Laboratory assessment of a head impact sensor for youth soccer ball heading impacts using an anthropomorphic test device

2021 ◽  
pp. 175433712110631
Author(s):  
Declan A Patton ◽  
Colin M Huber ◽  
Ethan C Douglas ◽  
Thomas Seacrist ◽  
Kristy B Arbogast
Keyword(s):  
Angular Velocity ◽  
Human Subjects ◽  
Linear Acceleration ◽  
Head Impact ◽  
Percentage Error ◽  
Test Device ◽  
Laboratory Assessment ◽  
Soccer Ball ◽  
Youth Soccer

Recent advances in technology have enabled the development of instrumented equipment, which estimate the head impact kinematics of athletes in vivo. One such headband-mounted impact sensor is the SIM-G (Triax Technologies, Norwalk, CT, USA), which has been previously used to investigate the biomechanics of soccer heading by human subjects. Previous studies have evaluated the accuracy of the SIM-G for pure rotation and pendulum, impulse hammer and drop rig impacts. The current study used a soccer ball heading model to evaluate the accuracy of the SIM-G. A soccer ball was projected at the head of an anthropomorphic test device (ATD) representing a 10-year-old to replicate the heading maneuver at various impact sites, angles and speeds previously identified in youth soccer. Linear regression revealed that the SIM-G sensor overestimated the peak angular velocity and linear acceleration recorded by the ATD headform by approximately 44% and 105%, respectively. Tests in which the ball directly contacted the SIM-G sensor resulted in the largest peak linear accelerations. Glancing impacts were significantly associated with a decrease in percentage error of the SIM-G sensor peak angular velocity data relative to the ATD reference data. While it may not demonstrate accuracy in estimating the magnitudes of head impacts, the SIM-G remains a useful tool to provide estimates of head impact exposure for soccer players.

Characterization of On-Field Head Impact Exposure in Youth Soccer

2020 ◽  
pp. 1-7
Author(s):  
Brian T. Tomblin ◽  
N. Stewart Pritchard ◽  
Tanner M. Filben ◽  
Logan E. Miller ◽  
Christopher M. Miles ◽  
...  
Keyword(s):  
Linear Acceleration ◽  
Head Impact ◽  
Video Data ◽  
Soccer Players ◽  
Youth Soccer ◽  
Head Impacts ◽  
Head Kinematics ◽  
Frequency Of Contact ◽  
Ball Contact

The objective of this research was to characterize head impacts with a validated mouthpiece sensor in competitive youth female soccer players during a single season with a validated mouthpiece sensor. Participants included 14 youth female soccer athletes across 2 club-level teams at different age levels (team 1, ages 12–13 y; team 2, ages 14–15 y). Head impact and time-synchronized video data were collected for 66 practices and games. Video data were reviewed to characterize the type and frequency of contact experienced by each athlete. A total of 2216 contact scenarios were observed; heading the ball (n = 681, 30.7%) was most common. Other observed contact scenarios included collisions, dives, falls, and unintentional ball contact. Team 1 experienced a higher rate of headers per player per hour of play than team 2, while team 2 experienced a higher rate of collisions and dives. A total of 935 video-verified contact scenarios were concurrent with recorded head kinematics. While headers resulted in a maximum linear acceleration of 56.1g, the less frequent head-to-head collisions (n = 6) resulted in a maximum of 113.5g. The results of this study improve the understanding of head impact exposure in youth female soccer players and inform head impact exposure reduction in youth soccer.

Laboratory Assessment of a Headband-Mounted Sensor for Measurement of Head Impact Rotational Kinematics

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Colin M. Huber ◽  
Declan A. Patton ◽  
Kathryn L. Wofford ◽  
Susan S. Margulies ◽  
D. Kacy Cullen ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Human Head ◽  
Head Impact ◽  
Laboratory Assessment ◽  
Sensor Performance ◽  
Rotational Kinematics ◽  
Angular Velocities ◽  
Potential Link ◽  
Kinematic Measures ◽  
Coupling Error

Abstract Head impact sensors measure head kinematics in sports, and sensor accuracy is crucial for investigating the potential link between repetitive head loading and clinical outcomes. Many validation studies mount sensors to human head surrogates and compare kinematic measures during loading from a linear impactor. These studies are often unable to distinguish intrinsic instrumentation limitations from variability caused by sensor coupling. The aim of the current study was to evaluate intrinsic sensor error in angular velocity in the absence of coupling error for a common head impact sensor. Two Triax SIM-G sensors were rigidly attached to a preclinical rotational injury device and subjected to rotational events to assess sensor reproducibility and accuracy. Peak angular velocities between the SIM-G sensors paired for each test were correlated (R2 > 0.99, y = 1.00x, p < 0.001). SIM-G peak angular velocity correlated with the reference (R2 = 0.96, y = 0.82x, p < 0.001); however, SIM-G underestimated the magnitude by 15.0% ± 1.7% (p < 0.001). SIM-G angular velocity rise time (5% to 100% of peak) correlated with the reference (R2 = 0.97, y = 1.06x, p < 0.001) but exhibited a slower fall time (100% to 5% of peak) by 9.0 ± 3.7 ms (p < 0.001). Assessing sensor performance when rigidly coupled is a crucial first step to interpret on-field SIM-G rotational kinematic data. Further testing in increasing biofidelic conditions is needed to fully characterize error from other sources, such as coupling.

scholarly journals A Review of Instrumented Equipment to Investigate Head Impacts in Sport

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Declan A. Patton
Keyword(s):  
Human Subjects ◽  
Field Studies ◽  
Head Impact ◽  
Impact Measurement ◽  
Head Impacts ◽  
Head Impact Biomechanics ◽  
Impact Biomechanics ◽  
Injury Mechanisms ◽  
Impact Data

Contact, collision, and combat sports have more head impacts as compared to noncontact sports; therefore, such sports are uniquely suited to the investigation of head impact biomechanics. Recent advances in technology have enabled the development of instrumented equipment, which can estimate the head impact kinematics of human subjectsin vivo. Literature pertaining to head impact measurement devices was reviewed and usage, in terms of validation and field studies, of such devices was discussed. Over the past decade, instrumented equipment has recorded millions of impacts in the laboratory, on the field, in the ring, and on the ice. Instrumented equipment is not without limitations; however,in vivohead impact data is crucial to investigate head injury mechanisms and further the understanding of concussion.

Vestibulo-Ocular Response of Human Subjects Seated in a Pivoting Support System During 3 Gz Centrifuge Stimulation

1995 ◽  
Vol 5 (5) ◽  
pp. 331-347
Author(s):  
B.J. McGrath ◽  
F.E. Guedry ◽  
C.M. Oman ◽  
A.H. Rupert
Keyword(s):  
Angular Velocity ◽  
Spatial Orientation ◽  
Human Subjects ◽  
Angular Acceleration ◽  
Linear Acceleration ◽  
Slow Phase ◽  
Ocular Reflex ◽  
Vertical Linear Acceleration ◽  
Acceleration And Deceleration ◽  
Vestibulo Ocular Reflex

The vestibulo-ocular reflex (VOR) and spatial orientation perceptions were recorded in 15 subjects during 3 Gz centrifuge runs. These data were obtained to study two issues: (1) to gain insight into reports of asymmetrical disorientation and disturbance during acceleration and deceleration of centrifuge runs like those used to train pilots on the procedures to counteract G-induced loss of consciousness (G-LOC); (2) to study the effects of sustained vertical linear acceleration on the vestibular system. The centrifuge angular velocity profile consisted of a 19 s angular acceleration to 3 Gz that was sustained for 5 min during a period of constant angular velocity, and a 19 s deceleration to 1 Gz. The runs were repeated three times with the subject facing the motion and three times with the subject’s back to the motion. The VOR and spatial orientation perceptions from the eight subjects who completed all six runs were analyzed. The total VOR response during acceleration and deceleration was composed of interacting angular (AVOR) and linear components (LVOR). Asymmetries in pitch orientation perception between centrifuge acceleration and deceleration were not matched by asymmetries in the total VOR slow phase velocity. During the constant velocity high-G phase of the run, sustained up-beating LVOR (Lz nystagmus) was present in 14 of the 15 subjects. Significant individual differences in Lz nystagmus were found, but the maximum Lz response in our 15 subjects was probably of insufficient magnitude to degrade visual scan of cockpit instruments. Mean magnitudes ranged from 0 to 10 deg/s at 90 s from onset of centrifuge run.

Pharmacological treatment with L-DOPA may reduce striatal dopamine transporter binding in in vivo imaging studies

2016 ◽  
Vol 55 (01) ◽  
pp. 21-28 ◽  
Author(s):  
C. Antke ◽  
H. Hautzel ◽  
H.-W. Mueller ◽  
S. Nikolaus
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Binding Sites ◽  
Human Subjects ◽  
Synaptic Cleft ◽  
Presynaptic Terminal ◽  
Imaging Studies ◽  
Psychiatric Conditions ◽  
Da Release

SummaryNumerous neurologic and psychiatric conditions are treated with pharmacological compounds, which lead to an increase of synaptic dopamine (DA) levels. One example is the DA precursor L-3,4-dihydroxyphenylalanine (L-DOPA), which is converted to DA in the presynaptic terminal. If the increase of DA concentrations in the synaptic cleft leads to competition with exogenous radioligands for presynaptic binding sites, this may have implications for DA transporter (DAT) imaging studies in patients under DAergic medication.This paper gives an overview on those findings, which, so far, have been obtained on DAT binding in human Parkinson’s disease after treatment with L-DOPA. Findings, moreover, are related to results obtained on rats, mice or non-human primates. Results indicate that DAT imaging may be reduced in the striata of healthy animals, in the unlesioned striata of animal models of unilateral Parkinson’s disease and in less severly impaired striata of Parkinsonian patients, if animal or human subjects are under acute or subchronic treatment with L-DOPA. If also striatal DAT binding is susceptible to alterations of synaptic DA levels, this may allow to quantify DA reuptake in analogy to DA release by assessing the competition between endogenous DA and the administered exogenous DAT radioligand.

Genetic Engineering of AAV Capsid Gene for Gene Therapy Application

2020 ◽  
Vol 20 (5) ◽  
pp. 321-332
Author(s):  
Yunbo Liu ◽  
Xu Zhang ◽  
Lin Yang
Keyword(s):  
Gene Therapy ◽  
Neutralizing Antibodies ◽  
Human Subjects ◽  
Genetic Diseases ◽  
Capsid Gene ◽  
Human Populations ◽  
Stable Gene ◽  
Efficient Gene ◽  
Gene Therapy Application

Adeno-associated virus (AAV) is a promising vector for in vivo gene therapy because of its excellent safety profile and ability to mediate stable gene expression in human subjects. However, there are still numerous challenges that need to be resolved before this gene delivery vehicle is used in clinical applications, such as the inability of AAV to effectively target specific tissues, preexisting neutralizing antibodies in human populations, and a limited AAV packaging capacity. Over the past two decades, much genetic modification work has been performed with the AAV capsid gene, resulting in a large number of variants with modified characteristics, rendering AAV a versatile vector for more efficient gene therapy applications for different genetic diseases.

scholarly journals Lightening Effect of Skin Lightening Cream Containing Piper betle L. Extract in Human Volunteers

Cosmetics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 32
Author(s):  
Sharifah Shakirah Syed Omar ◽  
Hazrina Hadi ◽  
Nadzira Mohd Hanif ◽  
Hawa Mas Azmar Ahmad ◽  
Shiow-Fern Ng
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Human Subjects ◽  
Skin Barrier ◽  
Skin Tone ◽  
In Vivo Studies ◽  
Piper Betle ◽  
Melanin Content ◽  
Skin Lightening

Hyperpigmentation affects people globally with negative psychological impacts. Piper betle L. leaf (PBL) extract has many benefits including skin lightening which may reduce hyperpigmentation. The objective of this study was to develop an effective skin-lightening cream containing PBL with ideal characteristics. A formulation of base cream and PBL cream was prepared and characterized by centrifugation, particle size and zeta potential analysis, rheological profile studies and physical properties’ observation. In vivo studies on 30 human subjects tested the effects of base and PBL cream on skin-lightening, hydration, trans-epidermal water loss (TEWL) and elasticity through weekly tests 4 weeks in duration. Base and PBL creams had a non-Newtonian property with acceptable color, odor, texture, zeta potential, particle size and showed no phase separation. The in vivo study indicated a significant reduction in melanin content and an improvement in skin tone for PBL cream but not in base cream. TEWL and elasticity also showed significant reduction for both formulations, indicating a healthier skin barrier and supple skin with consistent use, although hydration fluctuated with no significant changes. The developed PBL cream showed significant results in the reduction in melanin content and improving skin tone, which shows the formulation can confer skin-lightening effect.

Head Impact Biomechanics in Youth Flag Football: A Prospective Cohort Study

2021 ◽  
pp. 036354652110266
Author(s):  
Landon B. Lempke ◽  
Rachel S. Johnson ◽  
Rachel K. Le ◽  
Melissa N. Anderson ◽  
Julianne D. Schmidt ◽  
...  
Keyword(s):  
Mixed Model ◽  
Linear Acceleration ◽  
Cross Sectional Study ◽  
Head Impact ◽  
Rotational Acceleration ◽  
Event Type ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Head Impact Biomechanics ◽  
Impact Biomechanics

Background: Youth flag football participation has rapidly grown and is a potentially safer alternative to tackle football. However, limited research has quantitatively assessed youth flag football head impact biomechanics. Purpose: To describe head impact biomechanics outcomes in youth flag football and explore factors associated with head impact magnitudes. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We monitored 52 player-seasons among 48 male flag football players (mean ± SD; age, 9.4 ± 1.1 years; height, 138.6 ± 9.5 cm; mass, 34.7 ± 9.2 kg) across 3 seasons using head impact sensors during practices and games. Sensors recorded head impact frequencies, peak linear ( g) and rotational (rad/s2) acceleration, and estimated impact location. Impact rates (IRs) were calculated as 1 impact per 10 player-exposures; IR ratios (IRRs) were used to compare season, event type, and age group IRs; and 95% CIs were calculated for IRs and IRRs. Weekly and seasonal cumulative head impact frequencies and magnitudes were calculated. Mixed-model regression models examined the association between player characteristics, event type, and seasons and peak linear and rotational accelerations. Results: A total of 429 head impacts from 604 exposures occurred across the study period (IR, 7.10; 95% CI, 4.81-10.50). Weekly and seasonal cumulative median head impact frequencies were 1.00 (range, 0-2.63) and 7.50 (range, 0-21.00), respectively. The most frequent estimated head impact locations were the skull base (n = 96; 22.4%), top of the head (n = 74; 17.2%), and back of the head (n = 66; 15.4%). The combined event type IRs differed among the 3 seasons (IRR range, 1.45-2.68). Games produced greater IRs (IRR, 1.24; 95% CI, 1.01-1.53) and peak linear acceleration (mean difference, 5.69 g; P = .008) than did practices. Older players demonstrated greater combined event–type IRs (IRR, 1.46; 95% CI, 1.12-1.90) and increased head impact magnitudes than did younger players, with every 1-year age increase associated with a 3.78 g and 602.81-rad/s2 increase in peak linear and rotational acceleration magnitude, respectively ( P≤ .005). Conclusion: Head IRs and magnitudes varied across seasons, thus highlighting multiple season and cohort data are valuable when providing estimates. Head IRs were relatively low across seasons, while linear and rotational acceleration magnitudes were relatively high.

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