Are Grass and Cleats Best for the Knees?

Whether it’s your kid playing football for the high school team or you’re playing baseball and softball on the weekend, where you play and what’s on your feet do make a difference in preventing injuries. According to a new study published in theJournal of Biomechanical Engineering, a combination of natural grass – rather than artificial turf – and cleats seems to be the best option for decreasing the chances of a knee injury.

Researchers used lower extremities – knee, foot and ankle – from cadavers to test the strain placed on the ACL (the ligament in the center of the knee) by four different combinations of shoes and playing surfaces: turf shoe/Astroturf, turf shoe/playing turf, cleat/modern playing turf and cleat/natural grass.

When a similar turn was made with all four combinations, cleats on grass created the least force on the knee ligament, according to study authors.

Compared with the natural grass/cleat combination, the Astroturf/turf shoe put 80 percent more strain on the ACL. Strain was 48 percent greater with the modern playing turf/turf shoe, and 45 percent more with the modern playing turf/cleat combination.

Michael Ciccotti, MD, director of the Rothman Institute at Jefferson’s Sports Medicine Division, says the study provides preliminary support for what athletes have long suspected. “If you look at sports injuries, there’s been a general sense that there was a higher incidence of lower-extremity injuries on Astroturf surfaces and that modern surfaces might be better and that grass might be better yet,” Dr. Ciccotti notes.

He lauds this as an excellent biomechanical study: “It adds some scientific basis to what we generally thought – at least with respect to ACL injury.”

However, he also notes that the findings have not yet been borne by a large epidemiological study – in other words, a scientific examination of how and why people sustain such injuries on various surfaces. “There are many other factors involved, so this study is a great start but not necessarily the final word,” Dr. Ciccotti concludes.

What we do know is that if you or someone you care about tears their ACL – it is a long, slow recovery, so anything you can do to prevent the injury is important.

Learn more about the Jefferson Sports Medicine Center.