Windlass Test

Original Editor - Brooke Kennedy

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Description

This windlass mechanism is a mechanical model that describes the manner which plantar fascia supports the foot during weight-bearing activities and provides information regarding the biomechanical stresses placed on plantar fascia.

The test can be important in the decision-making process involved in the evaluation and treatment of plantar fasciitis.

Purpose of the test

The test achieves a direct stretch on the plantar aponeurosis which can be effective in examining plantar heel pain.

Clinically relevant anatomy

The plantar aponeurosis acts similarly as windlass mechanism. Windlass is typically a horizontal cylinder that rotates with a crank or belt on a chain or rope to pull a heavy objects. The common use of windlass is seen in pulling the anchor of the ship known as anchor windlass. This mechanism can be seen in foot. When the MTP joints are hyperextended, the plantar aponeurosis becomes taut as it is wrapped around the MTP joints. This actions brings the metatarsal and tarsal bones together converting it into a rigid structure and eventually causing the longitudinal arches to rise. This winding of the plantar fascia shortens the distance between the calcaneus and metatarsals to elevate the medial longitudinal arch.This function is important in providing a rigid lever for gait propulsion during push off.

Also with an increased hallux valgus or in cases of hallux limitus this mechanism didn’t function anymore.

Performong the test

A positive windlass test: heel pain reproduced with passive dorsiflexion of the toes.

The difference between bearing weight and non-weight is that the sensitivity is higher in weightbearing  De Garceau et al. showed 100% specificity for weightbearing and sensitivity of 32 % for non-weight bearing tests. 

Non-weight bearing position:   

Passively raise the toes of the patient while he/she is sitting to see whether this causes pain.

• Patient’s knee is flexed to 90° while in non-bearing position
• Examiner stabilized the ankle (with one hand placed just behind the first metatarsal head)  and extends the MTP joint while allowing the IP to flex (preventing motion limitations due to short hallucis longus)
• Positive test if pain was provocated at the end range of the MTP extension

Weight-bearing position  

With the patient in a weight bearing position, the examiner creates a great toe extension

• The patient stands on a step stool and positions the metatarsal of heads of the foot to be tested just over the edge of the step.
• The subject is instructed to place equal weight on both feet.
• The examiner then passively extends the first metatarsophalangeal joint while allowing the interphalangeal joint to flex.
• Passive extension (ie, dorsiflexion) of the first metatarsophalangeal joint is continued to its end of range or until the patient’s pain is reproduced.