Soleus Strengthening for ACL Rehab

I know I bang on A LOT about how important the quads are for ACL rehab (and this won't change anytime soon), but another muscle we need to make sure we don't overlook in ACL injury prevention & rehab is the soleus!

Maniar et al (2020) published data on muscle activity contributing to shear & rotational forces across the knee joint during single leg landing.

The most interesting finding was that they found the soleus generated the greatest amount of posterior shear force during a single leg land from a 30cm height.

This means that the these muscles have a great capacity to resist the anterior shearing forces that can overload the ACL possibly leading it to tear.

The soleus was also identified to reach peak posterior shear force within 20% of the landing cycle, compared to the hamstrings that gradually reached peak force at 50% of the landing cycle.

This is an important finding as ACL injury has been found to occur within 30-50mm/sec of initial contact after landing from a jump or looking to change direction.

These findings do have limitations as this study was performed on healthy males (not ACL injured patients) and direct ACL loading was not measured; but from an ACL injury prevention perspective, it does identify the soleus as an important muscle to bring into the weekly training environment.

Combine this with the data from Dorn et al, that shows soleus produces much more force at sub-maximal speeds than any other lower limb muscle; and you'll see that soleus is a muscle that should not be neglected and under-estimated.