Objective: This study was performed to investigate plantar pressure distribution in healthy adults to establish normal plantar pressure values.
Materials & Methods: In this descriptive and analytical study, 80 individuals (female and male) with healthy feet were selected from convenient samples by simple selection. This study was performed with usage of RS-Scan plantar pressure measurement device to measure plantar pressure in 9 anatomical regions of the foot during standing and walking. Data were analyzed by Paired T-test and Independent T-test.
Results: During walking the highest pressure was located under the heel area (31.43 n/cm2), 2th (30.86 n/cm2) and 3th (28 n/cm2) metatarsal heads, followed by big toe (23.51 n/cm2) and the lowest pressure was at 2-5 toes and midfoot. There were significant differences between male and female in static pressure values for the left forefoot (P<0.001), contact areas at rear foot(P<0.001) and right midfoot (P=0.02). Results showed significant differences in pressure under 4th metatarsal head of right (P=0.05) and left (P=0.04) foot, 5th metatarsal head of right foot (P=0.02) and under heel region pressures of both foot (P<0.001) between females and males.
Conclusion: There are many differences in distribution manner and values of plantar pressure between females and males that would be considered at therapeutic and rehabilitation procedures of at risk foot (for example: Diabetic foot) and shoe designing.

Objective: Patients with diabetic neuropathy lack pain sensation in their foot plantar surface and are susceptible to plantar ulcers. The objective of this study, in one way are the assessment of the foot plantar pressure in a group of type 2 diabetic patients with mild neuropathy and the comparison of their values with normal subjects and on the other way, the determination of the susceptible points of ulceration on plantar surface of these patients.

Materials & Methods: In this cross sectional study, the foot plantar pressure assessed in 20 subjects who were selected based on judgmental sampling method and assigned in two 10-participant groups of diabetic and normal during walking using foot scan system in 10 different zones under the feet. Following measurement recording, independent T statistics used to compare the means of two groups.

Results: While the lowest foot plantar pressure located under the toes 2-5, the highest foot plantar pressure was under the third and then the fourth metatarsal heads. Although diabetic patients had higher foot plantar pressure than the normal subjects in eight foot zones, but their mean differences were not significant (Toe1: P=0.281, Toe2-5: P=0.122, Metatars1: P=0.459, Metatars2: P=0.920, Metatars3: P=0.461, Metatars4: P=0.419, Metatars5: P=0.130, Midfoot: P=0.172, Medial Heel: P=0.978, Lateral Heel: P=0.985).

Conclusion: There was no significant difference in foot plantar pressure between diabetic patients and normal subjects probably because of mild severity of neuropathy and no existence of foot plantar ulcer in these patients. Also the third and fourth metatarsal heads had the highest ulceration susceptibility.

Objective: The aim of this study was the comparison of plantar pressure distribution and vertical ground reaction force between dominant and none-dominant limbs in healthy through using Principle Component Analysis (PCA) technique.

Materials & Methods: This study was quasi-experimental in which 20 healthy adult males and females were selected from available subjects. Subject’s plantar pressure distribution and vertical ground reaction force measured using the Pedar-X system. The obtained data were analyzed by Paired-t test, one way analyze of variance, Pearson coefficient correlation and PCA.

Results: ANOVA and Paired-t test did not show any significance difference between males and females and dominant and non-dominant limb pressure pattern, (P>0.05). PCA recognized pressure and force applied on the heel, fingers, big toe and first metatarsal regions for the dominant limb and lateral mid foot, lateral fore foot, first metatarsal and heel regions for non-dominant limb, as important parameters.

Conclusion: The results of this study showed that, dominant limb is responsible for propulsion and weight acceptance and non-dominant limb is responsible for balance control. Therefore during biomechanical evaluation of feet, difference between function of dominant and non-dominant limb must be considered.

Objective: Hallux Valgus is one of the most foot deformities which increase plantar pressure beneath big toe and first metatarsal. The aim of this study was to assess the effect of foot orthosis on plantar pressure distribution in subjects with mild and moderate Hallux Valgus.

Materials & Methods: in this quasi-experimental study, females 16 with Hallux Valgus were recruited. Plantar pressure in 8 area of foot was measured by Pedar-X insole when wearing standard shoe only shoe with foot orthosis and shoe with foot orthosis after a month of using orthosis. Data were analyzed by repeated measure analysis of variance test.

Results: using foot orthosis for a month leaded to decrease pressure in the big toe (P<0/019) first metatarsal and 3-5 metatarsals (P<0.001) and also increased pressure in medial mid foot (P<0.001).

Conclusion: Foot orthosis decreased peak pressure in fore foot and increased it in medial mid foot. Therefore redistribute plantar pressure to the more normal pattern in Hallux Valgus subjects. So it could be one of the effective methods to prevent the progression of this deformity in its initial steps of formation.

Objective: Rheumatoid arthritis is a chronic inflammatory disease which causes structural and functional changes in foot joints and results in alteration of plantar pressures. Therefore, the aim of this study was to investigate the immediate effect of insole with medial longitudinal arch support and metatarsal pad on plantar pressure distribution in females with rheumatoid arthritis.

Materials & Methods: This was a quasi-experimental study in which 15 volunteer females with rheumatoid arthritis were recruited using no-probability simple sampling method. Plantar pressures were assessed using Pedar-X system in four anatomical foot region in two conditions of walking with and without foot orthosis. Average maximum pressures (Kilopascal) were calculated in each region.

Results: Foot orthosis with medial longitudinal arch support and metatarsal pad reduced plantar pressure in heel (P<0.015), metatarsal heads (P<0.03) and increased pressure in mid-foot area (P<0.00). However, no significant differences in average maximum pressure were observed between two assessed conditions in the toe area.

Conclusion: The findings of the present study revealed that the orthosis with medial longitudinal arch support and metatarsal pad corrects increased pressure on heel and metatarsal heads in rheumatoid arthritis. It could increase plantar pressure in mid-foot while decrease it in metatarsal heads and heel regions. Therefore, this orthosis is recommended to be used as a treatment in this pathology in order to re-distribute the foot pressures more normally.