Kinematic Measurements Research Articles

Disease-Specific Speech Movement Characteristics of the Tongue and Jaw.

To advance our understanding of disease-specific articulatory impairment patterns in speakers with dysarthria, this study investigated the articulatory performance of the tongue and jaw in speakers with differing neurological diseases (Parkinson's disease [PD], amyotrophic lateral sclerosis, multiple sclerosis, and Huntington's disease). Fifty-seven speakers with dysarthria and 30 controls produced the sentence "Buy Kaia a kite" five times. A three-dimensional electromagnetic articulography was used to record the articulatory movements of the posterior tongue and jaw. Sentence-length kinematic measures (e.g., duration, tongue range of motion [ROM], jaw ROM, tongue speed, jaw speed) were extracted. Results revealed significant group effects for the duration, jaw ROM, and tongue speed but not for tongue ROM. Post hoc pairwise comparisons revealed more significant between-groups differences for duration and jaw ROM than for tongue speed. Statistically significant findings between clinical groups were predominantly driven by the difference between speakers with PD and speakers of other clinical groups. Reduced jaw ROM and trends toward reduced tongue ROM confirm hypokinesia as a distinguishing motor feature of speakers with PD. However, deviancies in speed or movement duration did not emerge as a distinguishing motor feature for any of the four studied clinical groups. Nevertheless, movement duration, but not movement speed, may be useful to index dysarthria severity.

Effect of Post-Activation Potentiation on Weightlifting Performance and Endocrinological Responses

Purpose: This study examined the acute performance-enhancing effects and endocrinological responses of a supramaximal clean pull performed at 120% of clean and jerk, one repetition maximum, on clean performance. Methods: Eight (n = 8) ranked collegiate level weightlifters attended two days of testing in a randomised order. A control session was used to identify a baseline measure of kinetic and kinematic clean performance and endocrinological status following three cleans interspersed with one-minute recovery between repetitions. The experimental condition required participants to perform a single clean pull at 120% of clean and jerk, one repetition maximum, followed by three minutes recovery, prior to executing three cleans with one-minute recovery between repetitions. All cleans were performed on a dual force plate set up, synchronised with a 3D motion capture system to simultaneously record barbell and ground reaction force data. All endocrinological data were measured prior to the participant warming up and also following each testing protocol. Results: The results indicated that no significant differences were found between the control and PAP condition (p = 0.140–0.902); however, effect sizes from group analysis identified moderately negative to trivial effects across kinetic, kinematic and endocrinological variables (d = −0.30–0.14). Further analysis on an individual level demonstrated values, both negative and positive, ranging from extremely large (d = −4.10) to trivial (d = 0.04). Conclusions: The findings suggest a potentially negative affect of PAP on kinetic and kinematic measures of clean performance. However, individual responses varied, and thus some weightlifters may find this useful.

Ventilatory and Perceived Ergogenic Effects of Mandibular Forward Repositioning During Running at Maximal Oxygen Uptake Intensity.

Cardoso, F, Costa, MJ, Colaço, P, Vilas-Boas, JP, Pinho, JC, Pyne, DB, and Fernandes, RJ. Ventilatory and perceived ergogenic effects of mandibular forward repositioning during running at maximal oxygen uptake intensity. J Strength Cond Res 39(1): e13-e19, 2025-Wearing an intraoral dental splint may enhance ventilatory function and exercise performance. Nineteen runners performed on a 400-m outdoor track: (a) an incremental protocol to assess the velocity at maximal oxygen uptake (vV̇ o2 max) and (b) 2 square wave bouts wearing 2 intraoral splints (with and without mandibular forward repositioning). The time until exhaustion at vV̇ o2 max (TLimv V̇ o2 max), ventilatory variables, oxygen uptake (V̇ o2 ) kinetics, energetic profiling, perceived exertion and kinematics, were all measured. Ventilatory data were assessed breath-by-breath and perceived exertion evaluated using the Borg 6-20-point scale at the end of TLimv V̇ o2 max bouts. Images were recorded by video cameras (120 Hz) and kinematic measures retrieved using Kinovea. A paired t test was computed for comparison of splints ( p ≤ 0.05). With (vs. without) mandibular forward repositioning, runners increased their TLimv V̇ o2 max by ∼6% ( p = 0.03), coupled with higher ventilation (151 ± 22 vs. 147 ± 23 L·min -1 , p = 0.04), end-tidal oxygen tension (114.3 ± 3.7 vs. 112.9 ± 3.9 mm Hg, p = 0.003), and lower inspiratory time (0.526 ± 0.083 vs. 0.540 ± 0.090 seconds, p = 0.02), despite similar V̇ o2 kinetics (e.g., 49.0 ± 8.7 vs. 47.7 ± 8.6 ml∙kg∙min -1 of fast component amplitude) being observed. The energy expenditure was ∼8% higher ( p = 0.03) with the mandible forward, coupled with lower perceived exertion scores ( p = 0.04). Mandibular forward repositioning was effective in acutely improving running performance at vV̇ o2 max with ergogenic effects on ventilatory and perceived variables.

Validity of Wearable Inertial Sensors for Gait Analysis: A Systematic Review.

Background/Objectives: Gait analysis, traditionally performed with lab-based optical motion capture systems, offers high accuracy but is costly and impractical for real-world use. Wearable technologies, especially inertial measurement units (IMUs), enable portable and accessible assessments outside the lab, though challenges with sensor placement, signal selection, and algorithm design can affect accuracy. This systematic review aims to bridge the benchmarking gap between IMU-based and traditional systems, validating the use of wearable inertial systems for gait analysis. Methods: This review examined English studies between 2012 and 2023, retrieved from the Scopus database, comparing wearable sensors to optical motion capture systems, focusing on IMU body placement, gait parameters, and validation metrics. Exclusion criteria for the search included conference papers, reviews, unavailable papers, studies without wearable inertial sensors for gait analysis, and those not involving agreement studies or optical motion capture systems. Results: From an initial pool of 479 articles, 32 were selected for full-text screening. Among them, the lower body resulted in the most common site for single IMU placement (in 22 studies), while the most frequently used multi-sensor configuration involved IMU positioning on the lower back, shanks, feet, and thighs (10 studies). Regarding gait parameters, 11 studies out of the 32 included studies focused on spatial-temporal parameters, 12 on joint kinematics, 2 on gait events, and the remainder on a combination of parameters. In terms of validation metrics, 24 studies employed correlation coefficients as the primary measure, while 7 studies used a combination of error metrics, correlation coefficients, and Bland-Altman analysis. Validation metrics revealed that IMUs exhibited good to moderate agreement with optical motion capture systems for kinematic measures. In contrast, spatiotemporal parameters demonstrated greater variability, with agreement ranging from moderate to poor. Conclusions: This review highlighted the transformative potential of wearable IMUs in advancing gait analysis beyond the constraints of traditional laboratory-based systems.

Validation of a Multi-Segment Kinematic Foot Model and Optical Motion Capture Using Bi-Planar X-Ray Fluoroscopy and a Markerless RSA Approach

Gait analysis with optical motion capture typically treats the foot as a single segment, which can measure clinically useful kinematics but is insufficient to measure the kinematics of joint motions within the foot. This study hypothesizes that a four-segment foot model, tracking the hindfoot, midfoot, forefoot, and hallux, can accurately measure intrinsic foot kinematics when validated against the gold standard of fluoroscopic X-ray radiostereometric analysis (RSA) during walking gait. Ten healthy volunteers were tested, with the left foot tracked during the stance phase from heel strike to toe off. The results indicated that the height-to-length ratio of the medial longitudinal arch (MLA) and the transverse plane motion of the hindfoot were the most reliable kinematic measures, showing the best agreement between the optical motion capture and RSA methods. In contrast, the frontal plane motions of the hindfoot and forefoot showed the greatest differences, though these were not statistically significant at p < 0.05. These findings demonstrate that the multi-segment foot model is a valid method for measuring intrinsic foot kinematics in a clinical setting, providing a reliable alternative to more invasive techniques.

Effect of recording angle on accuracy of Kinovea-based kinematic gait analysis compared to three-dimensional motion analysis in healthy dogs: optimal at 90° recording angle

Abstract OBJECTIVE The goal of this study was to investigate the effect of recording angle on the accuracy of 2-D Kinovea-based kinematic motion analysis (KMA) compared to 3-D KMA in dogs. METHODS In this prospective study, 3-D marker-based KMA (VICON-Nexus, version 2.12.1, and Procalc, version 1.6; VICON Motion Systems Ltd) was performed on healthy dogs (body weight ≥ 20 kg) walking on a treadmill (study period: November 2022). Simultaneously, dogs were video-recorded by 3 smartphones (iPhone SE; Apple Inc) at 1.50 m distance and 45°, 90°, and 135° recording angles relative to the shoulder for Kinovea-based, angle-calibrated KMA. Shoulder, elbow, carpal, hip, stifle, and tarsal joint kinematics were calculated for 3 synchronized gait cycles. Each gait cycle was divided into 10 increments. The estimated difference between 3-D KMA and Kinovea was assessed using robust linear mixed-effects models. RESULTS 34 dogs were included. Differences of less than 5° between methods were considered reasonable. At a 45° recording angle, the estimated joint angle difference was < 5° for the carpus and hip during ≥ 5 of 10 gait cycle increments. At 90°, the difference was < 5° across all joints for ≥ 9 of 10 increments and at 135° was < 5° for the elbow, carpus, and hip for ≥ 7 of 10 increments. CONCLUSIONS Kinovea-based kinematics were most accurate when recorded at 90°. At 45°, Kinovea provided accurate data for the carpus and hip and at 135° for the elbow, carpus, and hip. CLINICAL RELEVANCE While angle-calibrated kinematic measurements can be accurate when using Kinovea for canine KMA, a 90° recording angle is preferable.

Efficacy of Foot Orthoses With Sensorimotor Bars on Gait, Postural Control, and Muscle Activity in Healthy Individuals and Those With Musculoskeletal Disorders: A Systematic Review

Objectives: The foot and ankle complex is crucial in stability, propulsion, and musculoskeletal interactions. Optimizing orthotic interventions in this anatomical region is essential to improve motor outcomes. This systematic review investigates the impact of foot orthoses (FOs) with sensorimotor bars on gait, postural control, and muscle activity in healthy individuals and those with musculoskeletal disorders. Methods: We conducted an electronic search in January 2024 using the PubMed, Web of Science, and Scopus databases. The article identification, screening, and selection followed the PISMA (the preferred reporting items for systematic reviews and meta-analysis) guidelines. We conducted the quality assessment using the PEDro (the physiotherapy evidence database) checklist. Data extraction and synthesis were performed using the Cochrane handbook for systematic review of interventions. Results: FOs with sensorimotor bars can increase foot external rotation, dorsiflexion, and abduction while decreasing foot eversion. Additionally, they can reduce anteroposterior displacement of the hip, shoulder, and head. Furthermore, significant improvements have been observed in spatiotemporal parameters such as walking speed, stride length, stance time, swing time, and kinetic parameters such as plantar pressure. These orthoses can also impact clinical tasks and decrease center-of-pressure movements. Discussion: Sensorimotor bars have demonstrated beneficial effects on gait (kinematic, kinetic, and spatial-temporal measures), balance control (clinical performance and center of pressure displacement measures), and muscle activity recording.

Effects of Route Complexity and Lighting on Route Following in Alzheimer's Disease and Posterior Cortical Atrophy.

Visual processing deficits arising in dementia are associated with particular functional disability. This study aimed to investigate the effects of the built environment on mobility and navigation in people with dementia-related visual loss. Participants with posterior cortical atrophy (PCA; "visual-variant Alzheimer's"; n = 11), typical Alzheimer's disease (tAD; N = 10), and controls (n = 13) repeatedly walked down routes within a simplified real-world setting. Participant groups were of comparable age and gender. Routes were of different complexity (straight, U-shaped, and S-shaped), overhead lighting levels (low and high) and with or without a dynamic LED (light-emitting diode) cue (trial n = 24). Ratios of walking times for each experimental condition (each complex route vs the straight route, high lighting vs low, and LED cue vs no cue) were compared between participant groups. Kinematic measures were produced from a total of 10,813 steps using wearable inertial measurement units (IMUs). The walking time ratios relating to route complexity were higher in the PCA group than in controls: 30.3% (95% CI [13.5%, 49.5%] higher for U-shaped vs straight and 31.9% [21.1%, 55.3%] for S-shaped vs straight, averaged over other conditions). The analogous results relating to route complexity for the tAD group were intermediate between those for the PCA and control groups. There was no evidence that walking time ratios differed according to lighting level or the presence of the LED cue. Findings contribute to evidence-based design for dementia-friendly environments, emphasizing consequences of environmental complexity for functional independence and mobility in people with dementia-related visual loss. Findings inform recommendations for environmental design to support the independence of individuals with dementia.

A Prospective Study on Gait Impairment in Patients With Symptomatic Lumbar Canal Stenosis and Impact of Surgical Intervention on Gait Function.

Prospective observational cohort study. To analyze the effect of decompression surgery on gait characteristics in patients with stenosis. Also, to test the hypothesis that patient-reported functional outcomes and gait parameters (spatiotemporal, kinetic, and kinematic measures) will improve postoperatively and achieve normal values when compared with matched healthy controls. Lumbar spinal stenosis is one of the leading causes of disability among elderly population. Gait impairment is one of the primary symptoms of degenerative conditions involving lumbar spine. Research suggests that decompressive surgery can positively influence gait parameters in patients with spinal stenosis. Studies have shown improvements in walking speed, stride length, and balance post-surgery. Thirty-two patients with single-level lumbar stenosis and 32 healthy volunteers were prospectively recruited. All patients underwent gait analysis preoperatively and 6 months postoperatively as per standard protocol. Spatiotemporal, kinematic, and kinetic parameters were analyzed. Stepwise linear regression models were used to detect significant relationships between changes in functional score (Visual Analogue Scale/Oswestry Disability Index) and gait parameters. Significant improvement was noted in functional scores(P<0.05) 6 months post-surgery. Spatiotemporal (swing phase, mean velocity, cadence, stride length, step length, and step width) and kinetic parameters (hip, knee, and ankle power) were significantly better after surgery, reaching normal levels. Kinematic parameters significantly improved after surgery but did not reach normal levels when compared with controls. A significant correlation was found between changes in functional scores with changes in certain kinematic parameters (knee-power, ankle plantarflexion, swing time, peak ankle dorsiflexion in swing, peak-hip, and knee flexor moment). Decompression surgery in lumbar stenosis produces improvement in gait parameters, pain scores, and functional outcomes that significantly improve gait posture and speed.

Kinematic signature of high risk labored breathing revealed by novel signal analysis

Breathing patterns (respiratory kinematics) contain vital prognostic information. This dimension of physiology is not captured by conventional vital signs. We sought to determine the feasibility and utility of quantifying respiratory kinematics. Using inertial sensors, we analyzed upper rib, lower rib, and abdominal motion of 108 patients with respiratory symptoms during a hospital encounter (582 two-minute recordings). We extracted 34 features based on an explainable correspondence with well-established breathing patterns. K-means clustering revealed that respiratory kinematics had three dimensions apart from the respiratory rate. We represented these dimensions using respiratory rate variability, respiratory alternans (rib-predominant breaths alternating with abdomen-predominant ones), and recruitment of accessory muscles (increased upper rib excursion). Latent profile analysis of the kinematic measures revealed two profiles consistent with the established clinical constructs of labored and unlabored breathing. In logistic regression, the labored breathing profile improved model discrimination for critical illness beyond the Sequential Organ Failure Assessment (SOFA) score (AUROC 0.77 v/s 0.72; p = 0.02). These findings quantitatively confirm the prior understanding that the respiratory rate alone does not adequately represent the complexity of respiratory kinematics; they demonstrate that high-dimensional signatures of labored breathing can be quantified in routine practice settings, and they can improve predictions of clinical deterioration.

From particles to pixels: how many particles do I really need to construct stellar kinematic mock observational measurements?

ABSTRACT This work considers the impact of resolution in the construction of mock observations of simulated galaxies. In particular, when building mock integral field spectroscopic observations from galaxy formation models in cosmological simulations, we investigate the possible systematics that may arise given the assumption that all galaxies above some stellar mass limit will provide unbiased and meaningful observable stellar kinematics. We build a catalogue of N-body simulations to sample the range of stellar particle resolutions within the EagleRef0050N0752 simulation box and examine how their observable kinematics vary relative to a higher-resolution N-body control. We use these models to compile a table of the minimum number of particles-per-pixel to reach a given uncertainty in the fitted line-of-sight velocity distribution parameters. Further, we introduce a Voronoi-binning module to the mock observation code, SimSpin, in order to meet these minimum numbers. Using Eagle, we show the impact of this shot noise on the observed spin–ellipticity plane and the recovery of this space when observations are binned with increasing numbers of particles. In conclusion, we advise binning mock images to meet at least 200 particles-per-pixel to avoid systematically under-estimating the velocity dispersion along a given line-of-sight. We demonstrate that this is important for comparing galaxies extracted from the same simulation, as well as between simulations of varying mass resolution and observations of real galaxies.

Self-selected speed provides more accurate human gait kinematics and spatiotemporal parameters than overground simulated speed on a treadmill: a cross-sectional study

BackgroundWalking speed, a key element of gait analysis, is essential for evaluating the biomechanics of the musculoskeletal system and is typically assessed on flat surfaces, such as walkways or treadmills. While many authors have compared the differences and similarities between treadmill and overground walking, no studies have yet investigated the differences between treadmill gait analysis at self-selected speed (SS) and overground simulated speed (OS). The hypothesis is that accurate kinematic measurements depend on selecting the correct gait speed; however, a mismatch between the perceived comfortable treadmill speed and actual overground speed may affect the accuracy of treadmill gait analyses. This study aimed to assess treadmill gait in healthy young adults by comparing the SS with the OS. The objectives were to determine whether participants could match SS with OS on a treadmill, examine sex differences in gait kinematics and spatiotemporal parameters (KSP) at different speeds, and identify which speed better reflects natural gait kinematics.MethodsA total of 60 healthy men and 70 healthy women, aged 22–35 years, participated in this cross-sectional study to investigate the gait kinematics and spatiotemporal differences between the SS and OS. Student’s t-test, Bonferroni adjustment, Cohen’s effect size, and quadratic regression were employed to analyse differences across walking speeds and groups.ResultsA discrepancy between OS and SS was observed in 66.4% of the participants. Our findings revealed that the adjusted R² values for KSP at SS were consistently greater than those at OS, suggesting that SS offers a more robust and accurate representation of gait kinematics, whereas OS is less reliable.ConclusionsThese findings underscore the importance of individualized speed selection in gait analysis, as it significantly impacts the accuracy of kinematic and spatiotemporal measurements. This insight is pivotal for clinicians and researchers to develop more effective rehabilitation strategies and comprehensively understand gait dynamics.

Probing the atmospheric boundary layer with integrated remote-sensing platforms during the American WAKE ExperimeNt (AWAKEN) campaign

The American WAKE ExperimeNt (AWAKEN) collaboration is an observational-based field campaign in northern Oklahoma intended to analyze the potential influence of onshore wind farms and their collective wakes on wind power production, turbine structural loads, and on the atmospheric boundary layer (ABL). Focusing on the ABL effects, the University of Oklahoma and the Lawrence Livermore National Laboratory collected continuous high-resolution kinematic and thermodynamic profile measurements during 2022 and Summer 2023. The deployment strategy for these campaigns is detailed first, followed by an initial comparison of data from two sites in the AWAKEN domain: a near-farm site to examine collective wake impacts on the ABL, and a far-field site remaining outside the wind farm-waked region. We summarize the datasets available and demonstrate the benefits of these observations and multiple value-added products (VAPs) for investigation of ABL features observed during AWAKEN. We also highlight examples of preliminary analyses, including ABL height detection and nocturnal low-level jet examination, which are produced using novel VAPs based on optimal estimation to retrieve deeper Doppler lidar wind profiles than previously resolved, along with their uncertainty. By including the near-farm and far-field site in these analyses, we identified a pattern of stronger lower-atmospheric mixing at the near-farm site than the far-field site, motivating deeper investigation into the relationship between wind farms and general ABL characteristics. Future analysis will delve deeper into this relationship by examining other ABL characteristics, such as atmospheric stability and convection.

Cross-sectional Effects of Isolated Meniscal Tears on In Vivo Biomechanics of the Knee: A Systematic Review of Motion Analysis Studies

Objectives: To systematically review the effects of meniscal tears on in vivo knee biomechanics, with a focus on kinematic and kinetic outcome measures. Methods: Databases were queried for level I-IV studies that met the following criteria: in vivo studies of gait or motion analysis, cohorts with isolated meniscal pathology, and kinematics and/or kinetics outcome measures. Demographic data, methods of motion analysis, tasks performed, and kinematics and kinetics outcomes were extracted. Standardized mean differences with a random-effects model were calculated to compare cohorts with meniscal tears and healthy controls when outcomes were homogeneous. Results: Thirteen studies were eligible, with a pooled sample of 176 medial meniscal and 74 lateral meniscal tears. Eleven studies assessed gait biomechanics. There was considerable variability in reported outcomes and motion capture methods. Meta-analysis revealed statistically significant decreases in peak knee flexion angle, range of adduction-abduction, and internal-external rotation (p &lt; 0.05) for the pooled sample of lateral meniscus tears. In terms of kinetics, although qualitative evidence in individual studies suggested alterations (e.g., decreased total support moment of the injured limb), quantitative analysis failed to demonstrate significant differences in peak knee flexion moment and peak knee adduction moment (p ≥ 0.05). Conclusion: Lateral meniscus tears significantly impact in vivo knee kinematics across all three planes of motion. No significant differences were observed in the kinetics of medial meniscus tears, and the evidence for their impact on kinematics remains conflicting. Our findings suggest that analyzing more demanding functional tasks may be necessary to detect the biomechanical changes caused by meniscal tears.

Comparison of gait deviation index (GDI) and gait variability index (GVI) measured by marker-based and markerless motion capture systems in children with cerebral palsy (CP)

BackgroundThe Gait Deviation Index (GDI) is a metric clinicians use to assess overall gait pathology in children with cerebral palsy (CP) by comparing kinematic data to a normative sample. The Gait Variability Index (GVI) is a related metric that quantifies the variability in spatio-temporal variables during gait. The GDI and GVI have been verified using marker-based motion capture approaches, but video-based markerless motion capture has not been compared using these tools in children with CP. Research questionDo GDI and GVI scores differ when measured using markerlessTheia3D and a marker-based approach between the more and less affected legs in children with CP? MethodsFifteen children with CP (GMFCS levels I-IV) and 24 typically developing children aged 6–18 years were recruited for this study. Overground walking was performed at a self-selected pace while the pelvis and lower limb kinematics were simultaneously recorded using both motion capture systems. Differences in GDI and GVI scores when considering the effect of system and limb impairment were analyzed using two-way repeated-measures ANOVAs. ResultsGDI scores were 6.9 points lower (p < 0.05) when measured using Theia3D compared to the marker-based approach and 6.8 points lower (p < 0.05) in the more affected limbs than in the less affected limbs. These GDI score differences are considered clinically significant. No differences were identified in GVI scores between systems or limb impairment. Differences in kinematic measurements were found in children with CP, including pelvic tilt, hip flexion/extension, hip rotation, and foot progression angle, where root mean square differences between systems exceeded 10°. SignificanceTheia3D can adequately measure variability in spatio-temporal gait parameters for quantifying GVI scores in children with CP compared to the marker-based approach. However, caution is needed when quantifying lower limb kinematics and interpreting GDI and GVI scores using Theia3D in children with CP.

Kinematic Measurements of Swallowing by Ultrasound: A Scoping Review.

Ultrasound (US) is a non-invasive method used to study the kinematics of the swallowing function. Kinematic measurements are reported in studies evaluating swallowing using US, but there is no standardization. The aim of this scoping review was to identify and characterize the kinematic measurements of swallowing obtained by ultrasound. We followed the methodological recommendations of the Joanna Briggs Institute (JBI) and the reporting guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis-extension for scoping reviews (PRISMA-ScR). The research question followed the acronym PCC (population, concept, and context). Seven databases and gray literature were searched. Studies were selected using a blind, paired, and independent method. Data were extracted using a standardized tool. There were 2591 studies and 42 were eligible. Most studies had samples of less than 30 participants and mostly included healthy young adults and older people. The swallowing tasks during the assessments were not standardized. The most commonly studied measures were hyoid displacement and tongue movement during swallowing. However, there is no consensus between studies on the definition of the measures and the procedures for ultrasound assessment, including image acquisition and analysis.

Effectiveness of Injury Prevention Program Using a Global Systems Approach on High-Risk Movement Mechanics for Noncontact ACL Injury.

Injury prevention training using a global systems approach was designed to develop integrated trunk-lower extremity neuromuscular control using whole-body, rotational forces about the vertical Z-axis during simulated sports movements. Compared with traditional hip-focused exercises, injury prevention training using a global systems approach could improve kinetic and kinematic measures related to anterior cruciate ligament injury. Controlled laboratory study. Level 3. A total of 39 male and female athletes received 6 weeks of either global systems approach (n = 20), or hip-focused strengthening, balance, and plyometrics training (n = 19) exercises. Before and after the training program, participants performed a single-leg vertical drop jump task on their dominant leg. Peak vertical ground-reaction forces (GRFs), peak knee abduction, internal rotation moments, peak hip flexion, hip adduction, knee flexion, knee abduction, contralateral pelvic drop, and lateral trunk flexion angles were assessed. Biomechanical data were compared between the 2 groups using a random-intercept linear mixed-models analysis. A significant group × time interaction effect was found for vertical GRFs (P = 0.01; change difference relative to baseline: 4.5%), knee abduction moment (P = 0.01; 14.8%), hip adduction (P < 0.01; 16.7%), knee abduction (P < 0.01; 13.8%), contralateral pelvic drop (P < 0.01; change difference: 26.6%), and lateral trunk flexion (P = 0.04; 20.37%) angles, favoring the global systems approach group after 6 weeks of training. Participants who trained using the global systems approach had significantly decreased lateral trunk flexion, hip adduction, knee abduction and contralateral pelvic drop angles, peak vertical GRFs, and peak knee abduction moment during a single-leg vertical drop jump compared with participants who trained with hip-focused exercises. Incorporating additional external resistance at the proximal trunk results in improved biomechanics compared with conventional hip-focused exercises.

New measurement of the Hoyle state radiative transition width

The radiative decay of the Hoyle state serves as the gateway to the production of heavier elements in a stellar environment. Here, we present an exclusive measurement of electric quadruple (E2) transitions of the Hoyle state to the ground state of 12C through the 12C(p, p′γγ)12C reaction. A triple coincidence measurement yields the radiative branching ratio Γrad/Γ = 4.01 (30) × 10−4. This result was corroborated by an independent experiment based on the complete kinematical measurement via12C(p, p′)12C reaction, yielding a consistent result of Γrad/Γ = 4.04 (30) × 10−4. Combining our results with the currently adopted values of Γπ(E0)/Γ and Γπ(E0), the radiative width of the Hoyle state is determined to be 3.75 (40) × 10−3 eV. It is important to note that our finding do not align with a recently reported 34% increase in the radiative decay width of the Hoyle state but is consistent with the currently accepted value.

Performance of the Aptis distal radioulnar joint implant: kinematic and geometric analysis.

This study reviews the performance of the Aptis distal radioulnar joint arthroplasty by comparing multiple kinematic and geometric measurements in the operated and contralateral healthy forearm to elucidate whether these are altered after arthroplasty. Forearm geometry and motion were captured using 3-D and 4-D computed tomography in 12 patients with unilateral Aptis arthroplasties. After segmentation and registration, the axis of forearm rotation, translation of the radius along the ulna and range of wrist flexion-extension were measured, and the Dice coefficient and Hausdorff distance were calculated. The forearm rotation axis in the corrected arm deviated 2.3° from the healthy contralateral rotation axis, radial translation along the ulna decreased by 45% and wrist flexion-extension also decreased significantly. Multiple intra-individual geometric differences were observed. The Aptis distal radioulnar joint arthroplasty considerably alters forearm kinematics, which can have clinical implications.Level of evidence: IV.

A reliable and valid assessment of upper limb movement quality after stroke: the observational Drinking Task Assessment.

To develop and evaluate the reliability and validity of a new observational Drinking Task Assessment (DTA) designed to assess quality of movement in task performance after stroke. Reliability and validity. The DTA measures movement time and movement quality (smoothness, trunk, shoulder, elbow, and grasp movements) on a 4-level ordinal scale. Thirty participants with chronic stroke were assessed independently by 2 therapists. Intra-class correlation (ICC), standard error of measurement (SEM) and minimal real difference (MRD), weighted kappa, percentage of agreement, and Svensson method were used for reliability assessment. Motion capture-based kinematics and established clinical scales were used to evaluate validity. The absolute SEM and MRD for movement time were 0.4 and 1 s (11%), respectively. The ICC (≥ 0.93) and weighted kappa (0.71-1.0) showed good to excellent agreement for intra- and inter-rater reliability. DTA showed strong correlations with Fugl-Meyer Assessment (0.74), Action Research Arm Test (0.93), and kinematic measures of smoothness (0.93), trunk displacement (0.91), elbow extension (0.73), and shoulder movements (0.56), indicating good construct validity. The new DTA proved to be a reliable and valid tool for assessment of movement quality during task performance after stroke.