Electrical Stimulation & Quad Strength Testing after ACL Reconstruction
Quad Recovery at Risk: Can You Afford to Skip NMES and Strength Testing?
If You Are Not Measuring This, Does It Say You Don't Care About Your Patient's Functional Outcomes?
How does an old-time business principle relate to ACL reconstruction rehabilitation? Well, the old-time business principle is what gets measured gets managed. And this was a concept that we talked about with Dr. Lynn Snyder-Mackler where she said if you're not measuring it you're saying you don't care about it. This was applied to quad strength measurement, hamstring strength measurement post-ACL reconstruction. And we know that quad strength is related to all kinds of short and long-term outcomes and if you're not measuring it that means that you probably don't care about it and guess what the outcomes long and short term are going to be worse. So we talk about the ways that you can measure objectively after ACL reconstruction and I'll give you a hint: it is not closed kinetic chain leg press. There's a lot of other ways.
The Truth About Isokinetic Testing After ACL Reconstruction
Do you have to do isokinetic testing after ACL reconstruction? We tackled this question and the answer is no you don't have to do isokinetic testing but don't mishear me on this: you have to do open kinetic chain strength testing.
That can be through an isokinetic dynamometer which is the gold standard, but you can also do it through fixed dynamometry where you're the person isometrically kick out against the resistance (to be clear -- not handheld) but doing it against a fixed resistance with a strap.
Or you can do it with a leg extension machine where you're doing your one repetition max, you can use a five RM surrogate with that. But the key thing is you have to be doing open kinetic chain testing otherwise you really don't know the functional status of your patient after ACL reconstruction.
Quadriceps Strength: The Undisputed King of ACL Recovery
Look, if you want to know the number one predictor of success after ACL reconstruction, it's quadriceps strength – hands down!. This isn't just about short-term recovery; it's about long-term outcomes, including reducing the risk of re-injury and osteoarthritis. As a matter of fact, longevity research even says, "If you want to live a long life, be sure you have strong quads!" That’s a strong statement from Dr. Snyder-Mackler, but it’s the truth!
Functional appearance can be deceiving. Patients might look like they're doing well, but if we put them in the lab, we often see all kinds of adaptations and compensations. Why? Because they're shifting control away from the knee to the ankle and hip to achieve movement. This is why isolated quadriceps testing, ideally with tools like isokinetic dynamometry, is absolutely essential.
It breaks my heart when I hear from patients that have been discharged at six months, not feeling ready, and then I ask if they were strength tested or if they were doing isolated knee extensions, and the answer is "no and no!" We cannot underestimate the importance of getting that quad strength back. We even know that patients who recovered quad strength early never developed certain negative brain mapping changes that can happen after intra-articular knee injury!
Are You Doing E-Stim Wrong with Your Early Post-Operative ACL Reconstruction Patients?
Have I been doing electrical simulation with my early post-operative ACL reconstruction patients wrong? And the answer is yeah probably. We have to make the distinction between functional electrical stimulation and neuromuscular electrical stimulation. Functional electrical stimulation is what I've been doing—a Russian type E stem (high intensity with a quad set, SLR, or short arc quad). But neuromuscular E stem is getting the intensity to a maximal voluntary isometric contraction level without the contraction – it's a very intense E stem. To get all the details of the physiology and the research behind this and how it can be very effective for your post-op ACL reconstruction patients check out the episode!
Maximizing NMES Application: Beyond the Basics
When it comes to neuromuscular electrical stimulation (NMES), there are some key things we need to get right.
First, use large electrodes (think 4x6 inches roughly). Why? It helps with tolerance and ensures you’re stimulating all four quadriceps motor points effectively. Small electrodes mean too much current density and superficial intolerance, and it just doesn't get the job done right.
Second, we need to change the conversation with our patients. Instead of asking "Tell me when you can’t stand this anymore," shift to: "How can I help you tolerate what will be an uncomfortable level of contraction?". This empowers the patient and gets them invested in reaching that therapeutic dose – at least 50% of their maximal voluntary isometric contraction (MVIC) electrically. Remember, more is better. Dr. Snyder-Mackler even talks about how different personality types, "blunters" and "monitors," respond differently to these conversations.
As a monitor myself, I want to know everything! So tailor your explanation to their style. We start NMES on day one, pre-op if possible, and continue until they hit at least 80% quad strength compared to the uninvolved side. This isn't just about strength; it's about waking up that muscle and helping the brain remember how to activate it. It's a very powerful tool!
This has been a whirlwind of actionable insights, and I hope you're as pumped as I am to apply this in your clinic! These aren't just theories; these are proven strategies to get your patients with ACL reconstruction patients back to high-level performance and prevent long-term issues. If you want to dive even deeper into systematic strengthening after ACL reconstruction and other diagnoses, be sure to join us in the Coaches Club. Your Path of Mastery begins here.
You can listen to the episode at the links below. If you'd like CEUs, make sure to use the MedBridge link.
