The startle response during whiplash: a protective or harmful response?

2012 ◽  
Vol 113 (4) ◽  
pp. 532-540 ◽  
Author(s):  
Daniel W. H. Mang ◽  
Gunter P. Siegmund ◽  
J. Timothy Inglis ◽  
Jean-Sébastien Blouin
Keyword(s):  
Startle Response ◽  
Angular Acceleration ◽  
The Body ◽  
Whiplash Injuries ◽  
Loud Tone ◽  
Head Acceleration ◽  
Head Stabilization ◽  
Speed Change ◽  
Muscle Responses ◽  
Horizontal Head

Whiplash injuries are common following rear-end collisions. During such collisions, initially relaxed occupants exhibit brisk, stereotypical muscle responses consisting of postural and startle responses that may contribute to the injury. Using prestimulus inhibition, we sought to determine if the startle response elicited during a rear-end collision contributes to head stabilization or represents a potentially harmful overreaction of the body. Three experiments were performed. In the first two experiments, two groups of 14 subjects were exposed to loud tones (124 dB) preceded by prestimulus tones at either four interstimulus intervals (100–1,000 ms) or five prestimulus intensities (80–124 dB). On the basis of the results of the first two experiments, 20 subjects were exposed to a simulated rear-end collision (peak sled acceleration = 2 g; speed change = 0.75 m/s) preceded by one of the following: no prestimulus tone, a weak tone (85 dB), or a loud tone (105 dB). The prestimulus tones were presented 250 ms before sled acceleration onset. The loud prestimulus tone decreased the amplitude of the sternocleidomastoid (16%) and cervical paraspinal (29%) muscles, and key peak kinematics: head retraction (17%), horizontal head acceleration (23%), and head angular acceleration in extension (23%). No changes in muscle amplitude or kinematics occurred for the weak prestimulus. The reduced muscle and kinematic responses observed with loud tones suggest that the startle response represents an overreaction that increases the kinematics in a way that potentially increases the forces and strains in the neck tissues. We propose that minimizing this overreaction during a car collision may decrease the risk of whiplash injuries.

Impact of Electric Vehicle Lateral Dynamics on the Battery Pack

2014 ◽  
Vol 590 ◽  
pp. 451-457
Author(s):  
Sen Nan Song ◽  
Fa Chao Jiang ◽  
Hong Shi
Keyword(s):  
Mathematical Model ◽  
Angular Acceleration ◽  
Simulation Software ◽  
The Body ◽  
Battery Pack ◽  
Vehicle Body ◽  
Rolling Motion ◽  
Rolling Angle ◽  
On The Road ◽  
The Mathematical Model

The present work is concerned with the rolling motion of the battery pack when EV travelling on the road. First McPherson suspension system was regarded as the research object with detailed analysis of its structural features and motion characteristics. Establish the mathematical model which could apply to calculating the rolling motion of the vehicle body. Through MATLAB/Simulink simulation software, we could calculate the rolling angle on passive suspension. On this basis, assume that the battery pack mounted on the vehicle body and make it passive connection and PID connection. When the body rolls, the battery pack will produce a certain angle then. Next establish the mathematical model to summarize the relationship between the two variables. Then we set the parameters and calculate the roll angle of battery pack in both cases for comparison. Simulation results show that road irregularities will make battery rotate an angle and PID controller can effectively reduce the angle, especially angular acceleration. This paper put forward a new idea that battery is connected with body by active control on EV, and proves the superiority in reducing the rolling angle.

Head acceleration measurement techniques: Reliability of angular rate sensor data in helmeted impact testing

2017 ◽  
Vol 232 (2) ◽  
pp. 176-181 ◽  
Author(s):  
Bryan R Cobb ◽  
Abigail M Tyson ◽  
Steven Rowson
Keyword(s):  
Root Mean Square ◽  
Angular Rate ◽  
Angular Acceleration ◽  
Impact Testing ◽  
Sensor Data ◽  
Mean Square ◽  
Head Acceleration ◽  
Angular Rate Sensor ◽  
Impact Tests ◽  
Rate Sensor

This study sought to evaluate the suitability of angular rate sensors for quantifying angular acceleration in helmeted headform impacts. A helmeted Hybrid III headform, instrumented with a 3-2-2-2 nine accelerometer array and angular rate sensors, was impacted (n = 90) at six locations and three velocities (3.1, 4.9, and 6.4 m/s). Data were low-pass filtered using Butterworth four-pole phaseless digital filters which conform to the specifications described in the Society of Automotive Engineers J211 standard on instrumentation for impact tests. Nine accelerometer array data were filtered using channel frequency class 180, which corresponds to a −3 db cutoff frequency of 300 Hz. Angular rate sensor data were filtered using channel frequency class values ranging from 5 to 1000 Hz in increments of 5 Hz, which correspond to −3 db cutoff frequencies of 8 to 1650 Hz. Root-mean-square differences in peak angular acceleration between the two instrumentation schemes were assessed for each channel frequency class value. Filtering angular rate sensor data with channel frequency class values between 120 and 205 all produced mean differences within ±5%. The minimum root-mean-square difference of 297 rad/s2 was found when the angular rate sensor data were filtered using channel frequency class 175. This filter specification resulted in a mean difference of 28 ± 297 rad/s2 (1.8% ± 8.6%). Condition-specific differences (α=0.05) were observed for 11 of 18 test conditions. A total of 4 of those 11 conditions were within ±5%, and 10 were within ±10%. Furthermore, the nine accelerometer array and angular rate sensor methods demonstrated similar levels of repeatability. These data suggest that angular rate sensor may be an appropriate alternative to the nine accelerometer array for measuring angular head acceleration in helmeted head impact tests with impactor velocities of 3.1–6.4 m/s and impact durations of approximately 10 ms.

Kinematics of rotation in place during defense turning in the crayfish Procambarus clarkii

2001 ◽  
Vol 204 (3) ◽  
pp. 471-486 ◽  
Author(s):  
N. Copp ◽  
M. Jamon
Keyword(s):  
Angular Velocity ◽  
Procambarus Clarkii ◽  
Angular Acceleration ◽  
The Body ◽  
Simple Variation ◽  
Freely Behaving ◽  
Leg Motion ◽  
Two Phases ◽  
Analysis System ◽  
Final Orientation

The kinematic patterns of defense turning behavior in freely behaving specimens of the crayfish Procambarus clarkii were investigated with the aid of a video-analysis system. Movements of the body and all pereiopods, except the chelipeds, were analyzed. Because this behavior approximates to a rotation in place, this analysis extends previous studies on straight and curve walking in crustaceans. Specimens of P. clarkii responded to a tactile stimulus on a walking leg by turning accurately to face the source of the stimulation. Angular velocity profiles of the movement of the animal's carapace suggest that defense turn responses are executed in two phases: an initial stereotyped phase, in which the body twists on its legs and undergoes a rapid angular acceleration, followed by a more erratic phase of generally decreasing angular velocity that leads to the final orientation. Comparisons of contralateral members of each pair of legs reveal that defense turns are affected by changes in step geometry, rather than by changes in the timing parameters of leg motion, although inner legs 3 and 4 tend to take more steps than their outer counterparts during the course of a response. During the initial phase, outer legs 3 and 4 exhibit larger stance amplitudes than their inner partners, and all the outer legs produce larger stance amplitudes than their inner counterparts during the second stage of the response. Also, the net vectors of the initial stances, particularly, are angled with respect to the body, with the power strokes of the inner legs produced during promotion and those of the outer legs produced during remotion. Unlike straight and curve walking in the crayfish, there is no discernible pattern of contralateral leg coordination during defense turns. Similarities and differences between defense turns and curve walking are discussed. It is apparent that rotation in place, as in defense turns, is not a simple variation on straight or curve walking but a distinct locomotor pattern.

scholarly journals Operation of the alula as an indicator of gear change in hoverflies

2011 ◽  
Vol 9 (71) ◽  
pp. 1194-1207 ◽  
Author(s):  
Simon M. Walker ◽  
Adrian L. R. Thomas ◽  
Graham K. Taylor
Keyword(s):  
High Speed ◽  
Aerodynamic Force ◽  
Angular Acceleration ◽  
The State ◽  
The Body ◽  
Kinematic Parameters ◽  
Wing Kinematics ◽  
Change Mechanism ◽  
The Third ◽  
Gear Change

The alula is a hinged flap found at the base of the wings of most brachyceran Diptera. The alula accounts for up to 10 per cent of the total wing area in hoverflies (Syrphidae), and its hinged arrangement allows the wings to be swept back over the thorax and abdomen at rest. The alula is actuated via the third axillary sclerite, which is a component of the wing hinge that is involved in wing retraction and control. The third axillary sclerite has also been implicated in the gear change mechanism of flies. This mechanism allows rapid switching between different modes of wing kinematics, by imposing or removing contact with a mechanical stop limiting movement of the wing during the lower half of the downstroke. The alula operates in two distinct states during flight—flipped or flat—and we hypothesize that its state indicates switching between different flight modes. We used high-speed digital video of free-flying hoverflies ( Eristalis tenax and Eristalis pertinax ) to investigate whether flipping of the alula was associated with changes in wing and body kinematics. We found that alula state was associated with different distributions of multiple wing kinematic parameters, including stroke amplitude, stroke deviation angle, downstroke angle of incidence and timing of supination. Changes in all of these parameters have previously been linked to gear change in flies. Symmetric flipping of the alulae was associated with changes in the symmetric linear acceleration of the body, while asymmetric flipping of the alulae was associated with asymmetric angular acceleration of the body. We conclude that the wings produce less aerodynamic force when the alula is flipped, largely as a result of the accompanying changes in wing kinematics. The alula changes state at mid-downstroke, which is the point at which the gear change mechanism is known to come into effect. This transition is accompanied by changes in the other wing kinematic parameters. We therefore find that the state of the alula is linked to the same parameters as are affected by the gear change mechanism. We conclude that the state of the alula does indeed indicate the operation of different flight modes in Eristalis , and infer that a likely mechanism for these changes in flight mode is the gear change mechanism.

Functional significance and neural basis of larval lamprey startle behaviour

1987 ◽  
Vol 133 (1) ◽  
pp. 121-135 ◽  
Author(s):  
S. N. Currie ◽  
R. C. Carlsen
Keyword(s):  
Functional Significance ◽  
Action Potentials ◽  
Startle Response ◽  
Müller Cells ◽  
The Body ◽  
Simultaneous Action ◽  
Muller Cells ◽  
Neural Basis ◽  
Lateral Body ◽  
Motor Effects

1. The vibration-evoked startle response mediates rapid withdrawal in burrowed larval lampreys (ammocoetes). Ammocoetes withdraw in response to vibration by contracting pre-existing lateral bends in the trunk and tail, thus pulling their heads deeper into the burrow. 2. The motor effects of an ammocoete startle response are dependent on pre-existing posture. Areas of lateral body curvature contract more and exhibit larger electromyogram (EMG) amplitudes on their inner sides than on their outer sides. 3. Both of the anterior Mth and posterior Mth' (Mauthner) cells and both of the B1 and B2 (bulbar) Muller cells fired action potentials in response to vibration of the otic capsules. Both B3 and B4 Muller cells were inhibited by vibration, while M (mesencephalic) and I1 (isthmic) Muller cells were inhibited by ipsilateral vibration and excited by contralateral vibration. 4. Simultaneous action potentials in both of the anterior Mth cells were appropriate and sufficient for initiating the startle response EMG in a semi-intact preparation. 5. This study demonstrates a Mauthner-initiated startle response which activates musculature on both sides of the body to produce a rapid withdrawal movement and is thus adapted to the eel-like form and burrowed lifestyle of larval lampreys.

scholarly journals A Proposed Algorithm to Assess Concussion Potential in Rear-End Motor Vehicle Collisions: A Meta-Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Manon Limousis-Gayda ◽  
Rami Hashish
Keyword(s):  
Motor Vehicle ◽  
Meta Analysis ◽  
Angular Acceleration ◽  
Head Position ◽  
Future Research ◽  
Head Acceleration ◽  
Motor Vehicle Collisions ◽  
Research Papers ◽  
Data Set ◽  
Vehicle Collisions

Concussions represent an increasing economic burden to society. Motor vehicle collisions (MVCs) are of the leading causes for sustaining a concussion, potentially due to high head accelerations. The change in velocity (i.e., delta-V) of a vehicle in a MVC is an established metric for impact severity. Accordingly, the purpose of this paper is to analyze findings from previous research to determine the relation between delta-V and linear head acceleration, including occupant parameters. Data was collected from previous research papers comprising both linear head acceleration and delta-V at the time of incident, head position of the occupant, awareness of the occupant prior to impact, as well as gender, age, height, and weight. Statistical analysis revealed the following significant power relation between delta-V and head acceleration: head acceleration=0.465delta‐V1.3231 (R2=0.5913, p<0.001). Further analysis revealed that alongside delta-V, the occupant’s gender and head position prior to impact were significant predictors of head acceleration (p=0.022 and p=0.001, respectively). The strongest model developed in this paper is considered physiologically implausible as the delta-V corresponding to a theoretical concussion threshold of 80 g exceeds the delta-V associated with probability of fatality. Future research should be aimed at providing a more thorough data set of the occupant head kinematics in MVCs to help develop a stronger predictive model for the relation between delta-V and head linear and angular acceleration.

Some Dimensions of the Angular Acceleration Receptor Systems of Cephalopods

1984 ◽  
Vol 64 (1) ◽  
pp. 55-79 ◽  
Author(s):  
Linda Maddock ◽  
J. Z. Young
Keyword(s):  
Angular Velocity ◽  
Frequency Band ◽  
Deep Sea ◽  
Horizontal Plane ◽  
Angular Acceleration ◽  
The Body ◽  
The Other ◽  
Radius Of Curvature ◽  
Internal Radius ◽  
Neutrally Buoyant

The shapes and dimensions of the statocysts of cephalopods have been measured and compared with the semi-circular canals of vertebrates. The cavities grow much more slowly than the body as a whole, but there are knobs, anticristae, which restrict the cavity, and these grow relatively faster. This ensures that the flow of endolymph across the cupulae remains small. Where the liquid is constrained within canals the radius of curvature of the whole canal, R, is similar to that of fishes, whereas its internal radius, r, is twice as large in non-buoyant and four times as large in deep-sea buoyant cephalopods as in fishes of similar size. As in fishes the restriction is greatest in the horizontal plane, providing for operation at higher frequencies in turning about the yaw axis.The statocysts of seven species of Loligo all have similar proportions. The largest individuals of 16 genera of non-buoyant squids also have these same relative dimensions. The statocyst of Sepia is more like that of non-buoyant than of other buoyant cephalopods but yet differs significantly from that of Loligo at all sizes. On the other hand 21 genera of squids known to be neutrally buoyant are very different. Their statocysts are often larger than in the non-buoyant forms and there is less restriction of the cavity by anticristae. The greater flow of endolymph acting across the cupulae presumably provides greater sensitivity at the lower frequencies of turning of these deep-sea animals.The data suggest that the cristae of the cephalopod statocyst may operate in the frequency band where they act as angular accelerometers whereas the vertebrate semi-circular canals operate at higher frequencies as angular velocity meters.

Escape Responses of Herring Larvae to Visual Stimuli

1989 ◽  
Vol 69 (3) ◽  
pp. 647-654 ◽  
Author(s):  
R.S. Batty
Keyword(s):  
Startle Response ◽  
Larval Fish ◽  
Fish Larvae ◽  
Adult Population ◽  
Juvenile Fish ◽  
Reciprocal Inhibition ◽  
Contralateral Side ◽  
The Body ◽  
Different Types ◽  
Trunk Musculature

Predation is now considered the main cause of mortality in larval and juvenile fish (Hunter, 1984) and is therefore the most important factor controlling recruitment to the adult population. Marine fish larvae are prey for many different types of predator including medusae, crustaceans and larger fish. When predatory attacks are sensed both adult and larval fish may respond by making a 'C-start', a very fast, simultaneous contraction of the trunk musculature that deforms the body into a C-shape within 20 ms (Eaton & Hackett, 1984). This startle response is mediated by the Mauthner cells, a pair of prominent neurones in the hind brain or by other reticulo-spinal cells located in the same region. As a result of reciprocal inhibition and decussation of the cell axon, stimulation on one side of the body results in contraction of all the muscle on the contralateral side.

Validation of a Wireless Head Acceleration Measurement System for Use in Soccer Play

2010 ◽  
Vol 26 (4) ◽  
pp. 424-431 ◽  
Author(s):  
Erin Hanlon ◽  
Cynthia Bir
Keyword(s):  
Measurement System ◽  
Cross Correlation ◽  
Angular Acceleration ◽  
Strong Relationship ◽  
Head Acceleration ◽  
Acceleration Measurement ◽  
Hybrid Iii ◽  
Cross Correlations ◽  
Rms Error ◽  
Soccer Heading

Soccer heading has been studied previously with conflicting results. One major issue is the lack of knowledge regarding what actually occurs biomechanically during soccer heading impacts. The purpose of the current study is to validate a wireless head acceleration measurement system, head impact telemetry system (HITS) that can be used to collect head accelerations during soccer play. The HIT system was fitted to a Hybrid III (HIII) head form that was instrumented with a 3-2-2-2 accelerometer setup. Fifteen impact conditions were tested to simulate impacts commonly experienced during soccer play. Linear and angular acceleration were calculated for both systems and compared. Root mean square (RMS) error and cross correlations were also calculated and compared for both systems. Cross correlation values were very strong withr= .95 ± 0.02 for ball to head forehead impacts andr= .96 ± 0.02 for head to head forehead impacts. The systems showed a strong relationship when comparing RMS error, linear head acceleration, angular head acceleration, and the cross correlation values.

scholarly journals Lower rotational inertia and larger leg muscles indicate more rapid turns in tyrannosaurids than in other large theropods

2018 ◽  
Author(s):  
Eric Snively ◽  
Haley O'Brien ◽  
Donald M Henderson ◽  
Heinrich Mallison ◽  
Lara A Surring ◽  
...  
Keyword(s):  
Body Mass ◽  
Muscle Force ◽  
Angular Acceleration ◽  
The Body ◽  
Rotational Inertia ◽  
Leg Muscles ◽  
Mass Property ◽  
Mass Moment ◽  
Centers Of Mass ◽  
Error Probabilities

Synopsis: Tyrannosaurid dinosaurs had larger than predicted preserved leg muscle attachments and low rotational inertia relative to their body mass, indicating that they could turn more quickly than other large theropods. Methods: To compare turning capability in theropods, we regressed agility estimates against body mass, incorporating superellipse-based modeled mass, centers of mass, and rotational inertia (mass moment of inertia). Muscle force relative to body mass is a direct correlate of agility in humans, and torque gives potential angular acceleration. Agility scores therefore include rotational inertia values divided by proxies for (1) muscle force (ilium area and estimates of m. caudofemoralis longus cross-section), and (2) musculoskeletal torque. Phylogenetic ANCOVA (phylANCOVA) allow assessment of differences in agility between tyrannosaurids and non-tyrannosaurid theropods (accounting for both ontogeny and phylogeny). We applied conditional error probabilities a(p) to stringently test the null hypothesis of equal agility. Results: Tyrannosaurids consistently have agility index magnitudes twice those of allosauroids and some other theropods of equivalent mass, turning the body with both legs planted or pivoting over a stance leg. PhylANCOVA demonstrates definitively greater agilities in tyrannosaurids, and phylogeny explains nearly all covariance. Mass property results are consistent with those of other studies based on skeletal mounts, and between different figure-based methods (our main mathematical slicing procedures, lofted 3D computer models, and simplified graphical double integration). Implications: The capacity for relatively rapid turns in tyrannosaurids is ecologically intriguing in light of their monopolization of large (>400 kg), toothed dinosaurian predator niches in their habitats.

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