Although foot mobility tends to be greater in females, sex-based differences in foot torsional stiffness have not been investigated. It is also unclear whether assessing the medial longitudinal arch (MLA) height reflects foot torsional stiffness. This study included 52 healthy adults (26 females and 26 males) with an average age of 24.6 years. The arch height index was used to assess MLA height. To calculate foot torsional stiffness, a custom-built torque meter and a three-dimensional motion analysis system were employed. The forefoot was passively rotated from the maximum eversion to the maximum inversion at a rate of 2.5°/s. The forefoot\'s resistance torque and rotation angle relative to the rearfoot were recorded. Foot torsional stiffness was defined by establishing the slope of the regression line from 10° eversion to 10° inversion of the torque-angle curve, with the slope subsequently normalized by body weight. Gender differences in foot torsional stiffness and the correlation between MLA height and foot torsional stiffness were investigated. Foot torsional stiffness was significantly lower in females than in males (0.00237 ± 0.00061Nm/°･kg vs 0.00368 ± 0.00136 Nm/°･kg, p < 0.001, effect size: r = 0.65, statistical power = 0.99). MLA height was not significantly different between sexes. No significant correlations were found between foot torsional stiffness and MLA height in either sex. Foot torsional stiffness and MLA height reflect different mechanical properties of the foot, emphasizing the need for individual assessment and consideration of sex differences.

BACKGROUND: Abnormal foot anthropometry and posture of patients with Duchenne Muscular Dystrophy (DMD) can be considered as possible risk factors for performance and ambulation. It was aimed to examine the effects of foot posture and anthropometric characteristics, which deteriorated from the early period, on ambulation and performance of patients with DMD.
METHODS: The foot arch height (FAH), the metatarsal width (MW), subtalar pronation angle, and ankle limitation degree (ALD) were evaluated to determine the foot anthropometric characteristics of the patients. Foot Posture Index-6 (FPI-6) was used to evaluate foot posture. The performance of the patients was determined by the 6-minute walk test (6MWT), the 10-meter walk test (10MWT), and ascend/descend a standard 4-step test, and the ambulation was determined by the North Star Ambulatory Assessment (NSAA). Spearman\'s correlation coefficient was calculated to assess the relationship between foot anthropometric characteristics and posture, and performance and ambulation.
RESULTS: The sample consisted of 48 patients with DMD aged 5.5 to 12 years. Both of the right and left foot FPI-6 scores were associated with all parameters, except descending 4-step. The left FAH was associated with 6MWT and NSAA, and the left MW was associated with 6MWT. The ALD of right foot was associated with 6MWT, ascending/descending 4 steps, and NSAA, and left ankle limitation was associated with NSAA (p<0.05). There was no relationship between other parameters.
CONCLUSIONS: These findings suggest that postural disorders in the foot and ankle may contribute to the decrease in performance and ambulation in patients with DMD.

Cerebral palsy (CP) is a neurological condition that affects musculoskeletal system causing altered balance control, which is governed by constant adjustments by muscular activity and joint positioning. Since the foot is the platform upon which we stand and balance, it is important to study and characterize foot posture abnormalities in CP to better understand their possible effect on multidirectional limits of stability (MDLS) in standing. Our aim was to find relation between foot posture and MDLS in diplegic children. Thirty diplegics (13 pes-planus and 17 pes-cavus) between the age of 6 to 14, gross motor function classification system (GMFCS) levels I and II, whose parents consented were included in this study. Diplegics unable to stand unsupported for < 2 minutes, undergone lower-limb surgeries in 6 months, having visual impairments were excluded. Foot posture was assessed with arch index, MDLS were measured by GEAMASTER stabilometer. There was significant positive correlation between foot posture and limits of stability. Diplegic children having pes-planus have better MDLS as compared with pes-cavus.

OBJECTIVE: To investigate relationships between static foot posture, dynamic plantar foot forces and knee pain in people with medial knee osteoarthritis (OA).
METHODS: Data from 164 participants with symptomatic, moderate to severe radiographic medial knee OA were analysed. Knee pain was self-reported using a numerical rating scale (NRS; scores 0-10; higher scores worse) and the Knee Injury and Osteoarthritis Outcome Score pain subscale (KOOS; scores 0-100; lower scores worse). Static foot posture was assessed using clinical tests (foot posture index, foot mobility magnitude, navicular drop). Dynamic plantar foot forces (lateral, medial, whole foot, medial-lateral ratio, arch index) were measured using an in-shoe plantar pressure system while walking. Relationships between foot posture and plantar forces (independent variables) and pain (dependent variables) were evaluated using linear regression models, unadjusted and adjusted for sex, walking speed, Kellgren & Lawrence grade, shoe category, and body mass (for dynamic plantar foot forces).
RESULTS: No measure of static foot posture was associated with any knee pain measure. Higher medial-lateral foot force ratio at midstance, and a higher arch index during overall stance, were weakly associated with higher knee pain on the NRS (regression coefficient = 0.69, 95% confidence interval (CI) 0.09 to 1.28) and KOOS (coefficient=3.03, 95% CI 0.71 to 5.35) pain scales, respectively.
CONCLUSIONS: Dynamic plantar foot forces, but not static foot posture, were associated with knee pain in people with medial knee OA. However, the amount of pain explained by increases in plantar foot force was small; thus, these associations are unlikely to be clinically meaningful.

BACKGROUND: Generalized joint hypermobility (GJH) is prevalent among young adults, necessitating effective monitoring of musculoskeletal health, particularly among college-aged females. This study aimed to identify physical fitness and health-related quality of life (HR-QoL) characteristics associated with GJH.
METHODS: A total of 67 participants were assessed: 26 with GJH (mean age 20.06, SD 1.2 years), and 41 without (mean age 20.15, SD 2.2 years). Assessments included hypermobility, anthropometric data, foot posture, balance, flexibility, strength, and HR-QoL. We used the Mann-Whitney test for two independent samples, categorical variables were analyzed with Cramer\'s V test. The results indicated that participants with GJH exhibited inferior balance and back muscle static strength endurance but greater flexibility compared to those without GJH. Significant differences were observed in foot posture. However, handgrip strength, explosive strength, and abdominal muscle static strength endurance did not differ significantly between groups. No significant differences were observed in HR-QoL components between the two groups. In conclusion, there appears to be a link between GJH and increased flexibility, impaired balance, reduced back muscle static strength endurance, and altered posture of both feet.

BACKGROUND: Exercises strengthening foot muscles and customized arch support insoles are recommended for improving foot posture in flexible flatfoot. However, it is not known what the effects of exercises and insoles on plantar force distribution obtained during walking at different speeds. Also, randomized controlled trials comparing the effects of exercises and insoles are limited.
OBJECTIVE: What are the effects of foot exercises, customized arch support insoles, and exercises plus insoles on foot posture, plantar force distribution, and balance in people with flexible flatfoot? Do exercises, insoles, and exercises plus insoles affect outcome measures differently?
METHODS: Forty-five people with flexible flatfoot were randomly divided into three groups and 40 of those completed the study. The exercise group performed tibialis posterior strengthening and short foot exercises three days a week for six weeks. The insole group used their customized arch support insoles for six weeks. The exercise plus insole group received both interventions for six weeks. The assessments were performed three times: before the interventions and at the 6th and 12th weeks. Outcome measures were (1) foot posture, (2) plantar force distribution in the following conditions: static standing, barefoot walking at different speeds, and walking immediately after the heel-rise test, and (3) balance.
RESULTS: Foot posture improved in all groups, but insole was less effective than exercise and exercise plus insole (p<0.05). Plantar force variables obtained during standing and walking changed in all groups (p<0.05). The superiority of the interventions differed according to the plantar regions and walking speed conditions (p<0.05). Static balance improved in all groups, but limits of stability improved in the exercise plus insole and exercise groups (p<0.05).
CONCLUSIONS: The superiority of the interventions differed according to the assessed parameter. The management of flexible flatfoot should be tailored based on the assessment results of each individual.

BACKGROUND: Patellofemoral pain (PFP) is characterized by chronic pain in the anterior aspect of the knee during loading activities. Many studies investigating muscle morphology changes for individuals with PFP focus on the proximal joints, however, few studies have investigated muscles of the foot and ankle complex. This study aimed to explore the differences in peroneal muscle size and activation between individuals with PFP and healthy controls using ultrasound imaging in weight-bearing.
METHODS: A case-control study in a university lab setting was conducted. Thirty individuals with PFP (age: 20.23 ± 3.30 years, mass: 74.70 ± 27.63 kgs, height: 161.32 ± 11.72 cm) and 30 healthy individuals (age: 20.33 ± 3.37 years, mass: 64.02 ± 11.00 kgs, height: 169.31 ± 9.30 cm) participated. Cross-sectional area (CSA) images of the peroneal muscles were taken in non-weight bearing and weight-bearing positions. The functional activation ratio from lying to single-leg standing (SLS) was calculated.
RESULTS: There was a statistically significant (p = 0.041) group (PFP, healthy) by position (non-weight-bearing, weight-bearing) interaction for the peroneal muscle CSA with a Cohen\'s d effect size of 0.2 in non-weight-bearing position and 0.7 in weight-bearing position. The functional activation ratio for the healthy group was significantly more (p = 0.01) than the PFP group.
CONCLUSIONS: Peroneal muscles were found to be smaller in size in those with PFP compared to the healthy subjects in the weight-bearing SLS position. This study found that those with PFP have lower activation of peroneal muscles in functional position.

This study compared muscle strength and foot pressure among patients with metatarsalgia, patients with plantar fasciitis, and healthy controls. A total of 31 patients with foot pain (14 metatarsalgia and 17 plantar fasciitis) and 29 healthy controls participated in the study. The strengths of the plantar flexor and hip muscles were measured using isokinetic and handheld dynamometers, respectively. Foot pressure parameters, including the pressure-time integral (PTI) and foot arch index (AI), were assessed using pedobarography. Compared with the healthy control group, plantar flexor strength was significantly reduced in the affected feet of the metatarsalgia and plantar fasciitis groups (F = 0.083, all p < 0.001); however, hip strength was significantly decreased only in the affected feet of the metatarsalgia group (F = 20.900, p < 0.001). Plantar flexor (p < 0.001) and hip (p = 0.004) strength were significantly lower in the metatarsalgia group than in the plantar fasciitis group. The PTI was lower in the forefeet of the affected feet in the metatarsalgia (p < 0.001) and plantar fasciitis (p = 0.004) groups. Foot AI (p < 0.001) was significantly reduced only in the metatarsalgia group. These results suggest the need to consider the evaluation of muscle strength and foot pressure in both feet for the diagnosis and treatment of foot pain.

Foot posture describes the anatomical variance in an individual\'s overall foot shape, an important consideration in the provision of foot orthoses. Current orthoses designs could be optimized by considering the topographical organization of cutaneous mechanoreceptors. Currently, the effect of foot orthoses designs to enhance skin stimulation across different anatomical foot posture remains unknown. Thus, the purpose of this study was to investigate how foot posture variance modulates lower leg muscle activity when walking in non-textured orthoses and in textured orthoses which facilitates cutaneous mechanoreceptors under five different regions of the foot sole. Fifty-one (51) healthy young adults were subdivided by the Foot Posture Index and completed level walking trials wearing non-textured and textured foot orthoses. Surface and fine-wire electromyography (EMG) recorded muscle activity in 8 lower leg muscles. Statistically significant interactions were observed in each muscle\'s average EMG across textured location and Foot Posture Index score. For example, in pes cavus compared to pes planus feet, texture under the calcaneus generated greater aEMG of the tibialis anterior (44.9 mV ± 22.7 mV to 30.9 mV ± 11.4 mV) medial gastrocnemius (26.1 mV ± 16.7 mV to 17.5 mV ± 6.0 mV), and tibialis posterior (84.4 mV ± 77.1 mV to 64.4 mV ± 44.5 mV) muscles. This study demonstrates that lower leg muscle activity is modulated across the foot posture spectrum wearing non-textured and textured foot orthoses. Furthermore, in the development of new orthoses designs, specifically with texture, foot posture remains an important consideration when clinicians interpret EMG results and academics are designing new experimental protocols.

The aim of this work was to investigate the relationship foot pain and foot disability have with HRQoL in groups of women with RA, SLE and EDS, in comparison with a control group. A cross-sectional study was carried out with females with one of these conditions and a control group. The SF-12 questionnaire was used to collect data about quality of life. The type of foot was classified according to the footprint and the foot posture index. A total of 156 patients and 47 controls participated in the study (N = 203). Neither pain nor foot posture were different between groups. The physical and mental components of SF-12 were worse in rheumatoid arthritis and Ehlers-Danlos syndrome patients, and the physical component was worse in systemic lupus erythematosus patients, compared to controls. A significant difference was also observed in the mental component between systemic lupus erythematosus and Ehlers-Danlos syndrome patients, the latter having the lowest values among the groups. We can conclude that women with rheumatoid arthritis, Ehlers-Danlos syndrome, systemic lupus erythematosus and foot pain perceive a worse quality of life. There are no significant changes in foot posture. Pain and health-related quality of life are independent of foot posture.