ACL reconstruction rehab, Sydney
Run earlier and more safely after ACL surgery. Our anti-gravity treadmill protocol allows running to begin from Week 8–10 — weeks earlier than traditional timelines allow.
Post-surgical return to run · Week 8–20 · Knee loading
Why the anti-gravity treadmill
Traditional protocols delay running until 12–16 weeks post-op, because the compressive and shear forces of ground running are high while the graft is still maturing.
The anti-gravity treadmill changes this. By reducing body weight by 40–70%, the ground reaction forces through the knee are dramatically reduced — allowing the movement pattern of running to be introduced weeks earlier, without the loading that creates risk.
Before starting the protocol
Not every post-ACL patient is ready to begin anti-gravity running at Week 8. These criteria must be met before the protocol starts.
- Full knee range of motion
Full or near-full ROM in both flexion and extension. A persistent extension deficit is a red flag that should be resolved before loading through running begins.
- Minimal or no effusion
Significant swelling indicates the knee is not tolerating current loads. Effusion must be settling before adding the demands of running — even supported running.
- Good single-leg control
Adequate neuromuscular control on the operated leg — single-leg squat, step-down and balance performance are all assessed before running is introduced.
- Acceptable quad strength progression
Quad strength must be progressing before running loads are added. A significant quad deficit with early running creates asymmetrical loading patterns that increase re-injury risk.
The protocol
Four phases from first supported jog to full ground running. Progression is criteria-based — not purely time-based.
Supported jog introduction
- 50–70% body-weight support
- Short jog intervals with walking breaks
- Focus on relaxed, symmetrical movement
- Monitor swelling response post-session
Running capacity build
- 30–50% body-weight support
- Progress toward continuous jogging
- Increase duration before increasing speed
- Monitor cadence and avoid overstriding
Pre-ground running
- 10–30% body-weight support
- Continuous running with controlled pacing
- Prepare neurologically for ground running
- Avoid rapid speed or incline changes
Transition to ground running
- Alternate supported treadmill and outdoor sessions
- Progress based on swelling and symptom response
- Full ground running when criteria met
- Continues alongside broader ACL rehab
Progression & red flags
These criteria guide progression through the protocol and identify when to regress.
When to progress
- Running duration increased before reducing support percentage
- No increase in effusion the next day
- Symmetrical running pattern maintained
- Cadence stable and controlled
When to regress
- Effusion increases post-session
- Loss of extension develops or worsens
- Asymmetrical running pattern appears
- Increased knee pain post-session
Part of your broader ACL program
- Anti-gravity running runs alongside strength rehab — not instead of it
- Quad strength testing continues throughout
- The full ACL rehab program is available at Sydney ACL Physio
ACL Reconstruction & anti-gravity running
When can I start using the anti-gravity treadmill after ACL surgery?
Does it replace my ACL rehab program?
Will it put stress on my graft?
Do I need a referral?
Ready to start running again?
Book a free call. We'll tell you whether you're ready to start anti-gravity running and what the protocol looks like for your acl reconstruction stage.
No referral needed · Five Dock, Inner West Sydney · Health fund rebates available
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