Most people think the work begins after surgery. Rest up, show up to physio, follow the protocol. But here’s what the research confirms — and what we see in practice every day: the stronger, more mobile, and better-controlled your knee is going into the operating room, the faster and more completely you’ll recover coming out of it.
We call it prehabilitation. And at Sather Reid Sport Medicine, it’s a core part of how we approach knee surgery preparation for patients across Edmonton and St. Albert. The window before your surgery date may be the most important one you have — and most patients don’t use it.
A 2023 systematic review and meta-analysis published in JAMA Network Open, covering 48 trials and 3,570 patients, found that prehabilitation significantly improved function, muscle strength, and quality of life prior to orthopaedic surgery compared to usual care. Postoperatively, those same patients showed better function in the short to medium term. That’s not a marginal effect. That’s a meaningful head start.
Clinicians at Aspetar, one of the world’s leading orthopaedic and sports medicine hospitals, describe the goal of prehab this way: to allow the athlete and injured knee time to recover from the initial injury and optimize homeostasis and function of the knee prior to surgery — reducing complications in the immediate post-operative period while minimizing detraining that may influence the duration and outcomes of rehabilitation.
Here’s what that looks like in practice at our clinic.
Why Your Starting Point Matters So Much
Surgery is a significant physiological event. Your body’s response to it — how quickly swelling resolves, how well you recruit muscles, how soon you can bear weight and move freely — depends heavily on the condition you’re in when you go under.
Think of it like a bank account. The more you deposit before surgery, the more you can draw on during recovery.
Skip prehab, and you’re starting that account at zero — or in deficit. Patients who go into surgery with significant quad weakness, restricted ROM, and poor movement control face longer recovery timelines, higher rates of persistent strength asymmetry, and greater difficulty clearing return-to-sport criteria. The arthrogenic muscle inhibition that follows surgery is hard enough to overcome when you start strong. When you start weak, it compounds.
There’s a well-documented phenomenon called arthrogenic muscle inhibition (AMI): after knee surgery, the nervous system reflexively inhibits the quadriceps to protect the joint. This inhibition can persist for months, making it genuinely difficult to contract your quad even when there’s no structural reason you can’t. The stronger your quad is before surgery, the more muscle mass and neuromuscular capacity you have in reserve when AMI kicks in.
The Aspetar clinical team notes that prehab including muscular strength, balance, and perturbation training offers measurable benefit in quadriceps strength and single-leg hop scores three months after ACL reconstruction compared to no prehab. A separate comparison study they cite found that patients who completed progressive strengthening and neuromuscular training before surgery had greater functional outcomes and return-to-play rates two years post-reconstruction.
The same logic applies to every other structure we assess:
- Range of motion (ROM): The Sather Reid clinical team sets specific surgical readiness targets: full knee ROM, no oedema, and a normal gait pattern. These aren’t arbitrary benchmarks — they’re the conditions under which surgery and early recovery go most smoothly. Getting you to those targets before your surgery date is one of our primary goals.
- Hip strength: Weak hip abductors and external rotators effects how load is distributed onto the knee during gait and functional movement. Addressing this before surgery means better movement mechanics from day one of recovery.
- Core stability: A strong, well-coordinated core reduces compensatory loading at the knee. It also supports the postural demands of crutch use and early mobility work after surgery.
- Ankle mobility and calf strength: Limited ankle dorsiflexion alters how the entire lower limb absorbs force. Deficits in the plantar flexors can impact neuromuscular performance and motor control in the post-operative period. Patients with restricted ankle mobility will likely have difficulty squatting and negotiating stairs, the last thing you want post-operatively.
None of these are extras. They’re the foundation your surgical recovery is built on.
Optimal Knee Control: The Often-Overlooked Piece
Strength and range of motion get most of the attention in pre-op conversations. But there’s a third element that’s equally important and far less discussed: neuromuscular control of the knee.
Knee control refers to how well your nervous system coordinates the muscles around the joint to produce stable, efficient movement. It shows up in things like single-leg squat quality, dynamic valgus (inward knee collapse during loading), and the ability to decelerate and change direction without excessive joint stress.
Poor knee control before surgery means poor knee control after surgery. The motor patterns your brain has learned don’t reset on the operating table. If you habitually load your knee in a compromised position, you’ll continue doing so in recovery — and that creates unnecessary strain on healing tissue, grafts, or implants.
Why this matters clinically: A lack of knee confidence and fear of movement are directly related to lower levels of perceived physical function after ACL reconstruction. Addressing neuromuscular control and movement quality before surgery gives us a head start on one of the hardest parts of rehabilitation — and helps patients arrive at surgery with more confidence in their own knee.
These altered movement patterns can persist post-operatively if they aren’t identified and addressed in the pre-op period. That’s why our pre-op assessment specifically evaluates how you load and control the knee under dynamic conditions. We look at landing mechanics, single-leg stability, and movement asymmetries — not just as a screen, but to directly inform the exercise prescription we build for you.
How We Measure It: The Hawkin TruStrength and Force Plates
This is where our approach at Sather Reid differs from a standard pre-op physio visit. We don’t just assess you visually and prescribe a generic exercise program. We measure.
Every athlete is assessed objectively, the results are analyzed and discussed with the athlete and shared with their surgeon, and the length, content, and goals of the rehabilitation programme are then defined according to individual needs. We use two tools that give us the same quality of objective, quantifiable data — removing the guesswork from program design.
Hawkin TruStrength Dynamometer
The Hawkin TruStrength is a fixed dynamometer developed by Professor John Cronin of the Sports Performance Research Institute New Zealand. It measures isometric and dynamic force with lab-grade precision and is used by clinicians and performance coaches worldwide.
In a pre-op context, we use it to measure knee extension and flexion — giving us precise quadriceps and hamstring force output and side-to-side symmetry — as well as soleus strength, which reflects the lower-leg capacity that underpins safe loading throughout recovery.
The symmetry data is especially valuable. A limb symmetry index (LSI) is a simple ratio comparing the strength of your surgical leg to your non-surgical leg, expressed as a percentage. An LSI below 80-85% is a well-established risk factor for poor post-operative outcomes and elevated re-injury risk. In plain terms: if your surgical leg is producing significantly less force than the other side going in, recovery is harder and longer. We want to know exactly where you sit before we start — and track your progress toward a better number before your surgery date.
Force Plates
Our Hawkin Dynamics force plates give us a different layer of information: how you move under load, not just how much force you can produce in isolation.
Force plate assessments capture bilateral asymmetry in real time during dynamic tasks like countermovement jumps and single-leg loading. Key metrics include:
- Jump height and reactive strength index: Indicators of lower-limb power and neuromuscular readiness
- Braking rate of force development: How well you absorb and redirect force — critical for post-op movement safety
- Left/right asymmetry: Live feedback on loading imbalances that increase injury risk
- Propulsive impulse: A measure of how effectively you generate force through the full movement
Together, the TruStrength and force plates give us a complete picture: how strong you are, how symmetrically you load, and how your nervous system coordinates movement. That picture is what drives your individualized pre-op program — not a template.
What a Pre-Op Program Actually Looks Like
Once we have your assessment data, we build a targeted program around the gaps. The timeline matters: research suggests a minimum of 4 to 6 weeks at two or more sessions per week in the gym is needed to produce meaningful pre-operative improvements. If your surgery date is further out, we have more room to work. If it’s closer, we prioritize the highest-impact deficits first.
The Sather Reid team emphasizes that prehab is not a generic “one size fits all” recipe — it’s tailored to the individual’s physical and psychological needs. A typical pre-op program at our clinic addresses:
Knee-Specific Work
Progressive quad and hamstring loading, starting with isometrics (which are both safe and highly effective for building strength around a painful or unstable joint) and advancing to compound movements as tolerated. We’re targeting both absolute strength and the symmetry ratio between limbs. This is also where we directly address arthrogenic muscle inhibition before it becomes a post-operative problem: blood flow restriction training and neuromuscular electrical stimulation are tools we use when loading tolerance is limited and quad activation is inhibited, building quad strength with lower joint stress so that when AMI kicks in after surgery, you have more capacity in reserve.
Hip and Glute Strength
Hip abductor and external rotator strengthening to correct the movement patterns that put excess valgus stress on the knee. Single-leg work, lateral band exercises, and hip hinge patterns are all part of this.
Core Integration
Not isolated planks for time, but integrated core work that trains the trunk to stabilize under dynamic load. Pallof press variations, anti-rotation work, and functional carry patterns translate directly to the movement demands of early post-op recovery.
Ankle Mobility
Targeted mobilization to restore dorsiflexion range, combined with eccentric calf loading to build tissue tolerance. This includes single-leg heel raises in various positions and forefoot dissociation work are standard components of our pre-op protocol. A patient who walks into surgery with full ankle mobility has one less compensation pattern to fight during recovery.
Movement Re-Education
Using real-time force plate feedback, we work on landing mechanics, single-leg squat control, and loading symmetry. Seeing the numbers on a screen changes how patients move — it’s a more powerful cue than verbal instruction alone.
We reassess with the TruStrength and force plates at regular intervals throughout the program. If you’re progressing, we see it in the data. If something isn’t responding, we adjust. Nothing is left to guesswork.
The Bottom Line
Knee surgery is a major investment — in time, in recovery, in getting back to the things you care about. The evidence is clear, from large-scale meta-analyses to the clinical protocols used at world-class sports medicine facilities, that how you prepare for surgery directly influences how well it goes.
At Sather Reid Sport Medicine, we take that preparation seriously. Our pre-operative physiotherapy program is built on objective measurement, individualized programming, and a genuine commitment to getting you into surgery in the best possible condition.
If you’ve been scheduled for knee surgery in the next 6 to 12 weeks, that window is exactly when prehab has the most impact. Research supports a minimum of four to six weeks of structured pre-op work — which means the time to start is now, not after your pre-op appointment with your surgeon.
Book a pre-operative assessment at Sather Reid Sport Medicine and let’s build your plan.