Rotational Stiffness of American Football Shoes Affects Ankle Biomechanics and Injury Severity

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Keith D. Button ◽  
Jerrod E. Braman ◽  
Mark A. Davison ◽  
Feng Wei ◽  
Maureen C. Schaeffer ◽  
...  
Keyword(s):  
Injury Risk ◽  
Computational Models ◽  
Injury Severity ◽  
Proximal Tibia ◽  
American Football ◽  
Ankle Injuries ◽  
Rotational Stiffness ◽  
Natural Response ◽  
Stiff Shoes ◽  
Experimental Injury

While previous studies have investigated the effect of shoe–surface interaction on injury risk, few studies have examined the effect of rotational stiffness of the shoe. The hypothesis of the current study was that ankles externally rotated to failure in shoes with low rotational stiffness would allow more talus eversion than those in shoes with a higher rotational stiffness, resulting in less severe injury. Twelve (six pairs) cadaver lower extremities were externally rotated to gross failure while positioned in 20 deg of pre-eversion and 20 deg of predorsiflexion by fixing the distal end of the foot, axially loading the proximal tibia, and internally rotating the tibia. One ankle in each pair was constrained by an American football shoe with a stiff upper, while the other was constrained by an American football shoe with a flexible upper. Experimental bone motions were input into specimen-specific computational models to examine levels of ligament elongation to help understand mechanisms of ankle joint failure. Ankles in flexible shoes allowed 6.7±2.4 deg of talus eversion during rotation, significantly greater than the 1.7±1.0 deg for ankles in stiff shoes (p = 0.01). The significantly greater eversion in flexible shoes was potentially due to a more natural response of the ankle during rotation, possibly affecting the injuries that were produced. All ankles failed by either medial ankle injury or syndesmotic injury, or a combination of both. Complex (more than one ligament or bone) injuries were noted in 4 of 6 ankles in stiff shoes and 1 of 6 ankles in flexible shoes. Ligament elongations from the computational model validated the experimental injury data. The current study suggested flexibility (or rotational stiffness) of the shoe may play an important role in both the severity of ankle injuries for athletes.

Foot and Ankle Injuries in Motor Vehicle Accidents

2001 ◽  
Vol 22 (8) ◽  
pp. 649-652 ◽  
Author(s):  
Lynnford S. Wilson ◽  
Mark S. Mizel ◽  
James D. Michelson
Keyword(s):  
Injury Risk ◽  
Injury Severity ◽  
Motor Vehicle ◽  
Motor Vehicle Accident ◽  
Motor Vehicle Accidents ◽  
Ankle Injuries ◽  
Relative Risk Ratio ◽  
Foot And Ankle ◽  
Vehicle Accidents ◽  
Air Bags

Background: We studied foot and ankle (F/A) injuries that occurred in motor vehicle accidents treated in a Level 1 trauma center. Methods: The records of F/A injuries of 2248 consecutive orthopedic patients were reviewed to find foot and ankle injuries. Results: Pilon fractures were common. Motor Vehicle Accident (MVA) occupants with F/A injuries had a higher injury Severity Score than those without (17.9 vs. 11.6, p <. 001). MVA F/A injury risk was higher without restraint [relative risk ratio (rrr) 1.68, p <. 0032] than with restraint except for air bagged drivers who were similar to unrestrained drivers (rrr 1.18, p > .05, NS). Conclusion: Patients with F/A injuries may have serious associated injuries. Air bags may not protect feet.

scholarly journals An Experimentally Validated Finite Element Model of the Lower Limb to Investigate the Efficacy of Blast Mitigation Systems

2021 ◽  
Vol 9 ◽  
Author(s):  
Eduardo A. Rebelo ◽  
Grigoris Grigoriadis ◽  
Diagarajen Carpanen ◽  
Anthony M. J. Bull ◽  
Spyros D. Masouros
Keyword(s):  
Finite Element ◽  
Injury Risk ◽  
Injury Severity ◽  
Proximal Tibia ◽  
Assessment Tool ◽  
Traumatic Injury ◽  
Element Model ◽  
Fe Model ◽  
Loading Conditions ◽  
Injury Burden

Improvised explosive devices (IEDs) used in the battlefield cause damage to vehicles and their occupants. The injury burden to the casualties is significant. The biofidelity and practicality of current methods for assessing current protection to reduce the injury severity is limited. In this study, a finite-element (FE) model of the leg was developed and validated in relevant blast-loading conditions, and then used to quantify the level of protection offered by a combat boot. An FE model of the leg of a 35 years old male cadaver was developed. The cadaveric leg was tested physically in a seated posture using a traumatic injury simulator and the results used to calibrate the FE model. The calibrated model predicted hindfoot forces that were in good correlation (using the CORrelation and Analysis or CORA tool) with data from force sensors; the average correlation and analysis rating (according to ISO18571) was 0.842. The boundary conditions of the FE model were then changed to replicate pendulum tests conducted in previous studies which impacted the leg at velocities between 4 and 6.7 m/s. The FE model results of foot compression and peak force at the proximal tibia were within the experimental corridors reported in the studies. A combat boot was then incorporated into the validated computational model. Simulations were run across a range of blast-related loading conditions. The predicted proximal tibia forces and associated risk of injury indicated that the combat boot reduced the injury severity for low severity loading cases with higher times to peak velocity. The reduction in injury risk varied between 6 and 37% for calcaneal minor injuries, and 1 and 54% for calcaneal major injuries. No injury-risk reduction was found for high severity loading cases. The validated FE model of the leg developed here was able to quantify the protection offered by a combat boot to vehicle occupants across a range of blast-related loading conditions. It can now be used as a design and as an assessment tool to quantify the level of blast protection offered by other mitigation technologies.

scholarly journals Osteoarthritis Prevalence in Retired National Football League Players With a History of Ankle Injuries and Surgery

2019 ◽  
Vol 54 (11) ◽  
pp. 1165-1170
Author(s):  
Kyeongtak Song ◽  
Erik A. Wikstrom ◽  
Joshua N. Tennant ◽  
Kevin M. Guskiewicz ◽  
Stephen W. Marshall ◽  
...  
Keyword(s):  
National Football League ◽  
Surgical Intervention ◽  
Ankle Injury ◽  
American Football ◽  
Ankle Injuries ◽  
Daily Activities ◽  
Surgical Interventions ◽  
Exposure Variable ◽  
History Of ◽  
Estimate Prevalence

Context Ankle injuries are common at all levels of American football, and retired National Football League (NFL) players have a high prevalence of osteoarthritis (OA), but little is known about how ankle injuries influence OA prevalence and daily activities in this population or how surgical interventions for such injuries alter the risk of OA. Objective To examine (1) the association of ankle-injury history with OA prevalence, (2) the association of surgical intervention after ankle injury with OA prevalence, and (3) the relationships among ankle injuries, reported OA, and daily activities in retired NFL players. Design Case-control study. Setting Survey. Patients or Other Participants Data from the Retired NFL Players General Health Survey. Main Outcome Measure(s) We created a 7-category main exposure variable that differentiated respondents by football-related ankle injury and surgical intervention. Multivariable binomial regression models were used to estimate prevalence ratios and 95% confidence intervals. Among those reporting OA, we examined the distribution of responses regarding whether OA affected daily activities. Results Among the 2446 respondents, 920 participants experienced OA in any joint during their lifetime. Compared with those reporting no ankle injuries, the prevalence of OA was higher among those with a history of ankle injury. Also, the prevalence of OA was higher among those who had undergone surgery versus those who had not. The number of retired NFL players who reported that OA often affected their daily activities increased with the number of ankle injuries. Conclusions Among former NFL players, a history of ankle injury increased the prevalence of OA. More ankle injuries increased the probability that OA negatively affected daily activities. Future prospective research is needed to better determine the influence of surgical intervention at the ankle or foot on OA.

Investigation of chest biomechanical response by variation of restraint loads in frontal impact

2019 ◽  
Vol 234 (5) ◽  
pp. 1377-1388
Author(s):  
Sen Xiao ◽  
Yanchao Qie ◽  
Wu Chen ◽  
Jikuang Yang ◽  
Jeff R Crandall
Keyword(s):  
Injury Risk ◽  
Injury Severity ◽  
Peak Load ◽  
Chest Injury ◽  
Frontal Impact ◽  
Design And Optimization ◽  
Load Paths ◽  
Load Factors ◽  
Deflection Analysis ◽  
Injury Outcomes

The seatbelt restraint load is one of the primary sources of occupant chest injury. Thus, studying the different biomechanical responses of chest by varying the seatbelt loads will result in a significant improvement in seatbelt protection performance. Based on the high-biofidelity mechanical dummy model, a sled-dummy test was conducted to investigate the differences in chest injury outcomes caused by the variation of seatbelt load paths or load processes. The chest kinematics and kinetics are compared to determine the influence of load factors on these biomechanical outcomes. Results show that chest injury severity has a positive nonlinear correlation with impact speed. However, the injury risk is mainly determined by the seatbelt peak load in the chest deflection analysis. The results of this study can provide a reference to seatbelt safety design and optimization. The model and method can be used in other research works on the biomechanics of frontal impact.

Trends in match injury risk in professional male rugby union: a 16-season review of 10 851 match injuries in the English Premiership (2002–2019): the Professional Rugby Injury Surveillance Project

2020 ◽  
pp. bjsports-2020-102529
Author(s):  
Stephen W West ◽  
Lindsay Starling ◽  
Simon Kemp ◽  
Sean Williams ◽  
Matthew Cross ◽  
...  
Keyword(s):  
Injury Risk ◽  
Injury Severity ◽  
Rugby Union ◽  
Injury Surveillance ◽  
Injury Incidence ◽  
Match Play ◽  
Common Activity ◽  
Long Term Trends ◽  
The Mean

ObjectivesThe Professional Rugby Injury Surveillance Project is the largest and longest running rugby union injury surveillance project globally and focuses on the highest level of rugby in England.MethodsWe examined match injuries in professional men’s rugby over the period 2002/2003 to 2018/2019 and described trends in injuries over this time.ResultsOver the period 2002/2003–2018/2019, 10 851 injuries occurred in 1 24 952 hours of match play, equating to a mean of 57 injuries per club per season and one injury per team per match. The mean incidence, severity (days absence) and burden (days absence/1000 hours) of injury were 87/1000 hours (95% CI 82 to 92), 25 days (95% CI 22 to 28) and 2178 days/1000 hours (95% CI 1872 to 2484), respectively. The tackle accounted for 43% injuries with running the second most common activity during injury (12%). The most common injury location was the head/face with an incidence of 11.3/1000 hours, while the location with the highest overall burden was the knee (11.1 days/1000 hours). Long-term trends demonstrated stable injury incidence and proportion of injured players, but an increase in the mean and median severity of injuries. Concussion incidence, severity and burden increased from the 2009/2010 season onwards and from 2011 to 2019 concussion was the most common injury.ConclusionThe rise in overall injury severity and concussion incidence are the most significant findings from this work and demonstrate the need for continued efforts to reduce concussion risk as well as a greater understanding of changes in injury severity over time.

scholarly journals Similar head impact acceleration measured using instrumented ear patches in a junior rugby union team during matches in comparison with other sports

2016 ◽  
Vol 18 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Doug A. King ◽  
Patria A. Hume ◽  
Conor Gissane ◽  
Trevor N. Clark
Keyword(s):  
Injury Risk ◽  
Linear Acceleration ◽  
Rugby Union ◽  
Head Impact ◽  
American Football ◽  
Football Players ◽  
Head Impacts ◽  
Impact Acceleration ◽  
The Impact ◽  
Rugby Players

OBJECTIVE Direct impact with the head and the inertial loading of the head have been postulated as major mechanisms of head-related injuries, such as concussion. METHODS This descriptive observational study was conducted to quantify the head impact acceleration characteristics in under-9-year-old junior rugby union players in New Zealand. The impact magnitude, frequency, and location were collected with a wireless head impact sensor that was worn by 14 junior rugby players who participated in 4 matches. RESULTS A total of 721 impacts > 10g were recorded. The median (interquartile range [IQR]) number of impacts per player was 46 (IQR 37–58), resulting in 10 (IQR 4–18) impacts to the head per player per match. The median impact magnitudes recorded were 15g (IQR 12g–21g) for linear acceleration and 2296 rad/sec2 (IQR 1352–4152 rad/sec2) for rotational acceleration. CONCLUSIONS There were 121 impacts (16.8%) above the rotational injury risk limit and 1 (0.1%) impact above the linear injury risk limit. The acceleration magnitude and number of head impacts in junior rugby union players were higher than those previously reported in similar age-group sports participants. The median linear acceleration for the under-9-year-old rugby players were similar to 7- to 8-year-old American football players, but lower than 9- to 12-year-old youth American football players. The median rotational accelerations measured were higher than the median and 95th percentiles in youth, high school, and collegiate American football players.

scholarly journals Impact test comparisons of 20th and 21st century American football helmets

2012 ◽  
Vol 116 (1) ◽  
pp. 222-233 ◽  
Author(s):  
Adam Bartsch ◽  
Edward Benzel ◽  
Vincent Miele ◽  
Vikas Prakash
Keyword(s):  
Head Injury ◽  
21St Century ◽  
Injury Risk ◽  
Diffuse Axonal Injury ◽  
Angular Acceleration ◽  
Linear Acceleration ◽  
Severity Index ◽  
Head Impact ◽  
American Football ◽  
Acute Subdural Hematoma

Object Concussion is the signature American football injury of the 21st century. Modern varsity helmets, as compared with vintage leather helmets, or “leatherheads,” are widely believed to universally improve protection by reducing head impact doses and head injury risk for the 3 million young football players in the US. The object of this study was to compare the head impact doses and injury risks with 11 widely used 21st century varsity helmets and 2 early 20th century leatherheads and to hypothesize what the results might mean for children wearing similar varsity helmets. Methods In an injury biomechanics laboratory, the authors conducted front, oblique front, lateral, oblique rear, and rear head impact tests at 5.0 m/second using helmeted headforms, inducing near- and subconcussive head impact doses on par with approximately the 95th percentile of on-field collision severity. They also calculated impact dose injury risk parameters common to laboratory and on-field traumatic neuromechanics: linear acceleration, angular acceleration, angular velocity, Gadd Severity Index, diffuse axonal injury, acute subdural hematoma, and brain contusion. Results In many instances the head impact doses and head injury risks while wearing vintage leatherheads were comparable to or better than those while wearing several widely used 21st century varsity helmets. Conclusions The authors do not advocate reverting to leather headgear, but they do strongly recommend, especially for young players, instituting helmet safety designs and testing standards, which encourage the minimization of linear and angular impact doses and injury risks in near- and subconcussive head impacts.

Rotational Stiffness of Football Shoes Influences Talus Motion during External Rotation of the Foot

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Feng Wei ◽  
Eric G. Meyer ◽  
Jerrod E. Braman ◽  
John W. Powell ◽  
Roger C. Haut
Keyword(s):  
Ankle Joint ◽  
Joint Torque ◽  
Ankle Injuries ◽  
Design Parameters ◽  
Deltoid Ligament ◽  
Rotational Stiffness ◽  
Shoe Design ◽  
Tibiofibular Ligament ◽  
Ankle Ligament ◽  
Ligament Strain

Shoe-surface interface characteristics have been implicated in the high incidence of ankle injuries suffered by athletes. Yet, the differences in rotational stiffness among shoes may also influence injury risk. It was hypothesized that shoes with different rotational stiffness will generate different patterns of ankle ligament strain. Four football shoe designs were tested and compared in terms of rotational stiffness. Twelve (six pairs) male cadaveric lower extremity limbs were externally rotated 30 deg using two selected football shoe designs, i.e., a flexible shoe and a rigid shoe. Motion capture was performed to track the movement of the talus with a reflective marker array screwed into the bone. A computational ankle model was utilized to input talus motions for the estimation of ankle ligament strains. At 30 deg of rotation, the rigid shoe generated higher ankle joint torque at 46.2 ± 9.3 Nm than the flexible shoe at 35.4 ± 5.7 Nm. While talus rotation was greater in the rigid shoe (15.9 ± 1.6 deg versus 12.1 ± 1.0 deg), the flexible shoe generated more talus eversion (5.6 ± 1.5 deg versus 1.2± 0.8 deg). While these talus motions resulted in the same level of anterior deltoid ligament strain (approxiamtely 5%) between shoes, there was a significant increase of anterior tibiofibular ligament strain (4.5± 0.4% versus 2.3 ± 0.3%) for the flexible versus more rigid shoe design. The flexible shoe may provide less restraint to the subtalar and transverse tarsal joints, resulting in more eversion but less axial rotation of the talus during foot/shoe rotation. The increase of strain in the anterior tibiofibular ligament may have been largely due to the increased level of talus eversion documented for the flexible shoe. There may be a direct correlation of ankle joint torque with axial talus rotation, and an inverse relationship between torque and talus eversion. The study may provide some insight into relationships between shoe design and ankle ligament strain patterns. In future studies, these data may be useful in characterizing shoe design parameters and balancing potential ankle injury risks with player performance.

scholarly journals Injury surveillance in taekwondo and judo during physiotherapy coverage of the seventh all Africa Games

2001 ◽  
Vol 57 (1) ◽  
pp. 32-34 ◽  
Author(s):  
J. S. Phillips ◽  
J. M. Frantz ◽  
S. L. Amosun ◽  
W. Weitz
Keyword(s):  
Early Diagnosis ◽  
Injury Prevention ◽  
Risk Ratio ◽  
Medical Staff ◽  
Injury Risk ◽  
Injury Severity ◽  
Upper Limbs ◽  
Severe Injuries ◽  
High Incidence ◽  
Type Of Injury

Objective: To obtain data relating to the incidence of injuries sustained during taekwondo and judo competitions at the 7th All Africa Games.Methods: Prospective recording of injuries sustained by athletes who sought physiotherapy services at the games. Details of type of injury, injury sites and injury severity were obtained.Results: Seventy athletes out of 390 participants reported injuries. The overall injury risk ratio was 0.18. Injuries reported were strains/sprains (65,6%), bruises/contusions (16.1%) and dislocations or fractures (12,9%). The upper limbs were more commonly injured. Of the injuries sustained, approximately 18%, 69% and 13% were respectively classified as mild, moderate and severe injuries.Conclusions: The high incidence of moderate to severe injuries highlights the need for injury prevention programs and the presence of medical staff at major tournaments in order to make early diagnosis and appropriate intervention.

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