scholarly journals Measurement of lower-limb asymmetry in professional rugby league: a technical note describing the use of inertial measurement units

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9366 ◽  
Author(s):  
Daniel J. Glassbrook ◽  
Joel T. Fuller ◽  
Jacqueline A. Alderson ◽  
Tim L.A. Doyle
Keyword(s):  
Lower Limb ◽  
Mechanical Load ◽  
Rugby League ◽  
Match Play ◽  
Measurement Units ◽  
External Mechanical Load ◽  
Clinically Significant ◽  
Limb Asymmetry ◽  
Limb Load ◽  
Very High

Background Quantifying lower-limb load and asymmetry during team sport match-play may be important for injury prevention and understanding performance. However, current analysis methods of lower-limb symmetry during match-play employ wearable microtechnology that may not be best suited to the task. A popular microtechnology is global positioning systems (GPS), which are torso worn. The torso location, and the summary workload measures calculated by GPS are not suited to the calculation of lower-limb load. Instead, research grade accelerometers placed directly on the lower-limb may provide better load information than GPS. This study proposes a new technique to quantify external mechanical load, and lower-limb asymmetry during on-field team sport play using inertial measurement units. Methods Four professional rugby league players (Age: 23.4  ± 3.1 years; Height: 1.89  ± 0.05 m; Mass: 107.0  ± 12.9 kg) wore two accelerometers, one attached to each foot by the boot laces, during match simulations. Custom Matlab (R2017b, The Mathworks Inc, Natick, MA) code was used to calculate total time, area under the curve (AUC), and percentage of time (%Time) spent in seven acceleration categories (negative to very high, <0 g to >16 g), as well as minimum and maximum acceleration during match simulations. Lower-limb AUC and %Time asymmetry was calculated using the Symmetry Angle Equation, which does not require normalization to a reference leg. Results The range of accelerations experienced across all participants on the left and right sides were 15.68–17.53 g, and 16.18–17.69 g, respectively. Clinically significant asymmetry in AUC and %Time was observed for all but one participant, and only in negative (<0 g) and very high accelerations (>16 g). Clinically significant AUC differences in very high accelerations ranged from 19.10%–26.71%. Clinically significant %Time differences in negative accelerations ranged from 12.65%–25.14%, and in very high accelerations from 18.59%–25.30%. All participants experienced the most AUC at very low accelerations (2–4 g), and the least AUC at very high accelerations (165.00–194.00 AU vs. 0.32–3.59 AU). The %Time results indicated that all participants spent the majority of match-play (73.82–92.06%) in extremely low (0–2 g) to low (4–6 g) acceleration intensities, and the least %Time in very high accelerations (0.01%–0.05%). Discussion A wearable located on the footwear to measure lower-limb load and asymmetry is feasible to use during rugby league match-play. The location of the sensor on the boot is suited to minimize injury risk occurring from impact to the sensor. This technique is able to quantify external mechanical load and detect inter limb asymmetries during match-play at the source of impact and loading, and is therefore likely to be better than current torso based methods. The results of this study may assist in preparing athletes for match-play, and in preventing injury.

Player Activity Profiles in the Australian Second-Tier Rugby League Competitions

2016 ◽  
Vol 11 (6) ◽  
pp. 816-823
Author(s):  
Joanne Hausler ◽  
Mark Halaki ◽  
Rhonda Orr
Keyword(s):  
High Speed ◽  
New South ◽  
Rugby League ◽  
Relative Distance ◽  
Match Play ◽  
South Wales ◽  
Global Positioning ◽  
Second Tier ◽  
Sprinting Speed ◽  
Very High

Purpose:To investigate activity profiles of Australian rugby league players during match play by competition, position, and match outcome in the New South Wales (NSW) second-tier competitions.Methods:Eighteen NSW Cup (NSWC) and 22 National Youth Competition (NYC) players, participating in this prospective cohort study, were categorized into 3 positional groups: forwards, adjustables, and outside backs. Global positioning system devices were used to examine activity profiles (distance and relative distance covered in walking, jogging, moderate, high, very high, and sprinting speed zones and quantification of high-speed movement) during match play in 21 NSWC and 22 NYC matches (N = 339 files).Results:NSWC players performed more sprints (36.5 ± 9.3 vs 28.4 ± 9.2) and greater relative distance in moderate speed zones (18.4 ± 3.2 vs 15.8 ± 3.1 m/min) than NYC. NSWC outside backs covered greater relative distance in jogging (29.4 ± 2.9 vs 24.8 ± 2.7 m/min) and moderate speed zones (17.0 ± 2.6 vs 12.8 ± 2.8 m/min) than their NYC counterparts. Adjustables performed more sprints (39.4 ± 10.1 vs 27.0 ± 9.2), high-intensity accelerations (3.7 ± 1.4 vs 1.9 ± 1.4), and relative distance (84.8 ± 4.3 vs 88.6 ± 4.8 m/min) than forwards and greater relative distance (81.5 ± 3.8 m/min) and sprints (31.0 ± 8.0) than outside backs. Adjustables recorded greater relative distance (19.8 m/min) in moderate speed zones than forwards (16.7 ± 3.1 m/min) and outside backs (14.9 ± 2.7 m/min). Adjustables covered ~685 m more than outside backs during a win.Conclusions:This is the first study to document the activity profiles of the NSW second-tier rugby league competition. The findings underscore the elevated match demands of adjustables and indicate higher intensity of play in NSWC than NYC that may more closely resemble the demands of National Rugby League match play.

Investigations into the Clinical Utility of Latex D-Dimer in the Diagnosis of Deep Venous Thrombosis

1993 ◽  
Vol 69 (01) ◽  
pp. 008-011 ◽  
Author(s):  
Cedric J Carter ◽  
D Lynn Doyle ◽  
Nigel Dawson ◽  
Shauna Fowler ◽  
Dana V Devine
Keyword(s):  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Lower Limb ◽  
Clinical Utility ◽  
Rapid Test ◽  
Fibrin Degradation Product ◽  
Current Form ◽  
Non Invasive ◽  
Clinically Significant ◽  
D Dimer

SummaryThe serial use of non-invasive tests has been shown to be a safe method of managing outpatients who are suspected of having lower limb deep venous thrombosis (DVT). Objective testing has shown that the majority of these outpatients do not have venous thrombosis. A rapid test to exclude DVT in these patients, without the need for expensive and inconvenient serial non-invasive vascular testing, would have practical and economic advantages.Studies measuring the fibrin degradation product D-dimer using enzyme-linked immunoassays (EIA) in patients with veno-graphically proven DVT suggest that it should be possible to exclude this condition by the use of one of the rapid latex bead D-dimer tests.We have examined 190 patients with suspected DVT using both a latex and an EIA D-dimer assay. The latex D-dimer test used in this study was negative in 7 of the 36 proven cases of DVT. This sensitivity of only 80% is not sufficient to allow this type of assay, in its current form, to be used as an exclusion test for DVT. The same plasma samples were tested with an EIA assay. This information was used to mathematically model the effects of selecting a range of D-dimer discriminant cut off points for the diagnosis of DVT. These results indicate that 62% of suspected clinically significant DVT could have this diagnosis excluded, with a 98% sensitivity, if the rapid latex or equivalent D-dimer test could be reformulated to measure less than 185 ng/ml of D-dimer.

scholarly journals Loading and relaxation dynamics for a red blood cell

Soft Matter ◽  
2021 ◽  
Author(s):  
Fabio Guglietta ◽  
Marek Behr ◽  
Giacomo Falcucci ◽  
Mauro Sbragaglia
Keyword(s):  
Blood Cell ◽  
Numerical Simulations ◽  
Red Blood Cell ◽  
Mechanical Load ◽  
Detailed Comparison ◽  
Relaxation Dynamics ◽  
External Mechanical Load

We use mesoscale numerical simulations to investigate the unsteady dynamics of a single red blood cell (RBC) subjected to an external mechanical load. We carry out a detailed comparison between...

scholarly journals Effect of Functional Electrical Stimulation of the Gluteus Medius during Gait in Patients following a Stroke

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Sota Araki ◽  
Masayuki Kawada ◽  
Takasuke Miyazaki ◽  
Yuki Nakai ◽  
Yasufumi Takeshita ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Lower Limb ◽  
Stride Length ◽  
Gluteus Medius ◽  
Gait Velocity ◽  
Inertial Measurement Units ◽  
Stroke Patients ◽  
Inertial Measurement ◽  
Motion Range ◽  
Measurement Units

Many stroke patients rely on cane or ankle-foot orthosis during gait rehabilitation. The purpose of this study was to investigate the immediate effect of functional electrical stimulation (FES) to the gluteus medius (GMed) and tibialis anterior (TA) on gait performance in stroke patients, including those who needed assistive devices. Fourteen stroke patients were enrolled in this study (mean poststroke duration: 194.9 ± 189.6   d ; mean age: 72.8 ± 10.7   y ). Participants walked 14 m at a comfortable velocity with and without FES to the GMed and TA. After an adaptation period, lower-limb motion was measured using magnetic inertial measurement units attached to the pelvis and the lower limb of the affected side. Motion range of angle of the affected thigh and shank segments in the sagittal plane, motion range of the affected hip and knee extension-flexion angle, step time, and stride time were calculated from inertial measurement units during the middle ten walking strides. Gait velocity, cadence, and stride length were also calculated. These gait indicators, both with and without FES, were compared. Gait velocity was significantly faster with FES ( p = 0.035 ). Similarly, stride length and motion range of the shank of the affected side were significantly greater with FES (stride length: p = 0.018 ; motion range of the shank: p = 0.02 6). Meanwhile, cadence showed no significant difference ( p = 0.238 ) in gait with or without FES. Similarly, range of motion of the affected hip joint, knee joint, and thigh did not differ significantly depending on FES condition ( p = 0.115 ‐ 0.529 ). FES to the GMed and TA during gait produced an improvement in gait velocity, stride length, and motion range of the shank. Our results will allow therapists to use FES on stroke patients with varying conditions.

scholarly journals Lateral Preference and Inter-limb Asymmetry in Completing Technical Tasks During Official Professional Futsal Matches: The Role of Playing Position and Opponent Quality

2021 ◽  
Vol 12 ◽  
Author(s):  
Luiz H. Palucci Vieira ◽  
Carlos A. Kalva-Filho ◽  
Felipe B. Santinelli ◽  
Filipe M. Clemente ◽  
Sergio A. Cunha ◽  
...  
Keyword(s):  
Accuracy Rate ◽  
World Cup ◽  
Lateral Preference ◽  
Match Play ◽  
Frequency Of Use ◽  
Limb Asymmetry ◽  
Similar Accuracy ◽  
High Level

This study had the purpose of analyzing dominant and non-dominant limb performances (frequency of use and accuracy) during match-play technical actions with ball possession (receiving, passing, and shooting a ball) in professional futsal and also check for the possible influence of playing position and the quality of opponent. We have analyzed data pertaining to eight matches of the FIFA Futsal World Cup Thailand 2012™ in which 76 male professional senior futsal players participated (44 right-footed and 32 left-footed). In total, we coded 5,856 actions (2,550 ball receptions, 3,076 passes, and 230 shoots). Our main findings were that (a) players used the dominant limb more frequently than the non-dominant limb for all actions considered [p &lt; 0.001; effect size (ES) medium-to-large]; (b) accuracy was generally greater when using the dominant limb, regardless of the quality of opponent (p &lt; 0.01; ES large); and (c) in shooting actions, pivots showed similar accuracy between dominant and non-dominant limbs (p = 0.51; ES small). The study suggested that when completing technical actions with the ball in futsal, high-level players depended to a greater extent on the use of their dominant lower limb during official matches. Excepting a similarity detected between limbs on shooting performance of pivots, players from all positional roles generally showed a higher accuracy rate in receiving, passing, and shooting a ball when using their dominant limb as compared to their non-dominant one during match-play and the limb usage and accuracy seemed to be independent of the quality of opponents.

Endothermal ablation for the treatment of clinically significant incompetent lower limb perforating veins: factors influencing the early outcomes

2020 ◽  
pp. 026835552095508
Author(s):  
Kenneth R Woodburn
Keyword(s):  
Radiofrequency Ablation ◽  
Laser Ablation ◽  
Lower Limb ◽  
Closure Rate ◽  
Short Treatment ◽  
Endovenous Laser Ablation ◽  
Perforating Veins ◽  
Factors Influencing ◽  
Early Closure ◽  
Clinically Significant

Background To review the clinical experience and early outcomes of endothermal perforator ablation. Method Retrospective review of an endovenous practice from 2007-2019. Clinically significant incompetent perforators were treated by Endovenous Laser Ablation (EVLA), or segmental radiofrequency ablation (RFA). Result Complete data were available for 110 of the 116 symptomatic incompetent perforating veins treated. Radiofrequency ablation of 20 perforators produced a 55% perforator closure rate, while 90 EVLA perforator ablations resulted in a closure rate of 80%. Closure rates with EVLA varied by location and perforator length. Closure rates for truncal ablation were 95.5% for RFA and 97.2% for EVLA. Conclusion Early closure rates following endothermal ablation of incompetent lower limb perforating veins are lower than those obtained for truncal ablation. EVLA perforator closure appears to be more effective than segmental RFA in most situations but short treatment lengths and location at the ankle are associated with the poorest outcomes.

scholarly journals Reliability and Agreement of 3D Trunk and Lower Extremity Movement Analysis by Means of Inertial Sensor Technology for Unipodal and Bipodal Tasks

Sensors ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 141 ◽  
Author(s):  
Rob Van der Straaten ◽  
Amber K. B. D. Bruijnes ◽  
Benedicte Vanwanseele ◽  
Ilse Jonkers ◽  
Liesbet De Baets ◽  
...  
Keyword(s):  
Lower Limb ◽  
Sagittal Plane ◽  
Inertial Sensor ◽  
Movement Analysis ◽  
Sensor Technology ◽  
Inertial Measurement ◽  
Sit To Stand ◽  
Movement Strategies ◽  
Measurement Units ◽  
Healthy Participants

This study evaluates the reliability and agreement of the 3D range of motion (ROM) of trunk and lower limb joints, measured by inertial measurement units (MVN BIOMECH Awinda, Xsens Technologies), during a single leg squat (SLS) and sit to stand (STS) task. Furthermore, distinction was made between movement phases, to discuss the reliability and agreement for different phases of both movement tasks. Twenty healthy participants were measured on two testing days. On day one, measurements were conducted by two operators to determine the within-session and between-operator reliability and agreement. On day two, measurements were conducted by the same operator, to determine the between-session reliability and agreement. The SLS task had lower within-session reliability and agreement compared with between-session and between-operator reliability and agreement. The reliability and agreement of the hip, knee, and ankle ROM in the sagittal plane were good for both phases of the SLS task. For both phases of STS task, within-session reliability and agreement were good, and between-session and between-operator reliability and agreement were lower in all planes. As both tasks are physically demanding, differences may be explained by inconsistent movement strategies. These results show that inertial sensor systems show promise for use in further research to investigate (mal)adaptive movement strategies.

Posture of rugby league players and its relationship to non-contact lower limb injury: A prospective cohort study

2019 ◽  
Vol 40 ◽  
pp. 27-32
Author(s):  
Edward Langdon ◽  
Suzanne J. Snodgrass ◽  
Jodi L. Young ◽  
Andrew Miller ◽  
Robin Callister
Keyword(s):  
Cohort Study ◽  
Prospective Cohort Study ◽  
Lower Limb ◽  
Prospective Cohort ◽  
Rugby League ◽  
Lower Limb Injury ◽  
Limb Injury

Monitoring of the Airflow around the Façade of an Office Building

2019 ◽  
Vol 887 ◽  
pp. 579-586
Author(s):  
Peter Juras ◽  
Radoslav Ponechal
Keyword(s):  
Temperature Distribution ◽  
High Resolution ◽  
Air Temperature ◽  
Office Building ◽  
Wind Flow ◽  
Climate Conditions ◽  
Outdoor Climate ◽  
Measurement Units ◽  
Weather Stations ◽  
Very High

This paper describes measurement units on the building façade, which enable the possibility to conduct a full-scale measurement with a very high resolution of the outdoor climate parameters around the building. The façade of the Research center building, which is a part of University of Zilina campus, is equipped with 36 weather stations to measure the outdoor climate conditions and impact of the building on the approaching wind flow and air temperature distribution, solar radiance impact on the façade, etc. In this article, the wind flow around the building in different heights is monitored, analyzed and compared to the free wind flow.

scholarly journals Technology in Rehabilitation: Evaluating the Single Leg Squat Exercise with Wearable Inertial Measurement Units

2017 ◽  
Vol 56 (02) ◽  
pp. 88-94 ◽  
Author(s):  
Tomás E. Ward ◽  
Eamonn Delahunt ◽  
Brian Caulfield ◽  
Darragh F. Whelan ◽  
Martin A. O'Reilly
Keyword(s):  
Lumbar Spine ◽  
Lower Limb ◽  
Low Cost ◽  
Objective Evaluation ◽  
Inertial Measurement Units ◽  
Lower Limb Injury ◽  
Inertial Measurement ◽  
Increased Risk ◽  
Measurement Units ◽  
Single Leg Squat

SummaryBackground: The single leg squat (SLS) is a common lower limb rehabilitation exercise. It is also frequently used as an evaluative exercise to screen for an increased risk of lower limb injury. To date athlete/patient SLS technique has been assessed using expensive laboratory equipment or subjective clinical judgement; both of which are not without shortcomings. Inertial measurement units (IMUs) may offer a low cost solution for the objective evaluation of athlete/patient SLS technique.Objectives: The aims of this study were to determine if in combination or in isolation IMUs positioned on the lumbar spine, thigh and shank are capable of: (a) distinguishing between acceptable and aberrant SLS technique; (b) identifying specific deviations from acceptable SLS technique.Methods: Eighty-three healthy volunteers participated (60 males, 23 females, age: 24.68 +/− 4.91 years, height: 1.75 +/− 0.09 m, body mass: 76.01 +/− 13.29 kg). All participants performed 10 SLSs on their left leg. IMUs were positioned on participants’ lumbar spine, left shank and left thigh. These were utilized to record tri-axial accelerometer, gyroscope and magnetometer data during all repetitions of the SLS. SLS technique was labelled by a Chartered Physiotherapist using an evaluation framework. Features were extracted from the labelled sensor data. These features were used to train and evaluate a variety of random-forests classifiers that assessed SLS technique.Results: A three IMU system was moderately successful in detecting the overall quality of SLS performance (77% accuracy, 77% sensitivity and 78% specificity). A single IMU worn on the shank can complete the same analysis with 76% accuracy, 75% sensitivity and 76% specificity. Single sensors also produce competitive classification scores relative to multi-sensor systems in identifying specific deviations from acceptable SLS technique.Conclusions: A single IMU positioned on the shank can differentiate between acceptable and aberrant SLS technique with moderate levels of accuracy. It can also capably identify specific deviations from optimal SLS performance. IMUs may offer a low cost solution for the objective evaluation of SLS performance. Additionally, the classifiers described may provide useful input to an exercise biofeed-back application.

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