Preliminary investigation on the reduction of plantar loading pressure with different insole materials (SRP – Slow Recovery Poron®, P – Poron®, PPF – Poron®+Plastazote, firm and PPS – Poron®+Plastazote, soft)
Received 29 January 2009; received in revised form 13 December 2009; accepted 16 December 2009.
Abstract
Background
The aim of this study is to investigate the amount of pressure reduction for different padding and insole materials commonly used in the podiatry clinic.
Methods
Plantar pressure were taken for 5 subjects without insoles fitted (BF) in their daily sports shoes, and thereafter with 4 pairs of simple insoles (6.4mm thick) each as follow: SRP – Slow Recovery Poron®, P – Poron®, PPF – Poron®+Plastazote (firm) and PPS – Poron®+Plastazote (soft). In addition, subjects were also tested with semi-compressed felt (SCF) padding with a 1st metatarsophalangeal joint (MTPJ) aperture cut-out bilaterally. Minimum, maximum, mean pressure and peak pressure at the hallux, 1st, 2nd, 3rd/4th and 5th MTPJ across both feet were analysed. Repeated measures ANOVA with post hoc Bonferroni paired wise comparison was used to test for any statistical significance at the 95% confidence level for all pressure data.
Results
PPF was significant in reducing the minimum (p<0.005) and mean pressure (p<0.03) when compared to BF. This accounted for approximately 28% and 27% pressure reduction in minimum and mean pressure respectively. Peak pressure on the 1st MTPJ locality showed significant reduction of 37% and 29% with the use of SCF (p<0.004) and PPF (p<0.004), respectively.
Conclusions
All 4 commonly used insole materials were able to reduce pressure across the whole foot with PPF achieving significance. Off-loading the 1st MTPJ would still be best achieved with the commonly used plantar metatarsal pad of SCF with the aperture cut-out design.
aPodiatry Department, Blk 1 Level 1, Rehab Centre, Singapore General Hospital, Outram Road, Singapore 169608, Singapore
bSchool of Mechanical and Aerospace Engineering, College of Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
ABSTRACT