The more i talk to people about ankle rocker and ankle dorsiflexion, the more i realize they just do not have all the anatomical understanding behind it. But how does one apply the concepts if they don't fully understand it ? It is baffling.
The client should be assessed both passively and actively. When you look at someone's ankles during their gait, do you look at the knee response at ankle dorsiflexion or at heel rise or during forefoot loading? Do they momentarily hyperextend the knee? Flex the knee? Rotate the foot or leg internally or externally ? To they prematurely heel rise ? Do they prematurely unload the limb and lurch to the other limb thus shortening step length? Do they progress strongly to the lateral forefoot during loading or do they find a middle ground and begin the pronation phase timely with a proper progression to the medial foot tripod ? Remember, what you see is their strategy, not their problem, do not correct what you see, correct the cause of what you see.
In this video, look at the excessive right knee flexion that occurs here during active ankle dorsiflexion. One must understand what this could mean, and then should be able to see some of the causation during gait. One of the calf complex muscles crosses the knee, one does not. One of them is short on this right side in this client with acute achillies tendonitis. It is not necessarily the cause, but it a piece of the puzzle. Both the clinician and the client do not realize that there is often a knee flexion response during active and passive ankle dorsiflexion assessment, especially when there is mechanical pathology. Having a foam roller under the knee can really bring it out, as in this case. But, remember, this should not be the standard of your assessment, because you are putting slack into the posterior mechanism.