Trunk Coordination in Dancers and Non-Dancers

Variability, or how a task changes across trials, may reveal differences between athletes of differing skill levels. The purpose of this study was to examine trunk and lower extremity (LE) single joint kinematic variability and inter-segmental coordination variability in dancers and non-dancers during bipedal vertical dance jumps (sautés). Twenty healthy females, ten with no formal dance training and ten professional dancers, performed 20 consecutive sautés. Single joint kinematic variability was assessed using mean standard deviation of angular displacement, and inter-segmental coordination variability was assessed using angular deviation of the coupling angle between segments. Within the context of the standard error of measure, there was no difference in single joint kinematic variability between dancers and non-dancers. Inter-segmental coordination variability in the trunk was higher than variability in LE couplings for both groups. Dancers had lower inter-segmental coordination variability than non-dancers for LE sagittal, frontal and transverse plane couplings and sagittal plane trunk couplings. Trunk adjustments may be important for successful performance, but lower inter-segmental coordination variability in expert dancers indicates a higher level of control. Trunk coordination and postural control may be important factors to investigate in skilled athletes

Portability vs. Precedent: IMUs vs. 3D Motion Capture for Collecting Kinematic Data in Dancers

The emergence of portable kinematic data collection systems (Inertial Measurement Units - IMUs) have become a potential alternative to 3D video motion capture systems for real-world application. However, there remains little research on the application of IMU technology for the evaluation of dancers’ biomechanical movement. PURPOSE: To assess the validity of the Noraxon IMU system compared with the Cortex 3D video motion capture system for kinematic data collection during a sauté. METHODS: 10 healthy, advanced female dancers were equipped with both a Noraxon IMU (200Hz) system and reflective markers used with a 12-camera Motion Analysis system (Cortex, 250 Hz) for simultaneous data collection. Participants completed an independent After a 10-minute warmup, each participant performed one trial of 10 stationary sautés while barefoot, with feet in second position and arms in fifth position in time with music at 95 bpm. The middle 5 jumps of each participant’s trial were processed and analyzed with Visual3D and MATLAB for the Cortex data, and through Noraxon’s reporting system for the Noraxon data. All results were compared through SPSS with repeated-measures ANOVAs. RESULTS: A main effect of measurement system was found for peak joint angles in the sagittal ((6,4)=0.009, p \u3c 0.001), frontal ((9,1)=0.12, p \u3c 0.001), and transverse ((9,1)=0.009, p \u3c 0.001) planes. Pairwise comparisons revealed significant differences in peak hip flexion, hip extension, knee flexion, knee extension, ankle plantar flexion, ankle dorsiflexion, hip adduction, knee adduction, ankle inversion, hip internal rotation, hip external rotation, knee internal rotation, knee external rotation, and ankle internal rotation. No significant main effect was found between measurement systems for sagittal, frontal, and transverse plane joint excursions ((9,1)=0.12, p=0.253). CONCLUSION: Significant differences in most peak joint angles indicate that Noraxon IMUs do not have strong validity for capturing absolute joint angles compared to 3D video motion capture. However, joint excursion measurements were similar, indicating that Noraxon IMUs may be valid for measuring the total amount of motion during a particular movement. Additional analysis is warranted for further understanding of this technology

Modulation of host cell processes by T3SS effectors

Two of the enteric Escherichia coli pathotypes-enteropathogenic E. coli (EPEC) and enterohaemorrhagic E. coli (EHEC)-have a conserved type 3 secretion system which is essential for virulence. The T3SS is used to translocate between 25 and 50 bacterial proteins directly into the host cytosol where they manipulate a variety of host cell processes to establish a successful infection. In this chapter, we discuss effectors from EPEC/EHEC in the context of the host proteins and processes that they target-the actin cytoskeleton, small guanosine triphosphatases and innate immune signalling pathways that regulate inflammation and cell death. Many of these translocated proteins have been extensively characterised, which has helped obtain insights into the mechanisms of pathogenesis of these bacteria and also understand the host pathways they target in more detail. With increasing knowledge of the positive and negative regulation of host signalling pathways by different effectors, a future challenge is to investigate how the specific effector repertoire of each strain cooperates over the course of an infection

Priorities for synthesis research in ecology and environmental science

ACKNOWLEDGMENTS We thank the National Science Foundation grant #1940692 for financial support for this workshop, and the National Center for Ecological Analysis and Synthesis (NCEAS) and its staff for logistical support.Peer reviewedPublisher PD

Priorities for synthesis research in ecology and environmental science

ACKNOWLEDGMENTS We thank the National Science Foundation grant #1940692 for financial support for this workshop, and the National Center for Ecological Analysis and Synthesis (NCEAS) and its staff for logistical support.Peer reviewedPublisher PD

Effects of Dance Footwear on Kinetics and Lower Limb Joint Kinematics During Sauté Jumps

While some efforts have been made to design footwear that would be beneficial for dancers in terms of performance and injury prevention, most footwear commonly used by dancers offers very little support to the foot and ankle region. Footwear has the potential to modify the interaction between the foot and the floor, but there is minimal research examining the effects of footwear on dance performance. PURPOSE: The purpose of this study was to investigate the effects of footwear on ground reaction forces and lower extremity joint motion during a sauté (dance specific bipedal vertical jump) landing. METHODS: Eighteen healthy, experienced dancers provided informed consent to participate in this IRB-approved study. Three-dimensional analysis was performed using a 12-camera video motion analysis system (Motion Analysis) and two force plates (Kistler). Participants performed ten consecutive sauté jumps while barefoot, wearing Apolla dance socks, wearing regular socks, and wearing Bloch Spin II dance shoes, with the order of conditions randomized for each participant. The digital camera signals were processed and analyzed using Cortex software. Visual3D software (C-Motion, Inc.) was used to quantify ground reaction forces and hip, knee, ankle, and toe kinematics. Results between footwear conditions were compared using repeated measures ANOVAs. RESULTS: There were no differences in peak vertical ground reaction force between footwear conditions ((3,11)=0.955, p = 0.912). There was a main effect of footwear on peak lower extremity joint kinematics ((6,12)=0.163, p \u3c 0.001). Peak extension of the MTP joints was reduced while wearing both the Apolla dance socks and the Bloch shoes (-19.1 ± 11.6° barefoot, -12.6 ± 6.4° Apolla, -19.6 ± 8.3° socks, -10.7 ± 6.4° Bloch). CONCLUSION: Preliminary results from this study indicate that Apolla dance socks and Bloch Spin II shoes may provide some protection for the MTP joints in dancers performing jumping movements by reducing peak joint extension. Future analyses examining joint kinetics and other dance movements may allow for more evidence-based recommendations regarding footwear use in dancers

Clinical implementation of the first Cherenkov imaging system in a community-based hospital

Purpose: To document experiences with one year of clinical implementation of the first Cherenkov imaging system and share the methods that we developed to utilize Cherenkov imaging to improve treatment delivery accuracy in real-time. Methods: A Cherenkov imaging system was installed commissioned and calibrated for clinical use. The optimal room lighting conditions and imaging setup protocols were developed to optimize both image quality and patient experience. The Cherenkov images were analyzed for treatment setup and beam delivery verification. Results: We have successfully implemented a clinical Cherenkov imaging system in a community-based hospital. Several radiation therapy patient setup anomalies were found in 1) exit dose to the contralateral breast, 2) dose to the chin due to head rotation for a supraclavicular field, 3) intrafractional patient motion during beam delivery, and 4) large variability (0.5 cm to 5 cm) in arm position between fractions. The system was used to deliver deep inspiration breath hold (DIBH) treatment delivery of an electron treatment beam. Clinical process and procedures were improved to mitigate the identified issues to ensure treatment delivery safety and to improve treatment accuracy. Conclusion: The Cherenkov imaging system has proven to be a valuable clinical tool for the improvement of treatment delivery safety and accuracy at our hospital. With only minimal training the therapists were able to adjust or correct treatment positions during treatment delivery as needed. With future Cherenkov software developments Cherenkov imaging systems could provide daily surface guided radiotherapy (SGRT) and real time treatment delivery quality control for all 3D and clinical setup patients without adding additional radiation image dose as in standard kV, MV and CBCT image verifications. Cherenkov imaging can greatly improve clinical efficiency and accuracy, making real time dose delivery consistency verification and SGRT a reality