Cardinal Movements Research Articles

Cardinal Movements

Cardinal Movements

Foetus-specific neuromusculoskeletal modelling with MRI-driven vaginal delivery kinematics during the second stage of labor

Childbirth simulations lack realism due to an oversimplification of the foetal model, particularly as most models do not allow joint motion. Foetus-specific neuromusculoskeletal (NMS) model with a detailed articulated skeleton is still not available in the literature. The present work aims at proposing the first-ever foetus-specific NMS model and then simulating the foetal descent during a vaginal delivery by using in vivo medical resonance imaging (MRI) childbirth data. Moreover, the developed model is provided open source for the community. Our foetus-specific NMS model was developed using the geometries reconstructed from a foetal computed tomography (CT) scan (Female, mass = 2.35 kg, length = 50 cm). The model contains 22 joints (64 degrees of freedom) and 65 muscles with a particular attention to the cervical spine level to enable the simulation of the cardinal movements. Then, the skull-to-cervical-spine (S/CP) and cervical-spine-to-torso (CP/T) deflection angles were extracted from in vivo MRI data for motion simulation. The S/CP and CP/T deflexion angles range from 12 degrees of flexion to 2 degrees of extension and from 7 degrees of flexion to 22 degrees of extension respectively. The developed model opens new avenues in more biofidelic childbirth simulations with a complete foetal NMS model. Obtained outcomes with the in vivo MRI data enabled to perform a first simulation of the foetal descent kinematics using real childbirth data. Future works will focus on developing a novel muscle formulation of the foetus and combining such a NMS model with a deformable model to simulate childbirth and associated complication scenarios.

On the uncertainty quantification of the active uterine contraction during the second stage of labor simulation.

Uterine contractions in the myometrium occur at multiple scales, spanning both organ and cellular levels. This complex biological process plays an essential role in the fetus delivery during the second stage of labor. Several finite element models of active uterine contractions have already been developed to simulate the descent of the fetus through the birth canal. However, the developed models suffer severe reliability issues due to the uncertain parameters. In this context, the present study aimed to perform the uncertainty quantification (UQ) of the active uterine contraction simulation to advance our understanding of pregnancy mechanisms with more reliable indicators. A uterus model with and without fetus was developed integrating a transversely isotropic Mooney-Rivlin material with two distinct fiber orientation architectures. Different contraction patterns with complex boundary conditions were designed and applied. A global sensitivity study was performed to select the most valuable parameters for the uncertainty quantification (UQ) process using a copula-based Monte Carlo method. As results, four critical material parameters ( ) of the active uterine contraction model were identified and used for the UQ process. The stress distribution on the uterus during the fetus descent, considering first and second fiber orientation families, ranged from 0.144 to 1.234MPa and 0.044 to 1.619MPa, respectively. The simulation outcomes revealed also the segment-specific contraction pattern of the uterus tissue. The present study quantified, for the first time, the effect of uncertain parameters of the complex constitutive model of the active uterine contraction on the fetus descent process. As perspectives, a full maternal pelvis model will be coupled with reinforcement learning to automatically identify the delivery mechanism behind the cardinal movements of the fetus during the active expulsion process.

A Communication Tool for Uterine Manipulation: Surgical View Standardization and Simulation Communication Training

<h3>Study Objective</h3> To demonstrate a communication tool and a corresponding training program for uterine manipulation during laparoscopic surgery. <h3>Design</h3> Descriptive demonstration of uterine manipulation training using a novel communication tool and simulator model <h3>Setting</h3> Two community-based surgical practices affiliated with academic medical centers. <h3>Patients or Participants</h3> Surgical technicians who serve as primary surgical assistants during laparoscopic hysterectomy. <h3>Interventions</h3> A communication tool was developed and previously presented in AUGS and AAGL. A new simulator model was developed as part of a new uterine manipulation training curriculum established for surgical technicians at our institutions. The training session includes a presentation highlighting critical pelvic anatomy and reviewing the cardinal movements of uterine manipulation. The presentation is followed by hands-on practice using the simulator model. Consent was obtained for all surgical footage utilized in this video explicitly for education purposes <h3>Measurements and Main Results</h3> Using surgical and simulator footage, the video demonstrates each component of the training program implemented at our institutions. The training program was well-received and will be converted to an on-line interactive module paired with simulator training. The simulator model was accepted to the ACOG Simulation Toolkit and is available for local use. <h3>Conclusion</h3> Communication between a surgeon and assistant can be challenging, especially for the novice assistant. Standardized methods for education, training, and communication with the vaginal assistant during laparoscopic hysterectomy are needed. Our strategy of developing a training program that includes a communication tool and simulation hands-on training was well-received and serves as an example for other programs to implement if helpful.

Childbirth Computational Models: Characteristics and Applications.

The biomechanical process of childbirth is necessary to usher in new lives-but it can also result in trauma. This physically intense process can put both the mother and the child at risk of injuries and complications that have life-long impact. Computational models, as a powerful tool to simulate and explore complex phenomena, have been used to improve our understanding of childbirth processes and related injuries since the 1990s. The goal of this paper is to review and summarize the breadth and current state of the computational models of childbirth in the literature-focusing on those that investigate the mechanical process and effects. We first summarize the state of critical characteristics that have been included in computational models of childbirth (i.e., maternal anatomy, fetal anatomy, cardinal movements, and maternal soft tissue mechanical behavior). We then delve into the findings of the past studies of birth processes and mechanical injuries in an effort to bridge the gap between the theoretical, numerical assessment and the empirical, clinical observations and practices. These findings are from applications of childbirth computational models in four areas: (1) the process of childbirth itself, (2) maternal injuries, (3) fetal injuries, and (4) protective measures employed by clinicians during delivery. Finally, we identify some of the challenges that computational models still face and suggest future directions through which more biofidelic simulations of childbirth might be achieved, with the goal that advancing models may provide more efficient and accurate, patient-specific assessment to support future clinical decision-making.

'S' means stop! Critical examination of capsular tension ring movements with Miyake-Apple video analysis.

To examine capsular tension ring (CTR) implantation to establish whether there are predictable movements of the CTR during deployment, indicating complicated vs uneventful implantation. Intermountain Ocular Research Center, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah. Experimental study. Nine cadaver eyes were prepared using standard Miyake-Apple protocol with digital video recording. A 4 o'clock-hour zonular dialysis was created, followed by a capsulorhexis and hydrodissection. In 4 eyes, a suture-guided CTR (SGCTR) injector and 8-0 nylon suture through the leading eyelet served as a visible tracer for the CTR. In 5 eyes, a standard CTR was used. The movements of the CTR during implantation were observed. In all eyes, SGCTR and CTR movements were predictable during implantation. All CTRs displayed cardinal movements within the injector, initially adjacent to the side of the inner diameter of the CTR. As the CTR made contact with lens or capsule, it shifted first to the center and then to the opposite side of the injector lumen. The appearance of an S-curve in the surgeon's view coincided with an obstruction of the leading eyelet and stress on the zonular fibers, as viewed with Miyake-Apple analysis. Traumatic CTR implantation might be avoided by understanding the characteristics of uneventful insertion vs an insertion complicated by entrapment or entanglement of the CTR. By recognizing the abnormal movements of the CTR associated with an obstruction, a surgeon might avoid iatrogenic complications.

Subacromial Impingment Syndrome does not alter muscle onset activation patterns during shoulder cardinal movement at different speed and load

This study examines neuromuscular firing patterns in healthy and subjects diagnosed with SIS of the periscapular, prime-moving, and rotator cuff muscles during “clinical” cardinal plane physiological movements at different speeds and loads. EMG recordings were taken in 34 healthy and 34 subjects diagnosed with Subacromial Impingement Syndrome (SIS) of the prime movers, periscapular, and rotator cuff muscles during flexion, scaption, and abduction performed at fast, medium, and slow speeds with a loaded (3 kg) and unloaded arm. Differences in firing patterns between groups were analyzed by fitting mixed linear models with random intercepts per subject, and fixed factors for group, muscle, movement type, speed, and load. No difference in timing of activation was seen between the healthy and SIS. Onset timing of prime movers, periscapular, and rotator cuff muscles were prior to movement in all scenarios studied, with rotator cuff muscles firing last. Speed and load appear to independently vary muscle activation timing in a non-intuitive manner in both healthy and SIS. The lack of different firing neuromuscular patterns in subjects diagnosed with SIS and healthy subjects raises the need to consider individual assessment of motor patterns rather than generalized patterns.

A computer-based simulation of childbirth using the partial Dirichlet\u2013Neumann contact method with total Lagrangian explicit dynamics on the GPU

During physiological or ‘natural’ childbirth, the fetal head follows a distinct motion pattern—often referred to as the cardinal movements or ‘mechanisms’ of childbirth—due to the biomechanical interaction between the fetus and maternal pelvic anatomy. The research presented in this paper introduces a virtual reality-based simulation of physiological childbirth. The underpinning science is based on two numerical algorithms including the total Lagrangian explicit dynamics method to calculate soft tissue deformation and the partial Dirichlet–Neumann contact method to calculate the mechanical contact interaction between the fetal head and maternal pelvic anatomy. The paper describes the underlying mathematics and algorithms of the solution and their combination into a computer-based implementation. The experimental section covers first a number of validation experiments on simple contact mechanical problems which is followed by the main experiment of running a virtual reality childbirth. Realistic mesh models of the fetus, bony pelvis and pelvic floor muscles were subjected to the intra-uterine expulsion forces which aim to propel the virtual fetus through the virtual birth canal. Following a series of simulations, taking variations in the shape and size of the geometric models into account, we consistently observed the cardinal movements in the simulator just as they happen in physiological childbirth. The results confirm the potential of the simulator as a predictive tool for problematic childbirths subject to patient-specific adaptations.

Dysfunction of serotonergic neurons in Parkinson's disease and dyskinesia.

Parkinson's disease (PD) is characterized by the degeneration of dopaminergic neurons in the substantia nigra, the depletion of striatal dopamine and the presence of Lewy aggregates containing alpha-synuclein. Clinically, there are motor impairments involving cardinal movement symptoms, bradykinesia, resting tremor, muscle rigidity, and postural abnormalities, along with non-motor symptoms such as sleep, behavior and mood disorders. The current treatment for PD focuses on restoring dopaminergic neurotransmission by l-3,4-dihydroxyphenylalanine (levodopa), which loses therapeutic efficacy and induces disabling abnormal involuntary movements known as levodopa-induced dyskinesia (LID) after several years. Evidence indicates that the pathophysiology of both PD and LID disorders is also associated with the dysfunctional activity of the serotonergic (5-HT) neurons that may be responsible for motor and non-motor disturbances. The main population of 5-HT neurons is located in the dorsal raphe nuclei (DRN), which provides extensive innervation to almost the entire neuroaxis and controls multiple functions in the brain. The degeneration of DRN 5-HT neurons occurs in early PD. These neurons can also take exogenous levodopa to transform it into dopamine, which may disturb neuron activity. This review will provide an overview of the underlying mechanisms responsible for 5-HT dysfunction and its clinical relevance in PD and dyskinesia.

BS15. An evaluation of repetitive transcranial magnetic stimulation effectiveness on cardinal and eye movement control of patients with Parkinson’s disease

Introduction Changes in motor symptoms and mood resulting from repetitive transcranial magnetic stimulation (rTMS) in patients with Parkinson’s disease (PD) have been addressed. However, the best area of the brain to target for stimulation has been still unknown. Since oculomotor behavior suggests a common mechanism underlying a general deficit in the motor control, recording of eye movement might offer a new quantitative evaluation of PD pathophysiology. Methods We assessed the effects of high-frequency rTMS (HF-rTMS) on motor and mood disturbances in patients with PD to identify the best target for treatment in the primary motor area (M1), the supplementary motor area (SMA), and the dorsolateral prefrontal cortex (DLPFC). This randomized, double-blind crossover-design study examined 19 patients and investigated the efficacy of 3 consecutive days of HF-rTMS over the M1, SMA, and DLPFC. The results of rTMS at each location were compared to sham stimulation. We used several motor and/or non-motor scales to evaluate the Parkinsonian symptoms. Next, we enrolled 7 patients in order to learn how the performance of volitional saccade tasks and fixational eye movements were affected by HF-rTMS. We investigated bilateral 5 Hz rTMS over the M1 and assessed eye movement, which was recorded binocularly using a fast video-based eye tracker (the temporal and spatial resolutions were 500 Hz and 0.01°). Results The changes in the scores of the Unified Parkinson’s Disease Rating Scale part III (UPDRS–III) following the application of HF-rTMS over the M1 and SMA were significantly greater than those following sham stimulation. However, after the application of HF-rTMS over the DLPFC, the UPDRS–III scores were similar to those following sham stimulation. No significant improvements in mood disturbances were demonstrated. In the eye-movement study, the change of response time in anti-saccade performance improved significantly in patients with PD after applying HF-rTMS over the M1. The change of performance of saccade and frequency of fixational saccades for anti-saccade task which required reflex suppression showed a strong correlation with the posture and walk symptoms in PD. Conclusion The application of HF-rTMS to M1 and SMA significantly improved motor symptoms in patients with PD but did not affect mood disturbances. The volitional saccade performance may possibly reflect the pathogenesis of PD.

Simulation Training Regarding Vaginal Delivery Versus Traditional Medical Student Clinical Education

OBJECTIVE: To assess the impact of birth simulation training on medical student comfort, confidence and anxiety in performing a delivery, and knowledge of normal labor. METHODS: In this prospective study of 3rd-year medical students during their 4-week inpatient clinical experience, student groups were randomly assigned to “traditional” teaching versus traditional plus additional “simulation” teaching. All students were immersed in clinical experiences in the delivery room after an initial group education session regarding normal labor and delivery mechanisms and procedures. The group assigned to “simulation” underwent additional supervised simulation training for normal delivery and delivery complications. All groups underwent a pretest before training and a posttest on completion of their clinical rotation. Evaluated variables included: confidence and anxiety regarding performing a delivery; comfort controlling the head, shoulders and body during delivery; comfort in delivering a placenta; and knowledge of cardinal movements and stages of labor. Statistical analyses were accomplished using Pearson χ2 analysis and Student's T tests. RESULTS: Sixty students participated. Overall, both traditional teaching and simulation groups demonstrated significant improvements in their scores regarding measures of comfort, anxiety, and knowledge between the pre- and posttests (P≤0.05). However, comparison of posttest responses did not reveal those undergoing additional simulation training to have higher comfort or confidence in performing a vaginal delivery (P&gt;.05), or have lower anxiety at being involved in a vaginal delivery (P&gt;.05). Similarly, knowledge about the cardinal movements of labor and stages of labor at the posttest were similar between groups (P&gt;.05). CONCLUSION: In the context of an inpatient clinical rotation in which student comfort, confidence, anxiety, and knowledge regarding vaginal delivery improved significantly with traditional teaching, additional simulation training was not associated with improved outcomes.

Clinically acceptable agreement between the ViMove wireless motion sensor system and the Vicon motion capture system when measuring lumbar region inclination motion in the sagittal and coronal planes

BackgroundWireless, wearable, inertial motion sensor technology introduces new possibilities for monitoring spinal motion and pain in people during their daily activities of work, rest and play. There are many types of these wireless devices currently available but the precision in measurement and the magnitude of measurement error from such devices is often unknown. This study investigated the concurrent validity of one inertial motion sensor system (ViMove) for its ability to measure lumbar inclination motion, compared with the Vicon motion capture system.MethodsTo mimic the variability of movement patterns in a clinical population, a sample of 34 people were included – 18 with low back pain and 16 without low back pain. ViMove sensors were attached to each participant’s skin at spinal levels T12 and S2, and Vicon surface markers were attached to the ViMove sensors. Three repetitions of end-range flexion inclination, extension inclination and lateral flexion inclination to both sides while standing were measured by both systems concurrently with short rest periods in between. Measurement agreement through the whole movement range was analysed using a multilevel mixed-effects regression model to calculate the root mean squared errors and the limits of agreement were calculated using the Bland Altman method.ResultsWe calculated root mean squared errors (standard deviation) of 1.82° (±1.00°) in flexion inclination, 0.71° (±0.34°) in extension inclination, 0.77° (±0.24°) in right lateral flexion inclination and 0.98° (±0.69°) in left lateral flexion inclination. 95% limits of agreement ranged between -3.86° and 4.69° in flexion inclination, -2.15° and 1.91° in extension inclination, -2.37° and 2.05° in right lateral flexion inclination and -3.11° and 2.96° in left lateral flexion inclination.ConclusionsWe found a clinically acceptable level of agreement between these two methods for measuring standing lumbar inclination motion in these two cardinal movement planes. Further research should investigate the ViMove system’s ability to measure lumbar motion in more complex 3D functional movements and to measure changes of movement patterns related to treatment effects.

Normative Values for Active Lumbar Range of Motion in Children and Confounding Factors that Affects the Active Lumbar Range of Motion

Purpose: The purpose of this study was to establish normative values for active lumbar movement in children five, seven, nine, and 11 years of age and to find the confounding factors that affect the lumbar range. Method: End range active flexion, extension, and right- and left-side bending of the lumbar spine were measured for 400 normally developing children (200 girls, 200 boys) using dual inclinometric technique. Means were determined for each motion by age and sex. Group relationships were explored. Results: Normative values for lumbar spine cardinal plane movements were identified. Reduced lumbar movement was found in the 11-year-old group compared with the 5-year-old group in both girls and boys. Flexibility levels were defined using percentiles as poor ( 95th) respectively. The mean value for forward flexion, extension right and left lateral flexion for all participants was 55.9 + 17, 21.8 + 6, 15.2 + 5.1 and 14.9 + 5. Conclusion: Normative data for cardinal plane movements of the lumbar spine provide therapists with a baseline for assessing spinal mobility of children of these ages.

Evaluation of striatonigral connectivity using probabilistic tractography in Parkinson's disease.

The cardinal movement abnormalities of Parkinson's disease (PD), including tremor, muscle rigidity, and reduced speed and frequency of movements, are caused by degeneration of dopaminergic neurons in the substantia nigra that project to the putamen, compromising information flow through frontal-subcortical circuits. Typically, the nigrostriatal pathway is more severely affected on the side of the brain opposite (contralateral) to the side of the body that manifests initial symptoms. Several studies have suggested that PD is also associated with changes in white matter microstructural integrity. The goal of the present study was to further develop methods for measuring striatonigral connectivity differences between PD patients and age-matched controls using diffusion weighted magnetic resonance imaging (MRI).In this cross-sectional study, 40 PD patients and 44 controls underwent diffusion weighted imaging (DWI) using a 40-direction MRI sequence as well as an optimized 60-direction sequence with overlapping slices. Regions of interest (ROIs) encompassing the putamen and substantia nigra were hand drawn in the space of the 40-direction data using high-contrast structural images and then coregistered to the 60-direction data. Probabilistic tractography was performed in the native space of each dataset by seeding the putamen ROI with an ipsilateral substantia nigra classification target. The effect of disease group (PD versus control) on mean putamen-SN connection probability and streamline density were then analyzed using generalized linear models controlling for age, gender, education, as well as seed and target region characteristics.Mean putamen-SN streamline density was lower in PD on both sides of the brain and in both 40- and 60-direction data. The optimized sequence provided a greater separation between PD and control means; however, individual values overlapped between groups. The 60-direction data also yielded mean connection probability values either trending (ipsilateral) or significantly (contralateral) lower in the PD group. There were minor between-group differences in average diffusion measures within the substantia nigra ROIs that did not affect the results of the GLM analyses when included as covariates. Based on these results, we conclude that mean striatonigral structural connectivity differs between PD and control groups and that use of an optimized 60-direction DWI sequence with overlapping slices increases the sensitivity of the technique to putative disease-related differences. However, overlap in individual values between disease groups limits its use as a classifier.

Finite element model focused on stress distribution in the levator ani muscle during vaginal delivery

Introduction and hypothesisDuring vaginal delivery, the levator ani muscle (LAM) undergoes severe deformation. This stress can lead to stretch-related LAM injuries. The objective of this study was to develop a sophisticated MRI-based model to simulate changes in the LAM during vaginal delivery.MethodsA 3D finite element model of the female pelvic floor and fetal head was developed. The model geometry was based on MRI data from a nulliparous woman and 1-day-old neonate. Material parameters were estimated using uniaxial test data from the literature and by least-square minimization method. The boundary conditions reflected all anatomical constraints and supports. A simulation of vaginal delivery with regard to the cardinal movements of labor was then performed.ResultsThe mean stress values in the iliococcygeus portion of the LAM during fetal head extension were 4.91–7.93 MPa. The highest stress values were induced in the pubovisceral and puborectal LAM portions (mean 27.46 MPa) at the outset of fetal head extension. The last LAM subdivision engaged in the changes in stress was the posteromedial section of the puborectal muscle. The mean stress values were 16.89 MPa at the end of fetal head extension. The LAM was elongated by nearly 2.5 times from its initial resting position.ConclusionsThe cardinal movements of labor significantly affect the subsequent heterogeneous stress distribution in the LAM. The absolute stress values were highest in portions of the muscle that arise from the pubic bone. These areas are at the highest risk for muscle injuries with long-term complications.

A normative study of cervical range of motion measures including the flexion–rotation test in asymptomatic children: side-to-side variability and pain provocation

Objectives: Cervical movement impairment has been identified as a core component of cervicogenic headache evaluation. However, normal range of motion values in children has been investigated rarely and no study has reported such values for the flexion–rotation test (FRT). The purpose of this study was to identify normal values and side-to-side variation for cervical spine range of motion (ROM) and the FRT, in asymptomatic children aged 6–12 years. Another important purpose was to identify the presence of pain during the FRT.Methods: Thirty-four asymptomatic children without history of neck pain or headache (26 females and 8 males, mean age 125.38 months [SD 13.14]) were evaluated. Cervical spine cardinal plane ROM and the FRT were evaluated by a single examiner using a cervical ROM device.Results: Values for cardinal plane ROM measures are presented. No significant gender difference was found for any ROM measure. Mean difference in ROM for rotation, side flexion, and the FRT were less than one degree. However, intra-individual variation was greater, with lower bound scores of 9.32° for rotation, 5.30° for side flexion, and 10.89° for the FRT. Multiple linear regression analysis indicates that movement in the cardinal planes only explains 19% of the variance in the FRT. Pain scores reported following the FRT were less than 2/10.Discussion: Children have consistently greater cervical spine ROM than adults. In children, side-to-side variation in rotation and side flexion ROM and range recorded during the FRT indicates that the clinician should be cautious when using range in one direction to determine impairment in another. Range recorded during the FRT is independent of cardinal movement variables, which further adds to the importance of the FRT, as a test that mainly evaluates range of movement of the upper cervical spine.

Developmental Characterization of Tail Movements in the Appendicularian Urochordate Oikopleura dioica

Using high-speed video cinematography, we characterized kinematically the spontaneous tail movements made by the appendicularian urochordate Oikopleura dioica. Videos of young adult (1-day-old) animals discriminated 4 cardinal movement types: bending, nodding, swimming and filtering, each of which had a characteristic signature including cyclicity, event or cycle duration, cycle frequency, cycle frequency variation, laterality, tail muscle segment coordination and episode duration. Bending exhibited a more common, unilateral form (single bending) and a rarer, bilateral form (alternating bending). Videos of developing animals showed that bending and swimming appeared in rudimentary form starting just after hatching and exhibited developmental changes in movement excursion, duration and frequency, whereas nodding and filtering appeared in the fully mature form in young adults at the time of first house production. More complex behaviors were associated with inflating, entering and exiting the house. We also assessed the influence of descending inputs by separating the tail (which contains all muscles and most likely the neural circuits that generate most motor outputs) from the head. Isolated tails spontaneously generated either bending or swimming movements in abnormally protracted episodes. This together with other observations of interactions between bending and swimming behaviors indicates the presence of several types of descending inputs that regulate the activity of the pattern generating circuitry in the tail nervous system.

Pharmacological treatment of Tourette syndrome

Tourette syndrome (TS) is a highly heritable yet heterogeneous childhood onset disorder. The cardinal movement disorder required for diagnosis is tics. As persons with tics or TS often have obsessive/compulsiveness, inattention, hyperactivity, impulsivity, anxiety, and anger outbursts, the presence of tics should prompt clinicians to look for these other conditions. While randomized controlled trials provide valid evidence of efficacy for symptoms in isolation, implications for treatment of complex patients meeting criteria for multiple diagnoses is not always clear. In this review, the authors critically review factors influencing decisions whether and how to treat medically tics as well as OCD and ADHD in the presence of tics.

Functional relationship between cognitive representations of movement directions and visuomotor adaptation performance

The aim of our study was to explore whether or not different types of learners in a sensorimotor task possess characteristically different cognitive representations. Participants' sensorimotor adaptation performance was measured with a pointing paradigm which used a distortion of the visual feedback in terms of a left-right reversal. The structure of cognitive representations was assessed using a newly established experimental method, the Cognitive Measurement of Represented Directions. A post hoc analysis revealed inter-individual differences in participants' adaptation performance, and three different skill levels (skilled, average, and poor adapters) have been defined. These differences in performance were correlated with the structure of participants' cognitive representations of movement directions. Analysis of these cognitive representations revealed performance advantages for participants possessing a global cognitive representation of movement directions (aligned to cardinal movement axes), rather than a local representation (aligned to each neighboring direction). Our findings are evidence that cognitive representation structures play a functional role in adaptation performance.

Fetal heart rate in the second stage of labor: recording, reading, interpreting and acting

Although central to the cardinal movements that lead to the delivery of the fetus, the second stage of labor is often neglected from a cultural and clinical viewpoint. In this phase, acquisition is more difficult, and reading and interpretation may not be the same as in the active first phase. Namely, the most relevant findings are the occurrence and depth of bradycardia and its duration. This allows the evaluation of fetal heart rate (FHR) even without cardiotocographic recording. Instead, FHR can be accurately detected using Doppler auscultation, and it is reasonable to speak of “FHR during the second stage of labor” instead of “cardiotocography in the second stage of labor.” Regardless of the cause, including head compression, umbilical cord knots, loops around the fetal neck or body, and cord entanglement, the time for intervention is often so short that any intervention may be unable to prevent injury.