Start With the Injury You Actually Have

Not every PCL injury follows the same path. The most important distinction is whether the injury is isolated (only the PCL) or combined (other ligaments or structures are also damaged), and whether it is a low-grade or high-grade tear.

Most isolated low-grade PCL injuries begin without surgery. Rehabilitation focuses on protecting the ligament while it heals, then progressively rebuilding strength and control. Surgery is more often considered for high-grade tears, displaced bone avulsions, combined ligament injuries or persistent instability.

This guide describes general education for isolated PCL injuries. A combined injury or a knee that has been reconstructed needs condition-specific guidance from your surgeon and physiotherapist.

Before You Begin

An assessment matters before any exercise. A clinician can tell whether the injury is isolated, check the other ligaments and the posterolateral corner, and identify when imaging is needed.

Get prompt care after a high-energy impact, if the knee looks deformed or feels grossly unstable, if you have numbness or foot weakness, or if the foot is cool or pale.

One useful concept for PCL rehabilitation is posterior sag: after a PCL injury, the shin can drift backward relative to the thigh, especially when the knee is bent. Positions and exercises that push the shin further backward can stress the healing ligament, so early rehabilitation is planned around avoiding that.

Why PCL Rehabilitation Is Different From ACL Rehabilitation

The ACL stops the shin from sliding too far forward; the PCL stops it from sliding too far backward. That difference drives the whole exercise plan:

The quadriceps pull the shin forward, which protects the PCL — so quadriceps strengthening is the cornerstone of PCL rehabilitation.
The hamstrings pull the shin backward, which loads the PCL — so early resisted hamstring work is usually delayed.
Deep, heavily loaded knee flexion can create posterior sag, so early loading stays in a range the knee controls comfortably.

This is why a PCL program can look surprisingly different from an ACL program even though both start with settling the knee and restoring control.

Phase 1: Settle the Knee and Protect the Healing Position

Manage swelling and restore comfortable, full knee straightening early
Begin gentle bending with exercises such as heel slides
Activate the quadriceps with shallow wall-sit isometric holds and sit-to-stand from a higher surface
Avoid resisted hamstring work, deep squats and positions that let the shin sag backward
Use a brace only as directed. The type and duration depend on injury grade, whether other structures are involved, and whether the knee was reconstructed.

Phase 2: Restore Walking and Everyday Strength

Progress sit-to-stand, wall sits and low step-ups as the knee tolerates them
Add hip and lower-leg strengthening
Keep loaded knee bending within a range that does not provoke pain, swelling or a sense of sag
Rebuild a confident walking pattern, including stairs and slopes

Phase 3: Rebuild Single-Leg Capacity

Progress to single-leg strength and balance work as control improves
Increase the depth and load of knee-bending exercises gradually
Begin a running progression only after the knee is quiet, motion is restored, walking and single-leg loading are controlled, and quadriceps strength has been assessed. Some protocols introduce running around three months, but that is not a universal starting point.

Phase 4: Return to Running and Impact

Start with short walk–jog intervals on predictable, even surfaces
Progress distance and pace only when the knee settles normally after sessions
Add agility and jumping work after running is comfortable, under guidance

Phase 5: Reintroduce Cutting, Contact and Sport

Build sport-specific movement gradually: deceleration, direction change and, for contact sports, controlled contact
Return timing varies widely between an isolated injury treated without surgery and a reconstructed or multi-ligament knee.
Common return criteria include full comfortable range of motion, no significant swelling or giving way, measured quadriceps recovery, good movement quality, sport-specific capacity and psychological readiness. Higher-demand sport commonly uses strength and functional targets near 90% of the other side, interpreted by the treating team rather than as a stand-alone pass mark.

How Long Does PCL Rehabilitation Take?

An isolated injury managed without surgery may progress to running and sport sooner than a reconstructed or combined injury, but published protocols vary substantially. Use time as context only. Readiness depends on swelling, motion, stability, strength, movement quality, confidence and the demands of the activity.

What Should Exercise Feel Like?

Mild discomfort that settles may be acceptable. Stop and reassess if an exercise causes sharp pain, catching, giving way or a lasting increase in swelling. Posterior sag is a clinical alignment finding rather than a symptom you should try to diagnose during exercise.

Common PCL Rehabilitation Mistakes

Starting resisted hamstring work too early
Loading deep knee-bending positions before the knee can control them
Letting the shin sit in a sagged position during rest or exercise
Skimping on quadriceps strength, which is the most important muscle for this injury
Missing the assessment that rules out combined ligament damage

When Surgery Changes the Plan

After PCL reconstruction, the plan is different: weight-bearing and range are often restricted early, a brace is common, and progression is guided by the surgeon's protocol. Follow the restrictions from your surgeon and physiotherapist. This general guide does not replace those instructions.

Questions to Ask Your Clinician

Is my injury isolated, and what grade is it?
Do I need a brace, and for how long?
When can I load the knee, run, and return to sport?
Which exercises should I avoid early on?
What symptoms should make me stop and check in?

References

Wang D, Graziano J, Williams RJ 3rd, Jones KJ. "Nonoperative Treatment of PCL Injuries: Goals of Rehabilitation and the Natural History of Conservative Care." Current Reviews in Musculoskeletal Medicine. 2018;11:290-297. https://doi.org/10.1007/s12178-018-9487-y
Winkler PW, et al. "Return to Play after Posterior Cruciate Ligament Injuries." Current Reviews in Musculoskeletal Medicine. 2023;16:14-25. https://pmc.ncbi.nlm.nih.gov/articles/PMC9789230/
Senese M, et al. "Rehabilitation Following Isolated Posterior Cruciate Ligament Reconstruction: A Literature Review of Published Protocols." International Journal of Sports Physical Therapy. 2018;13(4):737-751. https://pmc.ncbi.nlm.nih.gov/articles/PMC6088114/
AAOS OrthoInfo. "Posterior Cruciate Ligament Injuries." https://orthoinfo.aaos.org/en/diseases--conditions/posterior-cruciate-ligament-injuries/

This information is for education only and is not a medical diagnosis or personalised rehabilitation program. Follow the restrictions from your surgeon or clinician after a combined injury or operation. Seek prompt care for a high-energy injury, numbness or foot weakness, a cool or pale foot, or a knee that repeatedly gives way.

PCL Rehabilitation Guide