A comparison of plantar pressures in a standard flip-flop and a FitFlop using bespoke pressure insoles

Price, C; Graham-Smith, P; Jones, R

Abstract

Purpose: The study was undertaken to quantify plantar pressures in a Havaiana flip-flop compared to a FitFlop. The FitFlop is a flip-flop designed to induce instability in the wearer during midstance as it incorporates a multi-density midsole in the design. It was hypothesised that in the Havaiana the toes are used to “grip” the shoe in swing and the loose upper and thin sole provide limited protection to the foot, producing higher plantar pressures than FitFlop. It is presumed that high plantar pressures are experienced in flip-flops and they may lead to discomfort in walking. Methods: Twenty female subjects walked in the footwear conditions while a bespoke instrumented insole quantified plantar pressures. Data analysis grouped sensors into regions for the heel, 1st MPJ and hallux to isolate pressures that have been linked to comfort and symptoms reportedly alleviated in FitFlop. Additional analysis was undertaken to measure hallux “gripping” during swing. Results: Significant reductions in plantar pressures in FitFlop, particularly in peak pressure in the heel (3.6%) and pressure time-integral in the 1st MPJ (12.0%) were identified. These findings were attributed to the thicker midsole with different EVA construction and a redistribution of load to the midfoot where contact area increased by 19.9% compared to Havaiana. Also evident were reductions in anterior-posterior centre of pressure velocity in FitFlop, attributed to its softer midfoot delaying progression. Hallux variables identified reductions in time spent “gripping” as well as the magnitude of force applied by the hallux in swing in FitFlop. Conclusions: Findings from the study identify that the FitFlop reduces pressure in key areas of the foot which are associated with walking comfort as well as clinical conditions. The “gripping” mechanism postulated to hold flip-flops on is lessened in the FitFlop, potentially reducing the likelihood of overuse injuries.

Citation

Price, C., Graham-Smith, P., & Jones, R. (2013). A comparison of plantar pressures in a standard flip-flop and a FitFlop using bespoke pressure insoles. Footwear Science, 5(2), 111-119. https://doi.org/10.1080/19424280.2013.790486

• Journal Article Type: Article
• Publication Date: Jan 1, 2013
• Deposit Date: Dec 4, 2014
• Journal: Footwear Science
• Print ISSN: 1942-4280
• Electronic ISSN: 1942-4299
• Publisher: Taylor and Francis
• Peer Reviewed: Peer Reviewed
• Volume: 5
• Issue: 2
• Pages: 111-119
• DOI: https://doi.org/10.1080/19424280.2013.790486
• Publisher URL: http://dx.doi.org/10.1080/19424280.2013.790486
• Additional Information: Funders : Knowledge Transfer Partnership