Reducing peak pressures under the saddle at thoracic vertebrae 10-13 is associated with alteration in jump kinematics

2018 ◽  
Vol 14 (4) ◽  
pp. 239-247 ◽  
Author(s):  
R.C. Murray ◽  
R. Mackechnie-Guire ◽  
M. Fisher ◽  
V. Fairfax
Keyword(s):  
Motion Analysis ◽  
High Speed ◽  
Peak Pressure ◽  
Video Data ◽  
Flexion Angle ◽  
Thoracic Vertebrae ◽  
Kinematic Data ◽  
Maximum Peak ◽  
Peak Pressures ◽  
Positive Effect

There is little information about horse-saddle interaction at take-off for a fence, although there is potential that this could have an influence on performance. It was hypothesised that (1) maximum peak pressure under the saddle would occur in the phase of maximum thoracolumbar flexion prior to hindlimb take-off; and (2) limb and trunk kinematics at take-off over the fence would be affected by reducing peak pressure at Thoracic vertebrae (T)10-13 at the point in the stride where peak pressures occur. The peak pressures under the usual saddle (Saddle S) and a saddle modified to reduce peak pressures at T10-13 (Saddle F) were measured during approach and take-off over a 1.30 m upright fence in 12 elite jumping horses. The timing of peak pressures was determined by comparison with simultaneous video data. Shoulder, carpal flexion angle and trunk angle to the horizontal at hindlimb take-off, take-off distance from the fence and fetlock height above the fence were determined using high speed motion analysis. Peak pressures under the saddle at T10-13 and kinematic data were compared between Saddles S and F. Maximum peak pressures occurred at forelimb vertical, during hindlimb protraction, consistent with thoracolumbar ventroflexion. Saddle F was associated with significantly lower peak pressures at T10-13, greater shoulder and carpal flexion, a steeper trunk angle, and higher fetlock height above the fence than Saddle S. Forelimb take-off distance from the fence was not different between saddles, but hindlimbs were significantly closer to the fence with Saddle F, indicating potential increase in ventroflexion through the thoracolumbosacral region. These findings suggest that reducing peak pressures under the saddle at T10-13 are associated with altered kinematics during the approach and take-off over a fence, which may have a positive effect on jumping performance.

scholarly journals Influences of High-Speed Train Speed on Tunnel Aerodynamic Pressures

2021 ◽  
Vol 12 (1) ◽  
pp. 303
Author(s):  
Jianming Du ◽  
Qian Fang ◽  
Jun Wang ◽  
Gan Wang
Keyword(s):  
High Speed ◽  
Peak Pressure ◽  
Stage I ◽  
Stage Ii ◽  
Stage Iii ◽  
High Speed Train ◽  
Railway Tunnel ◽  
Maximum Peak ◽  
Train Speed ◽  
Three Stages

To comprehensively investigate the characteristics of aerodynamic pressures on a tunnel caused by the whole tunnel passage of a high-speed train at different speeds, we conduct a series of three-dimensional numerical simulations. Based on the field test results obtained by other researchers, the input parameters of our numerical simulation are determined. The process of a high-speed train travelling through a railway tunnel is divided into three stages according to the spatial relationship between the train and tunnel. Stage I: before train nose enters the entrance; Stage II: while the train body runs inside the tunnel; Stage III: after the train tail leaves the exit. The influences of high-speed train speed on the tunnel aerodynamic pressures of these three stages are systematically investigated. The results show that the maximum peak pressure value decreases with increasing distance from the entrance and increases with increasing train speed in Stage I. There is an approximately linear relationship between the three types of maximum peak pressure (positive peak, negative peak, and peak-to-peak pressures) and the power of the train speed in Stage II. These three types of maximum peak pressure values of the points near tunnel portals increase with increasing train speed in Stage III. Moreover, these three types of maximum peak pressure in the tunnel’s middle section at different train speeds are more complex than those near the tunnel portals, and there is one or more turning points due to the superimposed effects of different pressure waves.

scholarly journals Three-dimensional motion analysis of ten common Asian sitting positions in daily living and factors affect range of hip motions

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Phob Ganokroj ◽  
Jirayu Chaowalitwong ◽  
Pichitpol Kerdsomnuek ◽  
Narumol Sudjai ◽  
Pisit Lertwanich ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Motion Analysis ◽  
External Rotation ◽  
Three Dimensional ◽  
Cross Sectional Study ◽  
Flexion Angle ◽  
Abduction Angle ◽  
Female Group ◽  
Cross Sectional ◽  
Kinematic Data

Abstract Background Sitting involves many activities of daily life and requires most motion in the hip joint. Asians have more hip flexion and external rotation motions than Westerners owing to cultural and lifestyle differences. Being aware of the normal range of hip motion is essential in clinical practice. Limited research has focused on the hip motions of common sitting positions. The objective was to determine the hip motions of 10 common sitting positions, and to determine whether gender or being overweight affects the range of hip motions. Methods An experimental cross-sectional study was conducted to determine hip motions by using a standard, three-dimensional, motion-analysis system. Healthy subjects performed 10 sitting positions during 3 trials. All hip-kinematic data were measured on the dominant leg of each participant, except for the right- and left-monk positions (both hips were analyzed). Density plots were constructed and statistical analyses were performed to detect the differences between groups (male and female; non-overweight and overweight). Results The 48 participants comprised 24 males and 24 females. Most were right-leg dominant (45 participants, 93.8%). Of the 22 participants in the overweight group (body mass index ≥23 kg/m2), 18 (75%) were male. Squatting showed the highest flexion angle (99.7°, 47.3°–122°). Cross-legged sitting had the highest abduction angle (28.9°, 9.9°–45.7°) and the largest external rotation angle (62°, 37.6°–81.7°). In the female group, there were trends toward a greater flexion angle (4 out of 10 sitting positions) and a smaller abduction angle (6 out of 9 positions), with P values < 0.05. As to body weight, the overweight participants had a smaller flexion angle but a greater abduction angle, with 5 out of 9 positions having a P value < 0.05. Kinematic data of the transverse plane revealed that the heterogeneity of the rotational angles depended on the sitting position. Conclusions This study provided the functional hip motions of common Asian sitting positions. The kinematic data can be utilized in clinical practice as reference values to determine safe positions. Gender and being overweight affected the hip angles in the sagittal and frontal planes. Trial registration Number TCTR20181021004, retrospectively registered at the Thai Clinical Trials Registry (http//:www.clinicaltrials.in.th).

scholarly journals Three-dimensional motion analysis of hip motions in ten common Asian sitting positions in daily living. Do gender and being overweight affect the range of hip motions?

2021 ◽  
Author(s):  
Phob Ganokroj ◽  
Jirayu Chaowalitwong ◽  
Pichitpol Kerdsomneuk ◽  
Narumol Sudjai ◽  
Pisit Lertwanich ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Motion Analysis ◽  
External Rotation ◽  
Three Dimensional ◽  
Cross Sectional Study ◽  
Flexion Angle ◽  
Abduction Angle ◽  
Female Group ◽  
Cross Sectional ◽  
Kinematic Data

Abstract Background Sitting involves many activities of daily life and requires most motion in the hip joint. Asians have more hip flexion and external rotation motions than Westerners owing to cultural and lifestyle differences. Being aware of the normal range of hip motion is essential in clinical practice. Limited research has focused on the hip motions of common sitting positions. The objective was to determine the hip motions of 10 common sitting positions, and to determine whether gender or being overweight affects the range of hip motions.Methods An experimental cross-sectional study was conducted to determine hip motions by using a standard, three-dimensional, motion-analysis system. Healthy subjects performed 10 sitting positions during 3 trials. All hip-kinematic data were measured on the dominant leg of each participant, except for the right- and left-monk positions (both hips were analyzed). Density plots were constructed and statistical analyses were performed to detect the differences between groups (male and female; non-overweight and overweight).Results The 48 participants comprised 24 males and 24 females. Most were right-leg dominant (45 participants; 93.8%). Of the 22 participants in the overweight group (body mass index ≥ 23 kg/m2), 18 (75%) were male. Squatting showed the highest flexion angle (99.7º; 47.3º–122º). Cross-legged sitting had the highest abduction angle (28.9º; 9.9º–45.7º) and the largest external rotation angle (62º; 37.6º–81.7º). In the female group, there were trends toward a greater flexion angle (4 out of 10 sitting positions) and a smaller abduction angle (6 out of 9 positions), with P values < 0.05. As to body weight, the overweight participants had a smaller flexion angle but a greater abduction angle, with 5 out of 9 positions having a P value < 0.05. Kinematic data of the transverse plane revealed that the heterogeneity of the rotational angles depended on the sitting position.Conclusions This study provided the functional hip motions of common Asian sitting positions. The kinematic data can be utilized in clinical practice as reference values to determine safe positions. Gender and being overweight affected the hip angles in the sagittal and frontal planes.Trial registration: Number TCTR20181021004, retrospectively registered at the Thai Clinical Trials Registry (http://www. clinicaltrials.in.th).

APPLICATION OF THE EARLY DAMAGE DIAGNOSTICS TECHNIQUE TO EXAMINATION OF THE AVIATION PANEL

2019 ◽  
Vol 85 (6) ◽  
pp. 53-63 ◽  
Author(s):  
I. E. Vasil’ev ◽  
Yu. G. Matvienko ◽  
A. V. Pankov ◽  
A. G. Kalinin
Keyword(s):  
Acoustic Emission ◽  
Damage Detection ◽  
High Speed ◽  
Early Stage ◽  
Video Data ◽  
High Speed Video ◽  
Damage Diagnostics ◽  
Subsurface Defect ◽  
Sensitive Coating ◽  
Early Damage

The results of using early damage diagnostics technique (developed in the Mechanical Engineering Research Institute of the Russian Academy of Sciences (IMASH RAN) for detecting the latent damage of an aviation panel made of composite material upon bench tensile tests are presented. We have assessed the capabilities of the developed technique and software regarding damage detection at the early stage of panel loading in conditions of elastic strain of the material using brittle strain-sensitive coating and simultaneous crack detection in the coating with a high-speed video camera “Video-print” and acoustic emission system “A-Line 32D.” When revealing a subsurface defect (a notch of the middle stringer) of the aviation panel, the general concept of damage detection at the early stage of loading in conditions of elastic behavior of the material was also tested in the course of the experiment, as well as the software specially developed for cluster analysis and classification of detected location pulses along with the equipment and software for simultaneous recording of video data flows and arrays of acoustic emission (AE) data. Synchronous recording of video images and AE pulses ensured precise control of the cracking process in the brittle strain-sensitive coating (tensocoating)at all stages of the experiment, whereas the use of structural-phenomenological approach kept track of the main trends in damage accumulation at different structural levels and identify the sources of their origin when classifying recorded AE data arrays. The combined use of oxide tensocoatings and high-speed video recording synchronized with the AE control system, provide the possibility of definite determination of the subsurface defect, reveal the maximum principal strains in the area of crack formation, quantify them and identify the main sources of AE signals upon monitoring the state of the aviation panel under loading P = 90 kN, which is about 12% of the critical load.

Image-Based Versus Signal-Based Sensors for Machine Fault Detection and Isolation

2014 ◽  
Author(s):  
Heshan Fernando ◽  
Vedang Chauhan ◽  
Brian Surgenor
Keyword(s):  
Fault Detection ◽  
High Speed ◽  
Fault Isolation ◽  
Video Data ◽  
Fault Detection And Isolation ◽  
Single Camera ◽  
Multiple Faults ◽  
Multiple Sensors ◽  
Machine Fault ◽  
And Performance

This paper presents the results of a comparative study that investigated the use of image-based and signal-based sensors for fault detection and fault isolation of visually-cued faults on an automated assembly machine. The machine assembles 8 mm circular parts, from a bulk-supply, onto continuously moving carriers at a rate of over 100 assemblies per minute. Common faults on the machine include part jams and ejected parts that occur at different locations on the machine. Two sensor systems are installed on the machine for detecting and isolating these faults: an image-based system consisting of a single camera and a signal-based sensor system consisting of multiple greyscale sensors and limit switches. The requirements and performance of both systems are compared for detecting six faults on the assembly machine. It is found that both methods are able to effectively detect the faults but they differ greatly in terms of cost, ease of implementation, detection time and fault isolation capability. The conventional signal-based sensors are low in cost, simple to implement and require little computing power, but the installation is intrusive to the machine and readings from multiple sensors are required for faster fault detection and isolation. The more sophisticated image-based system requires an expensive, high-resolution, high-speed camera and significantly more processing power to detect the same faults; however, the system is not intrusive to the machine, fault isolation becomes a simpler problem with video data, and the single camera is able to detect multiple faults in its field of view.

Application of the method of dimensional analysis in laser-shock-wave processing of titanium alloys with shape memory

2021 ◽  
pp. 66-72
Author(s):  
Keyword(s):  
Shock Wave ◽  
Finite Element ◽  
Plastic Zone ◽  
Shape Memory ◽  
Dimensional Analysis ◽  
Peak Pressure ◽  
Laser Shock ◽  
Zone Depth ◽  
Peak Pressures ◽  
Laser Shock Wave

The processes of laser-shock-wave processing of NiTi alloys with shape memory effect are investigated by the methods of dimensional analysis and finite element modeling. The dependences of the depth of the plastic zone on the peak pressure in the shock wave and the duration of the laser pulse are obtained at different peak pressures. Keywords: shape memory alloys, laser-shock-wave processing, dimensional analysis, residual stresses, plastic zone depth. [email protected]

Abstract TP250: Defining Technical Quality Standards for Mobile Telestroke Assessment: A Substudy of the Improving Treatment with Rapid Evaluation of Acute Stroke via Mobile Telemedicine (iTREAT) Mobile Telestroke Platform

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Jason M Lippman ◽  
Zachary G Sutton ◽  
Timothy L McMurry ◽  
Brian Gunnell ◽  
Jack Cote ◽  
...  
Keyword(s):  
Acute Stroke ◽  
High Speed ◽  
Low Cost ◽  
Video Quality ◽  
Stroke Care ◽  
Video Data ◽  
Acute Stroke Care ◽  
Technical Standards ◽  
Quality Ratings ◽  
Transmission Quality

Introduction: In-ambulance use of remote videoconferencing for prehospital stroke assessment (mobile telestroke) is an emerging innovation in acute stroke care. As a new technology, there is a dearth of technical standards to ensure transmission quality and guide deployment in various EMS settings. Hypothesis: Subjective video quality ratings during in-vehicle mobile telestroke assessment correlate to objective video data transmission metrics. Methods: We performed videoconferencing via a low-cost, utilitarian mobile telestroke platform: tablet endpoint, high-speed 4G LTE modem, external antennae, HIPAA-secure videoconferencing application, and portable bracket mounting. We held test calls along typical ambulance routes recording transmission quality by a stationary and a mobile rater. We used a standardized 6-point scale of video quality: rating ≥ 4 deemed acceptable for mobile telestroke assessment. We recorded jitter, the variance in transmission data reception order, as simultaneously reported by the videoconferencing application. Results: We completed five test runs yielding 64 data ratings. Average jitter for ratings 1 through 6 was 434.9ms (SD = 407), 106.1ms (SD = 110), 41.4ms (SD = 29), 35.3ms (SD = 15), 29.5ms (SD = 6), and 29.0ms (SD = 2) respectively. Analyzing the raw data yielded an R2 of 0.41. As seen in Chart 1, video quality decreased as average jitter increased, but jitter values as low as 30ms were still seen across video transmission of all qualities. Conclusion: These preliminary data suggest modest correlation of transmission variance with subjective quality ratings using a low-cost mobile telestroke platform along rural-based ambulance routes. However, average transmission variance correlated highly (R2 = 0.93) suggesting more data ratings may improve the correlation. Testing of our mobile telestroke platform to assess performance and clinical efficacy as well as incorporate live acute stroke encounters is ongoing.

Limb and thoracolumbosacral kinematics over an upright and parallel spread fence

2019 ◽  
Vol 15 (1) ◽  
pp. 55-67
Author(s):  
V.A. Walker ◽  
S.J. Dyson ◽  
C.A. Tranquille ◽  
J.B. Tacey ◽  
R.C. Murray
Keyword(s):  
Motion Analysis ◽  
High Speed ◽  
Great Variability ◽  
Head Neck

Jumping mechanics have been investigated at take-off, flight and landing, mainly in reference to the limbs with limited evaluation of the thoracolumbosacral region. The objectives of this study were to investigate head, neck, thoracolumbosacral and limb angles in a group of experienced showjumping horses (competing at 1.20-1.60 m) over an upright and parallel spread fence. Ten horses in active showjumping training were recruited (mean 8 years old). High-speed videography (240 Hz) was used to determine thoracolumbosacral kinematic variables of the approach and take-off. No significant differences between the upright and parallel spread fences were observed for any of the variables measured. Individual horse review showed that neck-trunk, thoracolumbar, lumbosacral, coxofemoral angles, take-off distance and speed patterns at take-off were consistent among horses and also repeatable between fence types. Head-neck, stifle and tarsal angles had great variability among horses. The main limitation of this study was that only 2D motion analysis was carried out. In conclusion, analysis of individual horse patterns showed that head, neck, back and limb angles were repeatable over submaximal upright and spread fences in ten horses. Some angles were consistent among horses, but others had individual horse variation.

scholarly journals Regaining motion among patients with shoulder pathology - are all exercises equal?

2021 ◽  
pp. 175857322110671
Author(s):  
Alon Rabin ◽  
Eran Maman ◽  
Oleg Dolkart ◽  
Efi Kazum ◽  
Zvi Kozol ◽  
...  
Keyword(s):  
Pain Intensity ◽  
Range Of Motion ◽  
Motion Analysis ◽  
The Self ◽  
Flexion Angle ◽  
Shoulder Range Of Motion ◽  
Shoulder Flexion ◽  
Shoulder Disorders ◽  
Level Of Difficulty ◽  
Shoulder Range

Background Little information exists to guide the choice of exercise for regaining shoulder range of motion (ROM). The purpose of this study was to compare the maximal ROM reached, pain and difficulty associated with 4 commonly prescribed exercises. Methods Forty (9 females) patients with various shoulder disorders and a limited flexion ROM performed 4 exercises for regaining shoulder flexion ROM in a randomized order. Exercises included the self-assisted flexion, forward bow, table slide and rope-and-pulley. Participants were videotaped while performing all exercises and the maximal flexion angle reached during each exercise was recorded using Kinovea motion analysis freeware (Kinovea 0.8.15). Pain intensity and the perceived level of difficulty associated with each exercise were also recorded. Results The forward bow and table slide generated significantly greater ROM compared with the self-assisted flexion and rope-and-pulley (P ≤ 0.005). The self-assisted flexion was associated with a greater pain intensity compared with the table slide and rope-and-pulley (P = 0.002) and a greater perceived level of difficulty compared with the table slide (P = 0.006). Conclusions Due to the greater ROM allowed, and similar or even lower level of pain or difficulty, clinicians may wish to initially recommend the forward bow and table slide for regaining shoulder flexion ROM.

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