Torso Motion Research Articles

Study of reverse planting techniques on rice as physical science learning materials

The spread of COVID-19 makes learning at every level of the education unit conducted from home online or distance learning. However, this is not an easy thing for teachers to do. Teachers are required to innovate in delivering materials so that students can easily understand and learn actively. Indonesia is an agricultural country where most of the population has a livelihood as farmers. As a form of contextual learning and alternative distance learning during the COVID-19 pandemic, teachers can take advantage of rice farming activities in Indonesia, known as rice Tandur (reverse planting), as physical science teaching materials. Therefore, this research aims to explore the concept of physical science contained in rice Tandur activities to be used for physical science learning. This research is descriptive research to describe the idea of physical science in rice planting activities. Data collection was conducted by documentation of rice planting activities as well as literature studies. After the documentation is collected, the analysis uses Kinovea software to find out the center of gravity (COG) and the corners formed by the limbs. Based on the results of analysis and literature studies, the concept of physics was obtained in the form of a third-class lever arm that can be used for science materials in high school classes. In addition, there is a center of gravity and torque concept in the torso's movement, which can be used as a material for learning physics in high school.

독립적 기능 제어를 이용한 몸통이 부착된 이족 로봇의 자연스럽고 유연한 평지 보행

We propose a method for generating natural and flexible limit cycles of a biped with a torso, and design controllers to stabilize both torso and leg movements simultaneously. The concept of passive dynamic walking enables us to produce natural gaits that follow free-falling trajectories during a passive swing phase. Flexible gaits are generated by changing energy levels, so we examine how wide the multiple limit cycles exist in terms of hip torque variations. Since input torques are applied to a joint that connects the torso and legs of a biped, we make use of anti-torques to separate generalized torques so that the torso controller and the leg controller function independently. The simulation results showed that our methods could generate and stabilize various walking gaits, including the natural movements of a torso. In this study, we have also discussed the effects of adding a torso compared to walkers without a torso and the relations between torso movements and walking properties.

Control of a virtual vehicle influences postural activity and motion sickness in pre-adolescent children.

Among adults, persons in control of a vehicle (i.e., drivers) are less likely to experience motion sickness compared to persons in the same vehicle who do not control it (i.e., passengers). This "driver-passenger effect" is well-known in adults, but has not been evaluated in children. Using a yoked-control design with seated pre-adolescent children, we exposed dyads to a driving video game. In each dyad, one child (the driver) drove the virtual vehicle. Their performance was recorded, and later shown to the other child (the passenger). Thus, visual motion stimuli were identical for the members of each dyad. During exposure to the video game, we monitored the quantitative kinematics of head and torso movements. Participants were instructed to discontinue participation immediately if they experienced any symptoms of motion sickness, however mild. Accordingly, the movements that we recorded preceded the onset of motion sickness. Results revealed that Passengers (73.08%) were more likely than Drivers (42.31%) to state that they were motion sick. Drivers tended to move more than passengers, and with a greater degree of multifractality. The magnitude of movement was greater among participants who later reported motion sickness than among those who did not. In addition, for the multifractality of movement a statistically significant interaction revealed that postural precursors of motion sickness differed qualitatively between Drivers and Passengers. Overall, the results reveal that control of a virtual vehicle reduces the risk of motion sickness among pre-adolescent children.

Interpersonal coordination in three-year-old children: Functions, morphology, and temporality

The temporal dimension of interpersonal macro- and micro-coordinations between young children and social partners, as well as its functions, has been well documented. However, the different morphologies that bodily micro-coordination can adopt during these interactions have received considerably less attention. This research studied the temporality and morphology of spontaneous child-adult micro-coordinations and their associated functions. For this purpose, three-year-old children (N = 35) were randomly assigned to storytelling sessions based on emotional or referential stories. Using motion capture technology, we traced rapid and spontaneous coordinations between torso movements, ranging from 0 to 1000 milliseconds. Results show that both mirror-like and anatomical coordinations spontaneously emerge in interactions between 3-year-old children and unfamiliar adults. Importantly, slightly delayed in time, mirror-like coordinations predominantly occur in emotional interactions, while zero-lag, anatomical coordinations occur in referential interactions. These results suggest that these morphologies might indeed inform different functions of coordination, as previously theorized in the literature. The evidence found could contribute to a better understanding of how interpersonal coordination shapes social interaction very early in development.

Localization of tones in a room by moving listeners

It is difficult to localize the source of a tone in a room because standing waves lead to complicated interaural differences that become uninterpretable localization cues. This paper tests the conjecture that localization improves if the listener can move to explore the complicated sound field over space and time. Listener head and torso movements were free and uninstructed. Experiments at low and high frequencies with eight human listeners in a relatively dry room indicated some modest improvement when listeners were allowed to move, especially at high frequencies. The experiments sought to understand listener dynamic localization strategies in detail. Head position and orientation were tracked electronically, and ear-canal signals were recorded throughout the 9 s of each moving localization trial. The availability of complete physical information enabled the testing of two model strategies: (1) relative null strategy, using instantaneous zeros of the listener-related source angle; and (2) inferred source strategy, using a continuum of apparent source locations implied by the listener's instantaneous forward direction and listener-related source angle. The predicted sources were given weights determined by the listener motion. Both models were statistically successful in coping with a great variety of listener motions and temporally evolving cues.

Quantification of Compensatory Torso Motion in Post-Stroke Patients Using Wearable Inertial Measurement Units

Occupational Therapy (OT) tasks performed at home are not usually observable by a clinician. For remote environments, wearable sensor technologies could provide quantitative assessment of movement strategies to support clinical evaluation via telemedicine. This work presents an algorithm for estimating torso orientation and an individualized metric of compensatory torso motion for upper extremity tasks using an Inertial Measurement Unit (IMU) worn on the sternum. Two post-stroke males with hemiparesis and two healthy age-matched males were evaluated during a series of OT assessments, including active range of motion, pinch strength, standing balance, Moberg pick-up test, Nine-hole peg test, and a custom peg board grasp task. Torso orientation was estimated by decomposing IMU orientation into angles (pitch, roll, yaw) in each anatomical plane (sagittal, coronal, transverse) and referenced against standing balance posture. For each participant, a threshold of nominal torso motion was created from the variance in orientation for tasks performed with the Dominant or Unaffected arm. A percentage of time out of range (PTOR) of nominal variation was developed to distinguish operationally relevant differences. In this study, large PTOR values (greater than 30%) were consistent with OT observations of notable compensatory movement. IMU sensitivity to sensor-to-torso alignment was also evaluated in simulation and demonstrated interactions between pitch and roll angles when an IMU misalignment existed about the yaw axis. These case studies support the use of wearable IMUs to quantitatively assess compensatory torso motions and convey operationally relevant information about movement strategy to a clinician without the use of visual observation.

Application of wearable inertial sensor in optimization of basketball player’s human motion tracking method

Basketball refers to a collective sport in which players put basketballs into the opponent’s net to score points under certain rules, and defend the opponent players so that they cannot get points. Basketball is a sport with the most competition rules, team tactics and sports skills in all ball sports, and is greatly affected by the players’ individual basketball skills. It also requires effective coordination and cooperation between the players. In a basketball game, the basketball skills of the main players have a greater impact on the entire team. If the basketball skills of the main players are average, it will reduce the overall strength of the team, which will increase the overall offensive and defensive capabilities of the team. Attenuation is not conducive to team performance, so it is more important to conduct scientific and reasonable individual basketball skills training for athletes. As far as basketball is concerned, the training plan for the players is mainly determined by the coaches based on personal observation and past experience. This method inevitably makes mistakes. This research is based on the recognition of the human torso movement posture, and the body torso posture of the basketball players is recognized and studied. The athlete’s torso sensor is installed to monitor the athlete’s physical state in real time, and the relevant basketball movement is divided. And the body posture detection and recognition method of athletes in basketball games. Real-time detection of human trunk motion status has always been the focus of research in the field of sports. However, domestic research on trunk posture detection of athletes is still rare. This research will add monitoring and analysis of various basketball sports complex movements in the follow-up.

Dynamic Torso Compliance Control for Standing and Walking Balance of Position-Controlled Humanoid Robots

The humanoid robot, one of the ideal unmanned systems, has the potential to perform tasks currently carried out by human workers in industry, manufacturing, service, and disaster response. In such complicated environments with unknown disturbances, compliance is important for a humanoid robot, especially a position-controlled one, to maintain balance while performing a task. This article presents a dynamic torso compliance method for position-controlled humanoid robots to adapt to unknown external disturbances while standing or walking. This method comprises two independent controllers. One controller, which is based on a linear inverted pendulum with a flywheel, is used to realize compliant behavior by controlling the torso postures according to the zero moment point. The other controller, which is based on a double inverted pendulum, is adopted to obtain the dynamic torso movements as well as maintain balance through a quadratic-programming-based controller. With the proposed method, controls for compliance and balance are decoupled, and a position-controlled robot can perform dynamic torso compliance and maintain balance while standing or walking. The performance of the proposed method is validated by simulations and experiments on a position-controlled humanoid robot (BHR-T).

Loss of peripheral vestibular input alters the statistics of head movement experienced during natural self-motion.

Sensory systems are adapted to the statistical structure of natural stimuli, thereby optimizing neural coding. Head motion during natural activities is first sensed and then processed by central vestibulo-motor pathways to influence subsequent behaviour, thereby establishing a feedback loop. To investigate the role of this vestibular feedback on the statistical structure of the head movements, we compared head movements in patients with unilateral vestibular loss and healthy controls. We show that the loss of vestibular feedback substantially alters the statistical structure of head motion for activities that require rapid online feedback control and predict this change by modelling the effects of increased movement variability. Our findings suggest that, following peripheral vestibular loss, changes in the reliability of the sensory input to central pathways impact the statistical structure of head motion during voluntary behaviours. It is widely believed that sensory systems are adapted to optimize neural coding of their natural stimuli. Recent evidence suggests that this is the case for the vestibular system, which senses head movement and contributes to essential functions ranging from the most automatic reflexes to voluntary motor control. During everyday behaviours, head motion is sensed by the vestibular system. In turn, this sensory feedback influences subsequent behaviour, raising the questions of whether and how real-time feedback provided by the vestibular system alters the statistical structure of head movements. We predicted that a reduction in vestibular feedback would alter head movement statistics, particularly for tasks reliant on rapid vestibular feedback. To test this proposal, we recorded six-dimensional head motion in patients with variable degrees of unilateral vestibular loss during standard balance and gait tasks, as well as dynamic self-paced activities. While distributions of linear accelerations and rotational velocities were comparable for patients and age-matched healthy controls, comparison of power spectra revealed significant differences during more dynamic and challenging activities. Specifically, consistent with our prediction, head movement power spectra were significantly altered in patients during two tasks that required rapid online vestibular feedback: active repetitive jumping and walking on foam. Using computational methods, we analysed concurrently measured torso motion and identified increases in head-torso movement variability. Taken together, our results demonstrate that vestibular loss significantly alters head movement statistics and further suggest that increased variability and impaired feedback to internal models required for accurate motor control contribute to the observed changes.

Effects of Torso Pitch Motion on Energy Efficiency of Biped Robot Walking

Gait pattern generation has an important influence on the walking quality of biped robots. In most gait pattern generation methods, it is usually assumed that the torso keeps vertical during walking. It is very intuitive and simple. However, it may not be the most efficient. In this paper, we propose a gait pattern with torso pitch motion (TPM) during walking. We also present a gait pattern with torso keeping vertical (TKV) to study the effects of TPM on energy efficiency of biped robots. We define the cyclic gait of a five-link biped robot with several gait parameters. The gait parameters are determined by optimization. The optimization criterion is chosen to minimize the energy consumption per unit distance of the biped robot. Under this criterion, the optimal gait performances of TPM and TKV are compared over different step lengths and different gait periods. It is observed that (1) TPM saves more than 12% energy on average compared with TKV, and the main factor of energy-saving in TPM is the reduction of energy consumption of the swing knee in the double support phase and (2) the overall trend of torso motion is leaning forward in double support phase and leaning backward in single support phase, and the amplitude of the torso pitch motion increases as gait period or step length increases.

Compensatory postural responses to backward loss of balance in patients with cerebellar disease

BackgroundImpaired control of balance and coordinated reactions are a primary deficit of cerebellar dysfunction. As compared to other neurological patients with balance impairments, there has been little research assessing the characteristics of compensatory responses associated with falls in patients with cerebellar disease (CD). Research questionThe aim of this study was to examine the effects of cerebellar disease on compensatory balance control in response to postural perturbation. Do CD patients increase the number of steps when responding to instability because of inappropriate initial step reactions or poor control of trunk motion or both? MethodsIn this explorative study, 10 patients suffering from degenerative cerebellar ataxia and 10 age-matched healthy controls were examined. The balance recovery reactions were assessed using a lean-and-release postural perturbation method. Spatiotemporal characteristics of stepping movement and COM variables associated with torso motion were analyzed using 3D motion capture system. ResultsCD patients took multiple steps whereas matched controls generally took single steps to recover balance following perturbation. The characteristics of the initial step at the time of the fall revealed that foot reaction time, foot response time, and step distance of the initial step were similar between CD patients and matched controls. However, CD patients exhibited a shorter foot-to−COM distance, higher COM velocity, and less trunk flexion with which to attenuate their body momentum after the landing of the first step than did matched controls. SignificanceAlthough initial step responses were probably adequate, poor control of torso motion appears to be a particular problem that causes multiple-step reactions in CD patients. This observation would help to guide the development of tailored fall intervention strategies in CD patients aimed at promoting their recovery capacity in response to a pronounced balance challenge.

Design of linear surfaces that restrict the range of permissible positions of links of the manipulator mechanisms in implementation of instantaneous states

Linear surfaces are used in various spheres of human activity. One of the most common techniques of designing linear surfaces is based on the three directing curves. In some cases, one of these directing curves is not set, but rather replaced by some geometric condition imposed on the emerging surfaces, which can in form of a certain point correspondence established between the points of the rest two directing curves. The article reviews the example of designing such surfaces, which in an approximate form would restrict the zone that sets the permissible positions of links of the manipulator mechanism of certain given configuration in realization of permissible instantaneous states. The acquired linear surfaces underlie the algorithm for calculation of configurations, which do not intersect the restricted zone in case of a deadlock situation. The result of this research is the computer simulation of the motions of arm and torso mechanism of the Android robot using the obtained algorithm for calculation of configurations. The simulation of motion demonstrates that the use of linear surfaces in analysis of the relative position of the manipulator and restricted zones in the deadlock situations allows reducing the calculation time by 50-60 percent. Such reduction of calculation time is highly demanded in computer control of the arm and torso motions of the Android robot on a real time scale.

Using Artificial Intelligence to Provide Visual Feedback for Golf Swing Training

Golf players spend hours perfecting their swing. It takes much practice and dedicated effort to train their body to make an effective swing. In order to train the body in such a way, golf players must be extremely mindful about the placement and motion of key body parts, such as wrists, elbows, shoulders, and torso. With correct placement and motion of key body parts, golf players can achieve great accuracy and consistency in their swings. In this research, we build on our previous work in evaluating the quality of a golf swing. Using a deep neural network, we are able to analyze a golf swing video, determine if it was an effective or ineffective swing, and provide feedback about the specific body parts that need improvement. This feedback can be used to improve player performance. Using this system consistently, a golf player can train their muscles and swinging technique.

A Live Speech-Driven Avatar-Mediated Three-Party Telepresence System: Design and Evaluation

AbstractIn this article, we present a live speech-driven, avatar-mediated, three-party telepresence system, through which three distant users, embodied as avatars in a shared 3D virtual world, can perform natural three-party telepresence that does not require tracking devices. Based on live speech input from three users, this system can real-time generate the corresponding conversational motions of all the avatars, including head motion, eye motion, lip movement, torso motion, and hand gesture. All motions are generated automatically at each user side based on live speech input, and a cloud server is utilized to transmit and synchronize motion and speech among different users. We conduct a formal user study to evaluate the usability and effectiveness of the system by comparing it with a well-known online virtual world, Second Life, and a widely-used online teleconferencing system, Skype. The user study results indicate our system can provide a measurably better telepresence user experience than the two widely-used methods.

Assessing the Ergonomic Benefits of a New Adjustable Forklift Backrest

A new forklift backrest has been developed by incorporating adjustability concepts into the design to facilitate comfort to a wide range of users. We have conducted a comparative study between the new and original backrests to assess the effectiveness of design features. Using the phenomenon of restlessness, discomfort of the user was associated with the amount of body movement, where we have used a motion- capture system and a force platform to quantify the individuals’ movement for a wide range of body sizes. Meanwhile, subjective comfort and design feedback were collected using a questionnaire. Our results showed a reduction in the mean torso movement and the maximum center of pressure change of location by 300 and 6 mm, respectively, for the new design. Taking advantage of adjustability feature, the new backrest design exhibited enhanced comfort for longer durations and reduced magnitude of discomfort for a wide range of participants’ body sizes.

The Behavioral Analysis of Dance Sports Judge's Visual Searching Strategies: Focusing on the Skating System

Objective: The purpose of this study was to investigate the differences between visual search, eye fixation positions, and eye fixation position on whole body regions while judging final matches of dance sports. Method: Ten experienced judges (male 6, female 4) and six dance sports couples belonging to the top Korean leagues in the Korea Dance sports Federation were participated. Wearable eye trackers were used for data collection. The independent t-test was conducted to examine the effects of gender, and the two-way ANOVA was conducted to examine the effects of judges'' gender, dance event, and ranking. Results: It was found that the movement of male contestants was preferred, and the gaze fixation was high for torso movements in the judges'' evaluations. Moreover, attention was focused on the upper body rather than the lower body; this was maintained for about seven seconds to evaluate each couple. Conclusion: This find was the relative comparison between the two couples was the determining factor in winning or losing.

Effect of Sacroiliac Joint Mobilization on Chronic Non-Spacific Low Lumbar Pain and Function in Women

Background. Research aim was to investigate the effect of sacroiliac joint mobilization on chronic non-specific lumbar pain and function in women.Methods. 1. VAS scale evaluation; 2. Measurement of lumbar range of motion; 3. Lumbar muscle stamina tests. Twenty women who felt chronic non-specific lumbar pain and havd sacroiliac joint disfunction were investigated in this research.Results. The results of the study showed that the pain decreased from 3.87 ± 0.41 to 1.86 ± 0.33 points in the study group, and from 3.4 ± 0.52 to 1.6 ± 0.28 points in the control group (p < 0.05). The mean value of the abdominal muscle endurance test in the study group increased by 21.2 ± 3.65 s, in the control group – by 19.6 ± 3.69 s (p < 0.05). The isometric means of the abdominal muscle endurance test increased by 21.7 ± 2.58 s in the study group – and by 18.1 ± 4.07 s in the control group (p < 0.05). After physiotherapy, a statistically significant improvement in torso movement amplitudes was observed in both groups, but no statistically significant change was observed between the groups.Conclusions. Spinal stabilization exercises combined with sacroiliac joint mobilization were more effective treatment than the use of stabilization exercises alone, as they statistically significantly reduced the intensity of perceived pain and increased torso muscle endurance.Keywords: sacroiliac joint mobilization, chronic non-specific lumbar pain, functional lumbar indicators.

Learn to Turn: Does Spotting Foster Skill Acquisition in Pirouettes?

ABSTRACT Purpose: The spotting technique (i.e., independent head from torso movement) has been revealed as the single feature that differentiates highly skilled from less-skilled dancers. In the current intervention study, the potential of a specific spotting training in novice dancers for learning double pirouettes was tested. Method: Novice dancers trained pirouettes in an experimental group and an active control group over a period of eight weeks by receiving either specific spotting instructions or technical instructions only. Pirouette performance was examined in a pretest, and a one-week-delayed retention test. In a further control test, effects of explicitly instructing how to perform the pirouettes (i.e., either with or without spotting) were investigated. Results: Different than expected, in the retention test, only few participants from the experimental group showed the spotting technique. Moreover, the spotting group did not perform better than the control group. Rather, the balance measure revealed that, while the control group improved over learning, the experimental group remained at the baseline values and showed a slight advantage for orientation only. In the control test, all groups showed inferior performance as compared to the retention test. Conclusion: In sum, the current findings show that—at least for beginners—the spotting technique is not suitable to be implemented in applied training settings. Moreover, in line with the expert performance approach, this study suggests to investigate the implementation of expert skills in applied training routines experimentally.

Booster cushion design effects on child occupant kinematics and loading assessed using the PIPER 6-year-old HBM and the Q10 ATD in frontal impacts

Objective Our objective was to study the effect on child occupant kinematics and loading by differences in booster cushion designs and attachment in a frontal impact. Methods Three different booster cushion designs were exposed to a frontal impact in vehicle rear seat interiors. The boosters were selected based on their difference in shape, stiffness, and guiding loop design. Tests were run varying the shoulder belt routing above or under the guiding loop, in addition to with or without attachment of the booster cushion to the vehicle ISOFIX anchorages. Eighteen simulations with the finite element PIPER 6-year-old human body model (HBM) were run investigating all combinations of parameters, in addition to 3 sled tests with a Q10 anthropomorphic test dummy (ATD). Results Across 2 different child sizes, using an HBM and an ATD, respectively, consistent sensitivity to the booster design differences were seen. Boosters providing similar initial static belt fit can result in different occupant responses during a crash, due to the design of the boosters and their dynamic performance. Compression of the booster cushion resulted in a delayed pelvis restraint, influencing the upper body kinematics. The guiding loop design as well as the belt routing above or under the guide also influenced the upper body kinematics and shoulder belt interaction. Conclusions Early pelvis coupling to initiate torso pitch, and thereby an upper torso motion controlled by the shoulder belt, is the preferred occupant protection for booster-seated children. A stable mid-shoulder belt position centered over the chest initially is a prerequisite. Additionally, it was seen that the design of the guiding loops helps provide favorable interaction with the torso during the crash. The option to allow the shoulder belt to be placed above and under the guiding loops will accommodate a larger span of child sizes and adapt to more vehicle seat belt geometries. This study provides evidence that the design of the booster cushion plays an important role in creating an early pelvis coupling, as well as supporting favorable torso–shoulder belt interaction.

Effect of core muscle exercises on subcutaneous fat percentage of Badminton players

Badminton involves jumping to reach a shuttle at the highest possible point when descending for a better stroke as in a smash and drop shot. Hence the body weight has to be lifted repeatedly against gravity, where the extra mass in the form of fat would be disadvantage. Moreover the fat tends to be localized in the trunk and lower body segments. Core stability is defined in athletic setting as the optimum production, which can transfer and control the force from the centre of the body to the limbs, through stabilization of the position and motion of torso. Core stability exercises are an essential fitness component of badminton players during smashing the shuttlecock through the game.The present study was conducted to assess the impact of core muscle exercises on subcutaneous fat percentage of badminton players. To achieve this purpose Twenty five badminton players were included in the study, whose age ranged from 17-21 years. During training ten core muscle exercises were performed with one minute each exercise and twenty seconds break in between the exercise. This is performed for three sets. This training is continued for 6 days in a week with one session per day for four weeks. The subcutaneous fat percentage at Arms, Trunk, Legs and Whole body was measured using the Omron HBF 375 Karada Scan before and after the training. The obtained pre and post test data were statistically analyzed using the ‘t’ test. Results shows that there is significant difference in the subcutaneous fat percentage at Arms, Trunk, Legs and Whole body of the badminton players.