Playing surface, alone, does not lead to an increased rate of ACL injury in athletes. Improper footwear, specifically various types of turf-cleats, are likely to leave athletes more susceptible to ACL injuries when worn on various playing surfaces. I am going to help you understand the significance of your cleat-buying decision by simplifying science in a way that every athlete, coach, and parent can understand. Let’s begin.
Every bone, muscle, ligament, and tendon in the human body has a force threshold of angles, torques, forces, and loads that can be withstood under stress. For the purpose of this breakdown, we are going to focus on the knee, specifically the ACL ligament, and how playing surface and cleat selection effects the volume of stressors inflicted on the knees during sport.
There are four primary cleat types. TURF SHOES are low profile, rubber soles with small, rubber studs that create friction for traction, change of direction, and stability. ROUND STUDDED cleats have fixed round studs at most if not all of the pressure zones of the sole. BLADED cleats have fixed, razor sharp studs that can vary in shapes from triangle to diamond, and sometimes linear as shown below. SOFT GROUND cleats have a hard plastic sole with interchangeable studs that vary in length to allow for adaptation to playing surface and inclement weather.
There are various playing surfaces. We will focus on the following. GYM TURF is thatched turf with foam or rubber backing that is often found in training facilities like Stadium Performance. This turf 1/2″ to 1″ blades of artificial turf and does not have rubber infill. OLD TURF is any turf greater than fifteen years old. These turf fields have 1/2″ of small black pellets to cut back on maintenance. OLD TURF is often found in indoor soccer and lacrosse facilities. GRASS is planted in sand or soil, watered, and manicured. NEW TURF 1.0 is the most common turf fields with 1″ of rubber pellet infill. NEW TURF 1.5 are typically municipal turf fields or professional fields with high volume usage. This turf has 1.5″ of rubber infill and is typically much softer under your feet.
NEW TURF 1.0
NEW TURF 1.5
Now that we’ve laid out the variables, let me tell you how to tear your ACL. Yes, you read that correctly. There are two primary opportunities to tear your ACL. The first phenomenon of ACL injury is called the PIVOT SHIFT. This moment of injury happens when an athlete has the majority of their weight on the forefoot of the a planted foot. The athlete then cuts away from the planted leg in the direction of the free leg, but instead of the planted foot rotating out of its fixation, it remains in the ground, and POP, the ACL ruptures. The second phenomenon is DECELLERATION in any direction. Athletic performance is typically a product of acceleration while injury prevention is a product of an athlete’s ability to decelerate safely. When the force produced at the knee exceeds the strength availability of the muscles and tendons above and below the knee, POP, the ACL tears.
It is my job to know the following information like the back of my hand. It is your job to read it, copy it, paste it, print it, share it, and live by it. If you don’t want to do your job, don’t. But I did warn you. You are more likely to remain injury free if you listen to my advice than if you do not.
SCIENTIFICALLY PROVEN TORQUE AT THE KNEE, RELATIVE ONLY TO CLEAT SELECTION.
The safest cleats are ROUND STUDDED.
TURF SHOES produce 8% more torque at the knee than ROUND STUDDED cleats.
BLADED CLEATS produce 20% more torque than ROUND STUDDED cleats.
SOFT GROUND generate 27% more torque than ROUND STUDDED.
SCIENTIFICALLY PROVEN TORQUE AT THE KNEE, RELATIVE ONLY TO PLAYING SURFACE.
GYM TURF is the safest playing surface for athletes.
OLD TURF creates 22% more knee torque than GYM TURF.
GRASS produces 32% more torque than GYM TURF.
NEW TURF 1.5 produces 39% more torque than GYM TURF.
NEW TURF 1.0 produces 46% more torque than GYM TURF.
SCIENTIFICALLY PROVEN TORQUE AT THE KNEE, RELATIVE TO CLEAT SELECTION & PLAYING SURFACE.
SOFT GROUND interchangeable stud cleats are the most dangerous regardless of playing surface.
ROUND STUDDED cleats are the safest, regardless of playing surface.
There’s no real significance to cleat selection on GRASS because you are at the mercy of the field condition.
GRASS is safer than both NEW TURF 1.0 and 1.5.
BLADED cleats pose significant risk on all playing surfaces but even greater risk on NEW TURF 1.0.
NEW TURF 1.0 is the most popular turf for High School and Collegiate fields.
After a VERY thorough search for male and female cleats, I have compiled a list of the safest cleats available for turf athletes. I do not support the validity of sport-specific cleats. Sport-specificity is a marketing tactic that does not possess any real value to performance or injury prevention. Seen below, are eight kinds of cleats that I will put my stamp of approval on. Six of the selections are highly approved. Two of them are tolerable. If you would like a complete list of these SP APPROVED cleats, please send an email to firstname.lastname@example.org.
Merry Christmas and Happy Holidays.
SP APPROVED CLEATS