In support of the recent launch of the Podalux
post-op shoe, DJO decided to conduct a comparison study on the biomechanical effect of wearing a post-op shoe on the foot loading and motion.
There were questions that we wanted to answer on the best post-op protection following forefoot surgery, more specifically the effects of current products of the first metatarsophalangeal joint (MTPJ), and also how the currently available products compared to the Podalux.
With this in mind we took our products to the University of Central Lancashire to request testing by Jim Richards, Professor of Biomechanics.
The Podalux was tested using one subject against the standard, rigid soled post-op shoe and also the wedge heel walker shoe. Data was also collected from the subject to show the ‘normal’ biomechanics when barefoot.
When barefoot, the first MTPJ shows 12º dorsiflexion at heel strike, a neutral position during midstance and a rapid dorsiflexion to 30º at toe off.
The standard, rigid soled post-op shoe showed complete restriction of the MTPJ, no off-loading of the forefoot and an adverse effect to the gait cycle due to increased ankle dorsiflexion.
The wedge heel walker shoe showed partial restriction of movement to the first MTPJ. Although giving a good off-load (up to 70%), the shoe was found to significantly disturb the gait pattern, increasing quad activity and adding tension to calf muscles.
The Podalux when tested allowed for a ‘safe’ range of motion to the first MTPJ, (8º of dorsiflexion with the Podalux insert, 10-12º of dorsiflexion without the insert). The Podalux allows for a natural gait pattern, showing ‘normal’ knee and ankle movements. In separate testing the Podalux showed up to a 40% off load of the forefoot.
In conclusion, the Podalux is the first product of its kind to not only off-load the forefoot but also maintain the range of movement of the first MTPJ within ‘safe’ limits, whilst allowing for a natural gait pattern.