Quadriceps strength receives considerable attention during ACL rehabilitation. But the calf muscles also help athletes manage the demands of running, jumping, landing, and changing direction. How closely are those muscles being assessed and trained throughout recovery?

In this episode of the University Orthopedics PT Podcast with Dan Bien, Devin Christman, PT, DPT, OCS, FAAOMPT, CSCS, explores calf strength after ACL injury. A physical therapist with Active Health Solutions and an adjunct faculty member at George Washington University, Christman discusses his co-authored 2025 International Journal of Sports Physical Therapy clinical commentary on the calf musculature and return-to-sport rehabilitation.

Understanding the calf’s role in movement

The gastrocnemius and soleus are commonly associated with pushing off through the foot. Christman explains that when the foot is on the ground, these muscles also contribute to controlling forces through the lower leg and knee.

Their roles differ because of their anatomy and the movement being performed. The gastrocnemius crosses both the knee and ankle, while the soleus acts across the ankle. The episode examines why understanding those differences can help clinicians look more closely at the calf during ACL recovery.

Considering calf function early in recovery

Christman describes noticing calf atrophy in some patients recovering from ACL reconstruction, prompting him to examine the available research. He discusses studies reporting changes in calf force production and muscle activation that can persist into later recovery.

Those observations inform his approach to early assessment. Rather than waiting until an athlete begins running or jumping, he considers calf activation and function from the beginning, while respecting surgical precautions and any restrictions related to associated meniscus or cartilage procedures.

The conversation includes clinician-directed use of isometric exercise, neuromuscular electrical stimulation, and blood flow restriction training. Christman discusses adapting exercise selection to the patient’s weight-bearing status and ability to generate a controlled contraction.

Progressing toward the demands of sport

As recovery advances, Christman emphasizes progressing the challenge beyond basic repetitions. Building strength matters, as does developing the ability to produce force quickly and control movement through different positions.

He describes how exercise can progress toward lunging, accepting weight, and moving in multiple directions once the athlete has adequate control. The goal is to prepare the lower extremity for the changing demands of sport, with progressions matched to the individual’s readiness.

Looking at how an athlete performs

Assessing calf function can be challenging, particularly when trying to isolate force production from compensations elsewhere in the leg. Christman discusses different testing options and the importance of watching technique, including toe gripping and altered movement strategies.

He also explains why he films hop testing. Distance and side-to-side symmetry provide useful information, but video can help reveal how the athlete achieves the result and identify areas that need further assessment or training.

Christman acknowledges that research on calf function after ACL injury remains limited. The episode raises questions for future study while encouraging clinicians to consider the entire lower extremity throughout rehabilitation.