Extracting proficiency differences and individual characteristics in golfers' swing using single-video markerless motion analysis.

In this study, we analyzed golfers' swing movement to extract differences in proficiency and individual characteristics using two-dimensional video data from a single camera. We conducted an experiment with 27 golfers who had a wide range of skill levels, using a 7-iron; we acquired video data with a camera on the sagittal plane. For data extraction, we used pose estimation (using HRNet) and object detection (using DeepLabCut) methods to extract human-joint and club-head data. We examined the relationship between proficiency and individual characteristics vis-à-vis forward tilt angle and club trajectory. The results showed that the stability and reproducibility of the forward tilt angle are characteristics of proficiency. Highly skilled golfers showed low variability and high reproducibility between trials in forward tilt angle. However, we found that club trajectory may not be a characteristic of proficiency but rather an individual characteristic. Club trajectory was divided roughly into clockwise rotation and counterclockwise rotation. Thus, the analysis based on video data from a single markerless camera enabled the extraction of the differences in proficiency and individual characteristics of golf swing. This suggests the usefulness of our system for simply evaluating golf swings and applying it to motor learning and coaching situations.

Structural equation modeling of female gait attractiveness using gait kinematics.

In our social lives, movement's attractiveness greatly affects interpersonal cognition, and gait kinematics mediates walkers' attractiveness. However, no model using gait kinematics has so far predicted gait attractiveness. Thus, this study constructed models of female gait attractiveness with gait kinematics and physique factors as explanatory variables for both barefoot and high-heel walking. First, using motion capture data from 17 women walking, including seven professional runway models, we created gait animations. We also calculated the following gait kinematics as candidate variables to explain walking's attractiveness: four body-silhouette-related variables and six health-related variables. Then, 60 observers evaluated each gait animation's attractiveness and femininity. We performed correlation analysis between these variables and evaluation scores to obtain explanatory variables. Structural equation modeling suggested two models for gait attractiveness, one composed of trunk and head silhouette factors and the other of physique, trunk silhouette, and health-related gait factors. The study's results deepened our understanding of mechanisms behind nonverbal interpersonal cognition through physical movement and brought us closer to realization of artificial generation of attractive gait motions.

Biomechanical strategies to maximize gait attractiveness among women.

Physical attractiveness is a key factor in social communication, and through this communication process, we attractively brand and express ourselves. Thus, this study investigated the biomechanical strategies used by women to express gait attractiveness. Our aim was to extend the current literature by examining this aspect of dynamic motion from the perspective of expressed, rather than perceived attractiveness. In this regard, we obtained motion capture data from 17 women, including seven professional fashion models. The participants walked on a treadmill under two conditions: 1) a normal condition in which they were instructed to walk as casually as possible; and 2) an attractive-conscious condition where they were asked to walk as attractively as possible. Then, we used whole-body kinematic data to represent motion energy at each joint, flexibility of the upper body, and the up-down/forward-backward silhouettes of the limbs, and compared these parameters between the two conditions by using statistical parametric mapping. During the attractive-conscious condition, the non-model women increased the energy of the hip and thoracolumbar joints, which emphasized the motions of their bosoms and buttocks. They also increased their upper body flexibility (possibly reflecting fertility) and continued to face front and downward. Conversely, although the fashion models partially shared the same strategy with the non-models (e.g., hip energy, upper body flexibility, and head bending downward), the strategy of the former was prominent in the stretching of the knee during the push-off phase and pulling the upper arm back, allowing them to showcase their youth and emphasize their chests. In addition, the fashion models used a wider variety of strategies to express their gait attractiveness. The findings indicate that the biomechanical strategy used to express gait attractiveness in women involves showcasing femininity, fertility, and youth. Our results not only deepen the understanding of human movement for self-expression through gait attractiveness, but they also help us comprehend self-branding behavior in human social life.

Muscle synergies of multidirectional postural control in astronauts on Earth after a long-term stay in space.

Movements of the human biological system have adapted to the physical environment under the 1-g gravitational force on Earth. However, the effects of microgravity in space on the underlying functional neuromuscular control behaviors remain poorly understood. Here, we aimed to elucidate the effects of prolonged exposure to a microgravity environment on the functional coordination of multiple muscle activities. The activities of 16 lower limb muscles of 5 astronauts who stayed in space for at least 3 mo were recorded while they maintained multidirectional postural control during bipedal standing. The coordinated activation patterns of groups of muscles, i.e., muscle synergies, were estimated from the muscle activation datasets using a factorization algorithm. The experiments were repeated a total of five times for each astronaut, once before and four times after spaceflight. The compositions of muscle synergies were altered, with a constant number of synergies, after long-term exposure to microgravity, and the extent of the changes was correlated with the increased velocity of postural sway. Furthermore, the muscle synergies extracted 3 mo after the return were similar in their activation profile but not in their muscle composition compared with those extracted in the preflight condition. These results suggest that the modularity in the neuromuscular system became reorganized to adapt to the microgravity environment and then possibly reoptimized to the new sensorimotor environment after the astronauts were reexposed to a gravitational force. It is expected that muscle synergies can be used as physiological markers of the status of astronauts with gravity-dependent change.NEW & NOTEWORTHY The human neuromuscular system has adapted to the gravitational environment on Earth. Here, we demonstrated that prolonged exposure to a microgravity environment in space changes the functional coordination of multiple muscle activities regarding multidirectional standing postural control. Furthermore, the amount of change led to a greater regulatory balancing activity needed for postural control immediately after returning to Earth and differences in muscular coordination before space flight and 3 mo after the return to Earth.

Role of heel lifting in standing balance recovery: A simulation study.

Although lifting the heels has frequently been observed during balance recovery, the function of this movement has generally been overlooked. The present study aimed to investigate the functional role of heel lifting during regaining balance from a perturbed state. Computer simulation was employed to objectively examine the effect of allowing/constraining heel lifting on balance performance. The human model consisted of 3 rigid body segments connected by frictionless joints. Movements were driven by joint torques depending on current joint angle, angular velocity, and activation level. Starting from forward-inclined and static straight-body postures, the optimization goal was to recover balance effectively (so that ground projection of the mass center returned to the inside of the base of support) and efficiently by adjusting ankle and hip joint activation levels. Allowing/constraining heel lifting resulted in virtually identical movements when balance was mildly perturbed at the smallest lean angle (8°). At larger lean angles (8.5° and 9°), heel lifting assisted balance recovery more evidently with larger joint movements. Partial and altered timings of ankle/hip torque activation due to constraining heel lifting reduced linear and angular momentum generation for avoiding forward falling, and resulted in hindered balancing performance.

Intermittent muscle activity in the feedback loop of postural control system during natural quiet standing.

The origin of continual body oscillation during quiet standing is a neural-muscular-skeletal closed feedback loop system that includes insufficient joint stiffness and a time delay. Thus, muscle activity and joint oscillations are nonlinear during quiet standing, making it difficult to demonstrate the muscular-skeletal relationship experimentally. Here we experimentally revealed this relationship using intermittent control theory, in which non-actuation works to stabilize the skeletal system towards equilibrium. We found that leg muscles were activated/inactivated when the state point was located in the opposite/same direction as the direction of anatomical action, which was associated with joint torque actuating the body towards equilibrium. The derivative values of stability index defined in the phase space approximately 200 ms before muscle inactivation were also larger than those before activation for some muscles. These results indicate that bipedal standing might be achieved by monitoring the rate of change of stability/instability components and generating joint torque to stabilize the body. In conclusion, muscles are likely to activate in an event-driven manner during quiet standing and a possible metric for on/off switching is SI dot, and our methodology of EMG processing could allows us to extract such event-driven intermittent muscle activities.

Switching Adaptability in Human-Inspired Sidesteps: A Minimal Model.

Humans can adapt to abruptly changing situations by coordinating redundant components, even in bipedality. Conventional adaptability has been reproduced by various computational approaches, such as optimal control, neural oscillator, and reinforcement learning; however, the adaptability in bipedal locomotion necessary for biological and social activities, such as unpredicted direction change in chase-and-escape, is unknown due to the dynamically unstable multi-link closed-loop system. Here we propose a switching adaptation model for performing bipedal locomotion by improving autonomous distributed control, where autonomous actuators interact without central control and switch the roles for propulsion, balancing, and leg swing. Our switching mobility model achieved direction change at any time using only three actuators, although it showed higher motor costs than comparable models without direction change. Our method of evaluating such adaptation at any time should be utilized as a prerequisite for understanding universal motor control. The proposed algorithm may simply explain and predict the adaptation mechanism in human bipedality to coordinate the actuator functions within and between limbs.

Joint Coordination and Muscle Activities of Ballet Dancers During Tiptoe Standing.

We aimed to investigate joint coordination of lower limbs in dancers during tiptoe standing and the relationship between joint coordination and muscle coactivation. Seven female ballet dancers performed tiptoe standing with six leg positions (fi e classical dance positions and one modern dance position) for 10 s. The kinematic data of the metatarsophalangeal (MP), ankle, knee, and hip joints was collected, and surface electromyography (EMG) of over 13 lower limb muscles was conducted. Principal component analysis was performed to determine joint coordination. MP-ankle and ankle-knee had in-phase coordination, whereas knee-hip showed anti-phase coordination in the sagittal plane. In addition, most EMG-EMG coherence around the MP and ankle joints was significant up to 50 Hz when these two joints swayed with in-phase. This suggests that different joint coordination patterns are associated with neural processing related to different muscle coactivation patterns. In conclusion, ballet dancers showed in-phase coordination from the MP to knee joints, which was associated with muscle coactivation to a higher frequency domain (up to 50 Hz) in comparison with anti-phase coordination.

Effect of intermittent feedback control on robustness of human-like postural control system.

Humans have to acquire postural robustness to maintain stability against internal and external perturbations. Human standing has been recently modelled using an intermittent feedback control. However, the causality inside of the closed-loop postural control system associated with the neural control strategy is still unknown. Here, we examined the effect of intermittent feedback control on postural robustness and of changes in active/passive components on joint coordinative structure. We implemented computer simulation of a quadruple inverted pendulum that is mechanically close to human tiptoe standing. We simulated three pairs of joint viscoelasticity and three choices of neural control strategies for each joint: intermittent, continuous, or passive control. We examined postural robustness for each parameter set by analysing the region of active feedback gain. We found intermittent control at the hip joint was necessary for model stabilisation and model parameters affected the robustness of the pendulum. Joint sways of the pendulum model were partially smaller than or similar to those of experimental data. In conclusion, intermittent feedback control was necessary for the stabilisation of the quadruple inverted pendulum. Also, postural robustness of human-like multi-link standing would be achieved by both passive joint viscoelasticity and neural joint control strategies.

[Transient Femoral Nerve Palsy after Ilioinguinal-Iliohypogastric Nerve Block: Comparison of Ultrasound-guided and Landmark-based Techniques in Adult Inguinal Hernia Surgery].

BACKGROUND: Transient femoral nerve palsy (TFNP) is a well-known complication associated with ilioinguinal-iliohypogastric nerve block (IINB). We compared the incidence of TFNP after ultrasound-guided IINB and that after anatomical landmark-based IINB. METHODS: We reviewed medical records of adult patients (ASA-PS 1-3, Age 21-87) who had received inguinal hernia surgery under general anesthesia and LINB retrospectively. IINB was performed using 0.5% ropivacaine either by ultrasound-guidance (US group, n = 16) or by landmark-based technique (LM group, n =17). TFNP was defined as sensory loss in the anterior aspect of the thigh or weakness of quadriceps femoris muscle in the nerve-blocked side. RESULTS: The frequency of TFNP in US group (6%) was lower than that in LM group (41%) in the post-anesthesia care unit (P = 0.019). TFNP symptom was resolved completely on the morning after surgery. The incidence of severe-intermediate postoperative pain and analgesic requirement were not different between the two groups. CONCLUSIONS: This study revealed that ultrasound-guided technique is effective to lower the incidence of TFNP after IINB in adult inguinal hernia surgery.

Inter- and intra-lower limb joint coordination of non-expert classical ballet dancers during tiptoe standing.

The main objective of this study was to compare ballet dancers' and non-dancers' joint coordination during tiptoe standing. Nine female non-expert ballet dancers and nine female non-dancers were asked to perform heel-toe and tiptoe standing for approximately 30s, during which the center of pressure (COP) and kinematic data from the metatarsophalangeal, ankle, knee, and hip joints were measured. Principal component analysis was performed on the angular displacements to determine joint coordination. The weighting vectors suggested that dancers' ankle and knee joints fluctuated in-phase in the anteroposterior direction, whereas all combinations of adjacent joints had anti-phase coordination for non-dancers. In addition, there was a significant difference in the intra-joint coordination pattern between groups. In particular, dancers' metatarsophalangeal (MP) and ankle joints tended to sway to the left-front or right-rear. However, there were no differences between the groups in the path length or rectangular COP. These results suggest that dancers maintained quiet postures via a decrease in the mechanical degree of freedom and that postural expertise may not be determined from a traditional COP analysis, even during unstable tiptoe standing. This in-phase coordination, which has an arch-like configuration, could be characteristic of dancers' lithe legs.

The impact of remifentanil on incidence and severity of postoperative nausea and vomiting in a university hospital-based ambulatory surgery center: a retrospective observation study.

BACKGROUND: Ambulatory surgery, including short-stay surgery, has become a common choice in clinical practice. For the success of ambulatory surgery, perioperative care with safe and effective anesthesia and postoperative analgesia, which can reduce the occurrence of postoperative nausea and vomiting (PONV), is essential. The effect of remifentanil on the occurrence and severity of PONV has not been thoroughly examined, particularly, in an ambulatory surgery setting. Here, we investigate whether remifentanil influences the occurrence and severity of PONV in a university hospital-based ambulatory unit. METHODS: We retrospectively analyzed a total of 1,765 cases of patients who had undergone general anesthesia at our ambulatory surgery unit. Parameters, such as occurrence and severity of nausea, vomiting or retching, use of antiemetic drugs, amount of postoperative analgesic and patient satisfaction, were extracted from the records and analyzed between the groups that received and not received remifentanil. RESULTS: Within 565 patients of the RF group, 39 patients (6.6%) experienced nausea, 7 patients (1.2%) experienced vomiting or retching, and 10 patients (1.8%) were given antiemetic; in addition, the maximum VAS value for nausea was 12.1 mm. In 1,200 patients of the non RF group, 102 patients (8.5%) experienced nausea, 19 patients (1.6%) experienced vomiting or retching, and 34 patients (2.8%) were given antiemetic, and the maximum VAS value was 13.2 mm. There were no statistically significant differences between the two groups. CONCLUSIONS: Our results indicate that remifentanil did not increase the occurrence of PONV in patients within the ambulatory surgery unit.

Pu-erh tea hot-water extract activates Akt and induces insulin-independent glucose transport in rat skeletal muscle.

Skeletal muscle is a major organ that is important for whole-body glucose metabolism. We found that when isolated rat epitrochlearis muscle was incubated with a Pu-erh tea hot-water extract (PTE) for 30 min, the rate of 3-O-methyl-D-glucose (3MG) transport increased in the absence of insulin. This activation was associated with an increase in Ser(473) phosphorylation of Akt, a signaling intermediary leading to insulin-dependent glucose transport, but not Tyr(458) phosphorylation of phosphoinositide 3-kinase p85, an upstream molecule of Akt. PTE-stimulated 3MG transport was also not accompanied by Thr(172) phosphorylation of the catalytic α-subunit of 5'-AMP-activated protein kinase (AMPK). Gallic acid, a water-soluble ingredient in Pu-erh tea, stimulated Akt phosphorylation, but not AMPK phosphorylation. These results suggest that Pu-erh tea potentially promotes skeletal muscle glucose transport at least in part by activating Akt.

[Safety in general anesthesia for ambulatory electroconvulsive therapy].

BACKGROUND: Ambulatory electroconvulsive therapy (ECT) is prevailing nowadays because of its lower cost and less disruption of the patient's social activity. We evaluated the safety and recovery profiles of general anesthesia for acute-phase or continuation/maintenance ambulatory ECT. METHODS: Forty outpatients with a mean age of 56 years for the management of mental disorders were reviewed. A total of 762 bilateral ECT procedures were performed under general anesthesia using propofol/ thiopental/sevoflurane and suxamethonium. RESULTS: During anesthesia, hypertension and tachycardia occurred in 281 (37%) and 214 procedures (28%), respectively. During post-anesthesia care unit stay, the medication most used was oxygen in 161 procedures (21%), and confusion and headache occurred in 54 procedures (7%) and 39 procedures (5%), respectively. No patients required unplanned hospital admission. Mean stay time in the day surgery unit was 172 min. Two ECT treatments (0.3%) in 2 patients needed unplanned return to our hospital within 24 hr after ECT due to worsening of their psychiatric conditions. CONCLUSIONS: General anesthesia for ambulatory ECT with our protocol was proven to be safe without causing serious complications.

Large postural fluctuations but unchanged postural sway dynamics during tiptoe standing compared to quiet standing.

The purpose of this study was to detect the characteristics of center of pressure (COP) movement during tiptoe standing (TS) compared to quiet standing (QS). Eight healthy subjects were asked to perform QS and TS on a force platform. During standing, surface electromyograms (EMGs) were recorded from the soleus (SOL), flexor hallucis brevis (FHB), medial gastrocnemius (MG), lateral gastrocnemius (LG), and tibialis anterior (TA) muscles. The path length and rectangular area of the COP trajectory were significantly larger during TS than during QS. In contrast, irrespective of standing condition, the scaling coefficients in the short and long regions were above and below 0.5, respectively. The coherence spectrum between the COP and EMG from the SOL and FHB muscles was statistically significant during TS at frequencies up to 17 Hz, while that for the QS was only significant below 1 Hz. In conclusion, the control of COP movement during TS was similar to that during QS despite large COP fluctuations during TS. Our results suggest that unstable posture during TS is compensated for by the activities of the SOL and FHB muscles, which enhance postural control.

Takotsubo cardiomyopathy during ambulatory anesthesia for bladder hydrodistension therapy -A case report-.

Stress-induced cardiomyopathy, also referred to Takotsubo cardiomyopathy or apical ballooning syndrome presents in perioperative period. We demonstrated a case of Takotsubo cardiomyopathy recognized after general anesthesia for bladder hydrodistension therapy as ambulatory surgery, which we surmise was due to inadequate blockage of surgical stress and sympathetic discharge against noxious stimulus during ambulatory anesthesia.

Index finger position fluctuations reflect multi-muscle coordination.

We hypothesized that movement fluctuations in the index finger reflect the integrated result of the coordination of multiple muscles because index finger movements are determined by the cooperation of multiple muscles spanning the metacarpophalangeal (MCP) joint. To evaluate this hypothesis, the aim of the present study was to examine the fluctuations of the index finger in abduction-adduction and extension-flexion directions during a position-holding task using two laser displacement sensors. Eleven healthy men maintained their index finger position while supporting a load at 5% of the maximal voluntary contraction force. To maintain the position of the index finger, displacement of the index finger in the abduction-adduction and extension-flexion directions was measured from a distance with two laser displacement sensors that were positioned to the lateral side of and above the index finger. The index finger movements fluctuated around the target position in not only the abduction-adduction direction but also the extension-flexion direction. The path length of finger displacement and the standard deviation of finger acceleration were significantly greater in the extension-flexion direction than in the abduction-adduction direction. These results suggest that the index finger movements quantified by two laser displacement sensors reflect the coordination of multiple muscles spanning the MCP joint.

Pituitary apoplexy during general anesthesia in beach chair position for shoulder joint arthroplasty.

Pituitary apoplexy is a rare but potentially life-threatening clinical syndrome caused by the sudden enlargement of pituitary adenoma secondary to infarction and/or hemorrhage. It may be the first presentation of previously undiagnosed pituitary adenoma. Although various precipitating factors of pituitary apoplexy are indicated, the pathogenesis remains unknown. In this report, we describe for the first time a case of pituitary apoplexy developed explicitly during general anesthesia supplemented with interscalene brachial plexus block in beach chair or barbershop position for shoulder joint arthroplasty.

Solutions for retention of female cardiologists: from the survey of gender differences in the work and life of cardiologists.

BACKGROUND: To prevent a future shortage of cardiologists, it is important for female cardiologists to continue working. Gender differences in the professional and private lives of cardiologists, as well as the barriers to work for female cardiologists, were surveyed. METHODS AND RESULTS: In August 2007, a questionnaire was mailed to all 195 faculty members/fellows and 155 alumni of the Department of Cardiovascular Medicine at Nippon Medical School. More female cardiologists were dissatisfied with their job than male cardiologists (34% vs 17%, P<0.005). Women reported greater career limitation by family responsibilities and housework. Men and women both reported that long working hours was the most problematic issue, but significantly more women reported this than men (76% vs 94%, P<0.05). Female cardiologists were more concerned about occupational radiation exposure (88% vs 59%, P<0.01) and wanted opportunities for retraining after childcare leave (100% vs 76%, P<0.01). CONCLUSIONS: The following measures should be taken: (1)establishment of more family-friendly working conditions in hospitals, (2)provision of various work positions that allow more flexibility and predictability for women, (3)establishment of a retraining system, and (4)development of work and research opportunities that are attractive to women. The Japanese Circulation Society is expected to establish a retraining system at certified institutions.

Pharmacokinetics and hepatic extraction of metoprolol in rats with glycerol-induced acute renal failure.

The aim of the present study was to evaluate the effect of glycerol-induced acute renal failure (ARF) on the pharmacokinetics and hepatic extraction of metoprolol in rats. Experimental ARF in rats was induced by injections of 50% glycerol into the leg muscle (10 ml/kg). Pharmacokinetics and hepatic extraction of metoprolol was evaluated by means of intravenous, intra-intestinal, and intra-portal administration of the drug. The blood metoprolol concentration following intravenous infusion in ARF rats was similar to that in control rats. On the other hand, the blood metoprolol concentration at 5--10 min after intra-intestinal administration in ARF rats was significantly higher than that in control rats, and the oral clearance (CL/F) of the drug was significantly decreased in ARF rats. Hepatic extraction following intra-portal infusion was not altered by glycerol-induced ARF; however, hepatic first-pass extraction of metoprolol was dose-dependent and saturable in both ARF and control rats. These results suggested that the decreased CL/F of metoprolol in rats with glycerol-induced ARF is mainly a result of the increased initial absorption rate in the intestine followed by partial saturation of hepatic first-pass metabolism.