Comprehensive biomechanical characterization of feet in USMA cadets: Comparison across race, gender, arch flexibility, and foot types

Effect of Arch Height Flexibility in Individuals With Flatfoot on Abductor Hallucis Muscle Activity and Medial Longitudinal Arch Angle During Short Foot Exercises

Flatfoot presents decreased medial longitudinal arch (MLA), and such foot deformity involves intrinsic foot muscles dysfunction. Flatfoot can be classified into flexible and stiff types according to arch height flexibility (AHF). Short foot exercise (SFE) is an intrinsic foot muscle strengthening exercise, which is reportedly effective against flatfoot. However, its effectiveness against flexible or stiff types in flatfoot is unclear. We examined the effect of AHF in individuals with flatfoot during abductor hallucis muscle (AbH) activity and medial longitudinal arch during SFE. Foot alignment was assessed using the arch height index during standing, and individuals with flatfoot (N = 16) were recruited. The AbH activity and MLA angle during SFE while maintaining single-leg standing were assessed. The relationship between AHF and AbH activity and between AHF and MLA angle ratio was analyzed using correlation coefficients. Additional correlations between AHF and AbH activity were observed with the outliers removed. There were no correlations between AHF and AbH muscle activity and between AHF and MLA angle ratio. However, with the 2 outliers removed, moderate correlations between AHF and AbH activity were significant (r = 0.64, p = .01). AbH activity during SFE increased in individuals with flatfoot for high AHF (flexible type). Thus, SFE may be more effective for individuals with flatfoot having a high AHF. These findings may be helpful when making decisions for surgery and rehabilitation.

Early Notice Pointer, an IoT-like Platform for Point-of-Care Feet and Body Balance Screening

Improper foot biomechanics associated with uneven bodyweight distribution contribute to impaired balance and fall risks. There is a need to complete the panel of commercially available devices for the self-measurement of BMI, fat, muscle, bone, weight, and hydration with one that measures weight-shifting at home as a pre-specialist assessment system. This paper reports the development of the Early Notice Pointer (ENP), a user-friendly screening device based on weighing scale technology. The ENP is designed to be used at home to provide a graphic indication and customised and evidence-based foot and posture triage. The device electronically detects and maps the bodyweight and distinct load distributions on the main areas of the feet: forefoot and rearfoot. The developed platform also presents features that assess the user's balance, and the results are displayed as a simple numerical report and map. The technology supports data display on mobile phones and accommodates multiple measurements for monitoring. Therefore, the evaluation could be done at non-specialist and professional levels. The system has been tested to validate its accuracy, precision, and consistency. A parallel study to describe the frequency of arch types and metatarsal pressure in young adults (1034 healthy subjects) was conducted to explain the importance of self-monitoring at home for better prevention of foot arch- and posture-related conditions. The results showed the potential of the newly created platform as a screening device ready to be wirelessly connected with mobile phones and the internet for remote and personalised identification and monitoring of foot- and body balance-related conditions. The real-time interpretation of the reported physiological parameters opens new avenues toward IoT-like on-body monitoring of human physiological signals through easy-to-use devices on flexible substrates for specific versatility.

Is the Planus Foot Type Associated With First Ray Hypermobility?

Background:

Many foot pathologies have been associated with foot type. However, the association of first ray hypermobility remains enigmatic. The purpose of this study was to investigate first ray hypermobility among participants with planus and rectus foot types and its influence on static measures of foot structure.

Methods:

Twenty asymptomatic participants with planus (n = 23 feet) and rectus (n = 17 feet) foot types were enrolled. Several parameters of static foot structure (arch height index, arch height flexibility, first metatarsophalangeal joint flexibility, and first ray mobility) were measured. Participants were further stratified into groups with nonhypermobile (n = 26 feet) and hypermobile (n = 14 feet) first rays. First ray mobility ≥8 mm was used to define “first ray hypermobility”. Generalized estimating equations, best-fit regression lines, and stepwise linear regression were used to identify significant differences and predictors between the study variables

Results:

Overall, 86% of subjects categorized with first ray hypermobility exhibited a planus foot type. Arch height flexibility, weightbearing first ray mobility, and first metatarsophalangeal joint flexibility showed no significant between-group differences. However, weightbearing ray mobility and first metatarsophalangeal joint laxity were associated with partial weightbearing first ray mobility, accounting for 38% of the model variance.

Conclusion:

The planus foot type was found to be associated with first ray hypermobility. Furthermore, weightbearing first ray mobility and first metatarsophalangeal joint laxity were predictive of partial weightbearing first ray mobility, demonstrating an interaction between the translation and rotational mechanics of the first ray.

Clinical Relevance:

Association of first ray hypermobility with foot type and first metatarsophalangeal joint flexibility may help understand the sequela to symptomatic pathologies of the foot.

Abnormalities of foot and ankle alignment in individuals with chronic ankle instability: a systematic review

Background

To prevent recurrent ankle sprain, it is important to clarify the pathology of chronic ankle instability (CAI). An association has been reported between CAI and abnormalities of foot posture and ankle alignment. There is no consensus on the types of these abnormalities that occur in individuals with CAI. The objective of this systematic review is to clarify the relevance of abnormality of foot posture and ankle alignment for CAI.

Methods

A systematic computerized literature search was performed of the PubMed, CINAHL, SPORTDiscus, Web of Science, and the Cochrane Register of Clinical Trials databases. The selected studies either compared CAI patients with a control group or CAI ankles with contralateral healthy ankles and specifically reported foot posture and alignment of the ankle in the outcomes. They were written in English and published prior to June 2021. The methodological quality of the included studies was evaluated using a 16-question index. Data were extracted independently by two reviewers, and the certainty of evidence was assessed using GRADE approach.

Results

Sixteen studies including 872 patients of high to low methodological quality were included. These showed there was significant anterior displacement and internal rotation of the talus in CAI ankles (low evidence), but there was no consensus on fibular alignment or foot posture.

Conclusions

This review showed there was significant anterior displacement and internal rotation of the talus in CAI ankles but found no consensus on the characteristics of fibular and foot alignment. Further investigations are required to clarify the characteristic foot and ankle malalignment in CAI to facilitate the development of efficient interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04537-6.

Effects of taping techniques on arch deformation in adults with pes planus: A meta-analysis

Objective

To investigate effects of taping techniques on arch deformation in adults with pes planus.

Methods

The following databases were searched up to March 2020, including Web of Science, Pubmed, EBSCO, CNKI and Cochrane Library. Heterogeneity and publication bias were assessed by I² index and funnel plots, respectively. In addition, Cochrane scale was used to evaluate the quality of research.

Results

Navicular height for three antipronation taping techniques significantly increased immediately post tape compared with baseline (mean difference = 4.86 mm, 95% CI = 2.86–6.87 mm, Z = 4.75, p < 0.001). The highest increase was observed in Augmented low-Dye (ALD). Modified low-Dye (MLD) was second only to ALD (p<0.001). Navicular height after walking for 10 min was much higher than baseline (p<0.001), with MLD decreased smaller than ALD.

Conclusions

ALD was the most effective taping technique for controlling foot arch collapse immediately post tape compared with baseline, followed by MLD. By contrast, MLD could possibly performed better than ALD in maintaining immediate navicular height after walking for 10 min. Low-Dye could make resting calcaneal stance position closer to neutral position. Although positive effects of Navicular sling, low-Dye and Double X taping interventions were observed, they could not maintain this immediate navicular height effect after a period of higher intensity weight-bearing exercise.

ISB recommendations for skin-marker-based multi-segment foot kinematics

The foot is anatomically and functionally complex, and thus an accurate description of intrinsic kinematics for clinical or sports applications requires multiple segments. This has led to the development of many multi-segment foot models for both kinematic and kinetic analyses. These models differ in the number of segments analyzed, bony landmarks identified, required marker set, defined anatomical axes and frames, the convention used to calculate joint rotations and the determination of neutral positions or other offsets from neutral. Many of these models lack validation. The terminology used is inconsistent and frequently confusing. Biomechanical and clinical studies using these models should use established references and describe how results are obtained and reported. The International Society of Biomechanics has previously published proposals for standards regarding kinematic and kinetic measurements in biomechanical research, and in this paper also addresses multi-segment foot kinematics modeling. The scope of this work is not to prescribe a particular set of standard definitions to be used in all applications, but rather to recommend a set of standards for collecting, calculating and reporting relevant data. The present paper includes recommendations for the overall modeling and grouping of the foot bones, for defining landmarks and other anatomical references, for addressing the many experimental issues in motion data collection, for analysing and reporting relevant results and finally for designing clinical and biomechanical studies in large populations by selecting the most suitable protocol for the specific application. These recommendations should also be applied when writing manuscripts and abstracts.

Effect of Gender and Load Conditions on Foot Arch Height Index and Flexibility in Japanese Youths

Arch height index (AHI) and arch height flexibility (AHF) are useful methods for evaluating foot structure. Although foot structure may be linked to intrinsic factors such as gender and load conditions, information on AHI and AHF in consideration of these factors is lacking. This study aimed to examine the effect of gender and load conditions on AHI and AHF. One hundred Japanese youths (50 males, 50 females) were recruited in this study. Arch height and truncated foot length were measured with an AHI measurement system. AHI was calculated for each load condition using truncated foot length and arch height. AHF was defined as the change in arch height from 10% to 50% of weightbearing load, and from 10% to 90% of weightbearing load. To satisfy the assumption of independence, only measurements from the right foot were analyzed. A gender × load condition interaction was found in AHI. AHI in all load conditions showed significant differences between the genders (p < .001), and AHI of female participants was significantly less than that of male participants (p < .001). In contrast, no significant gender × load condition interaction was noted in AHF, and only the main effect of the load condition was found (p < .001). In AHI use, the effects of gender and load conditions must be considered, and AHF may be used considering only changes in load conditions. The results of this study provide useful information regarding which normative values of AHI and AHF should be used.

Does QUICK TAPE Offer Comparable Support and Off-loading as Low-Dye Taping?

BACKGROUND

Low-Dye taping is commonly used to manage foot pathologies and pain. Precut one-piece QUICK TAPE was designed to facilitate taping. However, no study to date has demonstrated that QUICK TAPE offers similar support and off-loading as traditional taping.

METHODS

This pilot study compared the performance of QUICK TAPE and low-Dye taping in 20 healthy participants (40 feet) with moderate-to-severe pes planus. Study participants completed arch height index (AHI), dynamic plantar assessment with a plantar pressure measurement system, and subjective rating in three conditions: barefoot, low-Dye, and QUICK TAPE. The order of test conditions was randomized for each participant, and the taping was applied to both feet based on a standard method. A generalized estimating equation with an identity link function was used to examine differences across test conditions while accounting for potential dependence in bilateral data.

RESULTS

Participants stood with a significantly greater AHI (P = .007) when either taping was applied compared with barefoot. Participants also demonstrated significantly different plantar loading when walking with both tapings versus barefoot. Both tapings yielded reduced force-time integral (FTI) in the medial and lateral forefoot and increased FTI under toes. Unlike previous studies, however, no lateralization of plantar pressure was observed with either taping. Participants ranked both tapings more supportive than barefoot. Most participants (77.8%) ranked low-Dye least comfortable, and 55.6% preferred QUICK TAPE over low-Dye.

CONCLUSIONS

Additional studies are needed to examine the clinical utility of QUICK TAPE in individuals with foot pathologies such as heel pain syndrome and metatarsalgia.

The Influence of Gender, Age, and Body Mass Index on Arch Height and Arch Stiffness

Arch structure and arch function play an important role in maintaining balance, bearing body weight, and absorbing ground reaction forces. However, arch structure and arch function are known to vary extensively and may be affected by factors such as gender, age, and obesity. Therefore, the purpose of this study was to examine the influence of gender, age, and body mass index (BMI) on arch height and arch stiffness. A total of 173 participants (aged 57.60 ± 11.19 years, mean BMI 25.12 ± 3.93 kg/m²) participated in this cross-sectional study. A 3-dimensional laser scanner was used to measure foot structure information in each subject, from which arch height and arch stiffness were calculated. The results showed that women had low-arched feet compared with men (p = .001), and no arch stiffness difference was found. Older individuals tended to have a stiffer arch than middle-aged and younger individuals (p < .05), and no arch height difference was found. BMI had an impact on arch height (p < .05) but not arch stiffness. Finally, a weak positive relationship existed between arch height and arch stiffness (r = 0.32, p < .01). The findings suggest that gender, age, and obesity have a certain impact on arch structure and arch stiffness. Figuring out the relationship between these factors and arch structure may be helpful in understanding the bases of foot deformity and foot dysfunction.

The biomechanical effects of pronated foot function on gait. An experimental study

The relationship between foot kinematics and the development of lower extremity musculoskeletal disorders (MSD) has been the focus of recent attention. However, most studies evaluated static foot type and not dynamic foot function. The purpose was to compare lower limb and foot kinematics, and plantar pressures during gait in physically active individuals with pronated and non-pronated foot function. Foot function in 154 adult participants was documented as pronated (n = 63) or neutral (n = 91) using 2 established methods: The Foot Posture Index and the Center of Pressure Excursion Index. Difference between the groups in triplanar motion of the lower limb during barefoot gait was evaluated using a 3D motion capture system incorporating the Oxford Foot Model. Dynamic parameters of plantar pressure were recorded using a pressure platform. Anterior-posterior pelvic tilt range of motion (ROM), peak knee internal rotation, forefoot dorsiflexion ROM, peak forefoot abduction, and rearfoot eversion were all increased in those with pronated foot function. Hallux contact time and time to peak force under the medial forefoot were increased with pronated foot function, and maximal force under the lateral forefoot was reduced. Pronated foot function affected the whole lower limb kinematic chain during gait. These kinematic alterations could increase the risk of developing MSD. Further studies should elucidate the relationship between pronated foot function and MSD, and, if confirmed, foot function should be evaluated in clinical practice for patients with lower limb and low back pain.

Morphological variations of the human talus investigated using three-dimensional geometric morphometrics

INTRODUCTION

The shape of the talus determines the positional and kinematic features of the subtalar, talonavicular, and talocrural joints during walking. Thus, detailed knowledge of the pattern of sexual dimorphism of the human talus may be useful for revealing the pathogenetic mechanism of foot and knee disorders, which are more prevalent in females. The aim of this study was to characterize and visualize the three-dimensional shape variations of the talus in relation to sex and age using geometric morphometrics.

MATERIALS AND METHODS

Computed tomography images of 56 feet without talar injuries or disorders were used in this study. Thirty-seven anatomical landmarks were identified on a bone model of the talus to calculate principal components (PCs) of shape variations among specimens. PC scores were compared between sexes, and their correlations with age were also investigated.

RESULTS

The female talus had a longer neck and narrower head width than the male talus. The superior trochlea was tilted more laterally in the frontal plane in females. Furthermore, the female talar head was more twisted and was more elongated in the dorsoplantar direction.

CONCLUSIONS

Morphological features of the talus in females could alter the subtalar and talonavicular joint kinematics during walking and could be a structural factor in the pathogenetic mechanism underlying foot and knee disorders. This study contributes to the comprehensive understanding of shape variations in the human talus.

Bilateral Symmetry, Sex Differences, and Primary Shape Factors in Ankle and Hindfoot Bone Morphology

Background:

Ankle injuries and joint degeneration may be related to ankle bone morphology. Little data exist to characterize healthy hindfoot bone morphology. The purpose of this study was to characterize side-to-side symmetry and sex differences in ankle and hindfoot bone morphology, and to identify the primary shape factors that differentiate ankle and hindfoot bone morphology among individuals.

Methods:

Computed tomography was used to create 3D surface models of the distal tibia, talus, and calcaneus for 40 ankle and hindfoot bones from 20 healthy individuals. Morphologic differences between left and right bones of the same individual and between males and females were determined. Statistical shape modeling was performed to identify primary shape variations among individuals.

Results:

Side-to-side differences in bone morphology averaged 0.79 mm or less. The average distal tibia in males was larger overall than in females. No significant sex difference was noted in the tali. The average female calcaneus was longer and thinner than the average male calcaneus. Variability in ankle and hindfoot bone morphology is primarily associated with articulating surface shape, overall length and width, and tendon/ligament attachment points.

Conclusion:

In general, the contralateral ankle can serve as an accurate guide for operative restoration of native ankle morphology; however, specific regions demonstrate higher asymmetry.

Clinical Relevance:

Knowledge of regions of high and low bilateral symmetry can improve hindfoot and ankle reconstruction. Design of ankle prostheses can be improved by accounting for differences in bone morphology associated with sex and shape differences among individuals.

Hyperelastic tape modifies the kinematics of the pronated foot in young women: self-controlled clinical trial

Abstract Introduction: Excessive pronation has been linked to increased risk of developing lower limb injuries. In this respect, assessing the effectiveness of therapeutic resources, such as hyperelastic taping, becomes relevant. Objective: evaluate the influence of adhesive hyperelastic taping on excessive pronation of the ankle-foot complex in young women. Method: Self-controlled clinical trial of ten women with excessive pronation (Foot Posture Index ≥ 6). Three-dimensional gait was assessed according to the Vicon Oxford Foot Model before and after taping. Hyperelastic tape was applied on the side with greater pronation (experimental side) and the opposite side was used as control (control side). The segments evaluated were the hindfoot, midfoot and forefoot. The Shapiro-Wilk normality, paired t and Wilcoxon tests were applied and Significance was set at p <0.05. Results: No change (p> 0.05) was observed in the hindfoot on the experimental or control side; the midfoot showed a decrease in arch height (p <0.05) only on the experimental side; forefoot eversion (p <0.05) declined only on the experimental side. Conclusion: The use of hyperelastic tape reduced forefoot eversion; however, this decrease is not clinically desirable, since excessive pronation in a closed chain increased in the sample of young women studied.