Inside Shoulder Research Articles

At-Risk Tackling Techniques and Effectiveness in English Premiership Rugby.

Head-down tackling has been associated with higher rates of head and neck injuries and less successful tackles compared with head-up tackling in American football. In rugby, head and neck injuries have been associated with tackling, with the tackler's head positioned in front of the ball carrier. To assess the success and risks of tackling techniques used in the English Rugby Premiership matches. Cross-sectional study; Level of evidence, 3. Three reviewers analyzed 1000 consecutive solo defensive tackling attempts during the 2022 to 2023 season in 6 English Rugby Premiership matches. Slow-motion replays were used to analyze the success of the tackling attempt in terms of head angulation (head up vs head down), head position relative to the offensive player's waist at point of contact, and tackling method (inside shoulder, arm, head across the bow, and head-to-head). The chi-square test or Fisher exact test was used to analyze categorical data, and the 2-tailed Student t test or the Mann-Whitney U test was used to analyze continuous data. The mean interrater reliabilities for analyzing the tackles were good across all groups (κ = 0.715). Head-up and head-down tackling occurred in 848 tackle attempts (84.8%) and 152 tackle attempts (15.2%), respectively. Head-up tackles were successful in 80.7% of the tackle attempts compared with 71.1% of the head-down tackle attempts (P = .0072). Tackles made at or above the waist were successful in 80.7% of the tackle attempts compared with 73.1% of tackles below the waist (P = .0193). The inside-shoulder technique had the highest successful tackle rate at 90.8%, compared with 44.2% with the arm technique (P < .0001) and 72.4% with the head-across-the-bow technique (P < .0001). The inside-shoulder technique resulted in head-up tackling in 84.8% of players compared with 59.8% with the head-across-the-bow technique (P < .0001) and 94.9% with arm tackling (P = .0001). There were 4 recorded injuries to the tackler: 2 neck injuries, 1 shoulder injury, and 1 wrist/hand injury. Head-up tackling, tackles made at or above the level of the offensive player's waist, and inside-shoulder tackling were found to be more efficient in producing successful tackles. The head-down, tackling below the waist, and head-across-the-bow techniques were associated with poor tackling and lower success rates.

Exploring interacting effects of risk factors on run-off-road crash severity: An interpretable machine learning model joint with latent class clustering

Run-Off-Road (ROR) crashes are frequent and pose a significant risk of injury and fatality. Given the complexity of their mechanisms and the interaction of multiple factors, this study aims to comprehensively investigate the factors influencing the severity of ROR crashes, which have been understudied. Furthermore, addressing the current methodological challenge in machine learning (ML) crash modeling, this study proposes an approach to tackle unobserved heterogeneity in ML. An interpretable ML joint with prior latent class clustering is implemented. The significant risk factors and interactions are interpreted using SHAP (SHapley Additive exPlanations) method across clusters. This study utilizes ROR crash records, traffic, and geometric data from main suburban freeways in Iran collected over a 5-year period. The key interacting factors associated with severe ROR during adverse weather (cluster 1) are: co-occurrence of low congestion and higher speed variation; low congestion, nighttime darkness and rollover; roadway departure by buses and mini-buses and rollover occurrence; vehicle departure and collision with fixed objects. Moreover, the critical interactions for nighttime condition (cluster 2) are: curve sections combined with longitudinal slope; inside shoulder width <1.5 m and a hit median concrete NewJersey barrier. The risky interactions for crashes occurred in curves (cluster 3) are: departing in two-lane sections in low congestion conditions; vehicles collisions with the median concrete NewJersey barriers. The findings of this study enhance comprehension of the significant effects of interactions under various conditions, offering valuable insights for policymakers. Additionally, recommendations are offered to mitigate the risk of severe ROR crashes.

Tire deformation measurement technology based on digital image correlation method

The contact between the tire and the road surface causes tread deformation, and using traditional methods to measure tire tread deformation is difficult and time-consuming. Therefore, based on the principle of the digital image correlation method, this paper develops a binocular vision measurement system and realizes the measurement of tire tread deformation through the test bench for tire ground pressure distribution measurement. The related programs of the measurement system, including camera calibration, image matching, and strain fitting, are proposed. The deformation measurement accuracy of the test bench is validated by the sprayed speckle rubber sheet test, and the relative error of the theoretical value and measurement value is within 2%. The tire tread deformation test under static loading conditions was carried out using the test bench, and the tread strain distribution in the contact area was obtained. The analysis of the test results shows that the strain distribution in the contact patch is axisymmetric under static loading conditions. The longitudinal (tire rolling direction) deformation of the tread at the leading edge and the trailing edge area of the contact patch has the largest strain, while the deformation of the shoulder area on both sides of the contact patch is relatively small. For lateral (tire axial direction) deformation, the leading edge and the trailing edge areas of the contact patch are less deformed, and the strain distribution is approximately axisymmetric. The shoulder area of the contact surface has a larger deformation. The tire’s outer shoulder area has a larger deformation than the inside shoulder area, which may be due to the asymmetric tread structure of the tire. For the vertical deformation of the tread, the central area of the tread has the smallest strain, while the surrounding area has a much larger vertical strain.

Evaluating Safety of Type-A Weaving Sections Using Geometric and Traffic Operational Factors

The efficiency and safety of type-A freeway weaving sections in urban areas are constrained by recurrent bottlenecks. Limited space in freeway weaving sections cause traffic congestion and crashes during peak-hours. Various factors, including length of weaving section, continuity of lanes, and number of lanes will have significant effects on the level of service and safety performance of the weaving sections. Eight years (2010-2017) of crash data in the type-A weaving sections was used in this analysis. The objective of this study aims to evaluate geometric design factors and operational factors on total crashes and each of the four crash types: rear-end, sideswipe, angle, and single-vehicle in type-A weaving sections using traditional negative binomial approach and develop crash modification factors (CMFs) to improve safety in the type-A weaving section. The results revealed that on-ramp traffic per hour, off-ramp traffic per hour, non-weaving traffic per hour, weaving ratio, length of the weaving section, direction of the freeway, width of inside shoulder, and width of outside shoulder were influencing crashes in type-A weaving sections. Furthermore, the estimated crash modification factors (CMFs) result revealed that total crashes gradually decrease as inside shoulder width increases. This implies that widening inside shoulder width have positive effects on weaving section safety. In addition, ramp metering, and advisory warning signs could improve safety in type-A weaving sections.

104. At-risk tackling techniques in American football

BACKGROUND CONTEXT In American football, fewer fatalities and severe injuries have been seen annually since 1976, when rules were enacted to prohibit certain types of aggressive tackling. The National Football Head and Neck Injury Registry was established in 1975 and data from 1971-1975 were retrospectively reviewed to better understand the mechanisms involved in catastrophic cervical spine injury. PURPOSE This study was an assessment of (1) tackling techniques coaches were teaching at 3 levels: youth (4th–5th grades), middle (6th–8th grades), and high school (9th–12th grades); (2) tackling techniques used during games; and (3) successful tackle rates of these techniques. STUDY DESIGN/SETTING Descriptive epidemiology study. PATIENT SAMPLE Not applicable. OUTCOME MEASURES Not applicable. METHODS This study received IRB approval. Surveys were distributed via email to 500 coaches of football teams in Texas. Coaches provided video recordings of football games with players from youth league (YL), middle school (MS), and high school (HS). All tackle attempts were graded by one reviewer who watched game videos; 1000 consecutive tackles were observed for each group. Survey data included how coaches instructed their players to tackle, the types of tackles, the number of tackles vs missed tackles, the head position, and the initial contact. Data were analyzed using the chi-square test. A subset of 100 consecutive tackles at each level of play were reviewed by two blinded reviewers to assess intra- and interrater reliabilities using Cohen's Kappa calculations. RESULTS (1) In all groups, coaches instructed players to use the “head across the bow” tackling technique: 83%, YL; 81%, MS; 75%, HS. Coaches instructed players to “keep your head up” 89%, in the YL; 100%, MS; and 81%, in HS. (2, 3) During games, players used head-up, inside shoulder tackles more successfully across all groups: 97.5%, YL; 99.5%, MS; 98.8%, HS. While intra- and interrater reliabilities were in the good reliability range, these scores were lower in the youth group. CONCLUSIONS Our study supports the effectiveness of tackling with the head up and with making the initial contact with the inside shoulder. Lower reliability ratings for the youth group were likely due to lower video quality and lack of players’ tackling experience. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

At-Risk Tackling Techniques in American Football.

Background:In American football, fewer fatalities and severe injuries have been seen annually since 1976, after data from 1971 through 1975 were retrospectively reviewed to better understand the mechanisms involved in catastrophic cervical spine injury and rules were enacted to prohibit certain types of aggressive tackling. The National Football Head and Neck Injury Registry was established in 1975.Purpose:To assess (1) tackling techniques that coaches were teaching at 3 levels—youth level (YL; 4th to 5th grades), middle school (MS; 6th to 8th grades), and high school (HS; 9th to 12th grades); (2) tackling techniques used during games; and (3) the successful tackle rates of these techniques.Study Design:Descriptive epidemiology study.Methods:Surveys were distributed via email to 500 coaches of YL, MS, and HS football teams in Texas. Coaches provided video recordings of football games, and all tackle attempts were graded by a single reviewer who watched game videos; 1000 consecutive tackles were observed for each group. Survey data included how coaches instructed their players to tackle, the types of tackles, the number of tackles versus missed tackles, the head position, and the initial contact. Data were analyzed with the chi-square test. A subset of 100 consecutive tackles at each level of play was reviewed by 2 blinded reviewers to assess intra- and interrater reliabilities.Results:In all groups, coaches responded that they preferred to teach the at-risk “head across the bow” tackling technique (83% YL, 81% MS, 75% HS). Coaches stated that they instructed players to “keep your head up,” as currently recommended, 89% in YL, 100% in MS, and 81% in HS. During games, players used head-up, inside-shoulder tackles more successfully across all groups (97.5% YL, 99.5% MS, 98.8% HS). While intra- and interrater reliabilities were in the good range, these scores were lower in the youth group.Conclusion:Our study supports the effectiveness of tackling with the head up and making the initial contact with the inside shoulder. Lower reliability ratings for the youth group were likely due to lower video quality and the lack of players’ tackling experience.

Safety sensitivity to roadway characteristics: A comparison across highway classes

This paper examined the accident risk factors associated with highway traffic and roadway design, for each of three highway classes in the United States using a bivariate modeling framework involving two levels of accident severity. With regard to the highest class (Interstates), the results suggest that, compared to no-casualty accidents, casualty accidents are more sensitive to traffic volume and average vertical grade, but less sensitive to the inside shoulder width and the median width. For US Roads, it was determined that, compared to no-casualty accidents, casualty accidents are more sensitive to traffic volume, outside shoulder width, pavement condition, and median width but less sensitive to the average vertical grade. For the relatively lowest-class roads (State Roads), it was determined that, compared to no-casualty accidents, casualty accidents are more sensitive to the traffic volume, lane width, outside shoulder width, and pavement condition. Compared to the relatively lower-class highways, accidents at higher-class highways are more sensitive to: changes in traffic volume, average vertical grade, median width, inside shoulder width, and the pavement condition (no-casualty accidents only); but less sensitive to changes in lane width, pavement condition (casualty accidents only), and the outside shoulder width. This variation in sensitivity across the different road classes could be attributed to the differences in road geometry standards across the road classes, as the results seem to support the hypothesis that these standards strongly influence accident occurrence. It is hoped that the developed bivariate negative binomial models can help highway engineers to evaluate their current design standards and policy, and to assess the safety consequences of changes in these standards in each road class.

Bloom Development of the Beef Semimembranosus and Triceps Brachii as Influenced by Wet-Aging

The semimembranosus (SM) and triceps brachii (TB) from USDA Select beef carcasses were used to test the effect of wet-aging period on bloom development. Inside rounds (IMPS#168) and shoulder clods (IMPS #114) were randomly allocated to 0, 7, 14, 21, 28, and 35 d wet-aging at 2°C (n = 10 subprimal cuts/aging period). Each week, two 2.54-cm-thick, non-adjacent steaks were cut from aged inside rounds and shoulder clods, and instrumental color (L*, a*, and b*) of the SM and TB was measured at 10-min intervals for 2 h after cutting. Steaks from the SM and TB became a more vivid (greater C* values; P &lt; 0.05), redder (greater a* values; P &lt; 0.05), and yellower (greater b* values; P &lt; 0.05) color during the 120-min bloom period. Moreover, the calculated proportion of oxymyoglobin (OMb) in SM and TB steaks increased (linear, P &lt; 0.001) during the first 80 min after cutting but stabilized thereafter. Redness (a* and hue angles), b*, and C* values decreased (linear, P ≤ 0.050) in SM steaks as duration of wet-aging increased from 0 to 35 d, but length of wet-aging had no (P ≥ 0.127) effect on instrumental color measures of TB steaks. Neither the percentage of calculated OMb (P = 0.580) nor OMb asymptotic point (P ≥ 0.214) for SM steaks was affected by duration of wet-aging, and, even though the proportion of OMb in TB steaks was not altered (P = 0.459) by postmortem aging, OMb asymptotic points increased (linear, P = 0.001) in TB steaks with increasing durations of wet-aging. Results of these experiments indicate that 90%, or more, of the change in color was achieved within the first 50 to 60 min after cutting, but duration of wet-aging had little to no impact on bloom development in SM and TB steaks.

Experimental research on safety impacts of the inside shoulder based on driving simulation

Statistical data shows that single-vehicle crashes account for half of all traffic crashes on expressways in China, and previous research has indicated that main contributing factors were related to whether and how the inside shoulder was paved. The inside shoulder provides space for drivers to make evasive maneuvers and accommodate driver errors. However, lower-cost construction solutions in China have resulted in the design of numerous urban expressway segments that lack inside shoulders.This paper has two objectives. The first is to reveal the safety impacts of inside shoulders on urban expressways by driving simulator experiment. The second objective is to propose optimal range and recommended value of inside shoulder width for designing inside shoulders of urban expressways. The empirical data, including subjects’ eye movement data, heart rate (HR) and the lateral position of vehicles, were collected in a driving simulator. The data were analyzed to evaluate the safety impacts of the inside shoulder. The results have revealed that the inside shoulder has an impact on drivers’ visual perception, behaviors, and psychology; in particular, it has a significant effect on vehicle operations. In addition, this paper recommends the desired and optimal inside shoulder widths for eight-lane, two-way divided expressways.

Driving Simulator Study of Effect of Inside Shoulder on Vehicle Operation

According to the Chinese Design Specification for Highway Alignment (JTG D20-2006), eight-lane expressways should be paved with an inside shoulder of 2.5 m; however, this regulation is rarely obeyed in engineering practice. On the basis of driving simulator experiment, this research examined the impacts of inside shoulder on vehicle operation with and without the speed limitation. A virtual scenario, consisting of five expressways with different inside shoulder widths, was created and displayed in driving simulator, and vehicle operational data—speed and lane position—were recorded. Authors used analysis of variance (ANOVA) and contrast analysis to examine whether inside shoulder width had statistically significant effects on travel speed and lane position. Analytical results indicated that there is a kind of quadratic relationship between inside shoulder width and driver's speed choice, while driver's speed choice is not significantly affected by inside shoulder width. What is more, inside shoulder width has statistically significant effects on vehicle's lane positions, and vehicle's lane position is negatively correlated to inside shoulder width. Specifically, the vehicle can be maintained at the center of lane when the inside shoulder width is 2.5 m.

Factors Affecting Median Cable Barrier Crash Frequency: New Insights

This study evaluated the impact of roadway cross-sectional and geometric features, traffic characteristics, and median cable barrier placement to the frequency of median-related crashes through statistical modeling using multiyear data. A unique aspect of the model specification was the inclusion of median cable barrier placement data, horizontal curve data, and differential elevation of opposite travel lanes. Negative binomial model was used in linearizing and quantifying these factors with respect to median crossover crash frequency. The variables that were found to significantly influence the frequency of median crashes include the number of lanes, differential elevation, and cable barrier offset from the inside shoulder. Increasing traffic volume was found to increase the frequency of median barrier crashes as well as the presence of curves on a median barrier section was found to increase the frequency of crashes. Higher differential elevation between opposite travel lanes was also found to increase the frequency of median barrier crashes. Increasing the median barrier offset from the inside shoulder of the travel way decreases median barrier injury and fatal crash frequency. Segments with a higher number of lanes and a wider median width were associated with low crash frequencies.

Using multivariate adaptive regression splines (MARS) to develop crash modification factors for urban freeway interchange influence areas

Crash modification factors (CMFs) are used to measure the safety impacts of changes in specific geometric characteristics. Their development has gained much interest following the adoption of CMFs by the recently released Highway Safety Manual (HSM) and SafetyAnalyst tool in the United States. This paper describes a study to develop CMFs for interchange influence areas on urban freeways in the state of Florida. Despite the very different traffic and geometric conditions that exist in interchange influence areas, most previous studies have not separated them from the rest of the freeway system in their analyses. In this study, a promising data mining method known as multivariate adaptive regression splines (MARS) was applied to develop CMFs for median width and inside and outside shoulder widths for “total” and “fatal and injury” (FI) crashes. In addition, CMFs were also developed for the two most frequent crash types, i.e., rear-end and sideswipe. MARS is characterized by its ability to accommodate the nonlinearity in crash predictors and to allow the impact of more than one geometric variable to be simultaneously considered. The methodology further implements crash predictions from the model to identify changes in geometric design features. Four years of crashes from 2007 to 2010 were used in the analysis and the results showed that MARS's prediction capability and goodness-of-fit statistics outperformed those of the negative binomial model. The influential variables identified included the outside and inside shoulder widths, median width, lane width, traffic volume, and shoulder type. It was deduced that a 2-ft increase in the outside and inside shoulders (from 10ft to 12ft) reduces FI crashes by 10% and 33%, respectively. Further, a 42-ft reduction in the median width (from 64ft to 22ft) increases the rear-end, total, and FI crashes by 473%, 263%, and 223%, respectively.

Horizontal Curve Accident Modification Factor with Consideration of Driveway Density on Rural Four-Lane Highways in Texas

Agencies are seeking a better understanding of those roadway or roadside features that affect safety. The objectives of this study were to develop a horizontal curve accident modification factor (AMF) for rural four-lane divided and undivided highways and to determine if the effect of driveway density is different for horizontal curves as compared to tangent sections. Data available for use in the evaluation included 194.8 centerline km (121 centerline mi) of rural four-lane highways. Negative binomial regression models were used to determine the effects of independent variables on crashes. Variables considered in developing the base models included driveway density, lane width, outside shoulder width, median width (which included inside shoulder width), median type, degree of curve, segment length, and average daily traffic. Five years (1997–2001) of driveway and segment crashes were examined. An AMF for horizontal curves was identified. Reviewing the findings with respect to driveway density revealed that the effect of driveway density is different for horizontal curves and tangents; however, the differences were relatively minor.

Evaluating the Effects of Freeway Design Elements on Safety

Increased emphasis has been placed on improving the explicit role of highway safety in making decisions on highway planning, design, and operations. This end can be achieved by quantifying the safety effects of geometric design elements for various highway facilities. The objective of this study was to investigate the safety effects of two important design elements for freeways: ramp density and horizontal curve. Data available for use in the evaluation included 324.2 centerline mi of freeways collected in Texas. Five years (1997–2001) of freeway crashes were examined. Negative binomial regression models were used to estimate the effects of independent variables on crashes. The final model for evaluation revealed that crashes on freeway segments were associated with average daily traffic, on-ramp density, degree of curvature, median width with inside shoulder, the number of lanes (for urban freeways), and whether the freeway is in an urban or rural area. Off-ramp density was not statistically significant in the model. Furthermore, the effect of on-ramp density on freeway crashes was significant for horizontal curves but not for tangent sections and indicates that freeway designers should eliminate or minimize the number of on-ramps within the horizontal curves. The statistical modeling results were geared into the development of accident modification factors for on-ramp density and horizontal curves that can be used for safety prediction of freeways.

Safety Evaluation of Buffer-Separated High-Occupancy Vehicle Lanes in Texas

In Texas, high-occupancy vehicle (HOV) lanes are an integral part of urban mobility. Although an extensive system of permanent HOV lanes is planned for the Dallas-Fort Worth area, the Texas Department of Transportation and Dallas Area Rapid Transit have implemented interim HOV lanes by retrofitting them into existing freeways. Safety is examined for Dallas's buffer-separated concurrent-flow HOV lanes, which were implemented by lane widths being reduced and by the inside shoulder being converted to an HOV lane on 1-35 East and 1-635. Injury crash data from each corridor were analyzed on the basis of crash rates, frequency trends, and manually reviewing police reports. The analysis considered the impact of design elements, including buffer width, shoulder presence, and lane width. Operationally, the analysis considered the impact of speed differential between the HOV and general purpose lanes. This evaluation resulted in three key findings: (a) both corridors had an increase in crash rates after implementation of the HOV lane, (b) the increase in crashes is primarily focused on the HOV lane and the first adjacent general purpose lane, and (c) the increase in crashes is primarily attributed to the speed differential between the HOV and the general purpose lanes and the reduced HOV cross section. The recommendation, based on these findings, is to provide greater width for the total HOV cross section (inside shoulder + HOV lane + painted buffer) than that provided in the two interim corridors. An absolute minimum of 18 ft between the freeway barrier and the general purpose lanes may mitigate many types of crashes that occur because of the speed differential, with full inside shoulders being the desirable cross section.

Safety Evaluation of Buffer-Separated High-Occupancy Vehicle Lanes in Texas

In Texas, high-occupancy vehicle (HOV) lanes are an integral part of urban mobility. Although an extensive system of permanent HOV lanes is planned for the Dallas–Fort Worth area, the Texas Department of Transportation and Dallas Area Rapid Transit have implemented interim HOV lanes by retrofitting them into existing freeways. Safety is examined for Dallas's buffer-separated concurrent-flow HOV lanes, which were implemented by lane widths being reduced and by the inside shoulder being converted to an HOV lane on I-35 East and I-635. Injury crash data from each corridor were analyzed on the basis of crash rates, frequency trends, and manually reviewing police reports. The analysis considered the impact of design elements, including buffer width, shoulder presence, and lane width. Operationally, the analysis considered the impact of speed differential between the HOV and general purpose lanes. This evaluation resulted in three key findings: (a) both corridors had an increase in crash rates after implementation of the HOV lane, (b) the increase in crashes is primarily focused on the HOV lane and the first adjacent general purpose lane, and (c) the increase in crashes is primarily attributed to the speed differential between the HOV and the general purpose lanes and the reduced HOV cross section. The recommendation, based on these findings, is to provide greater width for the total HOV cross section (inside shoulder + HOV lane + painted buffer) than that provided in the two interim corridors. An absolute minimum of 18 ft between the freeway barrier and the general purpose lanes may mitigate many types of crashes that occur because of the speed differential, with full inside shoulders being the desirable cross section.

Forensic Engineering Analysis Of A Car Vs. Car Vs. Pedestrian Accident

This Paper Summarizes The Forensic Engineering Analysis And Reconstruction Of A Nighttime Vehicle Crash. The Crash Occurred On The Inside Shoulder Of A Divided Interstate Highway Separated By A Concrete Barrier. A Driver Had Stopped His Vehicle On The Inside Shoulder Of The Westbound Section Of The Highway, Presumably Due To Car Troubles. His Car Was Struck In The Rear By Another Vehicle. When Emergency Personnel Arrived At The Scene, The Owner Of The Disabled Vehicle Was Found Deceased On The Inside Lane Of The Opposing Eastbound Roadway. As The Crash Was Being Investigated, A Vehicle Returned To The Scene Where The Driver Indicated That He Thought He Had Run Over Something As He Was Traveling Eastbound On The Freeway. The Forensic Engineer Was Retained To Reconstruct The Accident, And To Determine How The Driver Of The Disabled Vehicle Came To Be In The Opposing Roadway. The Reconstruction Involved Photogrammetry, Momentum Analysis, Crush Energy Analysis, Proper Use Of Pedestrian Throw Formulae, And A Forensic Analysis Of Evidence On The Disabled Vehicle.