The Calcaneo Cuboid Locking Mechanism

Do you know what this is? You should if you walk or run!

It is the mechanism by which the tendon of the peroneus longus travels behind the lateral malleolus of the ankle, travels underfoot, around the cuboid to insert into the lateral aspect of the base of the 1st metatarsal and adjacent 1st cunieform.

When the peroneus longus contracts, in addition to plantar flexing the 1st ray, it everts the cuboid and locks the lateral column of the foot, minimizing muscular strain required to maintain the foot in supination (the locked position for propulsion). Normally, muscle strength alone is insufficient to perform this job and it requires some help from the adjacent articulations.

In addition, the soleus maintains spuination during propulsion by plantar flexing and inverting rear foot via the subtalar joint. This is assisted by the peroneus brevis and tertius which also dorsflex and evert the lateral column, helping keep it locked. Can you see why the peroneii are so important?

Signs of a faulty calcaneo cuboid locking mechanism:

-weak peroneus longus, brevis and or tertius

-excessive rear or midfoot pronation

-low arch during ambulation-poor or low gear “push off”

-subluxated cuboid

The calcaneo cuboid locking mechanism. Essential for appropriate supination and ambulation. Insufficiency, coming to a foot you will soon examine.

Would you like to know more? Join us for our “third Wednesdays“ online webinar: Biomechanics 313. Wednesday, June 18 at 6 MST. Onlinece.com

The Calcaneo Cuboid Locking Mechanism...Revisited...

Do you know what this is? You should if you treat folks who walk or run!

It is the mechanism by which the tendon of the peroneus longus travels behind the lateral malleolus of the ankle, travels underfoot, around the cuboid to insert into the lateral aspect of the base of the 1st metatarsal and adjacent 1st cunieform. Remember the peroneus longus?

The peroneus (or fibularis) longus arises from the head and upper two-thirds of the lateral surface of the fibula, from the deep surface of the fascia, and from the intermuscular septa between it and the muscles on the front and back of the leg; occasionally also by a few fibers from the lateral condyle of the tibia.  You can see from it attachments that it can influence the entire upper lateral leg.

It’s tendon runs down the fibular shaft, wraps around the lateral malleolus, travels obliquely under the foot, crossing the lateral cuboid (which it everts after midstance to help with supination) crosses the sole of the foot obliquely, and inserts into the lateral side of the base of the first metatarsal and lateral aspect of the 1st cunieform.  

It acts from just prior to heel strike to limit excessive rearfoot inversion, through midstance to decelerate subtalar pronation and assists in stabilization of the midfoot articulations, and into terminal stance and pre swing to lock the lateral column of the foot for toe off and plantar flex the 1st ray (creating a good foot tripod), allowing dorsal posterior shift of the 1st metatarsal-phalangeal joint axis (necessary for dorsiflexion of the hallux (big toe)).

When the peroneus longus contracts, in addition to plantar flexing the 1st ray, it everts the cuboid and locks the lateral column of the foot, minimizing muscular strain required to maintain the foot in supination (the locked position for propulsion). Normally, muscle strength alone is insufficient to perform this job and it requires some help from the adjacent articulations.

In addition, the soleus maintains spuination during propulsion by plantar flexing and inverting rear foot via the subtalar joint. This is assisted by the peroneus brevis and tertius which also dorsflex and evert the lateral column, helping keep it locked. Can you see why the peroneii are so important?

signs of a faulty calcaneo cuboid locking mechanism

• weak peroneus longus, brevis and or tertius
• excessive rear or midfoot pronation
• low arch during ambulation
• poor or low gear “push off”
• subluxated cuboid

The calcaneo cuboid locking mechanism. Essential for appropriate supination and ambulation. Insufficiency, coming to a foot you will soon examine.

The Calcaneo Cuboid Locking Mechanism

Do you know what this is? You should if you walk or run!

It is the mechanism by which the tendon of the peroneus longus travels behind the lateral malleolus of the ankle, travels underfoot, around the cuboid to insert into the lateral aspect of the base of the 1st metatarsal and adjacent 1st cunieform (see above)

For more cool info on the peroneus longus, see our blog post here.

When the peroneus longus contracts, in addition to plantar flexing the 1st ray, it everts the cuboid and locks the lateral column of the foot, minimizing muscular strain required to maintain the foot in supination (the locked position for propulsion). Normally, muscle strength alone is insufficient to perform this job and it requires some help from the adjacent articulations.

In addition, the soleus maintains spuination during propulsion by plantar flexing and inverting rear foot via the subtalar joint. This is assisted by the peroneus brevis and tertius which also dorsflex and evert the lateral column, helping keep it locked. Can you see why the peroneii are so important?

signs of a faulty calcaneo cuboid locking mechanism

• weak peroneus longus, brevis and or tertius
• excessive rear or midfoot pronation
• low arch during ambulation
• poor or low gear “push off”
• subluxated cuboid

The calcaneo cuboid locking mechanism. Essential for appropriate supination and ambulation. Insufficiency, coming to a foot you will soon examine.

The Gait Guys. Improving your GQ (Gait Quotient) each and every day with every post we write.

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

Supination, anyone? The importance of the calcaneocuboid locking mechanism.

Pronation gets all the press; but what about its yin counterpart, supination? There could not be one without the other.

Pronation is dorsiflexion, eversion and abduction of the foot. It provides shock absorption. Supination is plantar flexion, inversion and adduction. It make the foot into a rigid lever so we can GO (Like in Theo Selig’s “Go Dig Go”. OK, I have been reading that to my kids alot lately…)

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 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.

The peroneus longus tendon wraps around the cuboid (and the brevis attaches to the base of the 1st metatarsal) on its way to insert onto the base of the 1st metatarsal. When it 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.

all material copyright 2012 The Homunculus Group/The Gait Guys. All rights reserved. If you use our stuff without asking us, we will find you and put valgus wedges in all your shoes.