Sidelined: the ACL

Anterior Cruciate Ligament (ACL) injuries is often referred to as the “Mother of all injuries”. It can knock athletes out for a season and leave them hesitating from pivoting ever again. Skiers, basketball, football, lacrosse and soccer players shutter at the sound of this three letter word knowing a 6-9 month rehab is following this injury. ACL tears usually occur after an awkward landing or a pivoting motion on a planted foot. Hard hits also contribute to this injury but nearly 80 % of ACL injuries are caused by non contact. Training the muscles to fire properly in the legs and working on form can hopefully keep ACL’s from sidelining you.

runnerWhen ACL Is a Pain
The anterior cruciate ligament is a fascial band in the knee that connects the thigh bone (femur) to the shin bone (tibia) . It provides stability to the knee, controls rotation, and along with the hamstrings keeps the tibia from translating too forward on the femur.

Studies show the ACL is under more stress when the knee is straight or bend 5 to 20 degrees and is exposed to an inwardly directed force. (Think “knocked knee position”). If the force exceeds the tensile strength of the ligament a tear can occur and the knee loses its stability. Grinding and excessive motions occur, leading to wear and tear on the joint surface and meniscus. It can also strain surrounding ligaments and tendons.

Athletes often complain of a “popping” sound when the injury occurs and swelling and pain follows.

Why You Are Sidelined
It’s like the Perfect Storm when an ACL injury occurs – a few factors simultaneously hit, washing out an athlete’s season. Consider landing from a rebound in basketball with the knee fairly straight in that 5-20 degree knee bending zone where the ACL is stressed. Add sluggish hamstrings, and “rolling in” of the knee from a weak glute and the ACL is stressed even further. Suddenly POP!

Players participating in sports involving sudden stops, jumps and pivoting motions are more at risk for ACL injuries. Female athletes are 6-8 times more at risk compared to males. Studies say it could be due to delayed hamstring firing compared to male athletes, structural issues like hip/ knee alignment, or hormone levels.

Regardless of your gender, if your buttocks are weak, you can develop that “knocked knee position”. If your hamstrings are weak they can’t efficiently stabilize the tibia. The ligament is then subjected to more force, increasing risk of injury when landing or cutting and turning during your sport.

How to Stay In The Game
FORM! Our favorite four letter word when it comes to avoiding injury. Watch your form and build proprioceptive awareness of where that knee and foot relationship is while you are playing your sport. Besides overall core and quadriceps strengthening be sure to strengthen the hamstrings and gluteal muscles to help support the ACL.

Try these exercises:
Side to Side Shuffles

• Don’t allow knee to cave in!
• Start with slight bend at knees
• Leading with right foot sidestep pushing off with the left foot
• When you drive off with the left leg, be sure the hip/knee/ankle are in a straight line.
Do 30 seconds then switch direction 3 sets

Scissor Jump
• Start in lunge position right leg forward with knee over ankle
• Push off from your right foot and bring your left leg forward into lunge position.
• Don’t let knee roll in or out keep it in line with ankle
• As you land the weight should be accepted on the ball of your foot and knee should be bend slightly
Do 3 sets of 10 repetitions

Glute Sidelying
• Hips stacked lie on your side
• Lift leg up and SLOWLY lower down
• Don’t let leg come forward
3 sets of 10 repetitions

As always, be sure to check with a physician prior to any exercise program.


AmyMcGorry Physical TherapistAmy McGorry, PT, DPT MTC, Received her Bachelor’s of Science in physical therapy from SUNY Stony Brook in 1991 and earned her doctoral degree in physical therapy from the University of St. Augustine in 2011. In 2005 Amy, completed an advanced certification in Orthopedic Manual Joint Manipulation from the University of St. Augustine. In addition to her clinical skills, Dr. McGorry is a freelance news reporter for Channel 12 and contributes medical articles, short videos and slideshows to health and wellness websites.