PCL injury (posterior cruciate ligament injury) can cause posterior knee pain, heaviness, and a sense that the knee does not feel steady, especially when walking downhill, decelerating, or changing direction. Some people notice swelling and reduced confidence rather than dramatic giving way.

The PCL sits deep inside the knee and helps control backward movement of the shinbone (tibia) under the thighbone (femur). Because it is strong, many PCL injuries settle well with structured rehabilitation, provided your plan matches the injury grade and your sport or work demands.

If you want broader context, start with our knee injury guide and the knee ligament injury hub. If your symptoms feel more “twisty” or you get clicking or locking, you may also want to read about meniscal tears.

What is the posterior cruciate ligament (PCL)?

The PCL runs from the femur (medial femoral condyle) to the back of the tibia. It mainly limits posterior tibial translation and contributes to rotational control. As a result, PCL injury can affect kneeling, squatting, running mechanics, and confidence on uneven ground.

How common are PCL injuries?

PCL tears occur less often than ACL injuries. However, they can occur in contact sports and high-force trauma, and they may happen alongside other injuries such as meniscus damage, cartilage irritation, or posterolateral corner injury. That combined pattern often explains why symptoms vary between people.

Common causes of PCL injury

• Dashboard injury (motor vehicle accident): the tibia gets driven backwards.
• Fall onto a bent knee: a direct force to the front of the shin.
• Hyperextension or awkward landing.
• Sport contact: collision or tackle forces, especially when the knee is flexed.

PCL injury symptoms

PCL tears can feel subtle at first. Many people report a deep ache at the back of the knee, swelling, reduced power, and difficulty trusting the knee with downhill walking, stairs, or deceleration. Some people keep training, but performance drops because the knee feels heavy or less responsive.

Quick “People also ask” answer

Can you walk on a PCL injury? Many people can still walk after a PCL injury, especially with a lower-grade sprain. Even so, walking does not confirm the injury is minor. An assessment helps confirm what is injured and guides safe early loading so you protect healing tissues and reduce the risk of ongoing knee issues.

How a physiotherapist diagnoses a PCL tear

A physiotherapist will take a clear history and test posterior stability (for example, posterior drawer and related tests). They also assess swelling, range of motion, strength, balance, and movement patterns. If other structures may be involved, they will screen for associated issues such as posterolateral corner injury or meniscal tears.

Do you need an MRI?

MRI can confirm a PCL tear and check for associated damage (meniscus, cartilage, other ligaments). Your clinician may recommend imaging if the injury was high force, the knee feels unstable, swelling remains high, or you need a clearer plan for sport or work demands.

PCL injury grading

• Grade I: mild sprain or partial injury with minimal laxity.
• Grade II: partial tear with moderate laxity and symptoms.
• Grade III: complete tear with significant laxity, often with other injuries.

Treatment options for PCL injury

Treatment depends on grade, associated injuries, your sport, and your goals. Many isolated PCL injuries do well with progressive rehabilitation. In contrast, multi-ligament injuries often need a more structured pathway and, at times, surgical review.

Early management (first 1–3 weeks)

• Settle swelling and protect the knee from high posterior shear forces.
• Restore comfortable range of motion (often guided and gradual).
• Start strength work that suits early healing (often quads-focused).
• Build confidence with safe walking and daily activity progressions.

Rehabilitation progression (weeks 3–12+)

• Strength: progressive quadriceps, hip, and calf strengthening.
• Control: balance, landing mechanics, and change-of-direction preparation.
• Capacity: graded running and sport-specific work when criteria are met.
• Prevention: neuromuscular training and load planning to reduce recurrence risk.

Bracing for PCL tears

Some people benefit from bracing, particularly in higher-grade tears or early return-to-activity phases. A clinician may recommend a brace that helps reduce posterior sag and supports confidence while strength and control improve.

When surgery may be considered

Surgery is not routine for every PCL injury. A knee surgeon may consider reconstruction when there is a complete tear with ongoing functional instability, significant posterior laxity, combined ligament injury, or sport/work demands that require higher stability. Decisions work best when you combine clinical findings, imaging, and your goals.

Post-surgical rehabilitation

Outcomes after PCL surgery depend heavily on progressive rehabilitation and appropriate protection early on. For general guidance, see our post-operative physiotherapy FAQ. Rehab commonly focuses on restoring movement, rebuilding strength, and meeting clear return-to-sport criteria.

Sports with higher PCL injury risk

Sports with contact, falls, landing, and twisting carry more risk. These include AFL, rugby union, and basketball.

Return to sport timelines

Return to sport varies. Some people return sooner after a low-grade isolated injury, while others need longer if symptoms persist or other structures are involved. A safer approach uses objective criteria such as swelling control, strength symmetry, hop or control testing, and sport-specific tolerance.

FAQs

Can you walk on a PCL injury?

Many people can walk after a PCL injury, especially with a mild sprain. However, walking does not rule out a significant tear. Assessment helps confirm the grade and guide safe early loading.

How do you know if you tore your PCL or ACL?

PCL injuries often cause posterior knee ache, heaviness, and downhill difficulty. ACL injuries more often cause giving way with pivoting. A clinician uses specific tests and may recommend MRI to confirm.

Do PCL tears heal without surgery?

Many isolated PCL injuries improve with progressive rehabilitation, especially low to moderate grades. Surgery may be considered for complete tears with ongoing functional instability or combined ligament injury.

How long does PCL rehab take?

Timeframes vary. Mild injuries may improve over weeks, while higher-grade or combined injuries often take months. A physiotherapist can set milestones based on swelling, strength, control, and sport demands.

What exercises should you avoid early after a PCL injury?

Early on, you may need to limit activities that drive the tibia backwards under load. Your clinician will guide exercise selection and timing based on your grade and symptoms.

Guideline

If you want a plain-language overview of ligament injury aftercare principles, MedlinePlus explains key recovery steps and warning signs: Posterior cruciate ligament (PCL) injury – aftercare.

What to do next

• If swelling, pain, or instability lasts more than a few days, book an assessment to confirm what is injured.
• If you play sport, ask for a graded plan with clear return-to-training criteria.
• If you suspect multiple ligament injury, consider early review to guide imaging and next steps.

References

1. Gao S, et al. Management of posterior cruciate ligament injuries: an expert consensus from 17 countries. Int J Surg. 2025. https://pubmed.ncbi.nlm.nih.gov/40277372/
2. Sayum Filho J, et al. Interventions for treating posterior cruciate ligament injuries of the knee in adults: a systematic review and meta-analysis protocol. PLoS One. 2025. https://pubmed.ncbi.nlm.nih.gov/40997138/