Child safety seat checks in Salt Lake County: protective and risk factors.

BACKGROUND: Older children are at an increased risk of injury due to less commonly being in an appropriate child safety seat (CSS). Proper installation and consistent use of CSSs can significantly reduce child and infant automobile injuries. While research exists around parent behaviours concerning CSS use (or lack), little research takes place at the county level to identify normative beliefs as they contribute to risk factors. METHODS: Through a mixed-methods approach, this evaluation retrospectively determines the Salt Lake County Health Department's impact on CSS usage, as well as identify normative parent behaviours that impact CSS usage. RESULTS: Results indicated that parents' level of education and being in the car with family/friends was significantly associated with overall CSS usage. DISCUSSION: More research is needed to specify parent normative beliefs around CSS use (or lack).

Buckle me up! A randomised controlled trial using a tablet-based emergency department intervention for child car safety education.

BACKGROUND AND OBJECTIVES: Correct child car restraint use significantly reduces risk of death and serious injury in motor vehicle crashes, but millions of US children ride with improper restraints. We created a tablet-based car restraint educational intervention using Computer Intervention Authoring Software (CIAS) and examined its impact on knowledge and behaviours among parents in the paediatric emergency department (PED). METHODS: This was a non-blinded, randomised controlled trial of parents of PED patients ages 0-12 years. Participants were evaluated for baseline car restraint knowledge and behaviour. The intervention group completed an interactive tablet-based module, while the control group received printed handouts on car restraint safety. After 1 week, both groups received a follow-up survey assessing changes in car restraint knowledge and behaviour. Logistic regressions determined predictors of knowledge retention and behavioural changes. Parents in the CIAS group were also surveyed on programme acceptability. RESULTS: 211 parents completed the study with follow-up data. There was no significant difference in baseline car restraint knowledge (74.3% correct in intervention, 61.8% in control, p=0.15), or increase in follow-up restraint knowledge. Significantly more intervention-group caregivers reported modifying their child's car restraint at follow-up (52.5% vs 31.8%,p=0.003), and 93.7% of them found CIAS helpful in learning to improve car safety. CONCLUSION: Parents had overall high levels of car restraint knowledge. Using CIAS led to positive behavioural changes regarding child car restraint safety, with the vast majority reporting positive attitudes towards CIAS. This novel, interactive, tablet-based tool is a useful PED intervention for behavioural change in parents. TRIAL REGISTRATION NUMBER: NCT03799393.

Australian parental decisions about transitioning children from booster seats in a randomised trial: greater support may be needed.

BACKGROUND: Premature graduation to an adult seatbelt is common and detrimental to optimal crash protection. While there is an existing tool (the 5-step test) to support a parent's decision to graduate their child, its effectiveness is unknown. The aim of this study was to evaluate the 5-step test. METHOD: A randomised controlled design was used. Participants were parents of children aged 7-12 years. After exposure to information about the 5-step test or control material, participants assessed belt fit in three seating conditions and 'thought aloud' while making their assessment. Seating conditions provided a good, poor and partially good seatbelt fit based on the child's anthropometry. Participants were also assessed on their knowledge of good seatbelt fit criteria. RESULTS: Participants exposed to the 5-step test (n=18) had significantly improved their knowledge of the criteria required to achieve good seatbelt with, on average, 1.0 higher score in the 6-point assessment (95% CI 0.23 to 1.7, p=0.012) than those in the control group. There was also a greater percentage of participants in this group (44.4% intervention vs 27.8% control) who made accurate decisions about seatbelt fit, but this difference did not reach significance (OR 2.08, 95% CI 0.52 to 8.34). CONCLUSION: The results demonstrate that the 5-step test is effective in improving knowledge but are inconclusive about its effectiveness in promoting accurate decision-making. However, the proportion of participants making accurate decisions in the intervention group remained low. This suggests that parents may require greater assistance than what is currently provided.

Safety/booster seats in pediatric motor vehicle crashes: Public health concern.

INTRODUCTION: The American Academy of Pediatrics (AAP) guidelines recommend that children ≤12-years-old with height < 145 cm should use safety/booster seats. However, national adherence and clinical outcomes for eligible children involved in motor vehicle collisions (MVCs) are unknown. We hypothesized that children recommended to use safety/booster seats involved in MVCs have a lower rate of serious injuries if a safety/booster seat is used, compared to children without safety/booster seat. METHODS: This retrospective cohort study queried the 2017-2019 Trauma Quality Improvement Program database for patients ≤12-years-old and <145 cm (recommendation for use of safety/booster seat per American Academy of Pediatrics) presenting after MVC. Serious injury was defined by abbreviated injury scale grade ≥3 for any body-region. High-risk MVC was defined by authors in conjunction with definitions provided by the Centers for Disease Control and Prevention and the American College of Surgeons Committee on Trauma. RESULTS: From 8259 cases, 41% used a safety/booster seat. There was no difference in overall rate of serious traumatic injuries or mortality (both p > 0.05) between the safety/booster seat and no safety/booster seat groups. In a subset analysis of high-risk MVCs, the overall use of safety/booster seats was 56%. The rate of serious traumatic injury (53.6% vs. 62.1%, p = 0.017) and operative intervention (15.8% vs. 21.6%, p = 0.039) was lower in the safety/booster seat group compared to the no safety/booster seat group. CONCLUSIONS: Despite AAP guidelines, less than half of recommended children in our study population presenting to a trauma center after MVC used safety/booster seats. Pediatric patients involved in a high-risk MVC suffered more serious injuries and were more likely to require surgical intervention without a safety/booster seat. A public health program to increase adherence to safety/booster seat use within this population appears warranted.

Prevalence of intra-abdominal injury among patients with seatbelt signs, a systematic review and meta-analysis.

INTRODUCTION: The advancement of seat belts have been essential to reducing morbidity and mortality related to motor vehicle collisions (MVCs). The "seat belt sign" (SBS) is an important physical exam finding that has guided management for decades. This study, comprising a systematic review and random-effects meta-analysis, asses the current literature for the likelihood of the SBS relating to intra-abdominal injury and surgical intervention. METHODS: PubMed and Scopus databases were searched from their beginnings through August 4, 2023 for eligible studies. Outcomes included the prevalence of intra-abdominal injury and need for surgical intervention. Cochrane's Risk of Bias (RoB) tool and the Newcastle-Ottawa Scale (NOS) were applied to assess risk of bias and study quality; Q-statistics and I2 values were used to assess for heterogeneity. RESULTS: The search yielded nine observational studies involving 3050 patients, 1937 (63.5%) of which had a positive SBS. The pooled prevalence of any intra-abdominal injury was 0.42, (95% CI 0.28-0.58, I2 = 96%) The presence of a SBS was significantly associated with increased odds of intra-abdominal injury (OR 3.62, 95% CI 1.12-11.6, P = 0.03; I2 = 89%), and an increased likelihood of surgical intervention (OR 7.34, 95% CI 2.03-26.54, P < 0.001; I2 = 29%). The measurement for any intra-abdominal injury was associated with high heterogeneity, I2 = 89%. CONCLUSION: This meta-analysis suggests that the presence of a SBS was associated with a statistically significant higher likelihood of intra-abdominal injury and need for surgical intervention. The study had high heterogeneity, likely due to the technological advancements over the course of this study, including seat belt design and diagnostic imaging sensitivity. Further studies with more recent data are needed to confirm these results.

Chest wall bruising from 5-point car seat harness as a mimicker of child abuse.

Bruising rarely presents in infants younger than 9 months who are not ambulatory and is more prevalent among children beginning to walk, or "cruisers." We present the case of a healthy 3-month-old infant with asymptomatic, symmetric, bilateral, large bruises on the bony chest sparing the mid-chest/sternum with a negative non-accidental trauma work-up. The noted pattern of bruises matched the bilateral shoulder straps of a 5-point harness of the car seat belt designed for infants. Awareness of this unique pattern of bruises will help elicit a better-informed history to guide care in an appropriate setting.

Investigating Patient Perspectives on Using eHealth Technologies for the Self-Management of Inflammatory Bowel Disease: Mixed Methods Study.

BACKGROUND: Inflammatory bowel disease (IBD) poses significant challenges for patients, requiring continuous monitoring and self-management to improve quality of life. OBJECTIVE: This study aims to investigate the viewpoints of individuals living with IBD on the use of information and communication technology (ICT) for the self-management of their condition, with a particular focus on the concept of a "smart" toilet seat as an example of ICT for IBD self-management. METHODS: We conducted an analysis of questionnaire responses obtained from 724 participants. They were encouraged to share their use cases and identify any perceived barriers associated with ICT adoption for managing their condition. To assess their responses, we used descriptive quantitative analysis, summative content analysis, and thematic qualitative analysis. We combined these results in an epistemic network analysis to look for meaningful patterns in the responses. RESULTS: Of the 724 participants, more than half (n=405, 55.9%) were already using various forms of ICT for IBD self-management. The primary factor influencing their use of ICT was their affinity for interacting with technology. Distinct differences emerged between individuals who were using ICT and those who were not, particularly regarding their perceived use cases and concerns. CONCLUSIONS: This study provides valuable insights into the perspectives of individuals with IBD on the use of ICT for self-management. To facilitate wider adoption, addressing privacy concerns, ensuring data security, and establishing reliable ICT integration will be critical.

Covered endovascular reconstruction of the aortic bifurcation: A versatile technique with many potential applications.

We present our experience with using the bifurcated covered endovascular reconstruction technique in two unusual conditions. One patient with a traumatic "seat belt" aortic injury and a second patient with a bleeding aorto-enteric fistula were successfully treated with the CERAB technique. We discuss potential benefits of the technique outside the usual pattern of chronic atherosclerotic aortoiliac disease.

The Effect of Changing the Angle of the Passenger Car Seat Backrest on the Head Trajectories of the 50th Percentile Male Dummy.

The aim of the study is to compare the head displacement of the KPSIT C50 dummy during a frontal collision at a speed of 20 km/h, along with the change in the angle of the car seat backrest. Passenger car manufacturers recommend setting the backrest angle of the car seat between 100 and 125 degrees. It should be noted that the driver's position is of great importance in the event of a collision injury. In the event of a rear-end collision, the position of the headrest of the car seat is an element that affects the degree of the driver's injuries. In extreme cases, incorrect positioning of the headrest, even at low speed, can lead to serious injuries to the cervical spine and even death. The article is part of a large-scale study on low-speed crash testing. The research problem concerned the influence of the seat backrest angle on the head displacement during a low-speed collision. The article compares the displacement of the head of the KPSIT C50 dummy during a series of crash tests, where the angle of the car seat backrest was changed. On the basis of the research, it was found that the optimal angle of the car seat backrest is 110 degrees. In addition, a preliminary analysis of the displacements of the dummy's head showed a high risk of whiplash injury in people sitting in a fully reclined seat.

Effect of seat back angle on preferred seat pan inclination for the development of highly automated vehicles.

Recent studies on occupants' safety in reclined positions suggest that a more inclined seat pan could be needed to reduce the occurrence of submarining. This study aimed to investigate whether a more inclined seat pan would also be comfortable for occupants. Eighteen volunteers participated in the experiment. They were asked to self-select seat pan inclination for seat back angles from 20 to 60 degrees using a reconfigurable experimental seat from two initial seat pan angles (10 and 40 degrees from the horizontal). On average, preferred seat pan angle varied from 11.3(±2.1, standard deviation) to 29.9(±6.8), 12.5(±3.8) to 37.4(±3.7), and 12.8(±4.8) to 38.6(±2.7) degrees for seat pan angles of 20, 40, and 60 degrees respectively. The shear force analysis suggests that the seat pan inclination might be self-selected to reduce the forward shear, while a high inclination angle with a noticeable backward shear was also preferred.Practitioner summary: Preferred range of seat pan inclination for different seat back angles studied for the development of highly automated vehicles. The present work provides quantitative guidelines for specifying comfortable seating in a reclined position.

The Vehicle Seating Intervention Trial: Cross-Over Randomized Controlled Trial to Evaluate the Impact of 2 Car Seat Configurations on Spinal Posture.

Driving posture can lead to musculoskeletal pain. Most work focuses on the lower back; therefore, we know little about automobile seat design and neck posture. This study evaluated an automobile driver seat that individualized upper back support to improve head and neck posture. Specifically, we examined the system's impact on anterior head translation with secondary outcomes of spine posture and perceptions of comfort/well-being compared with a control. Forty participants were block randomized to experience either the activated or deactivated version of the same seating system first. Participants completed two 30-minute simulated driving trials, separated by washout, with continuous measures of anterior head translation, spine posture, and pelvis orientation. Perceptions of comfort/well-being were assessed by survey and open-ended questions immediately following each condition. Small, but statistically significant decreases in anterior head translation and posterior pelvic tilt occurred with the activated seat system. Participants reported lower satisfaction with the activated seat system. Order of the 2 seat conditions affected differences in pelvis orientation and participant perceptions of comfort/well-being. An anthropometric-based seat system targeting upper back support can significantly affect head and pelvic posture but not satisfaction during simulated driving. Future work should examine long-term impacts of these posture changes on health outcomes.

Influence of chair seat forward tilt angle on upper limb dexterity improvement in seated tasks: a pilot study.

[Purpose] This study aimed to investigate the influence of seat-forward tilt angles on improving upper limb dexterity in seated tasks and to contribute to the development of seating strategies. [Participants and Methods] Seventeen healthy men (age, 20.0 ± 0.5 years; height, 175.1 ± 4.9 cm; and body weight, 63.8 ± 6.7 kg) participated in this study. The forward tilt angles of the seat were set at 0°, 15°, and 30°, with knee pads used in all conditions. The Purdue Pegboard task was used to assess upper limb dexterity, with participants inserting pins into holes in the board for 60 s. Additionally, a visual analog scale was used to evaluate the perceived ease of the task. [Results] The Purdue Pegboard task scores were 30.0 ± 2.5, 30.6 ± 2.7, and 32.5 ± 2.9 for the 0°, 15°, and 30° conditions, respectively. The visual analog scale scores were 75.3 ± 9.8, 76.4 ± 14.6, and 84.1 ± 11.1 for the 0°, 15°, and 30° conditions, respectively. Both measurements showed significantly higher values under the 30° condition than under the other two conditions. [Conclusion] These results suggest that a tilt angle of 30° provides the most significant ease and upper limb dexterity.

Discontinuation of Car Seat Tolerance Screening and Postdischarge Adverse Outcomes in Infants Born Preterm.

OBJECTIVE: To study the association between discontinuing predischarge car seat tolerance screening (CSTS) with 30-day postdischarge adverse outcomes in infants born preterm. STUDY DESIGN: Retrospective cohort study involving all infants born preterm from 2010 through 2021 who survived to discharge to home in a 14-hospital integrated health care system. The exposure was discontinuation of CSTS. The primary outcome was a composite rate of death, 911 call-triggered transports, or readmissions associated with diagnostic codes of respiratory disorders, apnea, apparent life-threatening event, or brief resolved unexplained events within 30 days of discharge. Outcomes of infants born in the periods of CSTS and after discontinuation were compared. RESULTS: Twelve of 14 hospitals initially utilized CSTS and contributed patients to the CSTS period; 71.4% of neonatal intensive care unit (NICU) patients and 26.9% of non-NICU infants were screened. All hospitals participated in the discontinuation period; 0.1% was screened. Rates of the unadjusted primary outcome were 1.02% in infants in the CSTS period (n = 21 122) and 1.06% after discontinuation (n = 20 142) (P = .76). The aOR (95% CI) was 0.95 (0.75, 1.19). Statistically insignificant differences between periods were observed in components of the primary outcome, gestational age strata, NICU admission status groups, and other secondary analyses. CONCLUSIONS: Discontinuation of CSTS in a large integrated health care network was not associated with a change in 30-day postdischarge adverse outcomes. CSTS's value as a standard predischarge assessment deserves further evaluation.

The effect of social media campaign on parental knowledge, attitudes and practices regarding the use of children car seats in the Gulf region.

BACKGROUND: Motor vehicle crashes (MVCs) are the leading cause of child deaths in the Gulf Cooperation Council. This study aimed to investigate the effect of a social media educational campaign on parents' knowledge of child safety seats. METHODS: We conducted a pre-post interventional study as an online educational module in Arabic and English. The module link was shared on social media and was accompanied by a pre-post survey that included questions about demographics, knowledge, and practices of car seat use. RESULTS: A total of 303 participants completed the campaign, with 23.8% fathers and 76.2% mothers answered the survey. The majority of participants were from Saudi Arabia (95.7%), while 4.3% were from other Gulf Cooperation Council (GCC) countries. Most parents agreed on the importance of organizing awareness campaigns and having a law to enforce the use of car seats. The pre-survey mean knowledge score was 11.64, which significantly increased to 13.1 in the post-survey (p < 0.001). CONCLUSIONS: The intervention of the educational campaign through social media resulted in a significant increase in parents' knowledge and awareness of the importance of using car seats correctly. This study highlights the potential effectiveness of social media campaigns in improving parents' knowledge and awareness of child safety seats.

Biomechanical mechanism driving typical postural shifts of lower limbs during sleeping in an aircraft seat.

The purpose of this study was to determine the biomechanical mechanisms driving passengers' lower-limb postural shifts during seated sleep on a flight to prevent negative effects on passengers' physical health. Twenty subjects participated in an observational study and a subsequent experiment on fatigue development and tissue oxygenation changes during seated sleep in an economy-class aircraft seat. Three of the most frequently used postures, which involved four targeted muscles of the legs and the thigh-buttock region, were selected and examined in the experiment with the following measures: muscle electromyogram, tissue oxygenation, and body contact pressure distribution. The results showed that the fatigue of the tibialis anterior and gastrocnemius and the compression of the region under the medial tuberosities were relieved by alternations among the three positions-position 1 (placing the shanks forwards), position 2 (placing the shanks neutrally), and position 3 (placing the shanks backwards). This research reveals the mechanical properties of the biomechanical factors functioning in lower-limb postural shifts during seated sleep and provides design optimization strategies for economy-class aircraft seats to reduce the negative effects on passenger health.

The effects of standardised versus individualised seat height on 1-minute sit-to-stand test performance in healthy individuals: a randomised crossover trial.

PURPOSE: We aimed to (i) investigate differences in 1-minute sit-to-stand test (1MSTST) performance (i.e., the number of repetitions) between a standardised modality (i.e., starting from a conventional chair with 46 cm seat height) and an individualised modality (i.e., starting with a knee joint flexion angle of 90°), and to (ii) quantify the influence of tibia and femur length on 1MSTST performance. METHODS: Healthy participants were recruited for this randomised crossover study, performing each 1MSTST modality twice in a randomised order. The primary outcome was the number of repetitions in the 1MSTST. Secondary endpoints were the acute responses in peripheral oxygen saturation, heart rate, and leg fatigue and dyspnoea. Additionally, we investigated correlations of performance with knee extensor strength in both modalities. RESULTS: Thirty participants were recruited and completed the study. They achieved significantly less repetitions in the standardised 1MSTST compared to the individualised 1MSTST (B = - 12.1, 95% confidence interval [95% CI] = - 14.8/- 9.4, p < 0.001). We found a significant effect of femur length on 1MSTST performance (B = - 1.6, 95% CI = - 2.6/- 0.7, p = 0.01), tibia length showed significant interaction with the 1MSTST modality (B = 1.2, 95% CI = 0.2/2.2, p = 0.03). CONCLUSION: An individualisation of the 1MSTST starting position to 90° knee flexion angle leads to more repetitions compared to the traditional starting position. The higher repetition count is explained by controlling for differences in tibia length. We recommend individualisation of the 1MSTST, enabling more valid comparisons across populations and study samples. TRIAL REGISTRATION NUMBER: http://www. CLINICALTRIALS: gov , NCT04772417. TRIAL REGISTRATION DATE: February 26, 2021.

Parents' knowledge and socio-demographic determinants toward child's restraint system use.

BACKGROUND: Lack of protection or improper protection, is one of the most important reasons of child passenger's death and injury in traffic crashes. Based on what we see on the roads, Iranian children are unrestrained inside the car. The aim of this study was to investigate children restrained system (CRS) use rate, its socio-demographic determinants and parents' knowledge toward CRS use among Iranian parents. METHODS: Using multi-stage cluster sampling and direct in filed method of observation, the behavior of 700 children in cars was observed in the current cross-sectional study. Socio-demographic determinants and parents' knowledge, toward using the CRS were evaluated using questionnaires. The study was performed from July to August 2019 in Tabriz city, northwestern Iran. RESULTS: The rate of child safety seat (CSS) use was 15.1% CI 95%:(12.5%,18.0%), and the rate of booster use was 0.6%; CI 95%:(4.3%,8.0%). The majority of parents [e.g. 64.3%; CI 95%: (60.7%,67.9%)], had low knowledge about the use of CRS. The most important reasons for not using CRS was lack of laws and policies [e.g. 59.7%; CI 95%:(12.5%,18.0%)], lack of knowledge [e.g.59.6%; CI 95%:(57.9%, 63.3%)] and the high cost of CRS [e.g. 57.6%; CI 95%:(53.81%,61.2%)]. The most important predictors of not using CRS were the child's age, parental knowledge, and the socioeconomic status of the household (p < 0.05). CONCLUSIONS: Most children did not have CRS. The parents with higher education and those with higher socioeconomic status had higher rate of CRS use. Based on the low rate of CRS use and poor parental knowledge about it, education of parents toward boosters use and benefits of using CRS, enforcing mandatory laws and ploicies for CRS use in Iran, and allocation of government subsidies to low-income families for purchasing CRS are suggeted as essential strategies to increase CRS use.

Analysis of Musculoskeletal Biomechanics of Lower Limbs of Drivers in Pedal-Operation States.

In this study, to establish the biomechanical characteristics of commercial vehicle drivers' muscles and bones while operating the three pedals, a driver pedal-operation simulator was built, and the real-life situation was reconstructed in OpenSim 3.3 software. We set up three seat heights to investigate the drivers' lower limbs, and the research proceeded in two parts: experiment and simulation. Chinese adult males in the 95th percentile were selected as the research participants. In the experiment, Delsys wireless surface electromyography (EMG) sensors were used to collect the EMG signals of the four main muscle groups of the lower limbs when the drivers operated the three pedals. Then, we analyzed the muscle activation and the degree of muscle fatigue. The simulation was based on OpenSim software to analyze the driver's lower limb joint angles and joint torque. The results show that the activation of the hamstrings, gastrocnemius, and rectus femoris muscles were higher in the four muscle groups. In respect of torque, in most cases, hip joint torque > knee joint torque > ankle joint torque. The knee joint angles were the largest, and the ankle joint angles changed the most. The experimental results provide a reference for improving drivers' handling comfort in commercial vehicles and provide theoretical bases for cab design and layout optimization.

Measuring pressure distribution under the seat cushion and dividing the pressure map in six regions might be beneficial for comfort studies of aircraft seats.

Seat pressure maps are often used to evaluate comfort of the users. In this study, we explored the relationships between pressure maps and comfort/discomfort of users in aircraft seats with a focus on a new 6-division method on the pressure maps collected at the bottom of the cushions. An experiment was designed where three cushions with identical shapes but different stiffnesses were prepared. 33 subjects joined the experiment and after sitting on each cushion in 4 postures, they completed comfort questionnaires. Pressure maps on the top as well as the bottom of cushions were collected and analysed. Results indicated that measures on the proposed 6 divisions, especially on the distal posterior thigh regions and regions close to ischial tuberosity of the bottom pressure maps, had larger correlation values to comfort scores compared to other division methods. Practitioner summary: The relations between comfort/discomfort and seat pressure maps collected from the top/bottom of three cushions were studied with 33 subjects in four postures. The distal posterior thigh and ischial tuberosity regions in the proposed 6-division of the bottom pressure maps had larger correlation values to comfort/discomfort compared to other methods.

Whole-body vibration exposure in unfavourable seated postures: apparent mass and seat-to-head transmissibility measurements in the fore-and-aft, lateral, and vertical directions.

Mobile machinery operators are exposed to whole-body vibrations (WBV) and unfavourable postures which may lead to adverse effects on the spine. 14 subjects were exposed to WBV on a rigid seat without a backrest. They adopted nine different postures. Apparent mass MA(f) and seat-to-head transmissibility T(f) were measured in the horizontal (X), lateral (Y) and vertical (Z) directions. They were compared to the reference posture from the ISO 2631-1 standard. Head and thorax inclinations in the sagittal plane had significant effects. An increase in the main resonant frequency fr, together with a decrease in |MA(f)|max were observed in the Z direction. A second lower frequency peak also appeared (fr≈1 Hz for X, fr≈2.5 Hz for Z). fr increased in the X and Z directions for |T(f)|. |T(f)|max increased in the X direction. Head and thorax inclinations in the frontal and the horizontal planes had weak or non-significant effects.Practitioner summary: Mobile machinery operators are exposed to whole-body vibration and unfavourable body posture. Laboratory measurements of the apparent mass MA(f) and the seat-to-head transmissibility T(f) in the horizontal (X), lateral (Y) and vertical (Z) directions are presented for 9 postures relevant to the exposure at the driving position and to the effects of vibration on the spine.