Long-term training on sand changes lower limb muscle activities during running in runners with over-pronated feet

Background Running on sand could be a promising exercise intervention for the treatment of over-pronated feet. However, there is a lack of knowledge about the effects of running on sand on muscle activities. Therefore, this study aims to evaluate the long-term effects of running on sand on the activities of selected lower limb muscles in individuals with OPF compared with healthy controls. Methods Sixty recreational adult male runners with over-pronated feet (foot posture index > 10) were divided into two equal groups (intervention and control). Participants ran barefoot at a pre-defined speed (⁓3.3 m/s) over level stable ground both before and after long-term training on the sand. Muscle activities were recorded using a surface bipolar electromyography system. Results For the intervention group, we found a reduced foot posture index (p < 0.001; d = 2.00) and significant group-by-time interactions for gluteus medius activity during the mid-stance phase (p < 0.028; d = 0.59). Significantly higher gluteus medius activity (p = 0.028, d = 0.569) was found during the post-test. We also observed significant group-by-time interactions for medial gastrocnemius activity during the push-off phase (p < 0.041; d = 0.54). Significantly larger medial gastrocnemius activity (p = 0.041; d = 0.636) was found during the post-test compared to the pre-test. Conclusions Long-term running on sand resulted in reduced pronation, increased medial gastrocnemius activity, and improved frontal plane pelvic stability due to higher gluteus medius activity. Trial registration: IRCT20191211045704N1. Registered 25 February 2020. Retrospectively registered.

Relationship of Body Mass Index and Footprint Morphology to the Actual Height of the Medial Longitudinal Arch of the Foot

The medial longitudinal arch height of the foot is linked to individual characteristics such as sex and body mass index, and these characteristics have been shown to be associated with conditions such as flat feet. In this cross-sectional descriptive study, we examined the medial longitudinal arch morphology in an adult population to determine if there are differences related to sex and body mass index, and values were obtained for the foot posture index. Normalized anthropometric measurements and arch indices were calculated from footprints. Groups, defined by sex and body mass index, were compared, and the correlations between body mass index and the variables were determined. In the population studied (266 women and 177 men), significant differences between men and women for the foot posture index and normalized arch measurements were found. Analysis of the variables related to body mass index indicated there were significant differences in arch indices. Significant differences and positive correlations were also found between the arch index and body mass index for the left and right feet among the men and women studied. The results obtained allow us to reflect on and analyze whether the medial longitudinal arch morphology classification methods used in the clinical and research setting are adequate or whether the influence of factors such as body mass index can generate confusion.

Symmetry Criterion for Patients with Rheumatoid Arthritis of the Foot: A Cross-Sectional Study

Objective: The aim of the study was to analyze the feet of rheumatoid arthritis (RA) patients, to determine the degree to which both feet were affected, primarily analyzing the severity of RA in both feet looking at structure and morphology, and secondly looking at the symmetry in terms of the anthropometrics and posture. Method: This cross-sectional study was conducted from January to December 2018. The data from 229 patients with RA and with foot pain and no RA recruited (Granada, Spain) were analyzed. Two researchers independently interviewed the patients to obtain the study data. The clinical data were obtained using specific foot health and quality of life questionnaires and a validated platform for foot measurement. Anthropometric measurements were obtained by means of a foot measurement platform and the Foot Posture Index (FPI). The bivariate analysis was performed with the Student’s t test and the non-parametric Wilcoxon test. The level of significance was established at p < 0.05. Results: In the RA group, anthropometric measurements revealed significant differences between the left and right feet in 13 of the 23 parameters considered, as follows: (non-load-bearing) foot length, length of the first metatarsophalangeal joint, maximum height of the internal longitudinal arch, and width of the midfoot (p < 0.001, p = 0.038, p < 0.001, and p = 0.037 respectively); and Foot Posture Index (p = 0.001). Conclusions: In patients with RA, statistically significant differences were found in the Foot Posture Index and in several parameters related to foot structure and morphology. From this, we conclude that from a morphological, structural, and postural standpoint, a pattern of symmetric joint involvement should not be viewed as a specific criterion for RA in the foot.

Foot Posture Index Reference Values among Young Adults in Saudi Arabia and Their Association with Anthropometric Determinants, Balance, Functional Mobility, and Hypermobility

Background. The foot posture index (FPI) is a valid, reliable, and multidimensional method for determining foot posture in a wide range of clinical settings. To date, no normative data of healthy young adults in Saudi Arabia have been available for comparison and reference. Hence, this study is aimed at establishing the FPI reference values, gender, and side differences of FPI and their association with anthropometric determinants, balance, functional mobility, and hypermobility. Methods. FPI was assessed in 581 (291 men and 290 women) healthy young adults aged 18–25 years. The FPI range was obtained for both feet as the sum of the scores (–2, –1, 0, 1, and 2) given to each criterion: (–1 to –12) supinated foot, (0 to +5) neutral foot, and (+6 to +12) pronated foot. The study furthermore assessed the balance using a near tandem balance test, functional mobility by stair ascent and descent test, and joint hypermobility via the Beighton scale. Results. The average FPI score was 2.76 ± 5.23 for all subjects, 2.98 ± 5.02 for men and 2.55 ± 5.43 for women. Neutral foot posture was most frequent in this study (52.9%). A higher proportion of women had pronated (21.0%) and supinated (11.7%) feet than men which were 16.8% and 10.3%, respectively. This study also confirmed that side differences were found to be significant ( p value < 0.001), whereas gender differences were significant only in the normal, pronated, and supinated foot groups. Conclusion. The most common foot posture in both genders was ranged from neutral to slight pronation. We also found a correlation between balance with FPI in the supinated and hypersupinated foot groups, functional mobility with FPI of pronated and supinated foot groups, and joint hypermobility with FPI of the hyperpronated foot group.

Clinical measures of foot posture and ankle joint dorsiflexion do not differ in adults with and without plantar heel pain

Foot posture and ankle joint dorsiflexion have long been proposed to be risk factors for plantar heel pain, however body mass may be a confounder when investigating these factors. The aim of this study was to determine if clinical measures of foot posture and ankle joint dorsiflexion differ in adults with and without plantar heel pain after accounting for body mass. This was a cross-sectional observational study that compared 50 participants with plantar heel pain to 25 control participants without plantar heel pain who were matched for age, sex and body mass index. Foot posture was assessed using the Foot Posture Index and the Arch Index. Ankle joint dorsiflexion was assessed with a weightbearing lunge test with the knee extended and with the knee flexed. No significant differences (P < 0.05) were found between the groups for foot posture, whether measured with the Foot Posture Index or the Arch Index. Similarly, no significant differences were found in the weightbearing lunge test whether measured with the knee extended or with the knee flexed. Clinical measures of foot posture and ankle joint dorsiflexion do not differ in adults with and without plantar heel pain when body mass is accounted for. Therefore, clinicians should not focus exclusively on foot posture and ankle dorsiflexion and ignore the contribution of overweight or obesity.

Posture as a Non-Invasive Indicator of Arousal in American Toads (Anaxyrus americanus)

Animal welfare has become a priority for modern zoos and aquariums. However, amphibians have not yet been the focus of much welfare research, perhaps in part because they do not tend to display many quantifiable active behaviors. This study focused on nine zoo-housed American toads (Anaxyrus americanus), a species that displays long periods of sedentary behavior, to explore whether more subtle cues could serve as welfare indicators. A novel American toad posture index was developed that characterized toad posture based on the angle of their forelimbs, visibility of ventral regions, and body weight distribution. As an indicator of arousal, approximate breathing rates were assessed based on the rate of expansion of the toads’ throats. Subsequent analyses revealed that lower body postures were associated with slower rates of throat expansion and raised postures with faster rates of throat expansion, suggesting that posture may be a promising way to quickly and non-invasively assess toad arousal. This work lays important groundwork for assessing welfare of an understudied species, and we are optimistic that, with additional validation, these approaches can be applied in future amphibian welfare research.

Comparative analysis of the foot position in children with symptomatic and asymptomatic flatfoot using the foot posture index (FPI-6)

Aim. To compare the foot position in asymptomatic children and those who received conservative or surgical because of flatfoot.Materials and Methods. We consecutively recruited three patient groups: 112 healthy children, 74 children with a pronation position, and 80 children with an overpronation position of the foot. The Foot Posture Index (FPI – 6) was used for the clinical examination. Visual and manual clinical tests were used to determine the mobility of the foot joints. X-ray was performed in a standard lateral projection with a load; if necessary, multislice computed tomography of the foot was performed.Results. Healthy children commonly have pronation position of the foot during the first 10 years of life, with the further normalisation of the posture. In patients receiving conservative treatment of foot pronation, normalisation of the foot position was considerably less pronounced than in healthy children. Further, in those with overpronation position, there were no age-dependent changes in the posture and surgery was the only efficient approach to correct the flatfoot.Conclusion. FPI-6 is a highly sensitive tool for clinical diagnosis of flatfoot. Moderate pronation has a more favorable prognosis than the overpronation position, which is not corrected during the body growth or by the conservative treatment. Yet, surgery is a safe and efficient approach to relieve the pain syndrome and treat the flatfoot deformity.