Inventor and Designer of Postural Control Insoles

Foot Windlass Mechanics  

  • Drawing up (plantarflexing)  the hallux tightens up the inner longitudinal arch.

Windlass mechanics is an engineering principle used in moving heavy loads.

 In yachting, the windlass is that level system used to pull in the sails.  In a well, it is the pulley system used to lower and raise the bucket.

However, it is also important in foot mechanics.

  • The Foot Windlass Mechanism, first described by Hicks (1954), is the tightening action of the long plantar fascia (aponeurosis) of the foot to maintain arch stability when the heel comes off the ground (late stance phase of gait).  

  • Without the windlass function, the inner arch of the foot would collapse at heel lift preventing the foot from acting as an efficient level during push-off.

The Windlass effect can be demonstrated by drawing the big toe (hallux) upwards (See Animation below).

  1. The plantarflexion of the big toe (the lever) winds up the long plantar fascia (the cable) around the 1st metatarsal head (the drum).  This winding action develops tension in the long plantar fascia.  
  2. This increase tension in the long plantar fascia produces a rigid inner longitudinal arch by 'packing in' the medial column joints (talonavicular, navicular-cuneiform, cuneiform-1st metatarsal and 1st metatarsophalangeal joints).  
  3. This packing of the medial column joints is essential, as it maintains the foot as a rigid lever during the forward thrust of propulsion.

"The windlass foot mechanism functions each time a step is taken. During the phase when the foot is rising of the toes, the toes are being extended by pressure against the floor."

"This new concept which emerges is that the arch-raising is not the result of the action of muscles, but is a movement that must inevitably occur in every foot, even if dead or paralytic, every time the toes are extended."  (Page 29, Section V)

     Hicks JH 1954.  The mechanics of the foot.  II: The plantar aponeurosis and the arch.  Journal Anatomy, 88:25-30.

Foot WINDLASS Mechanics

Hicks 1954