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BackgroundSyngnathids are a highly derived and diverse fish clade comprising the pipefishes, pipe-horses, and seahorses. They are characterized by a plethora of iconic traits that increasingly capture the attention of biologists, including geneticists, ecologists, and developmental biologists. The current understanding of the origins of their derived body plan is, however, hampered by incomplete and limited descriptions of the early syngnathid ontogeny.ResultsWe provide a comprehensive description of the development of Nerophis ophidion, Syngnathus typhle, and Hippocampus erectus from early cleavage stages to release from the male brooding organ and beyond, including juvenile development. We comparatively describe skeletogenesis with a particular focus on dermal bony plates, the snout-like jaw morphology, and appendages.ConclusionsThis most comprehensive and detailed account of syngnathid development to date suggests that convergent phenotypes (e.g., reduction and loss of the caudal fins), likely arose by distinct ontogenetic means in pipefishes and seahorses. Comparison of the ontogenetic trajectories of S. typhle and H. erectus provides indications that characteristic features of the seahorse body plan result from developmental truncation. Altogether, this work provides a valuable resource and framework for future research to understand the evolution of the outlandish syngnathid morphology from a developmental perspective. published

Shear wave elastography (SWE) is a potential modality that quantitatively measures the elasticity (shear wave speed [SWS]) of musculoskeletal structure. This SWS was bilaterally measured in the rectus abdominis (RA), external oblique (EO) muscle, internal oblique (IO) muscle and transversus abdominis (TrA) using SWE in 28 patients with incisional hernia and 14 healthy controls. The differences in muscle thickness for IO and TrA were significant between the two groups (p < 0.05). The SWS of RA, EO, IO and TrA was significantly higher in the incisional hernia patient group than in the healthy controls (p < 0.05). Significant differences were also observed between the upper and lower points in both groups (p < 0.05). The measurements of SWS help in evaluating the elastic properties of abdominal wall muscles, which could further aid in preparing treatment plans to improve muscle strength.

Progressive training of horses focusses on the muscular development and flexibility to both the right and the left. However anecdotal evidence suggests that horses are not symmetrically structured through the thoracic region and this may have effects on saddle fitting and performance. The aim of this research was to determine if asymmetry exists in the thoracic musculoskeletal structure of ridden horses by analysing retrospective data of saddle fits (n=490) obtained from a saddle fitting company. A flexible wither tracer tool was used to obtain tracings of wither shape. Each tracing yielded four repeatable points (two on the left; two on the right) measured from the midline at the highest and lowest points of the withers. Descriptive assessments of shoulder, wither, and back shape, and demographic information on both horse and rider were recorded. A Wilcoxon signed-rank test compared the means of the wither shape measurements. A GLIMMIX procedure identified relationships between the wither measurements, descriptive assessments, and horse and rider demographics. The means of measurements from the wither tracer tool showed almost 60% of horses having larger measurements on the left side (P0.05). Rider age, gender, height, weight and level of training did not affect wither measurements (P>0.05). These results show that horses are asymmetric in their thoracic structure with a majority of horses larger on their left side than the right. This asymmetry may be due to genetics, environment or training and should be considered when fitting a saddle to the horse.

Running is one of the ‘low-cost’ popular activities for both competition and leisure. High occurrence of running injuries are observed due to repetitive loading on the lower extremities musculoskeletal structure. Although the association between shoes cushioning with running biomechanics have been established, the detailed relationships are yet to be identified due to limited instrumentation setup in exploring such association. This study compares the mechanical aging of shoe cushioning via developed instrumentation system versus the hydraulic testing machine. Preliminary comparisons between the latter were explored in this study.

Research has shown that women with large and hypertrophic breast sizes report an increased prevalence and severity of musculoskeletal pain in the upper torso. Despite this evidence, factors contributing to the development of musculoskeletal pain among these women are poorly understood, and the threshold at which breast size becomes problematic in terms of musculoskeletal pain is currently unknown.Three hundred Australian women (aged 18 to 82 years) who volunteered as participants were divided into four breast size groups (small, breast volume350 ml; medium, breast volume 350 to 700 ml; large, breast volume 701 to 1200 ml; and hypertrophic, breast volume1200 ml). The thoracic flexion torque, thoracic kyphosis angle, total upper torso musculoskeletal pain score, and regional upper torso musculoskeletal pain scores derived for participants in the four groups were compared using an analysis of covariance design, controlling for age and body mass index.Thoracic flexion torque significantly increased as breast size group increased. Women with hypertrophic breasts reported significantly higher total upper torso musculoskeletal pain scores compared with women who had small, medium, and large breasts, and this was significant for the upper back, shoulders, neck, and breasts. No significant difference was found in thoracic kyphosis angle among the four groups.Musculoskeletal pain became most pronounced in women with hypertrophic breasts who had the greatest breast volume and displayed the greatest thoracic flexion torque. Clinical and/or surgical treatment for symptomatic relief should aim to either counteract thoracic flexion torque or reduce breast volume.Risk, I.

Push-rim wheelchair propulsion is biomechanically inefficient and physiologically stressful to the musculoskeletal structure of human body. This study focuses to obtain a new, optimized propulsion shape for wheelchair users, which is within the ergonomic ranges of joint motion, thus reducing the probability of injuries. To identify the propulsion movement, forward dynamic optimization was performed on a 3D human musculoskeletal model linked to a handle based propulsion mechanism, having shape and muscle excitations as optimization variables. The optimization resulted in a handle path shape with a circularity ratio of 0.95, and produced a net propulsion power of 34.7 watts for an isokinetic propulsion cycle at 50 rpm. Compared to push-rim propulsion, the compact design of the new propulsion mechanism along with the ergonomically optimized propulsion shape may help to reduce the risk of injuries and thus improve the quality of life for wheelchair users.

Inspired by the human upper extremity, a musculoskeletal dual-arm manipulator is designed for light machining tasks such as hammering and sawing. We claim that musculoskeletal structure has the advantage over conventional robot structures in terms of less internal impulsive forces while performing these machining tasks. We investigated the advantages (in terms of external and internal impulses) of a musculoskeletal dual-arm model over a dual-arm model without muscles, musculoskeletal single arm model, and single arm model without muscles. Moreover, to model the hardness of the material during these tasks, an effective mass model was newly developed and experimentally verified for two different (soft and hard) materials. In order to validate the proposed methodology, a belted ellipsoid denoting the external and internal impulse geometry is employed to analyze the sawing and hammering tasks. Finally, it was found by performing a hammering task that the musculoskeletal dual-arm model is more effective in terms of generating more external impulse while experiencing less internal impulses at the joints.

Background Women with large breasts frequently experience upper torso pain secondary to their breast size. Evidence is lacking on the underlying causes of this pain. This study investigated whether upper torso pain and musculoskeletal structure and function differed between women with large breasts and women with small breasts. Methods A linear regression, adjusting for body mass, compared the upper torso pain, thoracic flexion torque due to breast mass, thoracic kyphosis, shoulder active range-of-motion, and scapular retraction muscle strength of 27 women with large breasts (bilateral breast volume > 1200 ml, age 45.9 y SD 9.9 y, BMI 29.0 kg/m2 SD 3.8 kg/m2) and 26 women with small breasts (bilateral breast volume Findings Women with large breasts reported a higher upper torso pain score (46.6, 95%CI 33.3–58.0 versus 24.1, 95%CI 12.5–37.8), accompanied by a larger flexion torque (5.9 Nm, 95%CI 4.5–5.8 Nm versus 0.9 Nm, 95%CI 0.8–2.4 Nm), greater thoracic kyphosis (34°, 95%CI 31–38° versus 27°, 95% CI 24–31°), decreased shoulder elevation range-of-motion (160°, 95%CI 158–163° versus 169°, 95%CI 166–172°), and decreased scapular retraction endurance-strength (511.4 s, 95%CI 362.2–691.3 s versus 875.8 s, 95%CI 691.5–1028.4 s) compared to the women with small breasts. Interpretation Differences in the upper torso posture, range-of-motion, and muscle strength of women with large breasts provides insight into underlying causes of their musculoskeletal pain. This information can be used to develop evidence-based assessment and treatment strategies to relieve and prevent symptom progression.

Background: In subcontinental underground mines, coal mining is carried out manually and requires many laborers to practice traditional means of coal excavation. Each task of this occupation disturbs workers&rsquo, musculoskeletal order. In order to propose and practice possible ergonomic interventions, it is necessary to know what tasks (drilling and blasting, coal cutting, dumping, transporting, timbering and supporting, loading and unloading) cause disorder in either upper limbs, lower limbs, or both. Methods: To this end, R-programming, version R 3.1.2 and SPSS, software 20, were used to calculate data obtained by studying 260 workers (working at different tasks of coal mining) from 20 mines of four districts of Punjab, Pakistan. In addition, a Standard Nordic Musculoskeletal Questionnaire (SNMQ) and Rapid Upper Limb Assessment (RULA) sheet were used to collect data and to analyze postures respectively. Results: In multi regression models, significance of the five tasks for upper and lower limb disorder is 0.00, which means that task based prevalence of upper and lower limb disorders are common in underground coal mines. The results of the multiple bar chart showed that 96 coal cutters got upper limb disorders and 82 got lower limb disorders. The task of timbering and supporting was shown to be dangerous for the lower limbs and relatively less dangerous for the upper limbs, with 25 workers reporting pain in their lower limbs, and 19 workers reporting pain in their upper limbs. Documented on the RULA sheet, all tasks got the maximum possible score (7), meaning that each of these tasks pose a threat to the posture of 100% of workers. The majority of participants (182) fell in the age group of 26 to 35 years. Of those workers, 131 reported pain in the lower limbs and slight discomfort (128) in the upper limbs. The significance value of age was 0.00 for upper limb disorder and was 0.012 for lower limb disorder. Frequency graphs show age in direct proportion to severity of pain while in inverse proportion with number of repetitions performed per min. Conclusions: All findings infer that each task of underground coal mining inflicts different levels of disorder in a workers&rsquo, musculoskeletal structure of the upper and lower limbs. It highlighted the need for urgent intervention in postural aspects of each task.

The musculoskeletal humanoid can move well under environmental contact thanks to its body softness. However, there are few studies that actively make use of the environment to rest its flexible musculoskeletal body. Also, its complex musculoskeletal structure is difficult to modelize and high internal muscle tension sometimes occurs. To solve these problems, we develop a muscle relaxation control which can minimize the muscle tension by actively using the environment and inhibit useless internal muscle tension. We apply this control to some basic movements, the motion of resting the arms on the desk, and handle operation, and verify its effectiveness.

Genetic abnormalities, especially polydactyly, are quite common among birds. Although there are numerous accounts of anatomically abnormal birds with polydactyly, few written anatomical descriptions have elucidated whether or not these physical aberrations extend to the musculoskeletal structure of the feet. Here, we present the findings of a dissection of a 14-week old female bald eagle that exhibited polydactyly and numerous other aberrations and discuss the functional impact these aberrations would cause. The specimen displayed a myriad of feather anomalies including missing feathers (i.e., had never grown in), ingrown feathers, stress bars, and most strikingly, bifurcated feathers wherein two feathers were seen to grow out of one rachis. Further, an extra, anomalous tendon was observed stemming from the tendinous origin of the m. extensor carpi radialis. The carpometacarpi were unable to reach full extension, stopping at less than 140º, and had phalanges bent downward at 45º. This mobility is limited in comparison to that of a normal bird. Most notably, the specimen exhibited polydactyly with one extra hallux on each foot. Several tendons of the left foot were seen to have aberrant connections as well.

Stroke is becoming a widely concerned social problem, and robot-assisted devices have made considerable contributions in the training and treatment of rehabilitation. Due to the compliance and continuous deformation capacity, rehabilitation devices driven by soft actuators are attached to widespread attention. Considering the large output force of pneumatic artificial muscle (PAM) and the biological musculoskeletal structure, an antagonistic PAM-driven rehabilitation robotic device is developed. To fulfill the need for control of the proposed device, a knowledge-guided data-driven modeling approach is used and an adaptive feedforward–feedback control approach is presented to ensure the motion accuracy under large deformation motion with high frequency. Finally, several simulations and experiments are carried out to evaluate the performance of the developed system, and the results show that the developed system with the proposed controller can achieve expected control performance under various operations.

This letter presents the advantages of human-like closed-chain architecture through the analytical computation of internal impulses experienced at joints and external impulses felt at the end point of the human-like manipulator during interaction with environment. The proposed human-like architecture consists of multiple closed-chains which are corresponding to mono- and biarticular muscles of the human-body. Especially, we investigate the contribution of mass and effect of change of mass of mono- and biarticular muscle models on external and internal impulses. The roles of mass of monoarticular and biarticular muscle models on internal and external impulses are analyzed in terms of new impulse measures. As an illustrative example, a 2-DOF manipulator resembling the musculoskeletal structure of the human upper extremity is introduced to examine the external and internal impulses, based on the proposed analytical tools. And it is discovered through simulation and experiment work that by increasing the mass of muscle models the external impulse is increased and internal impulses are decreased. Furthermore, it is observed that biarticular muscle models contribute more in external impulse and monoarticular muscle models absorbed more internal impulses than biarticular muscle models.

As it is responsible for a wide range of fine motor operations, the musculoskeletal structure of the hand is highly intricate and involves a host of minuscule bones, joints, and tendons working in concert to coordinate movement with great dexterity. Additionally, these operations also require the assistance of numerous vascular, nervous, and supportive tissues all located in a confined compartment. Therefore, the close proximity and abundance of these structures predisposes towards a host of hand conditions that can alter physical structures and generate pain to collectively hinder motor movement. These conditions often involve arthropathies, tendinopathies, and nerve entrapments. The appropriate diagnosis and management is instrumental in helping restore hand function.

Proximal femoral morphology and associated musculature are of special relevance to the understanding of hominoid locomotor systems. Knowledge of bone-muscle correspondence in extant hominoids forms an important comparative basis for inferring structure-function relationships in fossil hominids. However, there is still a lack of consensus on the correspondence between muscle attachment sites and surface morphology of the proximal femoral diaphysis in chimpanzees. Two alternative observations have been proposed regarding the attachment site positions of gluteus maximus (GM) and vastus lateralis (VL) relative to two prominent surface features of the proximal femoral diaphysis, the lateral spiral pilaster and the inferolateral fossa. Here, we use a combination of virtual and physical dissection in an attempt to identify the exact correspondence between muscle attachment sites and osteological features in two specimens of Pan troglodytes verus. The results show that the insertion of the GM tendon is consistently inferolateral to the lateral spiral pilaster, and that a part of the inferolateral fossa consistently forms the attachment site of the VL muscular fibers. While overall musculoskeletal features are similar in the two specimens examined in this study, GM and VL exhibit different degrees of segregation at the level of the inferolateral fossa. One specimen exhibited tendinous GM fibers penetrating the posteromedial part of VL, with both GM and VL inserting at the inferolateral fossa. In the other specimen, GM and VL were separated by a lateral intermuscular septum, which inserted into the inferolateral fossa. Variation of proximal femoral muscle attachments in chimpanzees is thus greater than previously thought. Our results indicate that a conspicuous osteological feature such as the inferolateral fossa does not necessarily correspond to the attachment site of a single muscle, but could serve as a boundary region between two muscles. Caution is thus warranted when interpreting the surface topography of muscle attachment sites and inferring locomotor functions.

The unique musculoskeletal structure of the human hand brings in wider dexterous capabilities to grasp and manipulate a repertoire of objects than the non-human primates. It has been widely accepted that the orientation and the position of the thumb plays an important role in this characteristic behavior. There have been numerous attempts to develop anthropomorphic robotic hands with varying levels of success. Nevertheless, manipulation ability in those hands is to be ameliorated even though they can grasp objects successfully. An appropriate model of the thumb is important to manipulate the objects against the fingers and to maintain the stability. Modeling these complex interactions about the mechanical axes of the joints and how to incorporate these joints in robotic thumbs is a challenging task. This article presents a review of the biomechanics of the human thumb and the robotic thumb designs to identify opportunities for future anthropomorphic robotic hands.

Obesity is becoming a widely prevalent issue worldwide. The excessive loading placed on the foot due to obesity can cause damage to the soft tissue and musculoskeletal structure which leads to foot discomfort and the development of foot pathologies. Experimental and computational methods of analysis were combined in this study to analyse the effects of obesity on the foot. It has been shown previously that foot pathology often starts subcutaneously and spreads towards the foot plantar. Hence the effect of obesity on the biomechanical behaviour of the foot was studied through an internal study of the bone structure using the modelling technique of finite element analysis. A 3-D anatomically correct model of a foot was created using density segmentation techniques reconstructed from Magnetic Resonance (MR) images. A non-linear finite element analysis of the reconstructed foot during balanced standing was conducted. The biomechanical differences were further classified through an external study of the foot using a gait measuring system. The finite element model of the obese foot suggests greater peak contact pressure. Experimental results suggest reduced joint angles and adjustments in the gait pattern. Preliminary results show that some differences in the biomechanical behaviour of the obese and non-obese feet are present where obese subjects compensate for the greater loading through changes in their gait.

We have been developing a human mimetic musculoskeletal humanoid called Kenshiro, whose design concept is to thoroughly pursue an unprecedented anatomical fidelity to the human musculoskeletal structure. We believe that research on human mimetic musculoskeletal humanoids advances our understanding of humans and expands the applications of humanoids-such as a human body simulator that can quantitatively analyze internal human motion data. This paper describes Kenshiro's musculoskeletal body characteristics, software system, and preliminary experiments explaining the concept of potential application.

Ultrasonography has many important advantages over other imaging modalities and many important applications in sports medicine. This article presents an evidence-based discussion of the use of ultrasound technology to diagnose and treat common musculoskeletal disorders, with emphasis on the shoulder, elbow, hip, knee, and foot and ankle. Topics include basic principles, scan artifacts, the appearance of musculoskeletal structure characteristics and pathologies, and various diagnostic and therapeutic applications in sports medicine.

Carriage of school items by children remains an issue of concern, mainly due to the large loads they have to bear, starting from early age when the musculoskeletal structure is still under development. As such, children are potentially exposed to important risks of acute or chronic injuries due to such carriage. While backpack remains the most common modality, in recent years trolley bags are increasingly considered and used. Trolleys may be of benefit, as much of the load can supported by the ground, and the muscular effort is limited to a pulling force. Nevertheless, there are situations (like stair ascent and descent, steps, and ramps) where the pulling force increases or, in some cases, has to be fully supported by a single arm. Under such conditions, the use of trolley bag might be disadvantageous versus a backpack, in that the latter allows a symmetrical distribution of the load on the body in a range of conditions. To provide more empirical evidence, which at present is very limited, this study aimed to characterize the pulling forces needed when using a school trolley bag, on a route that includes level and inclined ground surface, steps, and stairs. A sample of 195 students of primary school (age 8-11) participated, and they were asked to pull an instrumented trolley loaded with school items (total load = 62 N) from the school entrance to a classroom located one floor up in the school building. The results, expressed in terms of “pulling force vs. time” curves, show that particularly during stairs ascent and descent, one arm may exert quite large dynamic forces, and that these forces can be up to twice the mass of the carried load. Although exposure to such loads is quite limited, the methodology described here highlights the potential for concern and provides a basis for future investigations of the contribution of trolley bag carriage and disorders of the arm-shoulder complex among children.

cope The effects of a long-term high fat and sucrose diet (HFS) superimposed with aging on bone and muscle structure and/or function. Methods and results Male C57BL/6J mice (20 weeks of age) were randomized to 1 of 3 groups: baseline (BSL, n = 12), or assigned to a control (AGE, n = 12) or HFS (HFS-AGE, n = 11) diet for 13 weeks. Trabecular bone structure, volumetric bone mineral density (vBMD), and body composition, were measured longitudinally at 20, 24, and 32 weeks of age. In vitro contractile measures were performed on isolated soleus and extensor digitorum longus (EDL) muscles for each group. Both AGE and HFS-AGE had similar declines in trabecular bone structure, while HFS+AGE resulted in increased soleus cross-sectional area (CSA) compared to AGE, but this did not translate to greater twitch or tetanic peak force. The ratio of outcomes of bone to muscle declined in both AGE and HFS-AGE compared to BSL as a result of greater declines in trabecular bone structure than muscle function. Conclusion Consumption of a 13-week HFS diet at 20 weeks of age did not exacerbate age-related declines in bone or muscle, but these tissues do not decline in a coordinate manner with greater declines in bone than muscle. This article is protected by copyright. All rights reserved

Although magnetic resonance imaging (MRI) has been increasingly used as a diagnostic tool for cervical spine injuries in canines, a comprehensive normal MRI anatomy of the canine cervical spine muscles is lacking. Therefore, the purpose of this study was to build a magnetic resonance imaging atlas of the normal cross sectional anatomy of the muscles of the canine cervical spine. MRI scans were performed on a canine cadaver using a combination of T1 and T2-weighted images in the transverse, sagittal and dorsal planes acquired at a slice thickness of 1 mm. Muscle contours were traced manually in each slice, using local osseous structures as reference points for muscle identification. Twenty-two muscles were traced in 401 slices in the cervical region. A three dimensional surface model of all the contoured muscles was created to illustrate the complex geometrical arrangement of canine neck muscles. The cross-sectional area of the muscles was measured at the mid-level of each vertebra. The accuracy of the location of the mapped muscles was verified by comparing the sagittal view of the 3D model of muscles with still photographs obtained from anatomic canine cadaver dissection. We believe that this information will provide a unique and valuable resource for veterinary researchers, clinicians and surgeons who wish to evaluate MRI images of the cervical spine. It will also serve as the foundation for ongoing work to develop a computational model of the canine cervical spine in which anatomical information is combined with electromyographic, kinematic and kinetic data.

The musculoskeletal structure of the chest wall serves to protect the thoracic and mediastinal viscera, while providing integrity for respiration. The complex relationship of all anatomic components contributes to its function but also makes it susceptible to a wide variety of pathology. Thus, tumors of the chest wall represent a diagnostic and therapeutic challenge. Chest wall masses have a broad differential diagnosis including local extension of intrathoracic lesions, presentations of systemic diseases or inflammatory processes, metastasis, and less frequently, primary tumors of the chest wall, which can be benign or malignant. More than 50 % are malignant and are most commonly a result of direct invasion or metastasis from adjacent thoracic tumors [1]. Overall, primary chest wall tumors make up less than 5 % of thoracic malignancies and vary widely in pathology, as they arise from all anatomic structures comprising the chest wall [2, 3]. This chapter reviews the pathology, options for diagnosis, and standard treatment of the various lesions arising from the chest wall.

Purpose: To examine the effects of the world's most challenging mountain ultramarathon (MUM, 330 km, cumulative elevation gain of +24,000 m) on the energy cost and kinematics of different uphill gaits. Methods: Before (PRE) and immediately after (POST) the competition, 19 male athletes performed three submaximal 5-min treadmill exercise trials in a randomized order: walking at 5 km.h-1, +20%; running at 6 km.h-1, +15%; and running at 8 km.h-1, +10%. During the three trials, energy cost was assessed using an indirect calorimetry system and spatiotemporal gait parameters were acquired with a floor-level high-density photoelectric cells system. Results: The average time of the study participants to complete the MUM was 129 h 43 min 48 s (range: 107 h 29 min 24 s to 144 h 21 min 0 s). Energy costs in walking (-11.5 +/- 5.5%, P < 0.001), as well as in the first (-7.2 +/- 3.1%, P = 0.01) and second (-7.0 +/- 3.9%, P = 0.02) running condition decreased between PRE and POST, with a reduction both in the heart rate (-11.3, -10.0, and -9.3%, respectively) and oxygen uptake only for the walking condition (-6.5%). No consistent and significant changes in the kinematics variables were detected (P-values from 0.10 to 0.96). Conclusion: Though fatigued after completing the MUM, the subjects were still able to maintain their uphill locomotion patterns noted at PRE. The decrease (improvement) in the energy costs was likely due to the prolonged and repetitive walking/running, reflecting a generic improvement in the mechanical efficiency of locomotion after ~130 h of uphill locomotion rather than constraints imposed by the activity on the musculoskeletal structure and function.

SUMMARY Technological advances are often inspired by nature, considering that engineering is frequently faced by the same challenges as organisms in nature. One such interesting challenge is creating a structure that is at the same time stiff in a certain direction, yet flexible in another. The seahorse tail combines both radial stiffness and bending flexibility in a particularly elegant way: even though the tail is covered in a protective armour, it still shows sufficient flexibility to fully function as a prehensile organ. We therefore study the complex mechanics and dynamics of the musculoskeletal system of the seahorse tail from an engineering point of view. The seahorse tail derives its combination of flexibility and resilience from a chain of articulating skeletal segments. A versatile dynamic model of those segments was constructed, on the basis of automatic recognition of joint positions and muscle attachments. Both muscle structures that are thought to be responsible for ventral and ventral–lateral tail bending, namely the median ventral muscles and the hypaxial myomere muscles, were included in the model. Simulations on the model consist mainly of dynamic multi-body simulations. The results show that the sequential structure of uniformly shaped bony segments can remain flexible because of gliding joints that connect the corners of the segments. Radial stiffness on the other hand is obtained through the support that the central vertebra provides to the tail plating. Such insights could help in designing biomedical instruments that specifically require both high bending flexibility and radial stiffness (e.g. flexible stents and steerable catheters).Copyright © 2012 John Wiley & Sons, Ltd.

THE MOST KNOWN METHODS FOR STRENGTH TRAINING REVOLVE AROUND MUSCLE HYPERTROPHY, WHICH CAN EFFECTIVELY INCREASE MUSCLE MASS. IN THEORY, A METHOD FOCUSING ON ANATOMICAL ADAPTATION MAY BUILD A STRONG MUSCULOSKELETAL STRUCTURE BY STRENGTHENING CONNECTIVE TISSUES AND MUSCLES REQUIRED FOR SUPPORTING, BALANCING, AND STABILIZING THE BODY. STRENGTH TRAINING THROUGH THE USE OF HEAVY LOADS INCREASES THE NUMBER OF MOTOR UNITS RECRUITED. EXPLOSIVE MOVEMENTS MAY FAMILIARIZE THE NEUROMUSCULAR SYSTEM AND ENHANCE THE EFFICIENCY OF THE ACTIVATION FREQUENCY. THIS ARTICLE WILL EXPLORE VARIOUS TRAINING METHODS IN THEORY TO MAXIMIZE ATHLETIC PERFORMANCE.

In this study, a musculoskeletal robot is used as a tool to investigate how animals control their complex body. Sprinting is a challenging task that requires maximizing the potential resources of a musculoskeletal structure. Our approach to robotic sprinting is the Athlete Robot — a musculoskeletal robot with elastic blade feet controlled by feedforward motor command. We use a catapult launcher to provide a stable start to a sprint, and then examine the relation between the initial velocity imparted by the launcher and the change in orientation of the robot. We also investigate the influence of the change in elasticity of the blade foot. The results show that acceleration causes anterior inclination after the first step. The elasticity of the foot dominates the duration of the support phase. The musculoskeletal system of the Athlete Robot is modified to suit catapulted running. Based on the results from real robot experiments, we can provide a consistent propelling force using the catapult launcher. We de...

This paper proposes a new design of a robotic foot with an oblique mid-foot joint for stable bipedal walking. While a lot of humanoid robots are developed so far, their walking is not as adaptive as that of humans. For realizing such adaptive walking, it is supposed that musculoskeletal structure plays a great roll. Especially, the human's foot is so much different from the robot foot, and is supposed to contributing to walking adaptability. In this report, we discuss on an oblique axis of mid-foot joint, one of such complexities of the human foot. This joint is the most flexible joint in the human foot and is supposed to be contributing to walking stability. We design a robotic foot with the mid-foot joint and put it on a muscular-skeletal humanoid robot. Experimental results of the robot demonstrate that the mid-foot joint stabilize its bipedal walking.

The human body possesses a musculoskeletal structure in which muscles exist around the bones and joints. The musculoskeletal tendon-driven robot utilizes this structure. This robotic system uses sets of mechanical tendons, such as wire-cables and actuators instead of the vital muscles. The redundant actuation is necessary for the system when it does not actively use any external force nor a tensioner because the mechanical tendon can transmit only a tensile force. This structural characteristic enables feedforward motion-generation that does not need any sensory feedback. However, the convergent posture strongly depends on the tendon-arrangement. Targeting the tendon-driven manipulator, which has two links and six tendons, this paper expands the mathematical conditions for the convergence into the geometric conditions of tendon-arrangement. Based on the geometric conditions, a design method of the tendon-arrangement is discussed.

Humans can walk stably and adaptively in the presence of various environmental changes. Their bodies have very complex musculoskeletal structures that contribute to their walking stability and adaptability. In this paper, we focus on the gluteus medius, one of muscles contributing to the support of the pelvis. The gluteus medius supports the pelvis when the leg is in a standing position, but it should not inhibit its smooth swing motion. This mechanism is assumed to be realized by the musculoskeletal structure. This paper is devoted to explaining the mechanism by reproducing it using artificial pneumatic muscles. We developed a musculoskeletal robot with a gluteus medius, and showed that the mechanism is well-designed for realizing two seemingly contradictory functions: being stiff to support the pelvis while standing and being smooth to allow swinging. This finding can be utilized for adaptive walking of musculoskeletal humanoid robots.

We investigated the release angle that maximizes the distance attained in a long soccer throw-in. One male soccer player performed maximum-effort throws using release angles of between 10 and 60 degrees, and the throws were analyzed using two-dimensional videography. The player's optimum release angle was calculated by substituting mathematical expressions for the measured relationships between release speed, release height and release angle into the equations for the flight of a spherical projectile. We found that the musculoskeletal structure of the player's body had a strong influence on the optimum release angle. When using low release angles the player released the ball with a greater release speed and, because the range of a projectile is strongly dependent on the release speed, this bias toward low release angles reduced the optimum release angle to about 30 degrees. Calculations showed that the distance of a throw may be increased by a few metres by launching the ball with a fast backspin, but the ball must be launched at a slightly lower release angle.

Despite the greater prevalence of musculoskeletal disorders in obese adults, the consequences of childhood obesity on the development and function of the musculoskeletal system have received comparatively little attention within the literature. Of the limited number of studies performed to date, the majority have focused on the impact of childhood obesity on skeletal structure and alignment, and to a lesser extent its influence on clinical tests of motor performance including muscular strength, balance and locomotion. Although collectively these studies imply that the functional and structural limitations imposed by obesity may result in aberrant lower limb mechanics and the potential for musculoskeletal injury, empirical verification is currently lacking. The delineation of the effects of childhood obesity on musculoskeletal structure in terms of mass, adiposity, anthropometry, metabolic effects and physical inactivity, or their combination, has not been established. More specifically, there is a lack of research regarding the effect of childhood obesity on the properties of connective tissue structures, such as tendons and ligaments. Given the global increase in childhood obesity, there is a need to ascertain the consequences of persistent obesity on musculoskeletal structure and function. A better understanding of the implications of childhood obesity on the development and function of the musculoskeletal system would assist in the provision of more meaningful support in the prevention, treatment and management of the musculoskeletal consequences of the condition.

Overuse running injuries occur frequently, and generally could be said to occur as a result of a runner maintaining a stress/frequency combination which puts a vulnerable musculoskeletal structure within the injury portion of a stress-frequency relationship. Given a runner's specific anthropometric and biomechanical stride characteristics, the causes of all overuse running injuries could be classified as training errors, and thus, all overuse running injuries should be preventable. One of the goals of future research should be to focus on developing simple screening processes that may assist medical practitioners in identifying runners who are at a high risk for overuse injury.