ACL rehab

“At 13 months post ACLR (Anterior Cruciate Ligament Reconstruction), individuals exhibited average knee extensor moments that were 17% smaller in the surgical limb during a bilateral squat against body-weight resistance”

ACL injuries tend to be noted in some non-contact sports such as soccer and basketball. Contact sports, such as football, also have ACL tears noted during contact, such as a tackle that makes the knee buckle inwards.

The patient with an ACL tear will typically opt for surgery if he/she plans on returning to some type of sporting activity. There is a debate as to whether or not to have the surgery if there will be no return to sporting activity.

After the ACL surgery, the research above notes that patients are less likely to use the surgical side during a squatting activity (think getting up from the toilet) and will push more with the non-surgical side.

This makes sense to me. After the surgery, the patient is in a locked long leg brace and is unable to move fluidly on the affected leg. The patient will not spend as much time on the surgical leg because of this and will transfer the weight to the non-surgical side. It becomes a learned habit to transfer the weight to the non-surgical side, but this is just my opinion.


“The persistence of under-loading is concerning, as asymmetrical limb loading during landing tasks has been linked to increased risk for anterior cruciate ligament (ACL) reinjury”

This is important! If we never get the patient to load the leg in order to improve strength and motor control (ability move in the way that the brain dictates), then the patient is at a higher risk of future injuries.

Let me clarify: if you squat and allow your legs to go wet noodle during the squat, it will look like a knocked-kneed version of a squat. This is not inherently horrible, but when asking the body to absorb a large load in this positon, when not trained to absorb this load, may lead to an injury. It all comes down to progressively loading specific positions in order to learn how to hold this position.

This is a major component of Olympic weightling compared to powerlifting. In the performance of the snatch (the most explosive movement in sports), maintaining proper position is extremely important for completing the lift. In powerlifting, the position may be able to be off a little and the athlete can overcome the small error in position.

With regards to ACL rehabilitation, it is important that we ensure that the patient is able to have enough strength to maintain positions without the load (bodyweight jumps, external weight, etc) dictating positional changes.


“…the bilateral multijoint nature of a squat allows for compensations that can shift the task demands to the nonsurgical limb (interlimb compensation) or to adjacent joints within the surgical limb (intralimb compensation) to reduce knee extensor moments.”

The bodyweight squat can be performed differently and switches the load from either the hip to the knee.

If you watch someone squat (recommended for all people that will attempt to squat), the person should both watch the knee and the hip. If you look at opening and closing, this will be much easier.

  1. Watch the knee to see how much the knee “closes” or how much the angle changes from the calf to the hamstring
  2. Watch the hip to see how much the hip “closes” or how much the angle changes from the trunk to the thigh

Which joint moves more?

This will help the reader to understand whether the knee joint muscles or hip joint muscles will be the dominant movers during the squat. Those that have knee issues will tend to move the hip joint muscles more than knee joint muscles.

I’ll make a video on this at a later date.


“…individuals 1 month post ACLR performed bilateral sit-to-stand tasks with a 38% reduction in vertical ground reaction forces (vGRFs) in the surgical limb”

This very simply means that the person is pushing less with the surgical leg than the non-surgical leg.

This means that the surgical leg is taking less force through it and will not be able to generate the same amount of power. Also, it is typical to see the patient weight shifting towards the non-surgical leg.

“reduced knee extensor moments have been found along with increased hip extensor moments…may rely on interlimb compensations to unload the knee during early rehabilitation but adopt intralimb compensations as they progress through rehabilitation.”

This goes back to the differences in a powerlifting based squat and an Olympic weightlifting based squat. The more upright the torso, the more that the knee takes a load and the less upright the torso, the more the back and hips will take the load.

I am having this exact conversation with a patient currently following an ACLR, attempting to get the patient to increase the load on the knee.

“During early rehabilitation, strategies for restoring symmetrical weight bearing during bilateral tasks should be emphasized and reinforced even during submaximal tasks…efforts should be made to continue to focus on sagittal plane knee loading and avoid compensation with the hip extensors.”

I tend to use a mirror for visual feedback in order to allow the patient to see the weight shift between the legs. This tends to fix the problems for weight shifting. We then progress to doing the squatting motion away from a mirror in order to build in positional awareness without the need for visual cues.

In order to improve the knee to hip ratio regarding which joint moves more, the cues will switch from sitting back on a chair (similar to a box squat which is hip hinge emphasizd) to emphasizing sitting between the feet (similar to an overhead squat) which is more knee joint driven.

If you don’t have a PT that understands how to squat, this may be a difficult movement to restore with physical therapy alone.

It may be prudent to ask your PT to describe a squat prior to starting therapy in order to ensure that your therapist has at least a baseline knowledge of squatting.

If the therapist doesn’t start describing multiple techniques for squatting based on body shape, then the therapist may not be well versed in the movement.

If you have any questions about squatting or ACLR rehabilitation…comment below.



You can find me at and wherever you subscribe to podcasts at A physio’s perspective: movementthinker.





MORAL: We know a little more than we did 10 years ago, but we didn’t know much then either. We now know that we have been calling trochanteric bursitis by the wrong name. WHOOPEE! We think we know how to treat hip pain (isometrics progressing to loaded movement), but we aren’t completely sure yet. Don’t you love evidence-based medicine? I know I do. I feel smarter after reading this article (shaking my head no at the same time).


  1. “Gluteal tendinopathy is though to be the primary cause of lateral hip pain”


Gluteal, otherwise known as buttock, tendinopathy (a dysfunction of the tendon) is a major cause of lateral hip pain. Of course before we go here, the therapist or physician should rule out the spine as a cause of your symptoms. If he/she does not know how to do this, go to find a MDT therapist.

A long time ago (couple of years ago actually) there was this common diagnosis that we would get as a referral…trochanteric bursitis. It would make patients feel so smart that they remembered this term for their entire lives, because at some point a doctor may have told them that this is what is causing their pain. In 2 out of 10 patients with hip pain (outer border of the thigh), this diagnosis may be correct. If so…you are such a smarty pants. For the other 8 of 10, this article will apply to you (see below).


  1. “While this condition has traditionally been referred to as trochanteric bursitis, gluteus medius and/or minimus tendinopathy is now accepted as the most prevalent pathology in those with pain and tenderness over the greater trochanter…of 75 individuals…only 8 had bursal involvement”


This to me is awesome! Think about it…the medical profession has been around as long as prostitution and yet we still don’t know what we are selling. At least the other profession knows its product.


The research on this diagnosis is relatively new…the past 15 years, but I didn’t hear about this while going to PT school. I’ll tell you what I did learn about though…trochanteric bursitis. It’s a shame that the research is not making it into the school system. If your doctor/therapist/chiropractor/naturopath/neighbor calls it trochanteric bursitis it means one of two things, or both: 1. They don’t read current research 2. They graduated from a school that doesn’t teach current research. I know that it is semantics, a rose is but a rose and all, but a name is important. If we are treating trochanteric bursitis, we are assuming from the name that it is an inflammatory issue of the trochanteric bursa (fluid filled sack that hurts like heck when irritated). If we are treating gluteal tendinopathy, then we are treating a muscle tendon dysfunction. These are treated totally different based on tradition and current research; so the name matters.


  1. “While a number of risk factors for the development of gluteal tendinopathy have been proposed, few have been validated”


In other words, we think we know what places you at risk, but we can’t be sure. Modern science is awesome. Everyone wants information, but also needs to understand that we don’t have crystal balls. This whole evidence based practice thing is fairly new…considering the overall length of time that medicine has been practiced. It will take a long time in order to obtain answers. All we can give you at this point in time is our best guess.


  1. “…the prevalence of lateral hip pain (likely gluteal tendinopathy) in people with low back pain has been reported to be as high as 35%…Importantly, treating the tendon-related pain has been shown to improve the function of those with low back pain, suggesting an interaction if not a causal relationship”


Okay…the authors of this journal article just made some big boy claims. First, to say that the lateral hip pain is likely tendinopathy is biased and absurd. We can not say this until the spine has been ruled out as a cause of lateral hip pain. Lateral hip pain is just that…pain in the outside portion of the hip. Until we rule out the spine as a cause of the pain, we can’t even say that the pain is coming from the hip. To make a claim this bold is arrogant. KNOW THIS: MULTIPLE JOINTS CAN REFER PAIN TO THE LATERAL HIP. If there is a problem in the back, it can show up at the lateral hip, which as the authors say is very common to have both back pain and hip pain simultaneously. If the SI joint is causing you problems, it could also show up at the lateral hip (not as common, but at least we can test for this). Finally, if the hip joint is causing problems, this can also show up as pain at the lateral hip. This is all before even talking about the gluteal tendons! The above statement is arrogant.


The second statement that is a stretch is to say that gluteal tendinopathy is the cause of low back pain. If you truly believe that, then you should buy this bridge I’m selling. It overlooks the bay in San Fran. Treating the hip tendons (also knows as core stabilization) is shown to be helpful in a small category of patients with back pain. To say that the hip caused the back pain is just as absurd as making a broad statement as the back caused the hip pain. Neither can be said until the patient is evaluated by someone unbiased.


  1. “Many orthopedic hip tests can be used for diagnostic purposes for more than 1 condition”


This is like saying there are many tests that can be used to measure water pressure, but none of the tests can tell you where exactly the problem is coming from. The tests only tell us that you hurt when we do these tests. There is a good article by Jeremy Lewis, PhD called something along the lines of “Special tests aren’t that special”. This means that as much as we would like to hinge our decision making process on special tests…they don’t tell us much.


  1. “…signs of local soft tissue pathology at the greater trochanter are common in imaging of those without lateral hip pain; thus, diagnosis should not rely solely on imaging studies”


Holy mouthful Batman! I think that the authors just said that imaging doesn’t tell the whole picture. Healthy people…without pain healthy people…can have the same exact picture as you, only they have no pain! IMAGINE THAT! We know so much more now than 10 years ago, but some of our new knowledge just works to muddy the picture of the pathoanatomical model (saying that we know which tissue is the problem).


  1. “In studies of patients with clinical symptoms of lateral hip pain…atrophic changes in the gluteus minims and medius in 40% of the hips”


If your hip hurts, you may not use it as well (otherwise known as limping), which may cause a further problem with the muscles. This is just speculation, but the authors already speculated that hip pain causes back pain…so I feel justified.


  1. “The authors of a recent article have demonstrated that five 45-second isometric quadriceps contractions held at 70% of a maximum contraction provided almost complete relief of patellar tendon pain, immediately and for at least 45 minutes”


I find this study fascinating because based on MDT principles, maybe it wasn’t the force or the prolonged hold, but simply straightening out a knee that is typically bent. I’ll have to find the study and see if the authors of that study actually tried to classify the patients before giving the treatment.


  1. “Increases in night pain may indicate that the load has been too high and needs to be adjusted. Once each level of tensile load is well tolerated, the load should be slowly increased and the response monitored to maximize structural change in the musculotendinous unit, while avoiding or minimizing pain exacerbation. “


DON’T BE A MEATHEAD! Hi…my name is Vince and I am a meathead. I say this with love. If you do too much, you will create a chemical response in your body called INFLAMMATION (read it with the menacing voice like in the commercial for heinous diseases…like erectile dysfunction). If you do too much, you will hurt. The funny thing is that you won’t know you’ve done too much until you’ve actually done it. It’s like a new graduate not getting a job because they need 3 years of experience. The only way to get there is to get there.




Grimaldi A, Fearon A. Gluteal Tendinopathy: Integrating Pathomechanics and clinical Features in Its Management. J Orthop Sorts Phys Ther. 2015;45(11):910-922.




Many people have had Achilles tendinitis, or tendinosis depending on your doctor’s education level. The modalities for this are outdated and although I don’t go into detail, this paper does state that performing exercise (you doing something) is better than passive modalities (other people doing things to you). We are animals and need to move!


  1. “This isolated eccentric loading paradigm has since gained considerable popularity and is now widely regarded as the treatment of choice, although there is a lack of convincing evidence that it is the most effective exercise regime”

For tendinopathies, eccentric lowering based exercises are given very frequently in the clinic, although this may not be the only way to treat the tendon. As a quick review, tendons connect muscles to tendons and ligaments connect bone to bone. Picture eating a chicken leg… when you get towards the handle portion of the chicken leg, there is that hard ropy part that we all spit out or try to eat around. That is the tendon. Thick, ropy and attaching the delicious chicken meat to the bone. Tendinopathies are injuries to the tendon that haven’t seemed to heal correctly.

Eccentric contraction is the type of contraction performed when the muscle becomes longer. For the meatheads, this is considered the negative portion of the lift. I remember being in PT school and describing the exercise as the positive portion, static portion and negative portion. Meatheads will understand this terminology. My professor said “Vince, we don’t use those terms here. We use concentric, isometric, and eccentric” respectively. I was instantly smarter because of this. (Sense the sarcasm). Every profession has it’s own language and these languages is why healthcare is so expensive. We have come up with smarter ways of saying the same thing that gym rats say everyday.


  1. Paraphrasing: After exercising, there are physical changes that occur: increased blood flow, collagen formation, bigger muscles/tendons. This occurs from varying the intensity of exercise, which can be done as follows: force or weight of the load to be moved, range of motion through which the muscle is contracted, contraction type (see above)speed of contraction, number of repetitions, and rest between sets.

For anyone that has ever read FLEX or Muscle and Fitness, these are all basic tenets of exercise. We can all agree that to make an exercise harder, we can always add weight. This one is easy and all of my PT students say this answer first when asked how to make an exercise harder. That’s great, but PT students are now considered doctors and I can get the same advice from my Dad, who was a laborer. We as medical professionals have to be able to give better advice than our patients can get from their neighbors.

Range of motion is considered how far we are moving our joints while moving weight. If you have ever been to the gym and watched someone squat, you already understand range of motion. One guy almost always does the set and says “did I go deep enough?” If the question has to be asked, the answer is always no. Anyways, it is obvious that the person that just unlocks his knees and stands back up is doing much less overall work that someone that lowers their butt until it is just inches above the floor (aka A$$ to Gra$$). We all know that the first guy didn’t do the same amount of work as the second guy, even if he used heavier weight. For some reason though, no one ever tells him this…I don’t get it.

Speed of contraction is huge. Dr. Squat (Fred Hatfield PhD…if you are a lifter and don’t know this name…stop and google him right now! I won’t be offended if you don’t read the rest of this but come back asking for an explanation of compensatory acceleration) used to talk about the speed in which we transition from the eccentric to concentric phase. In many people, it looks like a smooth wave…NO GOOD! He wants it to look like a checkmark, with the least amount of time needed to transition from one type of contraction to another. Getting back to the point, speed is another way to change the intensity or power output of an exercise. The faster you move a certain weight or body part, the more power output you have compared to a slower movement. For instance, the snatch is one of the most powerful movements in sports, but most people in the US only think derogatorily with this word (shame on you…you know who you are.) MORAL: The faster you move, the more power you produce. The heavier you lift, the stronger your tissues. The smaller the range of motion in a squat…douche.


  1. “It is well known that the tendon cells (fibroblasts) respond to mechanical stimuli in the form of strain, and that depriving them of strain (relative tissue deformation) leads to degeneration and apoptosis (cell death).”

In other words, if you don’t want your cells to die, then you have to do something strainful to the tendon. In other words: Get up off the couch and move! Or your cells will die. What happens to the body when the cells start dying? That’s why I get paid the big bucks, I know the answer. DOH! I’m giving away the answers.


  1. “…the evidence suggests that increased time under load, increased number of load cycles, and increased loading rate result in a positive adaptive response”

Simply put, spending some time under the bar (time under load) with multiple repetitions (load cycles) frequently (loading rate) is good for you (positive adaptation). You don’t need me to say this, but I will anyway. The stronger person is always more functional than the weaker person…all other things being equal. As we age, we lose the ability to be powerful. Think of it…even Arnold doesn’t look like AHNOHLD anymore. Start today. Get bigger, stronger, faster. You may never beat Bolt, but you can always beat the you of yesterday.


  1. “slow loading may therefore produce particularly strong cell stimuli that can be beneficial to the tendon if the strain is sufficient”

Okay, we are much smarter today than our ancestors…or are we. There is a guy by the name of Arthur Jones (again…Google him. This guy may not be able to squat as much as Fred Hatfield, but my Lord this guy is way more interesting…Why are you still reading…GO GOOGLE!). That’s right, he carried a gun almost everywhere he went. Jones proposed last century the benefits of slow training. He knew inherently that it made the tissues stronger. We now know he was right.


  1. “…imply that given a sufficiently high force (and resulting strain on the fibroblast), the contraction mode is inconsequential”

WHO CARES WHAT TYPE OF EXERCISE YOU DO! PUT YOUR HAND ON THE SCREEN..GO FORTH AND EXERCISE AND YOU WILL BE HEALED! (I say this, all the while picturing the grey haired preacher, from the 90’s on tv) We have overcomplicated treatment of tendon injuries. We just need to make the tendon stronger. We can do this through negative or positive lifting, assuming that there is enough weight to actually make a difference. Now let me retract slightly because I typically follow MDT paradigms. In Mechanical Diagnosis and Therapy, a tendinopathy would be classified as a contractile dysfunction. Robin, in the 1980’s thought that we just have to get the tissue stronger (remodeled). In this method, the patient is told to lift the weight just enough to reproduce the symptoms (pain) and then perform this repeatedly multiple times per day. When this no longer produces pain…go heavier. I know! He was such as genius!


  1. “Therefore, collectively, there is no firm evidence to support the notion that eccentric loading is more efficient than concentric or other loading regimes”

Do I need to elaborate?


MORAL: The person that doesn’t move will die (apoptosis). Movement heals all (general overstatement) and the type of movement is not as important as simply moving.