Effectiveness of Custom Foot Insoles to Decrease Plantar Pressure: A Cross-over Randomized Trial Study

Plantar Pressure Characteristics and Prevention of Painful Accessory Navicular in Military Recruits

OBJECTIVE

The objective of this study was to provide practical guidance for the prevention of painful accessory navicular among recruits by comparing and analyzing the plantar pressure parameters of individuals with normal foot, flat foot, and accessory navicular.

METHODS

After training, a total of 90 military recruits were included in this study, comprising 30 with normal foot, 30 with flat foot, and 30 with painful accessory navicular. The plantar pressure distribution was measured for all participants.

RESULTS

In individuals with flat feet, there was an increase in plantar pressure on the medial side of the forefoot, as well as a significant increase in pressure on the medial side of the heel and arch (P<0.05). Conversely, there was a significant decrease in pressure on the lateral side of the heel and arch (P<0.05). In patients with painful accessory navicular, the medial pressure on the foot arch showed a further increase (P<0.001), while the lateral pressure on the foot arch exhibited a further decrease (P<0.001), indicating highly significant differences.

CONCLUSION

Compared to participants with flat feet, participants with accessory navicular demonstrated faster and more impulsive impact on the ground within the same stress area, resulting in more noticeable pain caused by the injury to the accessory navicular.

The Effectiveness of Hard Insoles for Plantar Pressure in Cycling: A Crossover Study

BACKGROUND

Hard insoles have been proposed to decrease plantar pressure and prevent foot pain and paresthesia due to repetitive loading. The aim of this research was to analyze the effect of three different hard insoles in cycling on healthy subjects.

METHODS

A crossover randomized trial was carried out. The mean age of the subjects was 35 ± 3.19 years, and all of them were men. While the subjects were cycling on a stationary bicycle, their plantar pressure was recorded with nine in-shoe sensors placed in nine specific foot areas to test a standard ethylene-vinyl-acetate 52° Shore A hardness insole, a polypropylene 58° Shore D insole, and a polypropylene 58⁰ Shore D insole with selective aluminum 60 HB Brinell hardness in the metatarsal head and hallux.

RESULTS

The maximum plantar pressure decreased significantly with the polypropylene insole containing selective aluminum in the metatarsal head and hallux areas. The maximum plantar data of the polypropylene aluminum insole in the M2 area (5.56 kgF/cm²), fifth metatarsal styloid process (6.48 kgF/cm²), M3-M4 area (4.97 kgF/cm²), and hallux (8.91 kgF/cm²) were of particular interest compared to the other insoles.

CONCLUSIONS

The use of insoles made of polypropylene with aluminum in the metatarsal head and hallux areas decreases the maximum plantar pressure in cycling compared to standard EVA and polypropylene insoles.