ACL InjuryKnee Stability & Recovery
Anterior cruciate ligament injury—learn symptoms, causes and how physiotherapy supports recovery with or without surgery.
What is an ACL injury and how does physiotherapy help?
The ACL helps control knee stability during cutting, pivoting and landing. Injury ranges from sprain to full rupture.
Physiotherapy focuses on swelling control, range, quadriceps/hamstring strength, balance and movement retraining. Many individuals return to activity with structured rehab; others pursue reconstruction with pre‑hab and post‑op guidance.
Choosing between non‑operative and surgical pathways depends on your goals, knee stability, sport demands and associated injuries. A structured, criteria‑based plan ensures that strength, control and confidence build in the right order.
Typical recovery timeline
- 0–6 weeks: swelling control, range, activation
- 6–12 weeks: strength, balance, gait/running prep
- 3–9+ months: return‑to‑sport progressions and testing
Sprain grading
- Grade I: microscopic fibre injury, typically stable knee
- Grade II: partial tear with some laxity
- Grade III: complete rupture with functional instability
Understanding ACL injury
Common mechanisms
- Non‑contact pivot with valgus/rotation
- Landing from a jump with knee collapse
- Direct contact causing twisting
Imaging considerations
MRI confirms extent and associated injuries (meniscus, collateral ligaments). Decision‑making includes goals, sports demands and knee stability.
Some people also experience associated bone bruising or meniscal tears, which your physiotherapist will account for when pacing loading and return‑to‑running.
Common contributing factors
Cutting sports
Football, netball, basketball.
Landing mechanics
Knee valgus, limited hip control.
Previous injury
History of ACL or meniscal injury.
De‑conditioning
Reduced strength/control after time off.
What are the symptoms?
Primary symptoms
- Pop at injury, rapid swelling
- Instability or giving‑way with pivoting
- Pain and reduced confidence
- Difficulty trusting the knee during cutting/landing
Functional limitations
- Cutting, pivoting and landing
- Longer walks, stairs or kneeling
- Return to sport readiness
Related symptoms: Knee pain, Swelling, Reduced range of motion, Walking difficulties
How can physiotherapy help?
Rehab builds strength, balance and movement quality for daily life, work and sport. Pre‑hab prepares for surgery; post‑op, rehab follows phase‑based criteria.
Non‑operative care progresses range, strength and control to restore stability and confidence. If surgery is chosen, pre‑hab improves outcomes and post‑op rehab follows tissue‑healing timelines with clear testing milestones.
Core components
- Education, swelling control and pain strategies
- Range, gait and cycling/rower as indicated
- Strength (quad/hamstring/hip), balance and landing mechanics
- Return‑to‑run and sport with objective testing (hop, strength, movement quality)
Effective treatments
Manual therapy
Soft‑tissue and joint techniques as indicated.
Exercise therapy
Strength, balance and landing drills.
Education
Bracing/taping options and pacing.
Lifestyle
Activity and training modifications.
What happens in a physiotherapy session?
Assessment reviews mechanism, swelling, range/strength and stability tests. Plan is goal‑driven and criteria‑based.
- Subjective: sport, goals, surgery preference
- Testing: range, strength, stability, hop prep
- Education: pathway (non‑op vs reconstruction)
- Plan: phased strength, balance, plyometrics
- Milestones: clear criteria for run, jump and return‑to‑sport
Home work supports progress across months with objective milestones.
Can you manage an ACL injury at home?
Yes—in collaboration with your physiotherapist. Early goals: swelling control, safe range and strength activation.
Weekly progression example
- Weeks 0–2: swelling control, quad sets, heel slides
- Weeks 3–6: bike/rower, closed‑chain strength, balance
- Weeks 6+: progressive strength, running and hop prep
- Criteria: pain/swelling controlled, near‑full range, adequate strength/control for each step
When should you seek help?
Urgent assessment
- Unable to fully weight‑bear, severe swelling or locking
- Concern for fracture or multi‑ligament injury
Consult a physiotherapist if
- Instability with daily tasks or sport
- Confidence in movement is limited
- You need guidance on return‑to‑sport criteria
Accessing care in the UK
Access physiotherapy via GP referral on the NHS, or directly through private clinics. Insurance or employer plans may help with costs.
FAQs
Do I need a scan?
MRI is helpful to confirm ACL tear and associated injuries; decisions consider goals and knee stability.
Can I keep training?
Yes—with modifications. Your physiotherapist will guide criteria‑based progressions.
How many sessions will I need?
Often over several months with key milestones; frequency varies by phase and goals.
When can I run again?
Typically after pain and swelling settle, range is near full, gait is normal and baseline strength/control tests are met. Your physio will set criteria and a graded plan.
Medical Disclaimer
This information is for educational purposes only and should not replace professional medical advice. Always consult a qualified healthcare provider for diagnosis and treatment.