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Our Research

Laboratory testing

ZeroSole is designed to reduce focal foot pressure for low-risk pressure-induced foot lesions such as corns and calluses. This study, conducted in collaboration with the Assistive Technology Innovative Centre (ATiC), set out to assess the ZeroSole Reliever insole for two capabilities. Firstly, its ability to better redistribute pressure across the foot when compared to standard shoe insoles. Secondly, the study assessed its offloading (direct pressure redistribution) ability when an offload cavity (low pressure zone) is created over a small area of the ball of the foot; in this case the second metatarsal phalangeal joint.

The second MTPJ was selected for this study, as this is a common site on the ball of the foot that is often subject to high pressure and subsequent corn or callus formation.

15 healthy participants were tested to evaluate its effects on foot pressure distribution. The results suggest the offloading effects exist without affecting the participant’s walking pattern (gait). On average, wearing ZeroSole insoles reduced overall pressure across the foot by 19% compared to standard insoles pre-existing inside the participants footwear, and with ‘cells’ removed to create an offloading cavity, the offloading pressure reduction stood at 28% on average. In addition, the ZeroSole has cushioning effects, evidenced by reduced plantar forces.

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Clinical testing

The purpose of this ZeroSole product evaluation was to test the effectiveness of the Kaydiar ZeroSole Reliever insole with respect to its practical application as an offloading treatment in combination with usual care for painful plantar foot lesions, such as corns or calluses. The evaluation assessed immediate pain reduction and prevention of these lesions when using the product. The evaluation period for each eligible participant was 6 weeks.

Throughout the study, pain levels associated with foot corn(s) were measured using the Numerical Pain Scale (NPS) which ranged from 0 (no pain) to 10 (worst pain imaginable), and the size of the corn(s) (length mm x width mm) was measured using disposable measuring tapes. 

For each participant, a pair of ZeroSole Reliever insoles were customised to create an offloading cavity beneath their painful plantar foot lesion(s) by removing the corresponding ‘cells’. The customised ZeroSole Reliever insoles were then placed inside the participant’s usual footwear and the participants were asked to walk for a short distance and rate the pain from their corn or callus. Pain scores were compared to the baseline (walking without the ZeroSole Reliever insole). 

The participants would then have their corn/callus debrided (shaved away) by the podiatrist before wearing the ZeroSole Reliever insoles for another 6 weeks. At the end of the 6-week study period, the size of the corn/calluses were re-measured and compared to baseline measurements.

Results from the study concluded that:

  • The ZeroSole Reliever Insole immediately reduced pain from the plantar corn/callus and improved overall comfort, when compared to the shoe’s regular insole.
  • Following debridement, there was clinical significance regarding lesion size reduction over time when wearing the ZeroSole Reliever insole after 6 weeks.

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