Supination, anyone?

Pronation gets all the press; but what about its counterpart, supination? There could not be one without the other. If anything, supination is at least as, if not more important to create propulsion.

Pronation is dorsiflexion, eversion and abduction of the foot. It provides shock absorption. Supination is plantar flexion, inversion and adduction. It helps the foot become a rigid lever so we can GO (Like in Theo Selig’s “Go Dig Go” ).

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Locking of the lateral column of the foot (4th and 5th metatarsal, cuboid and calcaneus) is a necessary prerequisite for normal force transmission through the foot and ultimately placing weight on the head of the 1st metatarsal for proper (high gear) toe off . Locking of the lateral column minimizes muscular strain as the musculature (soleus, peroneus longus and brevis, EHL, EDL, FDL and FHL) is usually not strong enough to perform the job on its own.

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This process is initiated by the opposite leg going into swing phase, which initiates dorsiflexion, inversion and abduction of the talus

The peroneus longus tendon aids this process by wrapping around the cuboid (the brevis attaches to the base of the 1st metatarsal) on its way to insert onto the base of the 1st metatarsal. When the peoneus longus contracts, it dorsiflexes and everts the cuboid, which, along with the soleus (which plantar flexes and inverts the subtalar joint) allows dorsiflexion of 4th and 5th metatarsals and “locks” the lateral column. Without this mechanism, there is no locking. Without locking, there is no supination. Without supination, there is little rigidity and inefficient propulsion.

The calcaneo cuboid locking mechanism. Another cool thing you learned about gait today from The Gait Guys.

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So you want to do a Gait Analysis: Part 4

This is the 4th in a multi part series. If you missed part 1, click here. For part 2, click here, part 3, click here

These are the basics, folks. We hope this is a review for many.

A quick review of the walking gait cycle components:

There are two phases of gait: stance and swing

Stance consists of:

  • Initial contact
  • Loading response
  • Midstance
  • Terminal stance
  • Pre-swing

Swing consists of:

  • initial (early) swing
  • mid swing
  • terminal (late) swing

today, lets explore Terminal stance

Terminal stance is one of the last stages of stance phase. Following midstance, where maximal pronation should be occurring, the stance phase foot should now begin supinating, initiated by the the opposite foot in swing phase moving forward of the center of gravity. 

Lets look at what is happening here at the major anatomical areas:

Foot

  • Supination begins from the opposite, swing phase leg (see above)
  •  the calcaneus inverts to neutral
  •  the center of gravity of the foot raises from its lowest point at midstance
  • The lower leg should begin externally rotating (as it follows the talus)
  • The thigh should follow the lower leg and should also be externally rotating; sometimes to a greater extent due to the shape and size of the medial condyle of the femur (which is larger than the lateral)
  • these actions are perpetuated by the gluteus maximus and posterior fibers of the gluteus medius, as well as posterior compartment of the lower leg including the flexor digitorum longus, flexor hallucis longus, peroneus longus and tibialis posterior
Ankle
  • The ankle should be 5 degrees dorsiflexed and in ankle rocker
  • the calcaneocuboid locking mechanism should be engaging to assist the peroneus longus in getting the head of the 1st metatarsal to the ground

Knee

  • near or at full extension. This is perpetuated by the quadriceps and biceps femoris, contracting concentrically and attenuated by the semi membranosis and tendonosis. The popliteus contracts eccentrically as soon as the knee passes midstance to keep the rates of external rotation of the tibia and femur in congruence.

Hip

  • The hip should be extending to 10 degrees.

Can you picture what is happening? Try and visualize these motions in your mind. Can you understand why you need to know what is going on at each phase to be able to identify problems? If you don’t know what normal looks like, you will have a tougher time figuring out what is abnormal.

Ivo and Shawn. Gait and foot geeks extraordinaire. Helping you to build a better foundation to put all this stuff you are learning on.

pictured used with permission from Foot Orthoses and Other Conservative Forms of Foot Care