ACL Tears Are On The Rise: How To Prevent Them

The Facts About ACL Tears And ACL Injuries:

  • 70% of all ACL injuries are non-contact injuries
  • High school and collegiate female athletes are 3-4 times more likely to suffer an ACL injury, and 6 times more likely to suffer a second ACL injury in the other leg than male athletes.
  • Each ACL tear results in $25,000 to $40,000 in surgery and rehab healthcare dollars.
  • ACL tears, even after surgery and rehab, predisposes the knee to premature osteoarthritis. This further increases the cost of healthcare on the knee in the future.
  • Incident rate of re-injury of a reconstructed ACL is 25%.
  • Prevention of ACL injuries is KEY.

What is the ACL?

The ACL, anterior cruciate ligament, is a ligament within the knee that prevents the anterior translation of the tibia during motion. In other words, it is responsible for the passive deceleration of the thigh bone (femur) while the body is decelerating during motion.

How does the ACL get injured?

Most injuries happen for two reasons:

  • The angle with which the knee and is decelerating is not healthy – the typical presentation of this is when the knee is not aligned in a straight vector with the ankle and the hip, and the knee saves downward and inward.
  • When deceleration of the body includes concurrent knee hyperextesion, i.e. an overly straightened knee. This typically happens when the athlete is landing from a jump without bending her knee.

Why are females more likely to get injured?

  • Anatomical Factors

Females have wider hips that therefore increase the unhealthy angle with which they land. (See reason #1 above) Females also have a narrower intracondylar arch where the ACL passes through. This increases the chances of the ligament fraying in the smaller space.

  • Neuromuscular Factors

The most preventable reason is that these female athletes have not been properly trained and conditioned during training to educate the body and the brain to decelerate their motions appropriately. Some athletes complete this training with their conditioning and strengthening regimens, but especially with rigorous performance schedules and pressure nowadays, coaches and players are opting to skip over these important strength and conditioning practices and only work on field drills.

  • Biomechanical Factors

A combination of the two factors above culminate in the female athlete landing with excessive knee valgus, which puts the ACL in a very winded-up position. Add to this, the unpredictability of sport and cutting maneuvers in slippery conditions and the result is an injured ACL.


So how do we prevent ACL injuries from happening?

The biggest effect that we can make in ACL injury prevention is via proper training, strength and conditioning and also a proper warm-up program.

In a study made by La Bella et al in 2011, they used 1492 soccer and basketball athletes and split them into control and intervention groups. Coaches were trained in a prevention program involving proper neuromuscular warm-ups that they took their intervention group through throughout the season. The results were staggering:

  • The intervention group had 56% reduction in acute noncontact injuries than the control (no warm-up) group.
  • All of the athletes that ended up requiring ACL reconstructive surgery were in the control (no warm-up) group.

What does this warm-up session include?

The warm-up involves a 20 minute pre-practice session each time to dynamically increase range of motion of the trunk, hip and ankle with activation of trunk and hip musculature in weight bearing and semi-weight bearing postures. See a video sample of our dynamic warmup.

Exercises include not only flexibility-based dynamic warmups but also strengthening exercises, balance activities and jump-landing training during tri-planar motion. Muscle groups targeted are: the gluteus maximus, gluteus medius, hamstrings, core and soleus muscles. These are the main muscles that control (keyword control not eliminate!) pronation and knee valgus. Proper progression of these exercises will train the athlete to properly decelerate during running, sprinting and landing activities.

More specifically, quadriceps training is given to lessen fatigue and decrease incidences of landing with knee hyperextended. Studies have also shown that core activation have a feed-forward effect before action and provides a stable base with which the lower extremity can power off of – this is clutch to achieving a strong and effective bounce-back from landing and take-off usually seen in cutting maneuvers.

It usually takes 4-6 weeks to retraining a motor habit, and 6-12 weeks to gain muscular strength and power, so this practice needs to be incorporated in the time and training before an intense game begins. For optimum results, this warm-up and strengthening routine should be incorporated at every single workout, pre and post-season.


Hoover, Donald et al. The influence of core musculature engagement on hip and knee kinematics in women during a single leg squat. The International Journal of Sports Physical Therapy,Vol. 7, o. 1. Feb 2012.

LaBella et al. Effect of Neuromuscular Warm-up on Injuries in Female Soccer & Basketball Athletes in Urban Public Schools Archives of Pediatric & Adolescent Med. 165 (11), Nov 2011.

Patterno M.V. et al. Incidence of contralateral and ipsilateral anterior cruciate ligament (ACL) injury after primary ACL reconstruction and return to sport. Sports Health and Performance Institute, The Ohio University Medical Center.

By Alice Holland, DPT.
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Alice Holland, DPT

Doctor of Physical Therapy, Director at Stride Strong Physical Therapy
Alice earned her Doctorate of Physical Therapy from USC in 2007, and have practiced Physical Therapy for 12+ years in the Outpatient Orthopedic Setting. Certified in ASTYM, she also has been a featured expert on Physical Therapy on numerous publications including health.com, healthline.com and yahoo.com.
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Ana Lucia Pinheiro
Ana Lucia Pinheiro
02:18 20 Oct 17
This place is amazing. I am so happy I found Stride Strong PT. Alice pays attention to all of the details, she watches every single move I make, my posture, and the way I move through every exercise. She is very knowledgeable, she was able to pin-point the problems in my back and she has a plan to help me become stronger where I need. The place is brand new, huge, and has nice exercise machines. I tried a few physical therapists in the area, and Alice is TOP, second to none, and I feel super lucky to have found her. Highly recommended!!
Prashant Gupta
Prashant Gupta
01:00 02 Oct 17
Dr. Alice at Stride Strong is one of the best PTs I have come across. Her attention to detail and assessment of the root cause of injury is very good. She is excellent in evaluating pain patterns and giving a training schedule for a rehab & injury prevention, she is extremely knowledgeable. I would strongly recommend Stride Strong to anyone looking for PT. It is easily the best PT clinics in Hillsboro area.
steven zollin
steven zollin
20:57 14 Sep 17
Highly recommend Stride Strong Physical Therapy , Alice showed me proper form to assist in recovery with my shoulder and is very knowledgeable.
Lindsay Nied
Lindsay Nied
23:33 18 Dec 17
I recently had a massage from Joel at the Hillsboro location. He was able to work on an ongoing issue I have been experiencing with my back after a sports injury, and I left feeling so much better. The whole facility looked incredible, and everyone I met was friendly and welcoming. I would highly recommend Stride Strong for massage and physical therapy.
JoAnn Hatch
JoAnn Hatch
08:20 08 Nov 17
Dr. Sydney is by far the absolute best physical therapist I've worked with ever! Her expertise in designing highly effective and efficient exercise plans is beyond compare. I feel so much better as my strength and function increases. She comes up with the most brilliant and fun ideas to motivate. To my delight she even offered to come to my home in Vancouver and work with me on my own equipment including a Stott Pilates Reformer. Talk about going above and beyond! Couldn't be more grateful I found her!!!
Clare Perry
Clare Perry
21:58 23 Oct 17
A full hour of a dedicated PT professional's time without aides or techs? That's just one of the things that sets this clinic apart from others. Competent, professional, and amiable, Dr. Alice Holland and her team are the best in the area. While I generally see them at the Cedar Mill Clinic on Cornell, situational constraints took me to their new Hillsboro clinic today near Intel Jones Farm. Beautifully furnished, spacious with easy parking and access. May you continue to grow and thrive, Stride Strong!
Joyce Heideman
Joyce Heideman
08:28 11 May 18
After foot surgery I went to Stride Strong for therapy with Alice Holland. She helped me reach my full mobility again by continuously introducing new and challenging exercises. The entire staff is friendly and professional. They are always on time and do not rush. I look forward to doing 1/2 marathons again and riding my recumbent trike. Thank you Stride Strong for your care and high level of expertise.
Suad Daher
Suad Daher
20:48 28 Feb 18
The best physical therapy ever. Both JP and Sydney were a great PT, they helped me understand how I can help treat my injury and how it may have caused. And also they informed about so many techniques that I can use to help my injuries or any other injuries I get in the near future. They are both friendly and nice to talk too, and verbunformative. And there is also Krystal, she is the best front desk receptionist ever, she is nice and friendly and can easily manage your schedule based on the patients comfort if they want to schedule or not. She can help and she replies fast to any patients email. And she is easy to talk to. Thank you Stride Strong Physical Therapy.
Amanda O'Rourke
Amanda O'Rourke
21:38 15 Jun 18
In just a month I've seen great progress! I've been incorporating the exercises taught to me into my daily workout routine. Im very happy with my continued results.
Albert Szal
Albert Szal
23:43 10 Jun 18
Mary Szal here: I've had three sessions with Brittany at the Hillsboro location. I can say that she has been the most effective and instructive physical therapist I've ever experienced. Her personality, energy, knowledge and results are top notch.
Osa Phiangdae
Osa Phiangdae
00:05 22 Mar 18
Awesome place for PT. Hillsboro location has plenty of parking and very spacious. I had the pleasure to work mostly with Dr. Alice Holland and JP. I came in with a shoulder injury and thank goodness they understood what I was going through. They are the best of what they do, I would recommend Stride Strong to anyone who needs PT.
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