What is Rearfoot Adduction?

Members do not see these Ads. Sign Up.

I came across the term rearfoot adduction in another thread and although I am sure that it must be self explanatory, unfortunately it isn't for me.

Can anyone define rearfoot adduction for me.

Many thanks.

Bill

 

I hope this helps, but it seems obvious.

When there is internal leg rotation, the talus and calcaneus will also internally rotate. This motion can occur relative to the ground or relative to the forefoot. When this motion is relative to the forefoot, there will be abduction of the forefoot on the rearfoot. (This is the sort of obvious part.) However, it is interesting to think about this in terms of the forces involved. Newton's first law states things will keep moving unless acted upon by an external force. So, once the leg and talus start internally rotating, something has to stop them. Compression at the calcaneal cuboid joint and tension in some structure on the medial side of the foot (spring ligament PT tendon) can create the moment needed to stop the internal rotation.

So, if the PT tendon is weak, internal rotation will not be slowed and there will be increased demand placed on the spring ligament and other medial structures. As we see with PT dysfunction (too many toes sign) there is increased adduction of the rearfoot and increased abduction of the forefoot. The article that you were alluding to was discussing position and not forces. However, with increased internal rotation of the rearfoot there will be a more medial position of the STJ axis relative to the weight bearing surface of the foot. So, there are some mechanical consequences to this change in position.

Eric