Currently I have six clients who are either recovering from ACL reconstruction or who are awaiting surgery on their knee to fix their ACL. In the past 5 years I’ve probably worked with 25 ACL clients, some with issues to both knees. With all of my ACL clients, they reached a certain point in their physiotherapy where their physio deemed them ready to begin a gym based program and had them contact me to continue where they left off in the clinic. In each case, there is a lot of carry-over between programs, the only real differences coming from things like goal activities afterwards, body size,
relative conditioning prior to injury/surgery, and type of graft being used.

Today I’m going to go through some of the most common components of an ACL
post-rehab program for personal trainers and for the Average Joe looking to get
their leg back in shape.

First things first, this isn’t meant to replace traditional rehabilitation in a clinical setting by a trained professional. The whole concept of Post-Rehab is that qualified trainers are able to work with those clients who have specific injury concerns after they have received clearance to begin working out on their own again, but who have some areas of concern they should be aware of. If you have a knee injury, go to a physio first, then once they give the green light, start on this.

Graft Type

The three main types of grafts the surgeon will use when re-building the ACL are semitendinosus/gracilis graft, patellar tendon with bone attachments, allograft from a cadaver, and a synthetic graft. The most common one I see is the semitendinosus graft. This is probably due to the fact that a 4 bundle composite of the semitendinosus is roughly 250% of the strength of the native ACL, and can handle and is a lot stiffer than a patellar tendon graft. The downside to this graft is that it can take up to 12 weeks to heal into the bone, whereas the patellar tendon is screwed into place and only typically requires about 8 weeks to heal into the bone. To see more detailed info on the comparison between graft choices, click HERE. 

Initial physiotherapy will focus on reducing swelling, restoring range of motion, balance and strengthening of the hamstrings and quads through a 0-90 degree range of motion. Beyond 90 degrees, the strain on the ACL increases which means there’s a chance of ripping the new graft or of stretching it out, both of which would require a new surgery to fix and one unhappy client.

When A Trainer Steps In

Typically most ACL reconstructions will require about 8-12 weeks rehab prior to setting foot into a trainers facility to being their post-rehab training. At this point, the trainer should always contact the physio to see what areas they would like worked on, whether it’s hamstrings, quads, balance work, or if there are any special considerations to avoid
altogether. They may be completely pain-free as the graft hasn’t developed any nerve growth into it yet, and won’t have any sensation for up to 20 weeks after surgery, meaning they may begin training pain free but then develop some aches and pains during the course of their workouts.

One big key to be aware of is that the knee won’t tolerate normal stretching exercises, as the graft will be more susceptible to damage when the knee is fully extended and when it is bent past 90 degrees, at least for the first few months. Stretching should be done primarily through foam roller work to avoid big changes in joint mechanics and potential compression on the graft.

Specific Concerns – Quad Strength

When a client first comes in, they may have a lot of atrophy through the affected quads and hamstrings. As they begin to strengthen and increase their walking ability, there will almost inevitably come a time when their VMO isn’t working as hard as their VLO, meaning they may develop some patellar tracking issues. While maximal activation out of the VMO isn’t achieved until the final 20 degrees of knee extension based on EMG analysis, most conventional squats or lunges place the greatest amount of stress on the knee closer to 90 degrees flexion. Leg extension machines should be avoided at all costs due to the high shear force within the joint, lack of coupling with the hamstrings,
and complete lack of ability to look cool while doing them.

Using some form of horizontal loading for the quads is preferential initially over vertical loading (squats) as it requires less range of motion, less than body weight strength, and can be used by clients with all physical capabilities. I prefer to start with a terminal extension using an elastic, like the video below. It also features some of the progressions I could use to strengthen the quads and entire leg systematically.

Once the individual has enough strength to squat on their own, I like to get them re-learning that pattern, focusing on getting the knee to track vertically over the ankle instead of bowing in towards each other.

Specific Concerns – Hamstrings Strength

This one may be more important overall than quad strength, especially when in the presence of a semitendinosus graft because of the rehab necessary for the harvest site, and also because fibers of the hamstring group bind in to the meniscus and can create stability within the knee joint that quad strengthening cannot. For initial stages, using a prone hamstring curl machine is preferable due to the less than body weight amount of force it can use, but also because of the reduced stress on the knee compared to a deadlift movement. We only have a crap-tacular prone hamstring machine in our gym that works sort of like a Nascar for getting in and out of. You kind of have to pull
a Dukes of Hazard to do it, you know?

Special Concerns – Proprioception

Prior to coming in to a trainer, the client should have been performing some sort of proprioceptive or plyometric work with their physio unless otherwise indicated (overweight, elderly, low bone density, etc), so they should have some ability to jump or stabilize on their own. For all the bosu lovers out there, the only time standing on a bosu has been found to benefit anything relating to fitness over other modalities or surfaces is when rehabbing the knee or lower leg, so you can go to town here!! Start with 1 foot
stepping onto the bosu, then progress to 2 foot squats, then 1 foot squats. For those who prefer not using a bosu, use different foot positions on the ground, progressing to single leg stance exercises.

Plyometrics are useful when someone is looking to return to a sport or activity that requires some degree of force production in a short time, but also for the average Joe looking to get some more strength without increasing the load on the joints. Basic plyometrics could involve hopping, progressing from 2 foot takeoff and 2 foot landing to 1foot takeoff and landing. Here’s a client 16 weeks after surgery with a semitendinosus graft on his left leg that was healing very well.

Some different variations you could use include forward/backward, side to side, and multiple plane patterns. Box jumps can also play a big role here. The primary benefit
of a box jump is the ability to use a massive concentric force with a minimal eccentric force due to the reduced downward velocity of the body at the top of the movement. The goal should be to jump off both feet equally and land on both feet equally, essentially making only one sound on contact. Here’s a series of progressively harder box jump variations you could use.

Special Concerns – Agility

This is one of those factors that gets added in either way too soon or way too late in most ACL rehab programs. Agility could be as simple as walking over an unstable surface, or performing a lunge forward and returning back to standing, or more advanced like on agility ladders or hurdles. The key is to use exercises at a pace that the client feels confident with and with a degree of mental processing they can handle successfully.

Once they are becoming proficient in controlling their basic change of direction, they can begin to utilize more advanced agility and plyometric exercises that can simulate a return to activities. Here’s a few videos of a client who is three years post-op and looking to play competitive tackle football and competitive basketball.

Here the key is to generate acceleration from a dead stop, cut off the bad leg, accelerate through negative momentum, cut again off the bad leg, accelerate and cross the line as quickly as possible. This is when I would love to have laser timed gates, but unfortunately I haven’t had anyone offer them to me yet.

This is a combination of a depth jump with a reaction cut for developing quickness. When he’s in the air, I subtly point one direction or the other, and he has to register that direction and make a cut towards that wall as fast as possible. The eccentric load of the depth jump at this stage is tolerable, so I’m not too concerned with his ability to not rip his knee apart.

While these aren’t pretty, they’re also at the end of his workout when he could barely hold his head vertically. The whole point to this was to get a countercurrent movement that would have him going through fast hip flexion with fast hip extension and in a controlled manner to land on the box.

While ACL rehab can be fairly straight forward, especially if following the advice of the physiotherapist, the trainer always has to exercise caution with the workouts to make sure the client doesn’t get too sore the following day. Swelling can also be a byproduct of the workout, and until the ACL gets more neural efficiency, the pain response may not be there, meaning there could be damage to the graft and the person wouldn’t even be aware.

Probably one of the coolest things that’s happened for an ACL client was the guy in the videos who was jumping all over the place has now played two seasons of full contact football, and his quad is now too big for the brace he was supposed to wear. The referring surgeon said he’s never seen someone with such great musculature on his legs following a reconstruction, which is pretty fantastic if you ask me.