• No results found

Children's Car Seat Restraints: When Top-Tether Straps Are Ignored, Are These Restraints Safe?

N/A
N/A
Protected

Academic year: 2020

Share "Children's Car Seat Restraints: When Top-Tether Straps Are Ignored, Are These Restraints Safe?"

Copied!
10
0
0

Loading.... (view fulltext now)

Full text

(1)

Children’s

Car

Seat

Restraints:

When

Top-Tether

Straps

Are

Ignored,

Are

These

Restraints

Safe?

Quentin H. McDonald, BA, MA

From The Bobby-Mac Company, lnc, Scarsdale, New York

The followingpaper written by the president ofone of the manufacturers of infant car seats will appear to some readers as self-serving advertisement. However, the reviewers and I both believe that the data are accu-rate and that the information is important for the pedia-trician and have, therefore, elected topublish this paper. Obviously, other manufacturers will be given equal op-portunity, if they have data to present.

R.J.H.

ABSTRACT. Children’s car seat restraints are impact

sled-tested to evaluate their safety qualities. To

deter-mine whether these restraints can protect the child, it is necessary to test in two different ways those restraints

that require a top-tether strap: (1) installed in accordance with the manufacturer’s directions; and (2) installed in

the manner they are actually used. In this study the five children’s car seat restraints top-rated by a leading con-sumer organization were impact sled-tested with a

top-tether strap in use. They were then tested without the top-tether strap-the way such restraints are often being

used as indicated by an Insurance Institute for Highway Safety survey. In addition, two leading restraints not requiring a top-tether strap, but secured by the auto lap

belt, were tested. This study shows that the five

top-tethered restraints, when installed with top-tether and lap belt, and the two restraints not requiring a top-tether give good protection in a frontal crash. It also shows that, with one possible exception, the five restraints that

re-quire a top-tether strap do not provide adequate protec-tion if the top-tether strap is not used. Pediatrics 64:848-855, 1979; accident prevention, automobile safety, child restraints, counseling.

Child safety is of major concern to all of us. Although it is encouraging that the incidence of deaths of children from seven preventable diseases

Received for publication, July 28, 1978; accepted March 7, 1979.

Reprint requests to (Q.H.M.) The Bobby-Mac Company, Inc, 95 Morris Lane, Scarsdale, NY 10583.

PEDIATRICS (ISSN 0031 4005). Copyright © 1979 by the

American Academy of Pediatrics.

(diptheria, pertussis, tetanus, polio, measles, ru-bella, mumps) has dramatically decreased to a mm-imal level within the past two decades, it is disturb-ing that the slaughter of young children on the

highways continues almost unabated.1 This is in

spite of the fact that we know injury and death of

children in automobiles can be substantially

re-duced by the correct use of properly designed child

restraints2’3 and by the use of auto lap belts.4

A contributing factor to the lack of progress in preventing death and injury to the child in the automobile has been the confusion that has existed, and continues to exist, as to just what is the best

way to restrain the child while riding in the

auto-mobile.

The US Department of Transportation took the first important step to protect the child passenger in April 1971, when it instituted Federal Motor Vehicle Safety Standard No. 213. This established a set of requirements that child restraints must meet, and it resulted in prohibiting the sale of the

most ineffective restraints.5 However, Standard 213

relies exclusively on static load testing of child restraints, a method that involves applying a load force of 1,000-lb pull on a wooden torso block

posi-tioned and/or harnessed in the restraint in

accord-ance with the restraint manufacturer’s directions. If the torso block moves more than 12 in, the restraint fails the test. Static load testing merely determines whether a restraint will hold together under a 1,000-lb pull. It in no way takes into account the dynamic forces at work in a real-life crash, nor does it give any indication of what happens to the occupant of

the restraint.

(2)

employing an impact sled on which an automobile seat is mounted. The sled is catapulted forward on a set of tracks; at the desired speed it impacts a barrier. Frontal crash tests are generally run at 30 mph and lateral tests at 20 mph. This method of testing requires an anthropometric test dummy to be harnessed in the child restraint according to the manufacturer’s directions.

Child restraints meeting the present Standard

213 but failing dynamic sled tests at 30 mph

con-tinue to be available on the market and are invari-ably the most reasonably priced restraints. These

units are still being purchased by unsuspecting

par-ents who confidently note that the restraint meets

or exceeds Standard 213, although the restraint is not necessarily crashworthy.7 During the years since the issuance of the original Standard 213 a number of safety-oriented institutions, organiza-tions, groups of physicians, and consumers tried to fill the dynamic-test-standard void with their own recommended lists of safe, dynamically tested child

restraints and helpful suggestions for child passen-ger safety. Some were factually based and know!-edgeably presented and were of significant help to the consumer; others only added to the confusion.8

One of the principal sources of consumer infor-mation on safe child restraints has been Consumers Union (CU). Since 1972 CU has published four car

seat evaluations. The most recent was issued in

June 1977. In this latest, 14 child restraints were rated according to the crash protection they provide

as judged by CU based on dynamic sled testing. The five restraints given the best marks all require a top-tether strap.9 A top-tether strap is an addi-tional strap attached to the top of the child re-straint; it is anchored: (1) to a specially installed bolt in the parcel shelf or cargo-area floor panel when the restraint is used in the rear seat of an automobile; or (2) over the back of the auto front

seat and onto a rear seat lap belt when the restraint

is used in the front seat. This latest CU evaluation, rather than simplifying the situation, actually cre-ated further confusion about child restraints. The CU report did not entirely disregard a study issued in 1975 by the Insurance Institute for Highway Safety but, unfortunately, it did not give this study proper emphasis.

The Insurance Institute study involved 5,050 cars containing at least one passenger under 10 years of age. Of 8,893 passengers under 10 years of age, 93% were not restrained, 16% of the child restraints observed were not used, and 73% of those in use were not used correctly. Of those restraints

requir-ing a top-tether strap, 47% of the tether straps were

not anchored.2 In the light of this report, immediate

concern was voiced because CU rated tether strap

restraints higher than restraints not requiring a

tether strap. Since one of the critical functions of a

child restraint is to limit head excursion to prevent contact with the automobile interior,’0 the concern

is whether top-tethered restraints can fulfill their

function when they are used without the top-tether strap.

The purpose of this study is to determine whether the protection provided by the five CU top-rated child restraints is reduced when the tether strap is not used, and if protection is reduced, to what extent.

METHOD OF TESTING

Selection of Occupant

A Sierra engineering anthropometric dummy,

37.5 in high, 32 lb in weight was used for all tests. The dummy approximated the size and weight of a 3-year-old child.

Test Environment

Tests were performed on an impact sled capable of simulating a crash, operating on rebound princi-ple. The restraints were mounted on a 1974 bench-type automotive adult seat.

Instrumentation and Data Handling Procedures

Seat belts and tether straps were preloaded to

17.5 ± 3.5 lb. Data were recorded simultaneously on

a Honeywell 7600 FM tape system and on a Hon-eywell 1612 light-beam oscillograph. High speed (1,000 ft/sec) 16-mm motion picture cameras posi-tioned to the side and overhead, plus a one-se-quence Polaroid camera were used to photograph each test.”

Test Matrix

Only frontal impacts were conducted on six of the restraints listed in the June 1977, Consumer Reports study, plus one restraint listed in previous Consumer Reports evaluations. All restraints tested were purchased in retail stores in Ann Arbor, MI, except for the Teddy Tot restraints, which could not be located and were obtained from the manu-facturer. All tests were 30 mph (21 g) impacts. Thirteen tests were performed, six with top-tether

straps secured, seven without top-tether straps

se-cured. No Bobby-Mac Company representative was present before, during, or after testing. All tests were conducted by Tandelta Associates, Inc, Ann Arbor, MI, at the facilities of the Highway Safety Research Institute of the University of Michigan in

July/August 1977.”

CRITERION FOR SAFE HEAD EXCURSION

A survey was conducted by the Bobby-Mac

(3)

TABLE. Sled Test Report Summary

Restraint Fig No. Maximum Absolute Evaluation per Test Report Head Excursion (in)

With Without Tether Tether 11.5 15.2 14.9 3 12.1 4 12.4 13.8

Teddy Tot Astroseat V 5

including compact and subcompact models. The distance between the forward-most point of the seat-back cushion of the front seat and the closest portion of the dashboard on the passenger’s side of the car was measured with the front seat in its full-forward position. The average of this measurement in these 43 autos was 21.4 in, the median 21.5 in. These data suggest that head excursion be limited to 21.5 in to be safe.’2

RESULTS OF TESTING

The five Consumers Union top-rated restraints (Strolee, Century, General Motors, Swyngomatic,

Strolee Wee Care Car Seat

2

Century Motor-Toter None

Safety Car Seat

None

General Motors Child None

Love Seat

Swyngomatic American None

Safety Child Safety Seat

None

6

Bobby-Mac 2-in-i Car None Seat

Bobby-Mac Deluxe Car 7

Seat

Teddy Tot), as well as the two Bobby-Mac

re-straints, were dynamically tested in 30-mph frontal

impacts with a 3-year-old size Sierra dummy. The

resulting head excursions (in inches), with and

with-out the top-tether straps secured (Bobby-Macs only

without tether), are listed in the Table together with Tandelta Associates evaluations of the per-formance of each restraint.”

The results of these tests are shown graphically in Figs 1 to 7. These figures are frames taken from

the high speed 16-mm films of the test crashes; each

illustration shows the position of that particular

restraint, and the dummy seated in it, at the very

height of the crash. Figs 1 through 4 show the

1. Head excursion excellent 2. Fair torso load distribution 25.7 1. Head excursion unacceptable

2. Very large shell deformation

1. Head excursion excellent 2. Overfiexion of the neck 3. Fair torso load distribution 24.9 1. Head excursion unacceptable

2. Shell deformation

3. Very poor torso load distribution

1. Head excursion excellent 2. Overfiexion of the neck 3. Poor torso load distribution

4. Tether strap pulled out of seat; did not have great effect on overall performance

1. Head excursion excellent

2. Overfiexion of the neck

-3. Fair torso load distribution

4. Seat back cracked at tether strap slot but did not

affect performance

27.0 1. Head excursion unacceptable 2. Shell deformation

3. Very poor torso load distribution 1. Head excursion excellent

2. Stomach shield high on torso during impact 3. Load distribution very poor

20.3 1. Head excursion good

2. Lap belt rode up high: loaded dummy’s chest 3. Very poor torso load distribution

4. Overfiexion of the neck

1. Head excursion excellent

2. Tether/harness brace on back of seat pulled out 3. Fair overall performance; fair load distribution 33.7 1. Head excursion uncontrolled and far above

ac-ceptable limits

2. Seat failed by total structural collapse 20.1 1. Head excursion good

2. Good torso load distribution

(4)

Figs 1 and 2. Strolee Wee Care Car Seat.

performance of two of the top-rated restraints when

used with the top-tether strap and when used

with-out the tether. Figs 5 and 6 are graphic crash evidence of what can happen to one of the

older-style tubular metal restraint types that have been,

and still are, widely available; this was also one of the Consumers Union top-rated restraints. Fig 7

shows the height of the test crash of a restraint that does not require a top-tether strap.

(5)

in-Figs 3 and 4. General Motors Child Love Seat.

creased appreciably when the tether straps were DISCUSSION not secured on those restraints that require them.

In fact, the head excursion allowed by four re- The evolution of dynamically tested child

re-straints increased sufficiently to propel the test straints is in its infancy. We are learning that there

(6)

Figs 5 and 6. Teddy Tot Astroseat V.

safety performance of a child restraint. Obviously

the best method, but the most difficult to achieve,

is to study and evaluate real-life accidents involving

children in child restraints. Until a greater fund of real-life accident data can be accumulated, how-ever, judgments must be drawn from dynamic

im-pact tests conducted in the artificial but controlled atmosphere of the laboratory. However, conclusions based on laboratory testing must be tempered by knowledge of how the restraint is actually being

used in real life, since the method of installing the

(7)

Fig 7. Bobby-Mac Deluxe Car Seat.

Williams2 of the Insurance Institute for Highway

Safety stated that “if child motor vehicle restraint

devices are not used correctly, they may not serve the purpose of restraining the child, and whatever crash protection they otherwise provide may be reduced or eliminated.” Shelness and Charles8 maintain that with respect to those restraints re-quiring top-tether straps, “ongoing scrutiny of re-straining devices in use shows that the majority are not anchored at the top.” Stalnaker’#{176} also maintains that “without these straps (top-tether and side

strap for side protection), the protection afforded

by those seats is greatly reduced.” This present

study substantiates conclusively what these experts

have maintained: if a safe child restraint requiring a top-tether strap is not properly installed in a car, the protection designed into the restraint is appre-ciably reduced.

IMPLICATIONS

It becomes obvious that the counseling of young

parents on the life-saving potential of child restraint

usage in the family auto must go beyond the mere

recommendation that a restraint be used. Since

improper use can markedly reduce a restraint’s

effectiveness, emphasis must be placed on correct

usage. Notwithstanding the variety of results shown in studies of safety education programs conducted

by pediatricians and hospitals,’32#{176} a major share of

the responsibility for restraint counseling must

con-tinue to rest with the pediatrician. After all, the pediatrician has early and repeated contact with the young parent and, most importantly, serves as the respected source of preventive medical advice for this parent. The participation of the pediatrician

is, therefore, critical to the furtherance of

automo-bile safety for the child. The more knowledge the

pediatrician has about child restraints, the more

effective this participation will be. Background

knowledge about restraints must be broad enough

to allow the pediatrician to match the type of

restraint to the motivation and responsiveness of

the parent in making restraint usage

recommenda-tions.

REFERENCES

1. United States Deaths from Specific Preventable Diseases and Automobile Accidents (Birth-24 Years). Irvington, NJ, Committee for a Safe Ride for Every Child, Physicians for

Automotive Safety, 1977

2. Williams AF: Observed Restraint Use of Children in Auto-mobiles. Washington, DC, Insurance Institute for Highway Safety, May 1975

3. Williams AF, Zador P: Injuries to Children in Automobiles in Relation to Seating Location and Restrzint Use.

Wash-ington, DC, Insurance Institute for Highway Safety, May 1976

(8)

Associ-ation for Accident and Traffic Medicine Resolutions. Jour-nal of Traffic Medicine/IAATM Newsletter. Stockholm,

January 1977

5. Federal Motor Vehicle Safety Standard 213, Child seating systems. Federal Register 35:14778, 1970

6. Federal Motor Vehicle Safety Standard 213-80, Child re-straint systems. Federal Register 43:21470, 1978

7. Cooney CE, Kummerow 5: Childsafe: when children travel by car, in Children Today. US Department of Health, Ed-ucation and Welfare Publication No. (OHD) 77-30014, July-August 1977, pp 11-15

8. Shelness A, Charles 5: Children as passengers in automo-biles: The neglected minority on the nation’s highways.

Pediatrics 56:271, 1975

9. Consumer Reports: Car Safety Restraints for Children.

Mount Vernon, NY, Consumers Union, June 1977, pp

314-317

10. Stalnaker RL: Tests of Current and Experimental Child Restraint Systems. New York, Society of Automotive Engi-neers (No. 740045), 1974, pp 1-26

1 1 A Report of Impact Tests Conducted for The Bobby-Mac Co, mc, Ann Arbor, MI, Tandelta Associates, Inc, August 7, 1977

12. Survey of 1977 Auto Seat Distances: Front Seat to Dash-board, Back Seat to Front Seat. Scarsdale, NY, The Bobby-Mac Co, Inc, 1977

13. Simons PS: Failure of pediatricians to provide automobile restraint information to parents. Pediatrics 60:646, 1977 14. Christophersen ER: Children’s behavior during automobile

rides: Do car seats make a difference? Pediatrics 60:69, 1977

15. Miller JR, Pless IB: Child automobile restraints: Evaluation of health education. Pediatrics 59:907, 1977

16. Reisinger KS, Williams AF: Evaluation of Three Educa-tional Programs Designed to Increase the Crash Protection of Infants in Cars. Washington, DC, Insurance Institute for Highway Safety, October 1977

17. Kanthor HA: Car safety for infants: Effectiveness of prenatal counseling. Pediatrics 58:320, 1976

18. Lieberman HM, Emmet WL, Coulson AH: Pediatric auto-motive restraints, pediatricians, and the academy. Pediatrics

58:316, 1976

19. Reichelderfer TE: A first priority-Childhood automotive safety. Pediatrics 58:307, 1976

20. Allen DB, Bergman AB: Social learning approaches to health education: Utilization of infant auto restraint devices. Pedi-atrics 58:323, 1976

TOO YOUNG TO PLAY??

Now recommendations from a six-year experimental sports study by the New

York State Public High School Athletic Association may lead schools

through-out the state and around the country to provide their students with the same

opportunities to excel outside their age group.

The study, involving 12,930 boys and girls from 722 public and private schools in New York State, dispels widely accepted educational theories about student

readiness for sports and places physical maturity, fitness, skill and prior sports

experience above age and grade level as criteria for eligibility in varsity sports. The injury rate of students who participated in the study was significantly lower than the state average for all students who compete in interscholastic

sports.

Submitted by Student

From Amdur, N: Scholastic study disproves age-old approach for gifted athletes. New York Times

(9)

1979;64;848

Pediatrics

Quentin H. McDonald

Restraints Safe?

Children's Car Seat Restraints: When Top-Tether Straps Are Ignored, Are These

Services

Updated Information &

http://pediatrics.aappublications.org/content/64/6/848

including high resolution figures, can be found at:

Permissions & Licensing

http://www.aappublications.org/site/misc/Permissions.xhtml

entirety can be found online at:

Information about reproducing this article in parts (figures, tables) or in its

Reprints

http://www.aappublications.org/site/misc/reprints.xhtml

(10)

1979;64;848

Pediatrics

Quentin H. McDonald

Restraints Safe?

Children's Car Seat Restraints: When Top-Tether Straps Are Ignored, Are These

http://pediatrics.aappublications.org/content/64/6/848

the World Wide Web at:

The online version of this article, along with updated information and services, is located on

American Academy of Pediatrics. All rights reserved. Print ISSN: 1073-0397.

References

Related documents

The average is affected to what happens in the tails (margin). 5) At the end of 2010, an estimate of the average probability of default is slightly higher than it was in 1979 for

The current review summarized the main findings of 26 studies performed in humans, with the aim of comparing results on the effect of coffee consumption on the main markers of

Child Seat Upper Tether Anchorage RR Head Restraints Outboard Seating Advanced Multistage Front Air Bags Supplemental Frt Seat Side Air Bags Front Seat Area Carpet*.

And, in doing so, Foucault is thought to make the following claim: the moral, ethical, and political valuing of emancipation or liberation, of humanity or

If employers want to win the war for top talent, they must provide a seamless experience between their online site and their mobile presence to attract potential candidates.. 55%

In the administrative system of the Tang dynasty, the State Council, or the Grand Council of the Secretariat-Chancellery ~ =1= F~ T, 7 appointed upper-level officials, which

Hypothesis (3) predicted that limited acclimation ability of the native montane rainforest species would cause their estimated photosynthetic optimum temperatures to be

Table S1, chemical shifts of the nucleotide protons; Table S2, chemical shifts of the trimethylene tether and amino acid protons; Table S3, NOE distance restraints used for