What is an ACL injury?

The ACL is one of the key stabilising ligaments of the knee. It helps control forward movement of the shin bone and rotational stability during cutting, pivoting and landing tasks.

ACL injuries commonly occur with:

• Sudden deceleration or change of direction

• Landing awkwardly from a jump

• Twisting on a planted foot

• Direct contact or collision

Common symptoms include:

• A "pop" or giving‑way sensation at the time of injury

• Rapid swelling of the knee

• Pain and difficulty weight‑bearing

• Ongoing instability, particularly with pivoting or sport‑specific movements

ACL injuries can occur in isolation or alongside meniscal, cartilage or other ligament injuries — which is why thorough assessment matters.

Do I need a scan?

ACL injuries are often suspected through a detailed history and physical examination by an experienced physiotherapist. However, imaging can be helpful in certain situations.

MRI scans

• MRI is the preferred scan to confirm an ACL tear

• It also assesses associated injuries such as meniscal tears, cartilage damage or collateral ligament injury

X‑rays

• X‑rays do not show the ACL itself

• They are mainly used to rule out fracture or bony avulsion, particularly soon after injury

When scans are commonly recommended

• Persistent knee instability or giving way

• Ongoing swelling or restricted movement

• Planning return to pivoting or contact sport

• When scan findings would influence the treatment pathway (surgical vs non‑surgical)

Our team can help coordinate imaging and explain what your results mean for your rehab and sport goals.

Non‑surgical ACL rehabilitation

High‑quality, structured rehabilitation is a valid and effective option for many people, particularly those who:

• Do not regularly participate in high‑level pivoting or contact sports

• Have good neuromuscular control

• Have partial or proximal ACL tears

• Are willing to commit to a progressive rehab program

Non‑surgical rehab still aims for:

• Symmetrical lower‑limb strength

• Excellent dynamic knee control

• Confidence with running, jumping and direction change

• Passing functional and hop‑test benchmarks before unrestricted activity

Emerging approaches

Some newer protocols, such as the Cross Bracing Protocol, explore short‑term bracing in knee flexion combined with intensive rehabilitation to promote ACL healing in selected acute tears. These approaches are still evolving and require careful screening and close supervision.

Surgical pathway and ACL reconstruction rehabilitation

ACL reconstruction is commonly recommended for people who:

• Participate in cutting, pivoting or landing sports

• Experience ongoing instability despite rehab

• Have additional knee injuries that compromise stability

It’s important to understand that surgery alone does not restore function — long‑term outcomes depend heavily on high‑quality rehabilitation.

Phase‑based, criteria‑driven rehabilitation

Rather than progressing purely by time, we use criteria‑based phases, ensuring your knee is ready before advancing.

Early recovery phase

• Control pain and swelling

• Restore full knee extension

• Regain early flexion

• Re‑establish normal gait

Mobility and strength phase

• Full knee range of motion

• Progressive quadriceps, hamstring and hip strength

• Neuromuscular control and balance training

Running and plyometric phase

• Gradual return to running

• Jumping, landing and change‑of‑direction drills

• Sport‑specific loading

Return‑to‑sport phase

• Strength and hop test symmetry typically >90–95% compared to the other leg

• Excellent movement quality under fatigue

• Consideration of psychological readiness and confidence

For most people, safe return to sport occurs around 9–12 months or longer, depending on progress and goals.

How our physiotherapists support your ACL recovery

At Fit2Function Allied Health, we:

• Provide evidence‑based ACL rehabilitation aligned with current research

• Guide both surgical and non‑surgical pathways

• Use objective strength and functional testing

• Tailor rehab to your sport, work and lifestyle demands

• Focus on confidence and long‑term knee health — not just getting you back quickly