Athletic Facility Safety/Performance Evaluation

Size: px

Start display at page:

Download "Athletic Facility Safety/Performance Evaluation"

Randolf Andrews
5 years ago
Views:

1 + + Athletic Facility Safety/Performance Evaluation St. Timothy s School 8400 Greenspring Ave Stevenson, MD July 23, 2012 Prepared for: Geo Turf 224 W30th Street, Suite 606 New York, NY Contact: Domenic Carapella Prepared by: ISA USA / DMA Sports Design Group Pembroke, NH *Seattle, WA*Lubbock, TX Phone: (508) Contact: Mr. Jeffrey Gentile

2 July 23, 2012 Geo Turf 224 W. 30 th Street, Suite 606 New York, NY Attn: Domenic Carapella RE: St. Timothy s School G-Max Impact Test Evaluation Mr. Carapella, On July 19, 2012, DMA Sports personnel conducted field tests at St. Timothy s School. The purpose of the tests was to evaluate the shock absorbing characteristics of the synthetic grass field. Gmax/HIC The Standard Test Method for Shock-Absorbing Properties of Playing Surface Systems and Materials (ASTM F ) was followed. The tests were performed using a Triax 2000 A- missile G max registration unit ( This report presents Background information on the test procedures, Conditions Summary, Test Results and Observations. Background The ASTM F-355 Procedure A and ASTM test methods covers the measurement of certain shock-absorbing characteristics, impact force-time relationships and rebound properties of playing surface systems. The test procedure involves dropping a 20 lb missile three times at the same location under a controlled consistent height of 24 inches. The G max testing was developed by NASA in association with the automotive industry to determine the magnitude of sustained force the human body (in particular, the head) could withstand before serious effects would occur. The G force, or acceleration of the mass that is applying the force, is correlated with the sustained duration of the force. As an example, a fighter pilot may be subject to G forces of as much as 8 times normal gravitational force (8 Gs) for up to several minutes at which time unconsciousness (a blackout) could occur. Relative to athletic fields, a player will encounter G forces of 100 to 200 G s over a period of less than 10 milliseconds. It has been determined that a G force of 200 over a period of at least 10 milliseconds is considered concussion level. This is for a single encounter. It has been shown by studies conducted by the AMA, that repetitive blows or encounters of up to four to five during an event reduces the needs to 160 G s. In the early 70 s, the artificial turf companies started to use this standard (G < 200) to determine the safety of their carpet systems. The artificial turf needed to stay inside this Pembroke, NH Sturbridge, MA Lubbock, TX Seattle, WA Ph (603)

3 St. Timothy s School Stevenson, MD envelope, so it was determined by the turf manufacturers that a drop height of 24-inches should be the standard. This particular drop height was established because the artificial turf systems would exceed the maximum allowable G max (> 200 G s) with a drop of 30-inches or more. As the industry has grown in sports surfacing and playground safety surfacing, so has the performance of these synthetics. Playground surfaces are now required to meet shock absorbency standards from minimum drop heights of 36-inches to as much as 8-feet. In addition, the antiquated carpet systems were directly accountable for sports injuries related to the carpet itself. Injuries such as turf toe and foot lock, and ankle, knee and shoulder sprains and breaks occurred, along with carpet burns and abrasions that were season long. The new synthetic grass systems offer much better results; achieving G max values of less than 200 from drop heights as much as 48-inches. Another important value tested is the Head Injury Criteria (HIC). HIC is a value that relates to the probability at which a head injury will occur as a result of an impact generating fall. The value is a mathematical interrogation of the impact deceleration curve over a time interval. HIC values as related to Minor, Moderate, Critical, and Fatal head injury probability are shown in the table below HIC Value HIC Related to Head Injury Probability Minor Head Injury Moderate Head Injury Critical Head Injury Fatal Head Injury 0 0% 0% 0% 0% % 20% 0% 0% % 40% 2% 0% % 70% 4% 0% % 90% 8% 2% % 95% 10% 2% % 98% 20% 4% % 100% 45% 10% % 100% 70% 30% % 100% 90% 70% % 100% 95% 90% % 100% 98% 95% % 100% 100% 100% The ASTM defines the head severities shown as the following: Minor Head Injury: A skull trauma without loss of consciousness; fracture of nose or teeth; superficial face injuries. Moderate Head Injury: A skull trauma with or without dislocated skull fracture and brief loss of consciousness. Fracture of facial bones, without dislocation; deep wound(s). July 23, 2012 Page 3

4 Probability of Injury St. Timothy s School Stevenson, MD Critical Injury: a skull trauma with loss of consciousness for 12 hours and having nonrecoverable brain damage 120% HIC Related to Head Injury Probability 100% 80% 60% 40% 20% Injury Severity None Minor Moderate Critical Fatal 0% HIC Value Conditions Summary The synthetic surface is a Limonta Sports Turf with Geo Fill organic infill. A complete ASTM Soccer Field test procedure was performed. Three consecutive drops were made at each location for each 24 drop height, at roughly 1 minute intervals. The second and third drops are averaged together. The data is summarized in the attached table. Field Testing Date: 7/19/2012 Local Air Temperature: 96 F Avg. Humidity: 70% Test Locations Wind Speed: 2.1 mph Turf Backing Temp: 124 F *End A is West July 23, 2012 Page 4

5 St. Timothy s School Stevenson, MD TRIAX Data Acquisition and Analysis Report Test Methods: ASTM F-355 Procedure A, ASTM F Loc # Drop # Gmax (G) Velocity (ft/sec) H.I.C Loc Description Gmax Avg (G) HIC Avg (HIC) Surface Temp (ºF) Infill Depth in MM Penalty Kick Line, End A, Center of Field ft. from center of field to corner of Penalty Box. Touch Line C. End A ft. from the half-way line to End A. 40 ft. from center of field to touch line C Half-way Line, Center of field ft. from half-way line to End B. 63 ft. from center of field to touch line D ½ the distance from penalty restraining arc to leading edge of Penalty Box at end B, center of field Touch Line D Team area, A side of the field End B Touchline C Southwest Corner Kick ft. from the goal line to half-way line, End A, Center of Field ft. from Goal line to half-way line, End B, Center of field Averages: July 23, 2012 Page 5

6 Location Number Location Number St. Timothy s School Stevenson, MD Average G-Max Reading per Location Average G-Max Reading Average Head Injury Criteria (HIC) Reading per Location Average HIC Reading July 23, 2012 Page 6

Average Infill Depth (mm) St. Timothy s School Stevenson, MD Average Infill Depth per Location 33.0 32.0 31.0 30.0 29.0 28.

7 Average Infill Depth (mm) St. Timothy s School Stevenson, MD Average Infill Depth per Location Location Number Pictures July 23, 2012 Page 7

8 St. Timothy s School Stevenson, MD Gmax Field Summary The G-max test results for the 24-inch drop indicated that the field is well within safe standards, ranging from 109 to The average for the entire field was This range and average meets ASTM Standards. The data for the Head Injury Criterion (HIC) is also shown and is within a safe and acceptable range. It is important to continue monitoring G-max values throughout the life of a synthetic turf field. The shock absorbency characteristics of a field will degrade over time as a result of material degradation and material re-distribution. Annual athletic facility safety evaluations produce court permissible evidence that can protect an owner from impact injury related lawsuits. These annual evaluations can also help to improve the quality and extend the life of an athletic facility Yours truly, Jeffrey T Gentile Vice President of Operations July 23, 2012 Page 8

Athletic Field Consultants, Inc.

Athletic Field Consultants, Inc. 1 Test Performed By: Jeff Clise Report No.: 16-019-2 on behalf of General Project Information Project Name: Richard Montgomery High School Football Field Project Address: 250 Richard Montgomery Drive,