"Knee muscles are capable of protecting ligaments and preventing injury," says Edward M. Wojtys M.D., professor of orthopaedic surgery, U-M Medical School, and Director of Sports Medicine at UMHS (University of Michigan Health System). "Female athletes are two to eight times more likely to tear their anterior cruciate ligament because they may not able to achieve the same muscle stiffness across the knee joint." Both female and male athletes could benefit from ballet classes, to learn the principles of turnout. Pointe shoes could pose an equal risk for dancers, because of the extra demand for strengthening turnout.
It is the running and pivoting team sports that this study addresses. Sprinters and runners go in one direction, and do not have to risk knee rotation. This article from Science Daily also reports:
"The thought is, if you play jumping, turning, twisting sports, that you should be better prepared to protect your knee against rotational forces," Wojtys says.
That's why the measurements for the females involved in non-pivoting sports were surprising when compared to females in the pivoting sports. Females in non-pivoting sports had an increase in knee stiffness of 198 percent - 27 percent higher than the females in pivoting sports.
"Women who played jumping, turning, twisting sports actually had the poorest ability to protect themselves against rotational strains," Wojtys says. "
Please note that the above reference to "stiffness" means deliberate tension of the knee muscles, not the kind of stiffness resulting from strain or over training.
Ballet is a pivotal movement system. We do turn and pivot both in adage, jumps and on pointe. But we have turnout to protect our knees, especially, but also all of our joints. We employ turnout to change direction smoothly.
And, of course, our movements are choreographed in advance, and well rehearsed.
The strength of our turnout and placement means we do not have to twist to turn or pivot. This takes years of training. Athletes also practise dodging and twisting movements for speed and reflex, but to date, do not generally understand how to protect their joints.
This study shows that female athletes are more likely to risk knee injuries. What a shame that so far, it is mainly football players who study ballet, to avoid the risk of injuries resulting from twisting and tearing joints.
In the field of Dance Medicine inspired authors like Deborah Vogel and Lisa Howell write about the finer details of functional anatomy, mostly in relationship to dance and working in pointe shoes. I recommend their works to any aspiring female athlete. They could learn some basic ballet exercises to build strength and avoid knee injuries.