In representative physiological scenarios, the joint behavior and muscle forces were computed. Furthermore, the load transmission of the proximal wrist joint was investigated. The model was able to calculate the parameters of interest that are not easily obtainable experimentally, such as muscle forces and proximal wrist joint forces. In the case of muscle force investigation, the computational model was able to accurately predict the computational outcome for flexion and extension motion. In the case of force distribution of the proximal wrist joint, the model was able to predict accurately the computational outcome for an axial load of 140 N. The presented model and approach of using a multi-body simulation model are anticipated to have value as a predictive clinical tool including effect of injuries or anatomical variations and initial outcome of surgical procedures for patient-specific planning and custom implant design. Therefore, patient-specific multi-body simulation models are potentially valuable tools for surgeons in pre- and intraoperative planning of implant placement and orientation.

Musculoskeletal Modelling of Elite Handcycling Motion: Evaluation of Muscular On- and Offset

Handcycling, as a competitive sport, has been a Paralympic discipline since 2004 and is performed by handicapped athletes with impairments of the spine or brain. In this work a musculoskeletal model of a handcyclist is developed in the software AnyBody using kinematic data from a previous study of handcycling of one male elite handbiker (class: H3.2). The on- and offset timing of several muscles of the upper body (left and right of: m. pectoralis, m. deltoideus, m. biceps brachii and m. triceps brachii) were calculated with different thresholds and compared to results from surface electromyography (sEMG) measurements recorded during the previously mentioned subject study. It could be shown, that the mean overlap of muscle activation times was between a satisfying 64% and 75% depending on the threshold used. However, especially for m. deltoideus a very different on- offset behaviour was observed in the simulation than in the sEMG measurements resulting from the positioning of the electrodes in the subject study on one specific branch of the m. deltoideus and insufficient knowledge about the actual course of the crank torque for this specific athlete. Thus given sufficient accuracy of input parameters - musculoskeletal modelling could be used to predict changes in muscle activity timing for different handcycle setups.

Development and Validation of a Portable Human Body Joint Power Test System

A portable human body joint power test system was developed using inertial sensor technology and wireless Bluetooth acquisition technology. A detailed description of the internal structure of the system and the data processing method involved is provided. The test system uses the cubic spline interpolation method, which is very convenient for obtaining the maximum peak points of muscle isotonic contraction joint power curves under different loads. Moreover, the system is portable and can be deployed in the classroom and the playground for education and testing. The test system is very useful in many respects, such as athlete selection and daily strength training. We established a model of our subject using a balanced proportion scaling method in the inverse dynamics software AnyBody modeling system. The muscle model uses the Hill muscle model. The data import interface program was written in the parameterized model definition language AnyScript to import data. The raw data was smoothed with a Butterworth low-pass filter. Dumbbell curl simulation was conducted in AnyBody. The results of the simulation and those of the real test system were tested using the paired samples t-test method; the value of Sig was determined to be greater than 0.05, indicating no significant difference and that the data of the test system are valid.

Control of the boundary conditions of a dynamic knee simulator

At Ghent University a dynamic knee simulator to analyse the kinematics of a human knee has been developed. The rig is designed to perform tests on a mechanical hinge or on a human knee (with or without a prosthesis). The rig has one degree of freedom in a hip joint and four degrees of freedom in an ankle joint. There is currently one actuator that simulates the quadriceps forces. Two additional actuators are proposed in this paper to simulate the hamstrings forces. The magnitude and phase of the forces varies significantly during the movement (e.g. cycling or squatting). Literature indicates that the maximum muscle forces do not exceed 2000 N. An inverse dynamic analysis, using the musculoskeletal software AnyBody, is proposed to determine the evolution of these forces during the studied movements.

Loads in the hip joint during physically demanding occupational tasks: A motion analysis study

Epidemiologic studies of osteoarthritis of the hip indicate a possible connection between work related activities and the pathogenesis of the disease. This study investigated the hip joint contact forces for physically demanding occupational tasks (lifting, carrying, transferring of a weight (mass: 25kg, 40kg and 50kg); stair climbing without and with additional load of 25kg; ladder climbing) and compared these with everyday activities (level gait, sitting down and getting up). The hip joint contact force was calculated with the human multibody simulation software AnyBody employing motion capture and ground reaction force measurements by force plates and an instrumented staircase and ladder. Although the results for 11 male test subjects showed individual variations, a general trend could be observed in regards of force curves' characteristics and maxima. The largest joint contact forces calculated were (637±148)%-body weight for horizontal transfer of a 50kg weight. For several of the occupational activities the computed hip joint contact forces were significantly larger compared to the investigated examples of activities of daily living. This study provides original data of simulated hip joint contact forces for physically demanding activities.

Analysis of Musculoskeletal Loadings in Lower Limbs During Stilts Walking in Occupational Activity

Construction workers often use stilts to raise them to a higher level above ground to perform many tasks, such as taping and sanding on the ceiling or upper half of a wall. Some epidemiological studies indicated that the use of stilts may place workers at increased risk for knee injuries or may increase the likelihood of trips and falls. In the present study, we developed an inverse dynamic model of stilts walking to investigate the effects of this activity on the joint moments and musculoskeletal loadings in the lower limbs. The stilts-walk model was developed using the commercial musculoskeletal simulation software AnyBody (version 3.0, Anybody Technology, Aalborg, Denmark). Simulations were performed using data collected from tests of four subjects. All subjects walked without or with stilts through a 12-m straight path. The moments of the knee, hip, and ankle joints, as well as forces in major muscles or muscle groups in the lower limbs, for stilts walking were compared with those for normal walking. Our simulations showed that the use of stilts may potentially increase the peak joint moment in knee extension by approximately 20%; induce 15% reduction and slight reduction in the peak joint moments in ankle plantar flexion and hip extension, respectively. The model predictions on the muscle forces indicated that the use of stilts may potentially increase loadings in five of eight major muscle groups in the lower extremities. The most remarkable was the force in rectus femoris muscle, which was found to potentially increase by up to 1.79 times for the stilts walking compared to that for the normal walking. The proposed model would be useful for the engineers in their efforts to improve the stilts design to reduce musculoskeletal loadings and fall risk.

Modeling of the muscle/tendon excursions and moment arms in the thumb using the commercial software anybody

A biomechanical model of a thumb would be useful for exploring the mechanical loadings in the musculoskeletal system, which cannot be measured in vivo. The purpose of the current study is to develop a practical kinematic thumb model using the commercial software Anybody (Anybody Technology, Aalborg, Denmark), which includes real CT-scans of the bony sections and realistic tendon/muscle attachments on the bones. The thumb model consists of a trapezium, a metacarpal bone, a proximal and a distal phalanx. These four bony sections are linked via three joints, i.e., IP (interphalangeal), MP (metacarpophalangeal) and CMC (carpometacarpal) joints. Nine muscles were included in the proposed model. The theoretically calculated moment arms of the tendons are compared with the corresponding experimental data by Smutz et al. [1998. Mechanical advantage of the thumb muscles. J. Biomech. 31(6), 565–570]. The predicted muscle moment arms of the majority of the muscle/tendon units agree well with the experimental data in the entire range of motion. Close to the end of the motion range, the predicted moment arms of several muscles (i.e., ADPt and ADPo (transverse and oblique heads of the adductor pollicis, respectively) muscles for CMC abduction/adduction and ADPt and FPB (flexor pollicis brevis) muscle for MP extension/flexion) deviate from the experimental data. The predicted moment potentials for all muscles are consistent with the experimental data. The findings thus suggest that, in a biomechanical model of the thumb, the mechanical functions of muscle–tendon units with small physiological cross-sectional areas (PCSAs) can be well represented using single strings, while those with large PCSAs (flat-wide attachments, e.g., ADPt and ADPo) can be represented by the averaged excursions of two strings. Our results show that the tendons with large PCSAs can be well represented biomechanically using the proposed approach in the major range of motion.