Here’s What You Need To Know…
1. It is estimated that over 200,000 ACL injuries occur in the United States every year. Despite approximately 90% of people opting for ACL reconstruction surgery, significant risk for re-injury after repair remains.
2. Despite the current trends in the physical therapy and rehabilitation communities, squatting BELOW 90⁰ while monitoring closed chain knee flexion provides the most advantageous environment for reimplementing gross motor patterns.
3. The low-bar squat represents a safe and effective exercise to incorporate into ACL rehabilitation, even in the early stages of healing of a post-operative ACL reconstruction.
4. Traditional exercises like the supported physio-ball wall squat just don’t provide enough training stimulus in the rehab process to protect against re-injury. Providing a controlled environment for reimplementing load in addition to proprioceptive challenges is the future of ACL rehabilitation.
5. Simply put, the biomechanics of the low-bar squat encourage maximal strength development with little risk to the ACL. This evidence is more than enough to change the way we rehab ACL reconstruction as a community of rehab specialists. Compound loaded movements will always prevail!
Staggering ACL Injury Rates
It is estimated that over 200,000 ACL injuries occur in the United States every year. Despite approximately 90% of people opting for ACL reconstruction surgery, significant risk for re-injury after repair remains. In fact, research has shown that subjects who undergo ACL reconstruction are still 15 times more likely to sustain an ACL injury in the following year and six times more likely in two years than those with no history of ACL injury (1-2).
Current criteria to return-to-sport after an ACL reconstruction usually involve a battery of testing including, but not limited to, isokinetic strength testing, jump evaluation, and knee arthrometer testing. Typically, strength criteria includes achieving less than 10% deficit in strength of the quadriceps and hamstrings on isokinetic testing at 180⁰/s and 300⁰/s (3). While this may be a great method to compare isolated muscle strength to the non-affected leg, I question its transfer to safety and performance on the field where isolated muscle contractions rarely occur.
The physical therapy community as a whole has done a tremendous job at implementing plyometric training into ACL reconstruction rehabilitation. Clinicians now routinely teach proper jumping mechanics and have made great progress in reducing the risk of ACL injury, but with re-injury rates as high as they are, are we, as a profession, still missing a major piece of the puzzle?
Barbells In The Clinic
Barbell training represents one of the most effective methods to increase strength and muscle mass, two key components to athletic performance. While barbells are often utilized in the gym and athletic training settings, their use in sports physical therapy is not standard. Exercises such as the squat and deadlift often are erroneously labeled by some as dangerous, stating “Squats will hurt your knees,” or “Deadlifts will hurt your back”.
Current dogma also suggests that squats should not be performed at knee flexion angles greater than 90⁰. The combination of fear of injuring patients and lack of knowledge on the biomechanics of a proper full ROM barbell squat often leaves this vital exercise in the dust, when, in reality, it may be EXACTLY what we need.
First, Some Anatomy and Kinesiology