ACL INJURY PREVENTION PROGRAMMES.
STOP THEM BEFORE THEY START!
Mark McCabe MISCP, MSc (SportsMed), CSCS
ACL ruptures and partial tears (sprains) are now far more commonly reported in the media and improved investigation and treatment options have improved athlete recovery and return to sport. The ACL (Anterior Cruciate Ligament) is the master ligament associated with the knee joint and while helping to stabilise the knee it also has a crucial role acting as a type of onboard computer feeding back information regarding speed, acceleration and position sense to local muscles, joints and tissues through its extensive sensory receptors.
Each year, estimated 80,000-250,000 ACL injuries occur in young athletes typically forcing an enforced absence from sport of a season or more. Recommended rehab post ACL reconstruction is generally accepted as 9 months hard labour in the gym and rehab physiotherapy area with huge work focussed on balance, strengthening exercises and re-education of normal movement patterns progressing to the demands required in the athlete’s sport. Female athletes suffer ACL injuries with 4-6 times greater incidence than males and studies have assessed the possible risk factors associated with this increased risk.
The vast majority of ACL injuries occur in non-contact situations (80%) such as sudden changes in direction or landing from jumping with improper landing mechanics. Through improving these mechanisms of landing and direction changes prevention is likely. The estimated cost per ACL injury averaged $17,000 in 1999 (Average) so surely if there is a way to prevent these everyone’s a winner.
Mechanism of Injury
The ACL is essential in control of pivoting / cutting movements. As discussed earlier the sensory receptor rich ACL (Proprioception: Big word meaning the ACL software talks to the hard drive in your brain.) is actively working to tell muscles and nearby joints when to work and rest resulting in improved co-ordination and synchronisation of movement. In a nutshell the brain is the BOSSMAN but he delegates duties off to the ACL.
Pivoting / Rotational mechanism of injury is the most common way to tear or rupture an ACL, here the knee typically twists internally uncontrolled till tension on ligament exceeds its strength and it tears (ouch!!). Improper Neuro-muscular patterns on landing and cutting have been implicated here where the athlete fails to recruit/maintain proper movement mechanics through trunk-hip-knee-ankle-foot at time of injury.
Studies have identified some of the following risk factors to injury:
- Environmental (Weather / surface / Footwear / Bracing).
- Anatomical (eg. You’ve got wide hips or curvy shins; blame your MA and DA!)
- Neuro-muscular: Here if you squat like a duck or fall over when standing on one leg you’re in trouble.
- Family History of similar injury: Again blame the parents.
- Female: Typical wider pelvis and other factors make the hips ability to maintain good alignment more difficult and increase risk injury.
ACL Injury prevention programs:
Do they work? Can training reduce the incidence of ACL injury?
Most studies show reduced incidence ACL injuries post implementation prevention program by comparison Control group. Meta-analysis shows general reduction in ACL occurrence in intervention vs. control groups. Limitations of studies to date include level of coaching time given to athlete’s to ensure proper learning and methods of ensuring athlete compliance with programme to ensure ongoing benefit of intervention.
What’s the difference between Strength and Conditioning and ACL Prevention program? In my own opinion there really should be no difference in so far as in my role as a Physiotherapist and CSCS I aim to train efficient neuromuscular patterns and movements always so that another additional prevention section in the training programme is superfluous.
I view “The Big 3” as key to ACL injury prevention and these should be trained from a mobility starting point to progress to explosive power and Game Speed.
The Big Three:
- 1. Squat
- 2. Deadlift
- 3. Lunge
Progressions are necessary the faster and more powerful the athlete is as they will have a bigger engine and therefore they need to control their movements better to prevent injury. They are going to have a big engine and we need to give them better brakes!
Neuro-Muscular: High demand balance exercises, standing on one leg with your eyes closed is only good enough for my Granny and she’s dead.
Single leg control with advances to include higher forces /speeds and planes of motion.
Strength and mobility of Hip rotation is essential for healthy knees.
So the take home message is teams /clubs and squads can reduce their injury risk by implementing appropriate strength and conditioning programmes. Ideal candidates to carry out these programmes should hold Sports Science / Physiotherapy qualifications with and extensive concurrent background in Strength and Conditioning (CSCS)