This article is a summary of the performance criteria for the recently approved ASTM F2772 Athletic Performance of Indoor Sport Systems standard that is to be promoted in North America.
As a true North American indoor sports flooring standard, ASTM F2772 has been designed to define the standards for Force Reduction and Ball Rebound, deemed as two of the most important and culturally relevant biomechanical and mechanical characteristics for North American indoor sports flooring
Force Reduction
Force reduction (also known as shock absorption) is a biomechanical property used to evaluate a sports surface’s ability to reduce impact related forces compared to impacts on concrete. The ASTM F2772 has categorized varying degrees of force reduction in order to clearly define ranges and limits while establishing acceptable indoor sports flooring classes. These categories will encompass all indoor sports flooring products and help to determine appropriate ranges of force reduction for specific sport applications and skill levels. Only after having conducted a thorough technical and cultural evaluation of the indoor sports flooring market did ASTM F2772 create the five unique force reduction categories. ASTM F2772 requires a minimum average of 10% force reduction in order to be classified as an acceptable indoor sports floor with no more than a 5% variance at any point. Testing methods for ASTM F2772 should adhere to ASTM F 2569 – 07 (methods for evaluating the force reduction properties of surfaces for athletic use).
Ball Rebound
Ball rebound (also known as ball bounce) is a mechanical property used to numerically determine if an indoor sports surface is appropriate for basketball based on the responsiveness of a ball and its interaction with the surface. In order to calculate ball rebound, one must test a ball’s rebound height on a sports surface compared to the rebound height of the same ball on concrete. The result is expressed as a percentage. According to the ASTM F2772 standard, the indoor sports surface must provide a minimum average of 90% ball rebound in order to be approved as an acceptable indoor sports floor with no more than a 3% variance at any point.
Reasoning for ASTM F2772
For years indoor sports floors were being built according to standards set forth by European or German committees. These previous standards were culturally and socio-economically biased as they failed to integrate the international needs and opinions of the indoor sports flooring community. The extended periods of time previously required to introduce a standard were also under scrutiny. The experienced delays were attributed to the committee’s inability to reach a consensus on acceptable standards for mechanical and biomechanical properties (the latest version of the EN standard took 17 years to create). In order to create a standard that was more reflective of the needs of North American indoor sports flooring, the ASTM assembled a diverse committee with the intent on creating a new indoor sports flooring standard in a timely manner.
Open and Timely Platform
With committee members representing varying socioeconomic and cultural backgrounds, an open platform was created to reflect the diverse needs and opinions of the indoor sports flooring community. In order to expedite the time between the creation and implementation of a much needed North American standard for indoor sports flooring, the committee decided to first focus on the two most relevant, important and non-disputable properties of an indoor sports floor. Those properties are force reduction and ball rebound.
Repeatability
It is no secret that a disconnect exists between laboratory and field testing of mechanical and biomechanical properties. Results that were obtained under ideal conditions in the laboratory are often not replicated in the field. In selecting to incorporate force reduction and ball rebound, ASTM F2772 focuses on two of the most commonly repeated properties experienced in a laboratory and field setting. As a result, end users and facility owners can seek comfort in knowing that the performance of their indoor sports floor truly conforms to the standard. In order to assure consistency of the standard in practice, it is important for facility owners and architects to request an ASTM F2772 certificate, issued by a 3rd party ASTM registered testing agency.
Consistency
While requirements for other standards have made distinctions based on surface construction or type, ASTM F2772 views standards and requirements related to athletic performance as absolute. All point elastic or area elastic surfaces will be kept to the same requirements, ensuring consistent athletic performance throughout.
The Future
After having successfully completed an open platform standard for force reduction and ball rebound, the attention now shifts to developing additional relevant mechanical and biomechanical standards for indoor sports flooring in North America. Until that time, it is our recommendation to continue to incorporate EN standards for rolling load and slip resistance as appose to DIN, as EN is a multilateral, living and more widely accepted standard.
Previous Standards Summary
DIN 18032 Part 2 is a standard for indoor sports flooring created by a German standardization body in 1991 that has commonly been used in North America. The standard which was established by and for Germans, covered mechanical and biomechanical properties which included: ball rebound, rolling load behavior, area indentation, force reduction, vertical deflection and slip resistance. The standard differentiated between varying types of indoor sports surfacing and outlined different performance criteria depending on the surface. No guidelines were provided for maximum allowable variances at testing points, only overall system averages were considered.
DIN pre-standard 18032 Part 2 (New DIN) was designed as an improvement to the previous 1991 version of DIN 18032 Part 2 by the same German standardization body in 2001 and has also been adopted in North America. The revised version of the standard integrated additional requirements that called for maximum tolerable variances at particular points and more stringent ranges of acceptability.
EN 14904 is an indoor sports flooring standard developed by the European Union’s European Standardization Committee. Approved in 2006, EN 14904 is a replacement of DIN 18032 Part 2 and is used in North America. The standard includes the same properties featured in both versions of DIN 18302 Part 2, but groups performance characteristics by technical and safety criteria. Compared to DIN 18032 Part 2, testing requirements for certain EN 14904 properties were designed to promote increased uniformity in the indoor sports system while other properties allowed for a much wider range. EN 14904 had been previously promoted as the approved successor to DIN 18302 Part 2 for various reasons. Due to the diversity of the standardization group, confusion related to multiple versions of DIN and the fact that DIN was to be discontinued, the living EN 14904 standard took precedence.
