How to Manage Persistent Symptoms Post-ACLR

Persistent pain and swelling beyond the initial ~12-month rehabilitation period following Anterior Cruciate Ligament Reconstruction (ACLR) can be confusing and concerning for patients.

With so much of the mainstream conversation focused on the injury itself, treatment decisions and the initial return-to-sport journey, we don’t often hear about those who come out the other side of rehab with persistent symptoms. But these symptoms occur, and they can be managed.

In his Case Study, Dr Lee Herrington shows us exactly how he approached this situation in a professional footballer struggling with persistent knee pain, swelling and load intolerance following ACLR.

This blog shares some key insights from his approach, focusing on two core principles for managing what Lee describes as knee load intolerance: building the capacity to produce force and increasing the knee’s resilience to load.

If you want to see exactly how an expert assesses and manages persistent problems after ACLR, watch Dr Lee Herrington’s full Case Study here.

Building capacity to produce force

One of the key principles Lee uses is to work backwards from performance: first, identify your patient’s performance requirements and then identify their current status through a thorough assessment. The gap between the requirements and their current status is what your intervention should focus on.

The athlete in Lee’s case was a professional footballer in her 30s with a history of ACL reconstruction in both knees. At the time of assessment, both knees were struggling to tolerate the demands of training, with selection for a major tournament only 12 weeks away.

One part of closing the gap was therefore improving her ability to produce force, both maximally and rapidly.

To develop maximal force, Lee included two strength sessions per week, using loads that allowed approximately 12–15 repetitions per set. Rather than simply prescribing three sets of a predetermined number of reps, the goal was for the athlete to work close to failure, ideally achieving around 15 reps initially but only managing around 12 by the final set.

But maximal force is only one part, football doesn’t give you several seconds to gradually reach your maximum force. Athletes need to produce large amounts of force, quickly. That makes rate of force development another important consideration.

Lee therefore incorporated exercises specifically targeting the athlete’s ability to rapidly produce force, rather than relying on traditional strength work alone.

See Lee explain some of the exercises he uses to target rate of force development in this clip from his Case Study:

Building the tissue’s resilience to load

Improving force production still doesn’t necessarily mean the knee is ready to tolerate training and game-play.

If increasing training volume repeatedly results in pain, stiffness or swelling, the knee needs progressive exposure to the amount of loading it will eventually have to tolerate.

A key principle to stick by is: increase volume first, then intensity. Early sessions in this case included high volumes of squatting, progressively building towards 500 squats across an hour-long session. As tolerance improved, the athlete progressed from bilateral to unilateral tasks, and then from vertical to horizontal landing tasks, gradually moving towards sport-relevant volumes and demands.

Running could also be manipulated to help manage knee load while continuing to build exposure. Lee discusses strategies such as increasing cadence, adopting a more forward trunk lean and altering foot strike to modify the demands placed on the knee.

The aim isn’t to continually protect the knee from load. It’s to find a level of loading the knee can currently tolerate and progressively increase what it can handle.

How do you know if the knee is tolerating it?

Lee monitored several simple markers, including morning stiffness (patient feedback on performing a squat), AM and PM pain, post-training symptoms, knee circumference, quadriceps strength and step count.

These measures provided a picture of whether the athlete was adapting to the increased loading or whether the knee was becoming increasingly reactive.

This is particularly relevant when trying to break what Lee describes as the load intolerance cycle, watch him explain in this snippet from his Case Study:

Persistent symptoms can lead to reduced loading. Reduced loading can then decrease physical capacity, leaving the athlete even less prepared when sporting demands increase again. Carefully building and monitoring exposure provides a way out of that cycle.

Wrapping up

For someone experiencing persistent symptoms after ACLR, getting their quadriceps strong may only be part of the solution.

We need to build their capacity to produce force, but we also need to make sure their knee has the resilience to tolerate load, repeatedly, at the volumes their sport demands.

Want to see how Lee puts his assessment and management together in practice? Watch Dr Lee Herrington’s full Case Study here.