It’s no surprise that after ACL-Reco, there are a lot of impairments and changes even at a microscopic level. Our body is amazing in adapting to every situation. (good or bad). Our body is so robust and always finds a way to do what you ask it to do (until they cant). This leads us to the study I’m about to discuss regarding compensation strategies post-ACL reco.
Compensatory strategies that reduce knee extensor demand during a bilateral squat change from 3 to 5 months following anterior cruciate ligament reconstruction
Breakdown of the study.
1) This study found that there was an average of a 38% decrease in knee extensor moment in the surgical limb compared to the unaffected side when performing a bilateral squat post-ACL-reco.
2) At 3 months post-op, individuals relied heavily on shifting weight to the non-operative limb in addition to shifting demand to the hip extensors of the surgical limb as the compensation strategy.
3) At 5 months, compensation was shifted to using the hip extensors more rather than the knee extensor muscles.
Importance of this study:
We can indirectly use this study to help guide our post-ACL rehab. We all know the importance of quad strength and symmetry post-ACL reco and we all try to choose exercises in the early stages of rehab to target the quadriceps.
Reflect back on how you treat post-op ACL patients. What exercises are you choosing? Most practitioners will choose large compound exercises at some stage of rehab. However, think about why you are choosing that exercise. Are you using squats/leg press exercises to target quadriceps? Are you choosing it for general strengthening of all muscles? How specific are you in rehab?
I would challenge those who use squats as a form of specific quadriceps strengthening. How confident are you that your patient is using their quadriceps for the exercise vs their glutes? Even if it looks like they are equal weight bearing, you most likely would not be able to tell without fancy force plates and EMG equipment. Don’t get me wrong, I love using squats for my rehab but I am using it more for “general strengthening” of the lower limb. I use it concurrently with other exercises that would isolate the quadriceps. (Yes, I use open chain knee extensions)
So what can we do with squats?
We can definitely try to fix the compensation by cueing our patients to load up their affected side more when performing a squat early into rehab. (If that is what you can see your patient doing as a compensation strategy) However, what if they look as if they are equal weight bearing and can’t tell whether they are compensating with their hip extensors? I would put them in a situation where they are forced to use their quadriceps more. For example, if you were prescribing bilateral squats as an exercise, have their unaffected limb slightly forward compared to their surgical limb. (Think neuro & stroke patients) We load up their affected limb by placing it slightly behind their unaffected limb to force them to use that limb.
The message I want to spread is to think about why you are choosing certain exercises and what the goals are. If you want to isolate a certain muscle, do everything you can to put them in a situation (+/- external cues) to only use that muscle. If your goal is for general strengthening, choose bigger compound movements. In my opinion, it is fairly important to be specific with ACL rehab. It could be the difference from a good rehab vs an excellent rehab!