Rapid Deceleration

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Jeffery T Podraza - One of the best experts on this subject based on the ideXlab platform.

  • multi plane multi joint lower extremity support moments during a Rapid Deceleration task implications for knee loading
    Human Movement Science, 2018
    Co-Authors: Jeffery T Podraza, Scott C White, Dan K Ramsey
    Abstract:

    Abstract The principle of lower limb support, and the contribution of hip, knee and ankle moments to an overall limb support strategy for an impact-like, Rapid Deceleration movement may help explain individual moment magnitude changes, thereby providing insight into how injury might occur or be avoided. Twenty subjects performed single limb, impact-like, Deceleration landings at three different knee flexion angles in the range of 0–25, 25–50 and 50–75°. Kinematic and kinetic measures identified hip, knee and ankle moment contribution to limb support moments (LSMs) in three planes. Repeated measures ANOVA compared LSMs and the contribution of individual joint moments at initial contact (IC) and 50 ms after. There were no significant differences in the overall LSMs at IC in any plane when the deeper knee flexion landings (25–50° and 50–75°) were compared to the 0–25° landing position but there were significant changes in the 50 ms period after IC. There were greater overall extensor LSMs, less resistance to medial opening of the knee and decreased support against internal tibia rotation when landing in greater knee flexion. The role of individual joint moments changed Rapidly in the 50 ms period after initial landing; and, the relative contribution of the hip and ankle moments depended on the degree of limb flexion at landing. Analyses of individual joint moments emphasized the critical role that the hip joint moments have in balancing potentially injurious knee moments in all three planes for all three landing conditions.

  • effect of knee flexion angle on ground reaction forces knee moments and muscle co contraction during an impact like Deceleration landing implications for the non contact mechanism of acl injury
    Knee, 2010
    Co-Authors: Jeffery T Podraza, Scott C White
    Abstract:

    Abstract Investigating landing kinetics and neuromuscular control strategies during Rapid Deceleration movements is a prerequisite to understanding the non-contact mechanism of ACL injury. The purpose of this study was to quantify the effect of knee flexion angle on ground reaction forces, net knee joint moments, muscle co-contraction and lower extremity muscles during an impact-like, Deceleration task. Ground reaction forces and knee joint moments were determined from video and force plate records of 10 healthy male subjects performing Rapid Deceleration single leg landings from a 10.5cm height with different degrees of knee flexion at landing. Muscle co-contraction was based on muscle moments calculated from an EMG-to-moment processing model. Ground reaction forces and co-contraction indices decreased while knee extensor moments increased significantly with increased degrees of knee flexion at landing (all p

  • effect of knee flexion angle on ground reaction forces knee moments and muscle co contraction during an impact like Deceleration landing implications for the non contact mechanism of acl injury
    Knee, 2010
    Co-Authors: Jeffery T Podraza, Scott C White
    Abstract:

    Investigating landing kinetics and neuromuscular control strategies during Rapid Deceleration movements is a prerequisite to understanding the non-contact mechanism of ACL injury. The purpose of this study was to quantify the effect of knee flexion angle on ground reaction forces, net knee joint moments, muscle co-contraction and lower extremity muscles during an impact-like, Deceleration task. Ground reaction forces and knee joint moments were determined from video and force plate records of 10 healthy male subjects performing Rapid Deceleration single leg landings from a 10.5 cm height with different degrees of knee flexion at landing. Muscle co-contraction was based on muscle moments calculated from an EMG-to-moment processing model. Ground reaction forces and co-contraction indices decreased while knee extensor moments increased significantly with increased degrees of knee flexion at landing (all p<0.005). Higher ground reaction forces when landing in an extended knee position suggests they are a contributing factor in non-contact ACL injuries. Increased knee extensor moments and less co-contraction with flexed knee landings suggest that quadriceps overload may not be the primary cause of non-contact ACL injuries. The results bring into question the counterbalancing role of the hamstrings during dynamic movements. The soleus may be a valuable synergist stabilizing the tibia against anterior translation at landing. Movement strategies that lessen the propagation of reaction forces up the kinetic chain may help prevent non-contact ACL injuries. The relative interaction of all involved thigh and lower leg muscles, not just the quadriceps and hamstrings should be considered when interpreting non-contact ACL injury mechanisms.

Lara K Maxwell - One of the best experts on this subject based on the ideXlab platform.

  • subacute pyridostigmine exposure increases heart rate recovery and cardiac parasympathetic tone in rats
    Clinical and Experimental Pharmacology and Physiology, 2017
    Co-Authors: Manushree Bharadwaj, Stuart D Katz, Carey Pope, Michael S Davis, Christian Cook, Lara K Maxwell
    Abstract:

    Heart rate recovery (HRR) describes the Rapid Deceleration of heart rate after strenuous exercise and is an indicator of parasympathetic tone. A reduction in parasympathetic tone occurs in patients with congestive heart failure, resulting in prolonged HRR. Acetylcholinesterase inhibitors, such as pyridostigmine, can enhance parasympathetic tone by increasing cholinergic input to the heart. The objective of this study was to develop a rodent model of HRR to test the hypothesis that subacute pyridostigmine administration decreases cholinesterase activity and accelerates HRR in rats. Ten days after implantation of radiotelemetry transmitters, male Sprague Dawley rats were randomized to control (CTL) or treated (PYR; 0.14 mg/ml pyridostigmine in the drinking water, 29 days) groups. Rats were exercised on a treadmill to record HRR, and blood samples were collected on days 0, 7, 14, and 28 of pyridostigmine administration. Total cholinesterase and acetylcholinesterase (AChE) activity in plasma was decreased by 32-43% and 57-80%, respectively, in PYR rats on days 7-28, while plasma butyrylcholinesterase activity did not significantly change. AChE activity in RBCs was markedly reduced by 64-66%. HRR recorded 1 min after exercise was higher in the PYR group on days 7, 14 and 28, and on day 7 when HRR was estimated at 3 and 5 min. Autonomic tone was evaluated pharmacologically using sequential administration of muscarinic (atropine) and adrenergic (propranolol) blockers. Parasympathetic tone was increased in PYR rats as compared with the CTL group. These data support the study hypothesis that subacute pyridostigmine administration enhances HRR by increasing cardiac parasympathetic tone. This article is protected by copyright. All rights reserved.

  • subacute pyridostigmine exposure increases heart rate recovery and cardiac parasympathetic tone in rats
    Clinical and Experimental Pharmacology and Physiology, 2017
    Co-Authors: Manushree Bharadwaj, Stuart D Katz, Michael S Davis, Christian Cook, C N Pope, Lara K Maxwell
    Abstract:

    Heart rate recovery (HRR) describes the Rapid Deceleration of heart rate after strenuous exercise and is an indicator of parasympathetic tone. A reduction in parasympathetic tone occurs in patients with congestive heart failure, resulting in prolonged HRR. Acetylcholinesterase inhibitors, such as pyridostigmine, can enhance parasympathetic tone by increasing cholinergic input to the heart. The objective of this study was to develop a rodent model of HRR to test the hypothesis that subacute pyridostigmine administration decreases cholinesterase activity and accelerates HRR in rats. Ten days after implantation of radiotelemetry transmitters, male Sprague Dawley rats were randomized to control (CTL) or treated (PYR; 0.14 mg/mL pyridostigmine in the drinking water, 29 days) groups. Rats were exercised on a treadmill to record HRR, and blood samples were collected on days 0, 7, 14, and 28 of pyridostigmine administration. Total cholinesterase and acetylcholinesterase (AChE) activity in plasma was decreased by 32%-43% and 57%-80%, respectively, in PYR rats on days 7-28, while plasma butyrylcholinesterase activity did not significantly change. AChE activity in red blood cells was markedly reduced by 64%-66%. HRR recorded 1 minute after exercise was higher in the PYR group on days 7, 14 and 28, and on day 7 when HRR was estimated at 3 and 5 minutes. Autonomic tone was evaluated pharmacologically using sequential administration of muscarinic (atropine) and adrenergic (propranolol) blockers. Parasympathetic tone was increased in PYR rats as compared with the CTL group. These data support the study hypothesis that subacute pyridostigmine administration enhances HRR by increasing cardiac parasympathetic tone.

John Boehmer - One of the best experts on this subject based on the ideXlab platform.

  • third heart sound during atrial fibrillation confirming the existence of cardiac vibrations during Deceleration phase of early diastolic filling while in af
    Heart & Lung, 2020
    Co-Authors: Qi An, Viktoria A Averina, John Boehmer, George Mark, Pramodsingh Hirasingh Thakur
    Abstract:

    Background The third heart sound (S3), which is caused by Rapid Deceleration of the blood against a stiff ventricle during early diastolic filling, is regarded as an early and specific sign of heart failure and elevated filling pressure. Objectives Studies have shown phonocardiogram-based S3 to be coincident with the Deceleration phase of E-wave and associated with a steeper E-wave. Atrial fibrillation (AF) is a common comorbidity in HF, however questions have arisen regarding the ability to reliably detect S3 during AF as typically it is more difficult to auscultate an S3 during AF. Here we present a case of simultaneous implanted device measured heart sound and echo data while the patient was in AF. Methods MultiSENSE enrolled patients were implanted with COGNIS CRT-D devices and followed for up to a year. At enrollment the CRT-Ds were converted to enable collection of heart sound (HS) data using the device-based accelerometer. HS data was periodically collected as ensemble averaged (EA) waveforms of multiple neighboring beats that closely matched in RR interval. An optional echocardiogram was conducted if the patient was hospitalized for worsening HF. An independent core laboratory measured parameters from the echo images, including E-wave timing within the cardiac cycle (Q-E interval and E-wave Deceleration time or EDT). EA waveforms over multiple days around the day of echo that matched the average heart rate (HR) around the echo exam to within 10 beats per min were identified and compared against E-wave timing. Results The patient, enrolled in November 2011 and reported to have a history of AF, was hospitalized for worsening HF on day 38 post enrollment. Device interrogation revealed ongoing AF burden of 24 hours since enrollment which transiently terminated on day 41 for several days before reverting to 24-hour AF burden. Patient underwent an echocardiogram starting at 9:22AM on day 39, which showed a Q-E interval of 562msec and EDT of 169msec. Figure shows one heart sound EA recorded at 10:49AM and clearly shows cardiac vibrations during the Deceleration phase of the E-wave as deduced from Q-E interval and EDT (horizontal line). This observation is consistent across all EAs collected over 5 days around the day of the echo with matched HR. Conclusion Consistent with its known physiologic genesis, the third heart sound measured using an implanted device occurred during the Deceleration phase of early diastolic filling even when the patient was in AF. A device based objective measure may provide more consistent assessment of S3 than auscultation amid an arrhythmic rumble of AF.

  • third heart sound during atrial fibrillation confirming the existence of cardiac vibrations during Deceleration phase of early diastolic filling while in af
    Heart & Lung, 2020
    Co-Authors: Qi An, Viktoria A Averina, John Boehmer, George Mark, Pramodsingh Hirasingh Thakur
    Abstract:

    Background The third heart sound (S3), which is caused by Rapid Deceleration of the blood against a stiff ventricle during early diastolic filling, is regarded as an early and specific sign of heart failure and elevated filling pressure. Objectives Studies have shown phonocardiogram-based S3 to be coincident with the Deceleration phase of E-wave and associated with a steeper E-wave. Atrial fibrillation (AF) is a common comorbidity in HF, however questions have arisen regarding the ability to reliably detect S3 during AF as typically it is more difficult to auscultate an S3 during AF. Here we present a case of simultaneous implanted device measured heart sound and echo data while the patient was in AF. Methods MultiSENSE enrolled patients were implanted with COGNIS CRT-D devices and followed for up to a year. At enrollment the CRT-Ds were converted to enable collection of heart sound (HS) data using the device-based accelerometer. HS data was periodically collected as ensemble averaged (EA) waveforms of multiple neighboring beats that closely matched in RR interval. An optional echocardiogram was conducted if the patient was hospitalized for worsening HF. An independent core laboratory measured parameters from the echo images, including E-wave timing within the cardiac cycle (Q-E interval and E-wave Deceleration time or EDT). EA waveforms over multiple days around the day of echo that matched the average heart rate (HR) around the echo exam to within 10 beats per min were identified and compared against E-wave timing. Results The patient, enrolled in November 2011 and reported to have a history of AF, was hospitalized for worsening HF on day 38 post enrollment. Device interrogation revealed ongoing AF burden of 24 hours since enrollment which transiently terminated on day 41 for several days before reverting to 24-hour AF burden. Patient underwent an echocardiogram starting at 9:22AM on day 39, which showed a Q-E interval of 562msec and EDT of 169msec. Figure shows one heart sound EA recorded at 10:49AM and clearly shows cardiac vibrations during the Deceleration phase of the E-wave as deduced from Q-E interval and EDT (horizontal line). This observation is consistent across all EAs collected over 5 days around the day of the echo with matched HR. Conclusion Consistent with its known physiologic genesis, the third heart sound measured using an implanted device occurred during the Deceleration phase of early diastolic filling even when the patient was in AF. A device based objective measure may provide more consistent assessment of S3 than auscultation amid an arrhythmic rumble of AF.

  • third heart sound during atrial fibrillation confirming the existence of cardiac vibrations during Deceleration phase of early diastolic filling while in atrial fibrillation
    Journal of Cardiac Failure, 2018
    Co-Authors: George Mark, Viktoria A Averina, Pramod Thakur, Qi An, John Boehmer
    Abstract:

    Introduction The third heart sound (S3), caused by Rapid Deceleration of the blood against a stiff ventricle during early diastolic filling, is an early and specific sign of heart failure and elevated filling pressure. Studies have shown S3 to be coincident with Deceleration phase of E-wave and associated with a steeper E-wave. Atrial fibrillation (AF) is a common comorbidity in HF, however questions have arisen regarding the ability to reliably detect S3 during AF as typically it is difficult to auscultate an S3 during AF. Here we present a case of simultaneous implanted device measured heart sound (HS) and echo data while the patient was in AF. Methods MultiSENSE enrolled patients implanted with COGNIS CRT-D devices and followed for up to a year. At enrollment CRT-Ds were converted to enable collection of HS data using device based accelerometer. HS data was periodically collected as ensemble averaged (EA) waveforms of multiple neighboring beats that closely matched in RR interval. An optional echo was conducted if the patient was hospitalized for worsening HF. An independent core laboratory measured parameters from the echo images, including E-wave timing within the cardiac cycle (Q-E interval and E-wave Deceleration time or EDT). EA waveforms over multiple days around the day of echo that matched the average heart rate (HR) around the echo exam to within 10 beats per min were identified and compared against E-wave timing. Results The patient, enrolled in November 2011 and reported to have a history of AF, was hospitalized for worsening HF on day 38 post enrollment. Device interrogation revealed ongoing AF burden of 24 hours since enrollment which transiently terminated on day 41 for several days before reverting to 24 hour AF burden. Patient underwent an echocardiogram starting at 9:22AM on day 39, which showed a Q-E interval of 562msec and EDT of 169msec. Figure shows one heart sound EA recorded at 10:49AM and clearly shows cardiac vibrations during the Deceleration phase of the E-wave as deduced from Q-E interval and EDT (horizontal line). This observation is consistent across all EAs collected over 5 days around the day of the echo with matched HR. Conclusion Consistent with its known physiologic genesis, S3 measured using an implanted device occurred during the Deceleration phase of early diastolic filling even when the patient was in AF. A device based objective measure may provide more consistent assessment of S3 than auscultation in the midst of an arrhythmic rumble of AF.

  • third heart sound during atrial fibrillation confirming the existence of cardiac vibrations during Deceleration phase of early diastolic filling while in atrial fibrillation
    Journal of Cardiac Failure, 2018
    Co-Authors: George Mark, Viktoria A Averina, Pramod Thakur, Qi An, John Boehmer
    Abstract:

    Introduction The third heart sound (S3), caused by Rapid Deceleration of the blood against a stiff ventricle during early diastolic filling, is an early and specific sign of heart failure and elevated filling pressure. Studies have shown S3 to be coincident with Deceleration phase of E-wave and associated with a steeper E-wave. Atrial fibrillation (AF) is a common comorbidity in HF, however questions have arisen regarding the ability to reliably detect S3 during AF as typically it is difficult to auscultate an S3 during AF. Here we present a case of simultaneous implanted device measured heart sound (HS) and echo data while the patient was in AF. Methods MultiSENSE enrolled patients implanted with COGNIS CRT-D devices and followed for up to a year. At enrollment CRT-Ds were converted to enable collection of HS data using device based accelerometer. HS data was periodically collected as ensemble averaged (EA) waveforms of multiple neighboring beats that closely matched in RR interval. An optional echo was conducted if the patient was hospitalized for worsening HF. An independent core laboratory measured parameters from the echo images, including E-wave timing within the cardiac cycle (Q-E interval and E-wave Deceleration time or EDT). EA waveforms over multiple days around the day of echo that matched the average heart rate (HR) around the echo exam to within 10 beats per min were identified and compared against E-wave timing. Results The patient, enrolled in November 2011 and reported to have a history of AF, was hospitalized for worsening HF on day 38 post enrollment. Device interrogation revealed ongoing AF burden of 24 hours since enrollment which transiently terminated on day 41 for several days before reverting to 24 hour AF burden. Patient underwent an echocardiogram starting at 9:22AM on day 39, which showed a Q-E interval of 562msec and EDT of 169msec. Figure shows one heart sound EA recorded at 10:49AM and clearly shows cardiac vibrations during the Deceleration phase of the E-wave as deduced from Q-E interval and EDT (horizontal line). This observation is consistent across all EAs collected over 5 days around the day of the echo with matched HR. Conclusion Consistent with its known physiologic genesis, S3 measured using an implanted device occurred during the Deceleration phase of early diastolic filling even when the patient was in AF. A device based objective measure may provide more consistent assessment of S3 than auscultation in the midst of an arrhythmic rumble of AF.

Scott C White - One of the best experts on this subject based on the ideXlab platform.

  • multi plane multi joint lower extremity support moments during a Rapid Deceleration task implications for knee loading
    Human Movement Science, 2018
    Co-Authors: Jeffery T Podraza, Scott C White, Dan K Ramsey
    Abstract:

    Abstract The principle of lower limb support, and the contribution of hip, knee and ankle moments to an overall limb support strategy for an impact-like, Rapid Deceleration movement may help explain individual moment magnitude changes, thereby providing insight into how injury might occur or be avoided. Twenty subjects performed single limb, impact-like, Deceleration landings at three different knee flexion angles in the range of 0–25, 25–50 and 50–75°. Kinematic and kinetic measures identified hip, knee and ankle moment contribution to limb support moments (LSMs) in three planes. Repeated measures ANOVA compared LSMs and the contribution of individual joint moments at initial contact (IC) and 50 ms after. There were no significant differences in the overall LSMs at IC in any plane when the deeper knee flexion landings (25–50° and 50–75°) were compared to the 0–25° landing position but there were significant changes in the 50 ms period after IC. There were greater overall extensor LSMs, less resistance to medial opening of the knee and decreased support against internal tibia rotation when landing in greater knee flexion. The role of individual joint moments changed Rapidly in the 50 ms period after initial landing; and, the relative contribution of the hip and ankle moments depended on the degree of limb flexion at landing. Analyses of individual joint moments emphasized the critical role that the hip joint moments have in balancing potentially injurious knee moments in all three planes for all three landing conditions.

  • effect of knee flexion angle on ground reaction forces knee moments and muscle co contraction during an impact like Deceleration landing implications for the non contact mechanism of acl injury
    Knee, 2010
    Co-Authors: Jeffery T Podraza, Scott C White
    Abstract:

    Abstract Investigating landing kinetics and neuromuscular control strategies during Rapid Deceleration movements is a prerequisite to understanding the non-contact mechanism of ACL injury. The purpose of this study was to quantify the effect of knee flexion angle on ground reaction forces, net knee joint moments, muscle co-contraction and lower extremity muscles during an impact-like, Deceleration task. Ground reaction forces and knee joint moments were determined from video and force plate records of 10 healthy male subjects performing Rapid Deceleration single leg landings from a 10.5cm height with different degrees of knee flexion at landing. Muscle co-contraction was based on muscle moments calculated from an EMG-to-moment processing model. Ground reaction forces and co-contraction indices decreased while knee extensor moments increased significantly with increased degrees of knee flexion at landing (all p

  • effect of knee flexion angle on ground reaction forces knee moments and muscle co contraction during an impact like Deceleration landing implications for the non contact mechanism of acl injury
    Knee, 2010
    Co-Authors: Jeffery T Podraza, Scott C White
    Abstract:

    Investigating landing kinetics and neuromuscular control strategies during Rapid Deceleration movements is a prerequisite to understanding the non-contact mechanism of ACL injury. The purpose of this study was to quantify the effect of knee flexion angle on ground reaction forces, net knee joint moments, muscle co-contraction and lower extremity muscles during an impact-like, Deceleration task. Ground reaction forces and knee joint moments were determined from video and force plate records of 10 healthy male subjects performing Rapid Deceleration single leg landings from a 10.5 cm height with different degrees of knee flexion at landing. Muscle co-contraction was based on muscle moments calculated from an EMG-to-moment processing model. Ground reaction forces and co-contraction indices decreased while knee extensor moments increased significantly with increased degrees of knee flexion at landing (all p<0.005). Higher ground reaction forces when landing in an extended knee position suggests they are a contributing factor in non-contact ACL injuries. Increased knee extensor moments and less co-contraction with flexed knee landings suggest that quadriceps overload may not be the primary cause of non-contact ACL injuries. The results bring into question the counterbalancing role of the hamstrings during dynamic movements. The soleus may be a valuable synergist stabilizing the tibia against anterior translation at landing. Movement strategies that lessen the propagation of reaction forces up the kinetic chain may help prevent non-contact ACL injuries. The relative interaction of all involved thigh and lower leg muscles, not just the quadriceps and hamstrings should be considered when interpreting non-contact ACL injury mechanisms.

Lisa Keay - One of the best experts on this subject based on the ideXlab platform.

  • predictors of older drivers involvement in Rapid Deceleration events
    Accident Analysis & Prevention, 2017
    Co-Authors: Aran John Chevalier, Anna Chevalier, Elizabeth Clarke, Kristy Coxon, Julie Brown, Kris Rogers, Soufiane Boufous, Rebecca Ivers, Lisa Keay
    Abstract:

    Abstract Rapid Deceleration occurs when substantial force slows the speed of a vehicle. Rapid Deceleration events (RDEs) have been proposed as a surrogate safety measure. As there is concern about crash involvement of older drivers and the effect of age-related declining visual and cognitive function on driving performance, we examined the relationship between RDEs and older driver’s vision, cognitive function and driving confidence, using naturalistic driving measures. Participants aged 75 to 94 years had their vehicle instrumented for 12 months. To minimise the chance of identifying false positives, accelerometer data was processed to identify RDEs with a substantial Deceleration of >750 milli-g (7.35 m/s 2 ). We examined the incidence of RDEs amongst older drivers, and how this behaviour is affected by differences in age; sex; visual function, cognitive function; driving confidence; and declines over the 12 months. Almost two-thirds (64%) of participants were involved in at least one RDE, and 22% of these participants experienced a meaningful decline in contrast sensitivity during the 12 months. We conducted regression modelling to examine associations between RDEs and predictive measures adjusted for (i) duration of monitoring and (ii) distance driven. We found the rate of RDEs per distance increased with age; although, this did not remain in the multivariate model. In the multivariate model, we found older drivers who experienced a decline in contrast sensitivity over the 12 months and those with lower baseline driving confidence were at increased risk of involvement in RDEs adjusted for distance driven. In other studies, contrast sensitivity has been associated with increased crash involvement for older drivers. These findings lend support for the use of RDEs as a surrogate safety measure, and demonstrate an association between a surrogate safety measure and a decline in contrast sensitivity of older drivers.

  • naturalistic Rapid Deceleration data drivers aged 75 years and older
    Data in Brief, 2016
    Co-Authors: Anna Chevalier, Aran John Chevalier, Elizabeth Clarke, Kristy Coxon, Julie Brown, Kris Rogers, Soufiane Boufous, Rebecca Ivers, Lisa Keay
    Abstract:

    The data presented in this article are related to the research manuscript “Predictors of older drivers’ involvement in Rapid Deceleration events”, which investigates potential predictors of older drivers’ involvement in Rapid Deceleration events including measures of vision, cognitive function and driving confidence (A. Chevalier et al., 2016) [1]. In naturalistic driving studies such as this, when sample size is not large enough to allow crashes to be used to investigate driver safety, Rapid Deceleration events may be used as a surrogate safety measure. Naturalistic driving data were collected for up to 52 weeks from 182 volunteer drivers aged 75–94 years (median 80 years, 52% male) living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Accelerometer data were recorded 32 times per second and Global Positioning System (GPS) data each second. To measure Rapid Deceleration behavior, Rapid Deceleration events (RDEs) were defined as having at least one data point at or above the Deceleration threshold of 750 milli-g (7.35 m/s2). All events were constrained to a maximum 5 s duration. The dataset provided with this article contains 473 events, with a row per RDE. This article also contains information about data processing, treatment and quality control. The methods and data presented here may assist with planning and analysis of future studies into Rapid Deceleration behaviour using in-vehicle monitoring.

  • Rapid Deceleration and crash events in an rct evaluating a safe transport program for older drivers
    Australasian Road Safety Conference 2016 Canberra ACT Australia, 2016
    Co-Authors: Lisa Keay, Aran John Chevalier, Elizabeth Clarke, Kristy Coxon, Kris Rogers, Soufiane Boufous, Rebecca Ivers, J Brown
    Abstract:

    The aim of this project was to determine if education can enhance self-regulation of driving and promote safety of older drivers. As crashes are rare events, Rapid Deceleration events were used as surrogate safety events and self-reported crashes as a secondary outcome. The randomised controlled trial (RCT) found that an individual education program (‘Behind the Wheel’) only reduced Rapid Deceleration events in the drivers with better visual and cognitive functioning and did not have an effect in older drivers with poorer function. It is possible that drivers with better function were better able to implement strategies to promote their safety.

  • 170 Rapid Deceleration and crash events in an rct evaluating a safe transport program for older drivers
    Injury Prevention, 2016
    Co-Authors: Lisa Keay, Anna Chevalier, Elizabeth Clarke, Kristy Coxon, Kris Rogers, Soufiane Boufous, Rebecca Ivers, Julie Brown
    Abstract:

    Background Older drivers have increased crash involvement and vulnerability to injury. It was hypothesised that a one-on-one safe-transport program, designed to encourage planning for retirement from driving and self-regulation, could improve the safety of older drivers. Methods The Behind the Wheel program (adapted from the KEYS® program) was evaluated using a randomised controlled trial involving 380 drivers aged 75 years and older, residing in the suburban outskirts of Sydney. The safety outcomes for this trial were >750 milli-g Rapid Deceleration events (RDE) and self-reported crashes. General linear models were used to model the impact of the program on the rate of RDEs and self-reported crashes, using distance travelled as an offset. Results We recruited 380 participants (230 men) with an average age of 80 years and 366/380 (96%) completed the 12 month study. The program was delivered to 183/190 (96%) of drivers allocated to the intervention. In vehicle monitoring data was available for 351 participants (92%) for a median of 52 weeks [inter-quartile range (IQR) 44–52] and 5487 [IQR 3294–8641] km of travel. 218/351 (62%) drivers had at least one RDE and the median number of RDEs was 1 [IQR 0–4]. There was no between group difference in the rate of RDEs per distance driven (incident rate ratio (IRR) 0.85, 95% CI 0.61–1.18). Crashes were reported by 14 participants in the intervention and 19 in the control group (p = 0.46). Pre-planned sub-group analyses showed that the intervention was effective in significantly reducing RDEs (IRR 0.41, 95% CI 0.20–0.81), in drivers with a DriveSafe/DriveAware score of 96 or higher (fit to continue driving). Conclusions Older drivers with good visual and cognitive function are responsive to a one-on-one education program to improve their safety on the road. These drivers reduced their involvement in RDE events by more than half, however this approach was not effective in drivers with poorer function.

  • older drivers and Rapid Deceleration events salisbury eye evaluation driving study
    Accident Analysis & Prevention, 2013
    Co-Authors: Lisa Keay, Beatriz Munoz, Donald D Duncan, Daniel Hahn, Kevin C Baldwin, Kathleen A Turano, Cynthia A Munro, Karen Bandeenroche, Sheila K West
    Abstract:

    Drivers who Rapidly change speed while driving may be more at risk for a crash. We sought to determine the relationship of demographic, vision, and cognitive variables with episodes of Rapid Decelerations during five days of normal driving in a cohort of older drivers. In the Salisbury Eye Evaluation Driving Study, 1425 older drivers aged 67-87 were recruited from the Maryland Motor Vehicle Administration's rolls for licensees in Salisbury, Maryland. Participants had several measures of vision tested: visual acuity, contrast sensitivity, visual fields, and the attentional visual field. Participants were also tested for various domains of cognitive function including executive function, attention, psychomotor speed, and visual search. A custom created driving monitoring system (DMS) was used to capture Rapid Deceleration events (RDEs), defined as at least 350milli-g Deceleration, during a five day period of monitoring. The rate of RDE per mile driven was modeled using a negative binomial regression model with an offset of the logarithm of the number of miles driven. We found that 30% of older drivers had one or more RDE during a five day period, and of those, about 1/3 had four or more. The rate of RDE per mile driven was highest for those drivers driving Language: en