In the last several years redress of ankle mobility restriction has been done with strictly talocrural mobilizations in ankle rocks with the knee flexing and advancing toward the pinky toe with the subtalar joint in neutral or slight inversion to, in effect, lock out the midtarsal joint. While the mobilization certainly has its perks and definitely improves dorsiflexion range of motion with the knee flexing as I have tested it, I’ve more and more begun to realize that it may be an incomplete picture for a number of reasons.
As anyone who uses the SFMA is surely aware, an apparent mobility issue in full weight bearing is not necessarily a mobility dysfunction as there could be extenuating stability deficits that block full excursion. A simple lack of a posterior shift of the center of mass, for example, may result in a dysfunctional toe touch. Additionally, the biomechanics professional would recognize that in true functional movement the talocrural joint is required to explore full ranges of motion with different relative positions of the subtalar joint and arrangement of the center of mass relative to the feet. These changes are especially apparent and easily illustrated with a simple model of gait.
In gait at ground contact; the center of mass advances rapidly from posterior relative to the foot just slightly to anterior of the foot at toe off. The subtalar joint strikes in an inverted or neutral position, everts through midstance or so, then reverses to inversion at toe off. The knee flexes through midstance and begins to extend toward toe off with requisite rotations relative to the hip and ankle. The talocrural joint first sees action in any gait cycle with slight plantar flexion prior to contact then experiences increasing dorsiflexion with a flexed knee prior to holding it on a gradually straightening knee through stance phase terminating with powerful plantar flexion.
If it stands to reason that movement specifics are different on a flexed and straight knee with a flexed and extended hip and that the center of mass’ position may influence relative mobility, we may not be getting it done with the usual knee drive. Hip extension plus knee extension plus dorsiflexion differs substantially from the traditional hip flexion plus knee flexion plus dorsiflexion configuration. Additionally, subtalar and midtarsal play and positions differ substantially from position to position in function. The ankle mobility is function dependent.
Where I see this playing a larger role is in running athletes who see early heel lift due to inadequate dorsiflexion with the knee and hip in extension. If the mobility is lacking in this point, you get a very “bouncy” gait at the expense of running economy. You also (or maybe because you) get some compensation that will ultimately erode proximal elasticity requiring more active and less reactive work of the hip flexors and abdominals. This mechanism may also be a proximal dysfunction that alters available dorsiflexion.
The solution, I believe, is very simple. As ankle mobility is function dependent (and position dependent) I am beginning to incorporate more mobilizations where the hip and knee get to extend on a dorsiflexed ankle and vice versa to see if we can make a difference. Backwards walking, skipping, various lunging reaches, wall exercises, and step up and down exercises have become a mainstay in dynamic warm ups provided we determine a need for the specific intervention. Inspired by some work of Gary Gray, I, too, have been toying with joint specific biases using wedges and manual overspeed actions to increase the effect.
What do you think? Plausible? Fact or Fiction?