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Health & Exercise Forum

ACL injury prevention for female athletes: Part 1 of 2

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Sep 5, 2016
Danielle Maurice, SPT

Danielle Maurice, SPT


Guest Contributor: Danielle Maurice, SPT 

Various studies have shown that female athletes are on average four times more likely than males to tear their anterior cruciate ligament (ACL) of the knee. Susceptibility for female athletes to an ACL injury is a multifaceted problem; anatomical, mechanical, physiological factors and landing technique are all involved. Studies done involving the Prevent Injury and Enhance Performance (PEP) program developed by the Santa Monica Sports Medicine Research Foundation has demonstrated a decrease in ACL injuries for those athletes that adopted the program, compared to those that did not engage in a prevention program. Usually, athletes first get exposed to such programs once they get to the college level, mostly being applied at the Division I level. As the coach of the Pocono Snow Junior’s U13 Girls Team and as an Pre-Physical Therapy/Exercise Science student at the University of Scranton, I have become very interested in applying an injury prevention program to the regular practice routine for the girls I coach sooner than the collegiate level. With the help of Dr. Paul Mackarey and University of Scranton Assistant Coach Sarah Jerome, we created an ACL prevention program, based off of the PEP program, to tend to the needs of these girls. Before getting into the program itself, here is some background information about the function of the ACL and why strengthening and retraining the surrounding muscles are important.

What is the ACL?

ACL stands for anterior cruciate ligament and it prevents anterior translation (forward movement of the femur/thigh bone from the tibia/shin bone) The ACL also acts to stabilize the knee joint and prevent hyperextension (Photo 2—Normal knee vs. Hyperextended knee)

How is it injured in female athletes?

70% of ACL injures are non-contact injuries, most commonly occurring during landing or sharp decelerations. Females are more prone to these injuries due to anatomical and physiological differences compared to males. Females have wider hips, resulting in “knocked-knees” (Photo 3—Normal knee vs. knocked-knees) and hyperextension of the knee. In addition, the hormone estrogen causes greater laxity in ligaments. Also, females have greater hamstring flexibility than males, allowing more anterior translation. Being more vulnerable to hyperextension as a result of these factors places more stress on the knee joint and the ACL, leaving females more susceptible to injury.

How do we prevent ACL injuries?

There are five essential components to a good ACL prevention program. They include:

  • Flexibility. Properly stretching is a key component in preventing injury to the muscles supporting the knee.
  • Balance. Improving balance helps counteract the stresses put on the knee.
  • Strengthening. Improves the ability of the surrounding muscles to support and protect the knee.
  • Plyometrics. Plyometrics are explosive exercises that help build speed, strength, and power.
  • Proper Technique (especially in sport specific activities). Often, female athletes land with their knees locked out (hyperextended), increasing the stress placed on the ACL. Instead, athletes should be directed to land on bent knees and on the balls of their feet, while ensuring proper body alignment. (Photo 4—Right vs. Wrong Landing Technique)

The ACL prevention program we created includes all five of these components. This program is intended to be completed two times per week, in a six week cycle. Below, the program has been broken up into weekly sessions, with a new element added after two weeks.

Weeks 1-2

  1. One lap around the field
  2. Dynamic warm up

The dynamic warm up is done to help increase flexibility for the athletes. Contrary to popular opinion, dynamic stretching is better for athletes when compared to static stretching. Dynamic stretching involves continuous movement while stretching, opposed to static stretching where athletes are stationary. Dynamic stretching is more beneficial as it helps increase range of motion and flexibility, which will ultimately reduce risk of injury and improve performance.

  • Calf stretch (Photo 5), 4 stretch (Photo 6)
  • Quad stretch (Photo 7), Hamstring stretch (Photo 8)
  • Hip stretches (open and close the gate) (Photo 9—Close the gate [top], Open the gate [bottom])
  • Front and back kicks (Photo 10—Front kicks [left], Back kicks [right])
  • Forward, backward, and sideways lunges
  • For the lunges, it is important that the athletes avoid hitting their knee on the ground and avoid going knee over toe (Photo 11—Lunges, Right vs. Wrong Technique). Also, the athlete should be instructed to keep their hands on the hips or out in front of them, and that they pause for about 3 seconds at the bottom of each lunge.
  • Back pedal. These stretches are to be done for 15 yards, then the athletes are to backpedal to the beginning. While backpedaling, coaches need to pay special attention, making sure their athletes do not lock out their knees. Lastly, to ensure balance while stretching, athletes should keep a slight bend in their standing leg.
  1. Hops

Although hops may seem like a simple exercise, they actually help encourage proper technique, while strengthening leg muscles and improving balance. To start, hops should be done over a line on the field, eventually progressing to jumping over cones or hurdles. While engaging in the exercise, coaches should make sure athletes are not locking out their knees and are maintaining proper body alignment (Photo 12—Two Legged Hops). Different hopping exercises include:

  • Two legged hops—forward, backward, and sideways
  • Single leg hops
  • Each progression is to be done for 30 seconds, 2 times each


NEXT WEEK: In Part 2 of 2 on ACL Prevention will present Weeks 3-4 and Weeks 5-6 of the Program.

Guest Contributor: Danielle Maurice, SPT, University of Scranton, Exercise Science/Pre-Doctor of Physical Therapy Student 2020, a native of Long Island, NY is a student physical therapy aide at Mackarey & Mackarey Physical Therapy Consultants, LCC

NEXT MONDAY – Read Dr. Paul J. Mackarey “Health & Exercise Forum!” Part II of II ACL Prevention. This article is not intended as a substitute for medical treatment. If you have questions related to your medical condition, please contact your family physician. For further inquires related to this topic email:

Paul J. Mackarey PT, DHSc, OCS is a Doctor in Health Sciences specializing in orthopaedic and sports physical therapy. Dr. Mackarey is in private practice and is an associate professor of clinical medicine at The Commonwealth Medical College.