Ensuring the Safety of Your Gym Floor
By: Chris Wedge
School leaders need to take time to evaluate several factors when making the decision for the type of athletic flooring in their facilities. These factors include the programming and mission of the facilities, the types of activities they will host, initial cost, the relative importance of each type of activity, life-cycle cost, and maintenance costs, to name a few.
One factor that should rise to the top of the list is safety. When we are talking about the safety of an indoor athletic surface, we can evaluate it in three ways: shock absorbency, impact attenuation, and surface friction.
This article will give a general overview to each of these aspects. This is not designed to be a science lesson in physics or an engineering project for these performance factors. The goal is to provide you with some basic, unbiased information regarding floor safety to aid in the decision-making process.
1. Shock Absorbency
Proper shock absorption should be considered highly important. As an athlete impacts a sports surface, the impacting force is translated into two resultant forces: one absorbed by the floor and the other returned to the athlete.
While hard surfaces such as concrete and asphalt provide little or no force reduction for the athlete upon impact due to running or jumping, a safe sports floor system should absorb a certain amount of these forces and are rated by the percentage of force reduction they provide as compared to hard surfaces. For example, a sports floor with a force reduction value of 40 percent will absorb 40 percent of the impact force and return 60 percent of that force to the athlete.
It is widely accepted in the indoor sports flooring industry that the minimal desired percentage is 50 percent. The general majority of wood gymnasium floors installed at the high school level and above will meet this rating; however, there are exceptions. Contrast this to the general majority of synthetic gym floors (rubber, urethane, PVC) installed over concrete, and their average is closer to 30 percent. This is why nearly every athlete, coach, participant, and official will acknowledge that synthetic floors are "harder" and "worse on my joints." This measurement is widely tested according to the German Institute of Normalization or "DIN" standard. The harder the athletic floor (concrete or asphalt being the worst), the more prone participants are to overuse or repetition injuries.
2. Impact Attenuation
For the sake of this discussion, impact attenuation refers to the impact of a part of an athlete's body part (head, shoulder, back, elbows, hands, and knees) with the surface. Athletic surfaces can be grouped into two general categories in how their measurements of impact attenuation (and to a lesser degree shock absorption) are determined: area elasticity and point elasticity.
Area elasticity refers to how well the floor surface will deform and absorb energy over the area of the impact. For example, a concrete floor would transmit zero area elasticity, and a trampoline would transmit tremendous area elasticity. The resulting impact attenuation would be very low for concrete (all of the impact goes right back to the athlete's body) and very high for a trampoline (the trampoline absorbs a substantial amount of the energy).
Cushioned wood athletic floors, like those found in most school gyms in America, are area elastic. Most synthetic floors, namely those installed directly on concrete, are not very area elastic. Point elasticity refers to how well the floor absorbs and returns energy over a small area ("soft underfoot"). For floor safety, soft under head, elbow, and knee is more relevant. The challenge is that athletic surfaces need to be hard enough to dribble a ball, but soft enough to be safe for falls. Wood gymnasium floor are less point elastic than synthetic floors. The resulting impact attenuation for wood vs. synthetic floors is therefore very comparable.
Currently, indoor sports floors are not rated by any standard in the measurement of impact attenuation. The school leader must therefore make their best decision based on the information provided. Shock absorbency ratings are a good comparative measure. Additionally, the American Society of Testing and Materials (ASTM) has conducted studies on the impact attenuation of surfacing materials with playground equipment. This study more directly reflects fall impacts from playground equipment and is certainly not definitive for athletic floors, but it does bare some relevance.
3. Surface Friction
Surface friction, often called the coefficient of friction or sliding coefficient, is used to measure a floor's ability to control the sliding of athletes on its surface. For an indoor sports floor, the surface friction must be high enough to prevent premature and uncontrollable sliding of athletes on its surface, but also low enough to permit sliding off an extreme force.
Rotating and pivoting motions can create strain on an athlete's joints unless the floor has the proper friction coefficients. The measurement is in Newtons, and the range for the proper range is .5N to .7N. To contrast the ranges, ice equates to .1N and fly paper is .9N. Typically for wood floors, surface friction is a direct function of the finish on the surface. For most types of synthetic floors, the measurement is higher. The maintenance of any of these floors is critical and can affect the measurements. This measurement is also tested according to the German Institute of Normalization or "DIN" standard.
All three of these criteria should be carefully evaluated prior to the decision of choosing an athletic floor type.
Chris Wedge is Southern regional manager for Aacer Flooring, LLC, www.aacerflooring.com.
Product Roundup
Future Pro T-Rex 54 SR
The affordable portable is at Future Pro! T-Rex 54 SR has the basic features of larger competition portables popular on arena courts, but this T-Rex is a compact portable that fits into gyms and multipurpose rooms where larger systems won't. T-Rex 54 SR has an official-size 72" unbreakable glass backboard with an unconditional lifetime warranty, breakaway goal, and DuraSkin backboard padding. Goal height adjusts 8' to 10' for all ages of play. Duraskin and base padding are available in 16 colors. This portable will meet your facility's needs and budget.
www.futureproinc.com
Mueller Shooter Sleeve
Mueller Sports Medicine has announced the newest addition to their basketball lineup. The Mueller Shooter Sleeve helps players hit the three-point shots with a unique compression fit that keeps muscles warm and less fatigued. The Shooter Sleeve can be used to cover cuts, scrapes, or other surface injuries and protect the arm from further harm. Made of smooth black Lycra fabric, the unique seamless design prevents skin irritation. Snug bands at the top and bottom keep sleeve in place and prevent slipping or bunching.
www.muellersportsmed.com
International Play Company
When selecting play structures, you will want to consider quality of materials, availability of repair parts, durability, safety, and warranty. Your supplier should look at your program, available space, and budget and then help you make the right decisions. IPC meets all of these requirements. IPC designs, manufactures, and installs creative play structures. They adhere to ASTM, IPEMA, CSA, ADA safety guidelines. IPC's professional and knowledgeable team will work hand in hand with your team to develop a proposal that meets your needs and budget.
www.iplayco.com
PlybooSport
Bamboo flooring and plywood pioneer Smith & Fong Co. now offers urea formaldehyde-free, FSC-certified bamboo sports flooring educational environments. Called PlybooSport, with three independently rated systems that meet both DIN and EN standards, this floor covers the range from basketball and volleyball to aerobics and dance. With superior stability, consistent longer lengths, and hardness equal to or greater than maple, PlybooSport bamboo flooring produces a higher quality product over the long or short term. DIN rated and EN standard systems are available for various activities.
www.plyboo.com
American Time & Signal
The American Time & Signal clock experts supply affordable timekeeping solutions to meet your school's specific needs. They manufacture clocks that work with all wired systems, including Simplex, battery clocks, extra-large gymnasium clocks, clock guards, and more. They specialize in fast clock repair and hard-to-find parts. If you are searching for a uniquely simple wireless clock system, consider SiteSync IQ. It synchronizes an existing wired clock and bell system with wireless clocks.
www.atsclock.com
Zenterra Sport Bamboo
The green alternative to traditional basketball floors is a Zenterra Sport Bamboo flooring system. That's because bamboo is much more renewable plant, growing to its full maturity in about five years, as opposed to the 40 to 60 years required for the more traditional flooring materials of oak or maple. And, you sacrifice no quality in purchasing a bamboo system. It passes the same DIN safety standards as traditional floors and is actually a harder material than either maple or oak. These bamboo floors are as attractive and affordable as any wood sports floor and carry a three-year warranty.
www.zenterrafloor.com
Boing Corner Strips
Boing Corner Strips are a unique solution for all play areas, indoors and outdoors. The product increases safety and reduces liability. Boing can be quickly and easily attached to any sharp or dangerous corners. The product is shock-absorbing, abrasion-resistant, anti-bacterial, and waterproof. It is available in nine vibrant colors.
www.BoingSafety.com
ProGym from Mateflex
ProGym interlocking modular flooring features a smooth playing surface for basketball, volleyball, and almost any gymnasium activity. ProGym is made from a resilient yet durable polypropylene material. It provides optimum playing characteristics, good player comfort, safety, and a short installation to enjoyment time. ProGym is available in 15 standard colors to meet any need. ProGym works for both new construction and for renovating or upgrading existing hard or worn floors. ProGym is made in America by Mateflex Modular Surfaces.
www.mateflex.com
Daktronics ColorSmart Scoreboards
Draw fans into the game with exciting color-changing digits on a new ColorSmart scoreboard from Daktronics. This new LED technology changes color depending on the game circumstances. ColorSmart digits become more game interactive than standard scoreboards by changing color to showing the leading team's score in green and the trailing team's score in red. If the game is tied, both scores are shown in amber. The digits for the game time also change color when the clock is stopped or running. ColorSmart scoreboards are designed to withstand unintentional blows from indoor balls.
www.daktronics.com
