ACL injuries are a well research topic that has no definitive answer. Although there are various opinions why they occur; more and more researchers and coaches are coming to the same conclusion on “How to try and prevent it.”
You can never say an injury will not occur. The best a coach / teacher can do is to try and minimize the chances of it occurring. Research on 42 different ACL prevention programs showed that Sports Metrics, and PEP ‘…had a positive influence on injury reduction and athlete performance tests.” (1)
There are common themes in all the programs which include a proper dynamic warm up which was covered in Warm-up (Warm-up.xls download), neuromuscular training (a topic covered in a later post) and strength training the hips which is the focus of this article.
When the foot contacts the ground the force goes through the foot to the shin past the knee and quads ends in the hips. For a detailed description of each segment go to (Glute Activation: Optimizing the Function of the Posterior Power Center by Fraser Quelch)
We are only going to focus on the action that occurs from the knee to the hips. The muscles of the hips need to be strong enough to decelerate (lengthen or eccentrically contract) in a manner that keeps the femur from internally rotating, causing the knee to collapse inward and stretching the ACL until it tears. (Figure 1) The athlete needs to develop the muscles of the Power Zone to so they can land correctly. To strengthen the Power Zone the athlete needs to focus on targeting specific muscles of the hips / core and use all three parts of the lift.
THREE PARTS OF A LIFT:
In every lifting movement there are three parts; the concentric (shortening of the muscle), the isometric (muscles does not move) and the eccentric (lengthening of the muscle). “…it is a matter of central importance to understanding of all muscle movement and it is essential that its role be recognized in all kinesiological analysis and muscle conditioning” (2). Watch many young lifters and they go through the eccentric and isometric phase so quickly they do not get the full benefit of the lift. Coaches must teach the young lifter to stop at the end of the movement and then control the lowering. Yes, it is harder and will require more time. However, the benefit will be worth it.
When talking about the power zone it is necessary to include the HIPS and CORE because they are linked together. A quick anatomical review shows that both areas are integrated. First we will separate the HIPS into the Glutes, Hamstrings, Quads and Core to discuss the muscles involved then how they move and stabilize. Showing how the areas are integrated to produce correct movement patterns and how they stabilization gives the coach a clear understanding why it is important to focus on the exercises to develop maximum efficiency and injury prevention.
Hips: The hip joint is a triaxial joint because it moves in all three planes of motion. It can flex, extend, abduct, adduct internally rotate and externally rotate. Generally the hip musculature is broken into 4 groups which are made up of 17 different muscles.
The main musculature we are focusing on is the GLUTES; which are made up from the Glutes Maximus / Medius / Minimus, HAMSTRINGS; which are made up from the Biceps Femoris, Semitendinosus, Semimembranosus, Iliotibial Band and QUADRICEPS; which are made up from the Vastus Lateralis, Rectus Femoris, Vastus Medialis, and Vastus Intermedius. (Figure 2)
Some coaches refer to the section around the waist / hips as the trunk while others call it the core. For our purposes we are defining the core as “… the musculature around the hips and abdomin region”. This includes the Erector Spinae, Quadratus Lumborum, Rectus Abdominis, External / Internal Obliques, Transverse Abdominis, Multifidus, Rotatores, Interransversalis and Interspinalis.
The hip joint is a triaxial joint because it moves in all three planes of motion. It can flex, extend, abduct / adduct, internally rotate and externally rotate.
Below is a list of basic hip exercises: Clam shells (with small bands) Wind shield wipers
Glut bridge Donkey kick C with band
Two way glut buster (front / back, ab / adduction with small band) Circles forward (with small band)
4 point opposite push pull with band (41 inch band)
Lay on back band on toe push legs outs pull in (with small band)
Lay on back band on toe legs knee to chest push out (with small band)
Fire hydrant with a kick
1) Anterior Cruciate Ligament Injury Prevention Training in Female Athletes: A Systematic Review of Injury
Sports Health: A Multidisciplinary Approach published online 13 December 2011 Frank R. Noyes and Sue D. Barber Westin
2) Super Training, Sixth Edition Verhoshansky, Siff