Potential for head injuries in infants from low-height falls

2008 ◽  
Vol 2 (5) ◽  
pp. 321-330 ◽  
Author(s):  
Brittany Coats ◽  
Susan S. Margulies
Keyword(s):  
Child Abuse ◽  
Impact Force ◽  
Head Injuries ◽  
Skull Fracture ◽  
Angular Acceleration ◽  
Objective Data ◽  
Time Duration ◽  
Impact Forces ◽  
Force Data ◽  
Peak Impact Force

Object Falls are the most common accident scenario in young children as well as the most common history provided in child abuse cases. Understanding the biomechanics of falls provides clinicians with objective data to aid in their diagnosis of accidental or inflicted trauma. The objective of this study was to determine impact forces and angular accelerations associated with low-height falls in infants. Methods An instrumented anthropomorphic infant surrogate was created to measure the forces and 3D angular accelerations associated with falls from low heights (0.3–0.9 m) onto a mattress, carpet pad, or concrete. Results Although height significantly increased peak angular acceleration (αp), change in peak-to-peak angular velocity, time duration associated with the change in velocity, and peak impact force (Fp) for head-first drops onto a carpet pad or concrete, none of these variables were significantly affected by height when dropped onto a mattress. The αp was not significantly different for drops onto a carpet pad and concrete from 0.6 or 0.9 m due to compression of the carpet pad. Surprisingly, sagittal αp was equaled or surpassed by axial αp. Conclusions These are the first 3D angular acceleration and impact force data available for head impact in infants from low-height falls. A future study involving a computational model of the infant head will use the loads measured in this study to predict the probability of occipital skull fracture on impact from head-first low-height falls. Together, these studies will provide data that will aid clinicians in the evaluation of accidental and inflicted head injuries, and will contribute to the design of safer environments for children.

scholarly journals Brain injury in sports

2016 ◽  
Vol 124 (3) ◽  
pp. 667-674 ◽  
Author(s):  
John Lloyd ◽  
Frank Conidi
Keyword(s):  
Brain Injuries ◽  
Scientific Evidence ◽  
Head Injuries ◽  
Skull Fracture ◽  
Angular Acceleration ◽  
Linear Acceleration ◽  
Impact Testing ◽  
Common Belief ◽  
Percentage Reduction ◽  
Football Helmets

OBJECT Helmets are used for sports, military, and transportation to protect against impact forces and associated injuries. The common belief among end users is that the helmet protects the whole head, including the brain. However, current consensus among biomechanists and sports neurologists indicates that helmets do not provide significant protection against concussion and brain injuries. In this paper the authors present existing scientific evidence on the mechanisms underlying traumatic head and brain injuries, along with a biomechanical evaluation of 21 current and retired football helmets. METHODS The National Operating Committee on Standards for Athletic Equipment (NOCSAE) standard test apparatus was modified and validated for impact testing of protective headwear to include the measurement of both linear and angular kinematics. From a drop height of 2.0 m onto a flat steel anvil, each football helmet was impacted 5 times in the occipital area. RESULTS Skull fracture risk was determined for each of the current varsity football helmets by calculating the percentage reduction in linear acceleration relative to a 140-g skull fracture threshold. Risk of subdural hematoma was determined by calculating the percentage reduction in angular acceleration relative to the bridging vein failure threshold, computed as a function of impact duration. Ranking the helmets according to their performance under these criteria, the authors determined that the Schutt Vengeance performed the best overall. CONCLUSIONS The study findings demonstrated that not all football helmets provide equal or adequate protection against either focal head injuries or traumatic brain injuries. In fact, some of the most popular helmets on the field ranked among the worst. While protection is improving, none of the current or retired varsity football helmets can provide absolute protection against brain injuries, including concussions and subdural hematomas. To maximize protection against head and brain injuries for football players of all ages, the authors propose thresholds for all sports helmets based on a peak linear acceleration no greater than 90 g and a peak angular acceleration not exceeding 1700 rad/sec2.

The Correlation of Segment Accelerations and Impact Forces with Knee Angle in Jump Landing

2007 ◽  
Vol 23 (3) ◽  
pp. 203-212 ◽  
Author(s):  
Niell G. Elvin ◽  
Alex A. Elvin ◽  
Steven P. Arnoczky ◽  
Michael R. Torry
Keyword(s):  
Contact Angle ◽  
Ground Reaction Force ◽  
Knee Flexion ◽  
Impact Force ◽  
Reaction Force ◽  
Least Square ◽  
Jump Height ◽  
Impact Forces ◽  
Axial Acceleration ◽  
Peak Impact Force

Impact forces and shock deceleration during jumping and running have been associated with various knee injury etiologies. This study investigates the influence of jump height and knee contact angle on peak ground reaction force and segment axial accelerations. Ground reaction force, segment axial acceleration, and knee angles were measured for 6 male subjects during vertical jumping. A simple spring-mass model is used to predict the landing stiffness at impact as a function of (1) jump height, (2) peak impact force, (3) peak tibial axial acceleration, (4) peak thigh axial acceleration, and (5) peak trunk axial acceleration. Using a nonlinear least square fit, a strong (r= 0.86) and significant (p≤ 0.05) correlation was found between knee contact angle and stiffness calculated using the peak impact force and jump height. The same model also showed that the correlation was strong (r= 0.81) and significant (p≤ 0.05) between knee contact angle and stiffness calculated from the peak trunk axial accelerations. The correlation was weaker for the peak thigh (r= 0.71) and tibial (r= 0.45) axial accelerations. Using the peak force but neglecting jump height in the model, produces significantly worse correlation (r= 0.58). It was concluded that knee contact angle significantly influences both peak ground reaction forces and segment accelerations. However, owing to the nonlinear relationship, peak forces and segment accelerations change more rapidly at smaller knee flexion angles (i.e., close to full extension) than at greater knee flexion angles.

Serious Head Injury in Infants: Accident or Abuse?

PEDIATRICS ◽  
1985 ◽  
Vol 75 (2) ◽  
pp. 340-342 ◽  
Author(s):  
M. Elaine Billmire ◽  
Patricia A. Myers
Keyword(s):  
Child Abuse ◽  
Head Injury ◽  
Medical Records ◽  
Motor Vehicle ◽  
Motor Vehicle Accident ◽  
Head Injuries ◽  
Skull Fracture ◽  
Intracranial Injury ◽  
Vehicle Accident ◽  
History Of

The medical records and computed tomography (CT) scans of all children less than 1 year of age admitted to the hospital with head injury over a 2-year period were reviewed. Sixty-four percent of all head injuries, excluding uncomplicated skull fracture, and 95% of serious intracranial injuries were the result of child abuse. The occurrence of intracranial injury in infants, in the absence of a history of significant accidental trauma, such as a motor vehicle accident, constitutes grounds for an official child abuse investigation.

Biomechanics of the toddler head during low-height falls: an anthropomorphic dummy analysis

2010 ◽  
Vol 6 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Nicole G. Ibrahim ◽  
Susan S. Margulies
Keyword(s):  
Mechanical Load ◽  
Tissue Injury ◽  
Head Injuries ◽  
Skull Fracture ◽  
Angular Acceleration ◽  
Soft Tissue Injuries ◽  
Altered Mental Status ◽  
Neurological Impairment ◽  
Clinical Findings ◽  
Facial Soft Tissue

Object Falls are the most common environmental setting for closed head injuries in children between 2 and 4 years of age. The authors previously found that toddlers had fewer skull fractures and scalp/facial soft-tissue injuries, and more frequent altered mental status than infants for the same low-height falls (≤3 ft). Methods To identify potential age-dependent mechanical load factors that may be responsible for these clinical findings, the authors created an instrumented dummy representing an 18-month-old child using published toddler anthropometry and mechanical properties of the skull and neck, and they measured peak angular acceleration during low-height falls (1, 2, and 3 ft) onto carpet pad and concrete. They compared these results from occiput-first impacts to previously obtained values measured in a 6-week-old infant dummy. Results Peak angular acceleration of the toddler dummy head was largest in the sagittal and horizontal directions and increased significantly (around 2-fold) with fall height between 1 and 2 ft. Impacts onto concrete produced larger peak angular accelerations and smaller impact durations than those onto carpet pad. When compared with previously measured infant drops, toddler head accelerations were more than double those of the infant from the same height onto the same surface, likely contributing to the higher incidence of loss of consciousness reported in toddlers. Furthermore, the toddler impact forces were larger than those in the infant, but because of the thicker toddler skull, the risk of skull fracture from low-height falls is likely lower in toddlers compared with infants. Conclusions If similar fracture limits and brain tissue injury thresholds between infants and toddlers are assumed, it is expected that for impact events, the toddler is likely less vulnerable to skull fracture but more vulnerable to neurological impairment compared with the infant.

scholarly journals Experimental Studies on a Powder-Snow Avalanche

1989 ◽  
Vol 13 ◽  
pp. 129-134 ◽  
Author(s):  
K. Kawada ◽  
K. Nishimura ◽  
N. Maeno
Keyword(s):  
Large Scale ◽  
Impact Force ◽  
Experimental Studies ◽  
Block Type ◽  
Impact Forces ◽  
Wave Forms ◽  
The Impact ◽  
Force Data

To make clear the structure and behaviour of a large-scale avalanche, the impact force-data obtained in the avalanche project of 1972–78 were analysed in detail. The wave forms of impact forces are classified into two types. Type 1 is composed of many separate spikes each of which represents the collision of a snow block. Type 2 has wider peaks, caused by collisons of snow blocks mixed with fluidized snow. Most of the type 1 peaks were in the width range corresponding to 0.005–0.01 s duration, and most type 2 peaks fell into the 0.02–0.1 s range.The internal velocities of an avalanche were estimated by calculating cross-correlation spectra for a time series of impact-force records. It was discovered that these internal velocities varied from 10 to 50 m/s over time. The mean distance between snow blocks was found to be in the range 1.6–5.4 m in a type 1 avalanche, and between 0.7 and 3 m in type 2 avalanches. Sizes of snow blocks or snow clouds of type 1 and type 2 were in ranges 0.26–0.52 and 0.37–1.9 m, respectively.This paper also reports on the project created to initiate artificial powder-snow avalanches in the Shiai-dani area and to make systematic observations of a variety of physical aspects. Results obtained in 1988 for both artificial and natural avalanches are given.

Design and development of a force sensing skin adapted to a child surrogate to identify potential bruising locations

TECHNOLOGY ◽  
2014 ◽  
Vol 02 (01) ◽  
pp. 49-54 ◽  
Author(s):  
Raymond D'souza ◽  
Gina Bertocci
Keyword(s):  
Child Abuse ◽  
Impact Force ◽  
Data Acquisition System ◽  
The Body ◽  
Test Device ◽  
Image System ◽  
Body Mapping ◽  
System A ◽  
Sensing Skin ◽  
Force Data

Bruising is an early sign of child abuse. Bruising locations on the body can be an effective delineator of abusive vs. accidental trauma. However, the ability to predict potential bruising locations associated with falsely reported events (e.g. bed falls, stair falls) in child abuse does not exist. In our study we adapted an existing pediatric anthropomorphic test device (ATD) with custom developed force sensors integrated into a conformable skin. The sensors were coupled to a data acquisition system through which recorded force data was displayed on a computerized body mapping image system. A simulated abdominal blow demonstrated the modified ATD's capability to predict potential bruising location and impact force.

Effect of Running Speed and Aerobic Dance Jump Height on Vertical Ground Reaction Forces

1994 ◽  
Vol 10 (1) ◽  
pp. 14-27 ◽  
Author(s):  
Mark D. Ricard ◽  
Steve Veatch
Keyword(s):  
High Frequency ◽  
Loading Rate ◽  
Impact Force ◽  
Reaction Force ◽  
Running Speed ◽  
Dance Movement ◽  
Aerobic Dance ◽  
Impact Forces ◽  
Peak Impact Force ◽  
Frequency Impulse

Aerobic dance movement sequences are similar to running in repetitive frequency. The purpose of this study was to compare ground reaction force variables in aerobic dance and running. Five female subjects performed 10 trials of five running speeds (2.4–4.0 ± 0.4 m/s) and five heights (0–8 ± 0.2 cm) of front knee lift aerobic dance steps on an AMTI force plate (1000 Hz). First peak impact force, peak loading rate, high-frequency impulse, and 50-ms impulse increased with increased running speed and jumping height. Time to first peak impact force decreased as running speed and jumping height increased. Although first peak impact forces resulting from airborne aerobic dance movements (1.96–2.62 BW) were greater than first peak impact forces in running (1.30–2.01 BW), running compared to aerobic dance resulted in shorter time to first peak impact force and higher values for loading rate, high-frequency impulse, and 50-ms impulse. When compared to aerobic dance, running exhibits smaller peak vertical forces but higher loading rates and vertical impulses.

scholarly journals Factors affecting peak impact force during soccer headers and implications for the mitigation of head injuries

PLoS ONE ◽  
2020 ◽  
Vol 15 (10) ◽  
pp. e0240162
Author(s):  
Joshua Auger ◽  
Justin Markel ◽  
Dimitri D. Pecoski ◽  
Nicolas Leiva-Molano ◽  
Thomas M. Talavage ◽  
...  
Keyword(s):  
Impact Force ◽  
Head Injuries ◽  
Factors Affecting ◽  
Peak Impact Force

scholarly journals Sex Disparity in Bilateral Asymmetry of Impact Forces during Height-Adjusted Drop Jumps

2021 ◽  
Vol 18 (11) ◽  
pp. 5953
Author(s):  
Chin-Yi Gu ◽  
Xiang-Rui Li ◽  
Chien-Ting Lai ◽  
Jin-Jiang Gao ◽  
I-Lin Wang ◽  
...  
Keyword(s):  
Anterior Cruciate Ligament ◽  
Impact Force ◽  
Cruciate Ligament ◽  
Ligament Injury ◽  
Drop Jump ◽  
Impact Forces ◽  
Drop Jumps ◽  
Anterior Cruciate ◽  
Sex Disparity ◽  
Peak Impact Force

Side-to-side asymmetry of lower extremities may influence the risk of injury associated with drop jump. Moreover, drop heights using relative height across individuals based on respective jumping abilities could better explain lower-extremity loading impact for different genders. The purpose of the current study was to evaluate the sex differences of impact forces and asymmetry during the landing phase of drop-jump tasks using drop heights, set according to participants’ maximum jumping height. Ten male and ten female athletes performed drop-jump tasks on two force plates, and ground reaction force data were collected. Both feet needed to land entirely on the dedicated force plates as simultaneously as possible. Ground reaction forces and asymmetry between legs were calculated for jumps from 100%, 130%, and 160% of each participant’s maximum jumping height. Females landed with greater asymmetry at time of contact initiation and time of peak impact force and had more asymmetrical peak impact force than males. Greater values and shorter time after ground contact of peak impact force were found when the drop height increased to 160% of maximum jumping ability as compared to 100% and 130%. Females exhibited greater asymmetry than males during drop jumps from relative heights, which may relate to the higher risk of anterior cruciate ligament injury among females. Greater sex disparity was evident in impact force asymmetry than in the magnitude of peak impact force; therefore, it may be a more appropriate field-screening test for risk of anterior cruciate ligament injury.

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