EN 17435:2021

Surfaces for sports areas - Test method for the determination of Head Injury Criterion (HIC) and Critical Fall Height (CFH)

This document specifies test methods for measuring the impact attenuation of sports surfaces. Three different methods are specified. In Procedure A, a series of tests are undertaken from differing drop heights and the HIC values are plotted, and the Critical Fall Height determined. In Procedure B, a single test is undertaken from differing drop heights and the HIC values are plotted, and the Critical Fall Height determined. In Procedure C a series of tests are made at a fixed drop height and the maximum value of HIC is calculated.
This test method is primarily intended for use on both natural and synthetic turf sport surfaces. It may be carried out in a laboratory on test specimens or in situ on installed sports surfaces. This test method may not be suitable for sports surfaces covered by EN 14904.

Sportböden - Prüfverfahren für die Bestimmung des Kopf-Verletzungs-Faktors (HIC) und der kritischen Fallhöhe (CFH)

Dieses Dokument legt Prüfverfahren für die Messung der Stoßdämpfung von Sportböden fest. Es werden drei verschiedene Verfahren festgelegt. In Verfahren A werden eine Reihe von Prüfungen aus unterschiedlichen Fallhöhen durchgeführt, die HIC Werte aufgezeichnet und die kritische Fallhöhe bestimmt. In Verfahren B wird eine einzige Prüfung aus unterschiedlichen Fallhöhen durchgeführt, die HIC Werte aufgezeichnet und die kritische Fallhöhe bestimmt. In Verfahren C werden eine Reihe von Prüfungen mit fester Fallhöhe durchgeführt und der Höchstwert des HIC berechnet.
Dieses Prüfverfahren ist vor allem für den Einsatz sowohl auf Natur  als auch auf Kunststoffrasenflächen vorgesehen. Es darf entweder in einem Labor an Probekörpern oder vor Ort an eingebauten Sportböden durchgeführt werden. Dieses Prüfverfahren könnte für Sportböden, die von EN 14904 erfasst werden, ungeeignet sein.

Sols sportifs - Méthode d'essai pour la détermination du Critère de blessure à la tête (HIC) et de la Hauteur de Chute Critique (HCC)

Le présent document spécifie les méthodes d'essai permettant de mesurer l'atténuation de l'impact des sols sportifs. Il indique trois méthodes différentes. Dans le Mode opératoire A, une série d'essais est réalisée à partir de différentes hauteurs de chute ; la courbe des valeurs du HIC est tracée, et la Hauteur de Chute Critique déterminée. Dans le Mode opératoire B, un unique essai est réalisé à partir de différentes hauteurs de chute ; la courbe des valeurs du HIC est tracée, et la Hauteur de Chute Critique déterminée. Dans le Mode opératoire C, une série d'essais est réalisée à une hauteur de chute fixe, et la valeur maximale du HIC est calculée.
La présente méthode d'essai est principalement destinée à être utilisée sur les sols sportifs en gazon naturel ou synthétique. Elle peut être appliquée en laboratoire sur des éprouvettes, ou sur site sur des sols sportifs installés. La présente méthode d'essai ne s'applique pas aux sols sportifs couverts par l'EN 14904.

Podloge za športne dejavnosti - Preskusna metoda za ugotavljanje kriterija poškodbe glave (HIC) in kritične višine padca (CFH)

Ta dokument določa preskusne metode za merjenje kriterija poškodbe glave (HIC) podlog za šport. Opredeljeni sta dve različni metodi. V postopku A se izvede niz preskusov z različnih višin padca, vrednosti HIC se vrišejo v diagram in določena je kritična višina padca. V postopku B se izvede niz preskusov pri fiksni višini padca in izračuna se srednja vrednost HIC.
Ta preskusna metoda je namenjena predvsem za uporabo na umetnih travnatih podlogah. Izvede se lahko v laboratoriju na preskuševancih ali na mestu uporabe podloge za šport.
OPOMBA:    Dodatek A vsebuje okvirno preskusno metodo, pri kateri se izvede en preskus pri posamezni višini padca in izračuna okvirna vrednost HIC. To preskusno metodo je mogoče uporabiti tudi za druge oblike podlog za šport, ki so lahko namenjene zaščiti pred udarci z glavo.

General Information

• Status: Published
• Publication Date: 30-Nov-2021
• Withdrawal Date: 29-Jun-2022
• ICS: 97.220.10 - Sports facilities
• Technical Committee: CEN/TC 217 - Surfaces for sport areas
• Drafting Committee: CEN/TC 217/WG 11 - Test methods for sports surfaces.
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 01-Dec-2021
• Due Date: 25-Oct-2021
• Completion Date: 01-Dec-2021
• Ref Project: SIST EN 17435:2022 - Surfaces for sports areas - Test method for the determination of Head Injury Criterion (HIC) and Critical Fall Height (CFH)

Overview

EN 17435:2021 is a CEN European standard specifying a test method for measuring impact attenuation of sports surfaces, with the objective of determining the Head Injury Criterion (HIC) and the Critical Fall Height (CFH). The method is intended primarily for natural and synthetic turf and can be applied in laboratory on test specimens or in situ on installed sports surfaces. The standard defines three test procedures (A, B, C) and sets out apparatus, test conditions, data recording and reporting requirements. Note: EN 17435 may not be suitable for surfaces covered by EN 14904.

Key Topics and Requirements

• Test procedures
  • Procedure A: Series of drops from different heights; plot HIC vs drop height to determine CFH.
  • Procedure B: Single test series from differing heights; plot HIC vs drop height to determine CFH.
  • Procedure C: Series of tests at a fixed drop height; calculate maximum HIC.
• Headform and impactor
  • Headform mass ~4.6 kg and impacting face diameter 160 mm ±5 mm (as specified).
  • Headform types: aluminium ball or hemispherical missile; inspect for deformation when testing hard surfaces.
• Acceleration measurement
  • Accelerometers: tri-axial for free-fall or uniaxial for guided tests; mounted near the centre of gravity.
  • Frequency response: measure 20 Hz to 1 000 Hz with amplitude errors <5%.
  • Recording: sampling rate at least 20 kHz; anti‑aliasing and compatible signal conditioning required.
• HIC and CFH calculation
  • HIC calculation algorithm and software verification (Annex B).
  • HIC = 1 000 is adopted as an upper tolerance level; the standard documents the injury risk correlation (e.g., HIC 1 000 relates to higher probabilities of serious head injury).
• Apparatus, calibration and verification
  • Release, guidance, velocity/drop-height measurement systems and signal transmission requirements.
  • Calibration recommended per EN ISO/IEC 17025; accelerometer uncertainty ≤1%.
• Reporting
  • Test report requirements and traceability of results are specified.

Applications and Users

• Who uses EN 17435
  • Sports-surface manufacturers and product developers
  • Independent testing laboratories and calibration bodies
  • Facility managers, sports governing bodies and procurement teams
  • Safety engineers and risk assessors involved in sports facility design
• Practical uses
  • Product compliance, performance specification and quality control
  • Site acceptance testing and periodic safety verification (in situ)
  • Informing procurement criteria and risk mitigation for head-impact injuries

Related Standards

• EN 12229 - Preparation of synthetic turf test pieces (referenced)
• EN 12504-2 - Non-destructive testing (referenced)
• EN 14904 - Surfaces for which EN 17435 may not be suitable (see scope)

Keywords: EN 17435, HIC, CFH, Head Injury Criterion, Critical Fall Height, sports surfaces test method, impact attenuation, synthetic turf testing, CEN.

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2022
Podloge za športne dejavnosti - Preskusna metoda za ugotavljanje kriterija
poškodbe glave (HIC) in kritične višine padca (CFH)
Surfaces for sports areas - Test method for the determination of Head Injury Criterion
(HIC) and Critical Fall Height (CFH)
Sportböden - Prüfverfahren für die Bestimmung des Kopf-Verletzungs-Faktors (HIC) und
der kritischen Fallhöhe (CFH)
Sols sportifs - Méthode d'essai pour la détermination du Critère de blessure à la tête
(HIC) et de la Hauteur de Chute Critique (HCC)
Ta slovenski standard je istoveten z: EN 17435:2021
ICS:
97.220.10 Športni objekti Sports facilities
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 17435
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2021
EUROPÄISCHE NORM
ICS 97.220.10
English Version
Surfaces for sports areas - Test method for the
determination of Head Injury Criterion (HIC) and Critical
Fall Height (CFH)
Sols sportifs - Méthode d'essai pour la détermination Sportböden - Prüfverfahren für die Bestimmung des
du Critère de blessure à la tête (HIC) et de la Hauteur Kopf-Verletzungs-Faktors (HIC) und der kritischen
de Chute Critique (HCC) Fallhöhe (CFH)
This European Standard was approved by CEN on 1 November 2021.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17435:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Test apparatus . 6
5 Test conditions . 9
6 Test specimens . 10
7 Test procedure . 10
8 Test report . 13
Annex A (informative) Typical examples of trace acceleration against time and curve of HIC
values against drop height . 14
Annex B (informative) Verification of computer algorithm used for the calculation of HIC . 15
Bibliography . 16

European foreword
This document (EN 17435:2021) has been prepared by Technical Committee CEN/TC 217 “Surfaces for
sports areas”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by June 2022, and conflicting national standards shall be
withdrawn at the latest by June 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
Introduction
Sports injuries occur for a variety of reasons; in many contact sports they are as a result of athlete on
athlete collisions. Injuries also occur when athletes fall onto the surface on which they are playing. Of
these the most severe are likely to be injuries to the head, which can be life changing or even life
threatening. Consequently, a test method has been developed to measure the ability of sports surfacing
materials to reduce the likelihood of severe head injuries occurring. It is intended that this test method
will be specified in standards for sports surfaces used for activities where head impacts with the surface
are likely.
The test method is based on work undertaken by CEN committee CEN/TC 136 “Sports, playground and
other recreational facilities and equipment”. The Head Injury Criterion (HIC) at a tolerance level of 1 000
has been adopted as it is considered to be the upper limit for the brain injury severity unlikely to have
disabling or fatal consequences.
By choosing the measurement of HIC as one criterion of sports surfacing athlete protection, the method
considers only the kinetic energy of the head when it impacts the surface. This is considered to be the
best model available to predict the likelihood of head injury from falls.
The HIC value of 1 000 is merely one data point on a risk severity curve where an HIC of 1 000 is
equivalent to a 3 % chance of a critical injury (MAIS 5), a 18 % probability of a severe (MAIS 4) head
injury, a 55 % probability of a serious (MAIS 3) head injury, a 89 % probability of a moderate injury
(MAIS 2), and a 99,5 % chance of a minor head injury (MAIS 1), to an average male adult.
This method of test and HIC and Critical Fall Height (CFH) performance requirements are specified in
product and facility specifications published by CEN and a number of sports governing bodies.

Maximum Abbreviated Injury Scale, first developed by the Association for the Advancement of Automotive
Medicine and used extensively in the automotive industry as an indicator of the severity of head-related injuries.
1 Scope
This document specifies test methods for measuring the impact attenuation of sports surfaces. Three
different methods are specified. In Procedure A, a series of tests are undertaken from differing drop
heights and the HIC values are plotted, and the Critical Fall Height determined. In Procedure B, a single
test is undertaken from differing drop heights and the HIC values are plotted, and the Critical Fall Height
determined. In Procedure C a series of tests are made at a fixed drop height and the maximum value of
HIC is calculated.
This test method is primarily intended for use on both natural and synthetic turf sport surfaces. It may
be carried out in a laboratory on test specimens or in situ on installed sports surfaces. This test method
may not be suitable for sports surfaces covered by EN 14904.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 12229, Surfaces for sports areas - Procedure for the preparation of synthetic turf and needle-punch test
pieces
EN 12504-2, Testing concrete in structures - Part 2: Non-destructive testing - Determination of rebound
number
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
impact attenuation
property of a surface, which dissipates the kinetic energy of an impact by localized deformation or
displacement such that the acceleration is reduced
3.2
critical fall height
calculated drop height producing a HIC value corresponding to the limits set by the pass/fail criteria for
the surface. If no limit is set it should be assumed to be 1 000 HIC
3.3
Head Injury Criterion (HIC) value
measure of the severity of a head injury likely to arise from an impact, determined as described in 7.3.4
3.4
test position
position on the surfacing to be tested, located vertically below the centre of the headform
3.5
free fall impact test
test undertaken where the impactor is free to find its own path from the point of release to the surface
3.6
guided impact test
test undertaken where a method of maintaining the impactor in the correct orientation is used and which
may inhibit the progress of the impactor by preventing it from rotating
3.7
drop height
distance between the test position on the surfacing and the lowest point of the free falling headform prior
to release
Note 1 to entry: In the case of a guided headform, this value is calculated from measurement of velocity at impact.
3.8
drop test
single impact measurement from the selected drop height
4 Test apparatus
4.1 Suitability
The same apparatus and recording procedures are used for the three methods of test described in this
document.
4.2 Components of the apparatus
4.2.1 General
The equipment comprises: a headform (4.2.2) fitted with one or more accelerometer(s) (4.2.3), optionally
a signal processor (4.2.4), a release system for the headform (4.2.7), means for measuring the effective
free fall height (4.2.6), a signal transmission system (4.2.8) and impact measuring equipment (4.2.9). If
the equipment is using a uniaxial accelerometer, it shall also have a guidance system for the headform
(4.2.5).
4.2.2 Headform
4.2.2.1 The headform shall consist of either:
a) an aluminium alloy ball; or
b) a hemispherical ended aluminium alloy missile.
4.2.2.2 The impacting face of the headform shall have a diameter of 160 mm ± 5 mm. The maximum
deviation from the hemispheric surface shall be 0,5 mm (See Note). The total mass of the headform shall
be 4,6 kg ± 0,05 kg. In the case of a wired headform, the weight of any connector which is directly attached
to or mounted on the headform and the mass of 1,5 m of the wire or cable shall be included in the
determination of the mass of the headform.
NOTE The inclusion of the mass of the wiring is to avoid errors in measurement caused by vibrations of the
lower boundary.
If the alloy from which the headform is made is too soft, deformation of the surface of the aluminium may
occur when testing hard or rigid sports surfaces. This will result in unquantifiable errors in the
measurement of HIC. When testing surfaces of this type, the impacting surface of the headform should be
inspected frequently. If deformation of the headform surface is observed, the test shall be considered
invalid.
4.2.3 Accelerometer
The measuring accelerometer(s) shall be comprised and be incorporated into the headform as follows:
a) accelerometer(s) aligned to measure 3 axes for free falling headform, mounted at the centre of
gravity (±5 mm in the vertical or horizontal axis) of the headform; or
b) a uniaxial accelerometer for guided headforms aligned to measure in the vertical axis ± 5° and
located directly above the centre of mass.
4.2.4 Signal processor (optional)
Depending on the accelerometer technology, different signal processors may be used. This could be, for
example, a charge amplifier (internal or external), a wheatstone bridge and an amplifier or an integrated
electronic conditioner.
4.2.5 Guidance system
When using a uniaxial accelerometer, a vertical guidance for the headform shall be provided, including a
means to measure the velocity of the headform immediately prior to impact (see 4.2.6).
4.2.6 Fall height measuring equipment
In all cases, the effective free fall height of the headform shall be recorded using one of the following two
methods:
— For free falling impact tests, by physical measuring of the drop height or by calculating the drop
height from the measured time between release and contact of the headform with the surface.
When calculating the drop height from the measured time between release and contact of the missile
with the surface special attention should be paid to possible time differences between the start of
time measurement and the effective release of the headform (e.g. caused by permanent magnetism
in a magnetic release system). A comparison of the measured height of fall and the calculated height
of fall may be needed;
— For guided impact tests, by measuring the velocity of the headform immediately prior to the impact
and calculating the theoretical free fall drop height. To allow for frictional losses, the velocity of the
headform immediately prior to impact shall be recorded and the equivalent drop height calculated,
as if the headform had been in free fall.
4.2.7 Release system
The release system for free-fall impact test shall not create a significant rotation moment or any other
forces on the headform, when released.
NOTE A rotation moment or other forces on the headform would cause additional accelerations at impact in
the accelerometer, leading to an uncontrollable error of the resultant for the vertical measurement.
4.2.8 Signal transmission system
When using a signal cable for transmission of the accelerometer signal it shall not cause any significant
restraining, or pushing forces or cause unsteadiness of the headform.
4.2.9 Impact measuring equipment
4.2.9.1 The impact measuring equipment shall consist of an accelerometer measurement system (see
4.2.9.2), a recording device (see 4.2.9.3) and an HIC calculation program (see 4.2.9.4).
4.2.9.2 Accelerometer measurement system, capable of measuring all signal frequencies in the
range 20 Hz to 1 000 Hz and having a sufficient response at all frequencies to keep amplitude
errors < 5 %. It shall be capable of measuring, recording and displaying the acceleration and time
du
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