Classification of the height and flexibility of the medial longitudinal arch of the foot

Pelvic floor muscle strength and dysfunctions in women with pes planus: A case-control study

BACKGROUND/AIM

Distal extremity misalignment may give rise to pelvic floor dysfunctions (PFDs). This study aimed to compare pelvic floor muscle strength (PFMS) and dysfunctions in women with and without pes planus.

MATERIALS AND METHODS

Women with (pes planus group, n = 30) and without pes planus (control group, n = 30) were included. The presence of PFDs questioned. Pes planus with the Feiss Line Test, PFMS with the Modified Oxford Scale, and the severity of PFDs with the Pelvic Floor Distress Inventory-20 (PFDI-20), including three subscales (Pelvic Organ Distress Inventory-6 (POPDI-6) for pelvic organ prolapse, Colorectal-Anal Distress Inventory-8 (CRADI-8) for colorecto-anal symptoms, and Urinary Distress Inventory-6 (UDI-6) for urinary symptoms, were assessed.

RESULTS

It was seen that no difference was found between groups in terms of PFMS (p > 0.05). However, urinary incontinence and anal incontinence were higher in women with pes planus than in women without pes planus (p < 0.05). Only the PFDI-20, CRADI-8, and UDI-6 scores were higher in women with pes planus compared to controls (p < 0.05). There was no difference was found between groups in terms of POPDI-6 scores (p > 0.05).

CONCLUSION

The PFMS did not change according to the presence of pes planus. However, the prevalence of PFDs and their severity were higher in women with pes planus in comparison to controls. Posture assessments of individuals with PFDs, especially examination of foot posture, and pelvic floor assessments of individuals with posture disorders should be considered.

Causal Relationships Between Physical Activity and Arthrokinematic Integrity of the Ankle Joint-Foot Complex Across Normal and Pathological Phenomena: A Case-Control Analysis

Introduction Muscles, ligaments, tendons, bones, and cartilage undergo age-related changes, affecting the foot-ankle joint complex biomechanics in both genders. While international studies have extensively researched these dynamics, Indian studies are limited. Our study aims to fill this gap by analyzing the anthropometric and biomechanical function of the foot-ankle joint complex in normal individuals and those with painful pathologies at All India Institute of Medical Sciences (AIIMS) Rajkot's OPD. Methods In a two-year case-control study of the cross-sectional type conducted at AIIMS Rajkot's OPD, 158 patients with similar pain intensity on the Numeric Pain Rating Scale were examined. Anthropometric and biomechanical measurements were taken for both affected and non-affected foot and ankle joints. Cases comprised patients with foot and ankle joint pain, while controls were selected based on predefined criteria and were without such pain. Ethical approval was acquired from the Institutional Ethical Committee of AIIMS Rajkot. Results The sprain of the ankle joint and foot was the most common musculoskeletal pathology (65 out of 158 cases, i.e., 41.13%) affecting the ankle joint-foot complex. Patients involved in occupations requiring higher physical inactivity suffer more commonly from ankle joint-foot pathologies. The mean difference in the range of motion, i.e., dorsiflexion, plantar flexion, inversion, and eversion, between affected and non-affected feet was found to be lower in the patients who belonged to occupations involving low physical activity compared to those patients having occupations with high physical activity. Conclusion Reduced physical activity increases the stiffness and reduces the flexibility of the tendons, muscles, and ligaments of any joint (the ankle joint-foot complex in this study) and is associated with a higher incidence of musculoskeletal pathologies.

EXERCISES AND NEUROMUSCULAR ELECTRIC STIMULATION FOR MEDIAL LONGITUDINAL ARCH: CLINICAL TRIAL

Objective

The extrinsic muscles, such as the posterior tibialis and long flexor of the hallux and the intrinsic of the foot, are part of the active subsystem of the central system of the foot and play an essential role in the control of the medial longitudinal arch resulting from difficulty in contracting the muscle, neuromuscular electrostimulation (NMES) becomes a resource combined with strengthening and recommended for rehabilitation. T this work aims to evaluate the effectiveness of NMES associated with exercise in deforming the medial longitudinal arch.

Methods

This is a randomized blind clinical trial. 60 asymptomatic participants were divided into three groups: NMES, exercise and control. The NMES and exercise group performed seven exercises for the intrinsic and extrinsic muscles twice a week for 6 weeks, and the NMES group used an NMES associated with five exercises. Navicular height and medial longitudinal arch angle were taken before and after the intervention period.

Results

No statistically significant differences existed between groups for navicular height and medial longitudinal arch angle.

Conclusion

NMES associated with exercise does not change the characteristics of the medial longitudinal arch in association with asymptomatic. Level of Evidence I; Randomized clinical trial.

Examining the Relationship between Pes Planus Degree, Balance and Jump Performances in Athletes

The foot absorbs shocks with its arches, muscles, ligaments and joints, and bodyweight transmission and it pushes the body forward during all movement patterns. Pes planus is more important in sports activities that include balance and sports performance, such as walking, running, jumping, or transferring weight to a single lower limb. This study, conducted with this information in mind, aims to examine the effects of pes planus deformity on balance and vertical jump performance. Fifty athletes were included in the study. The presence of pes planus was evaluated according to the Feiss line. Balance measurements were performed with a Balance System SD Biodex. Vertical jump performance was recorded using an Omegawave jumping mat. The relationship between the pes planus grades of the participants and their balance and jump performances was analyzed using the Spearman correlation method. Vertical jump and Limit of stability (LOS) was significantly correlated with pes planus.

Monitoring the Role of Physical Activity in Children with Flat Feet by Assessing Subtalar Flexibility and Plantar Arch Index

Flat foot is a common pediatric foot deformity which involves subtalar flexibility; it can affect the plantar arch. This study analyzes the evolution of two parameters, i.e., plantar index arch and subtalar flexibility, before and after physiotherapy and orthoses interventions, and examines the correlation between these two parameters. Methods: The study included 30 participants (17 boys, 12 girls, average age 9.37 ± 1.42 years) with bilateral flat foot. We made two groups, each with 15 subjects. Assessments of the subtalar flexibility and plantar arch index used RSScan the platform, and were undertaken at two time points. Therapeutic interventions: Group 1—short foot exercises (SFE); Group 2—SFE and insoles. Statistical analyses included Student’s t-test, Cohen’s D coefficient, Pearson and Sperman correlation. Results: Group 1—subtalar flexibility decreased for the left and right feet by 28.6% and 15.9% respectively, indicating good evolution for the left foot. For both feet, a decrease of the plantar index arch was observed. Group 2—subtalar flexibility decreased for the right and left feet by 43.4% and 37.7% respectively, indicating a good evolution for the right foot. For both feet, a decrease of plantar index arch was observed. Between groups, subtalar flexibility evolved well for Group 2; this was attributed to mixt intervention, physical therapy and orthosis. For plantar arch index, differences were not significant between the two groups. We observed an inverse correlation between subtalar flexibility and plantar arch index. Conclusions: Improvement of plantar index arch in static and dynamic situations creates the premise of a good therapeutic intervention and increases foot balance and postural control. The parameter which showed the most beneficial influence was the evolution is subtalar flexibility.

Validity and inter-rater reliability of ankle motion observed during a single leg squat

BACKGROUND

The single leg squat (SLS) test is a clinical functional test commonly used to evaluate clinically aberrant movement patterns of the knee. The SLS could be an interesting option to analyze ankle control in the frontal plane during dynamic load analysis. However, to date, there are no studies that have analyzed the associations between the increased subtalar joint pronation by navicular drop (ND) test and ankle control with single leg squat (SLS_ankle) using a three-point scale. The purpose of this study was to evaluate the reliability of a clinical observation method to assess and determine the relationship between navicular drop (ND) and ankle control on the SLS_ankle score.

METHODS

A total of fifty-five healthy, physically active (31 females and 24 males) volunteers participated in this study. The degree of subtalar pronation was assessed through the ND test, and the ankle control was defined as the ankle displacement in the frontal plane during the SLS.

RESULTS

We found good intra-rater and inter-rater agreement during SLS_ankle, with Kappa values from 0.731 to 0.750. The relationship between the SLS_ankle and ND was significant ; the Spearman's rank correlation coefficient was 0.504 (p < 0.05).

CONCLUSIONS

The SLS_ankle score supplied the clinical practice with a reliable and valid alternative for quantifying foot mobility in comparison to the ND test.

A Study on the Contribution of Medial and Lateral Longitudinal Foot Arch to Human Gait

This study aimed to investigate the contribution of medial longitudinal arch and lateral longitudinal arch in human gait and to study the correlation between foot features and gait characteristics. The foot arch plays a significant role in human movements, and understanding its contribution to spatiotemporal gait parameters is vital in predicting and rectifying gait patterns. To serve the objectives, the study developed a new foot feature measurement system and measured the foot features and spatiotemporal gait parameters of 17 young healthy subjects without any foot structure abnormality. The foot-feature parameters were measured under three movement conditions which were sitting, standing, and one-leg standing conditions. The spatiotemporal gait parameters were measured at three speeds which were fast, preferred, and slow speeds. The correlation study showed that medial longitudinal arch characteristics were found to be associated with temporal gait parameters while lateral longitudinal arch characteristics were found to be associated with spatial gait parameters. The developed system not only eases the burden of manual measuring but also secures accuracy of the collected data. Inviting variety of subjects including athletes and people with abnormal foot structures would extend the scope of this study in the future. The findings of this study break new ground in the field of the foot- and gait-related research work.Clinical Relevance-This study demonstrated that the medial longitudinal arch and lateral longitudinal arch characteristics were related to the temporal and spatial gait parameters, respectively. These underlying findings can be applied to investigate relationships between foot abnormality and gait characteristics.

The Design and Validation of a Low-Cost Foot Measurement System

It is estimated that approximately 40% of the population suffers from abnormal foot posture, specifically high arched or low arched feet. While the evaluation of foot posture can involve many aspects, it commonly requires the measurement of basic dimensions of the foot. Clinicians and researchers often rely on the use of specialized devices or three-dimensional (3D) scanners to evaluate specific aspects of a patient's foot posture. However, current technologies are extremely expensive, therefore highlighting the need for a cost-effective device to be used in rural and clinical settings. As a result, the purpose of this study was to develop an inexpensive system to measure total foot length, truncated length, dorsum height, navicular height, and foot width. Bland-Altman plots showed significant differences between this measurement system and a 3D scanner for total foot length, truncated length, and navicular height (p < 0.001) and significant differences when assessing the repeatability of dorsum height (p = 0.022). However, the magnitudes of these differences were minimal compared to the overall measurement. Additionally, interclass correlation coefficients revealed that this system had excellent validity when compared to a 3D scanner (interclass correlation coefficients = 0.908-0.994), and good to excellent repeatability when compared between days (interclass correlation coefficients = 0.867-0.996). These results demonstrate that it is possible to design an inexpensive, valid, and repeatable system that can be used in clinical, research, and rural settings to successfully evaluate basic dimensions of the foot that can be used for the determination of foot type.

Foot Posture and Plantar Loading With Ankle Bracing

CONTEXT

Arch height is one important aspect of foot posture. An estimated 20% of the population has pes planus and 20% has pes cavus. These abnormal foot postures can alter lower extremity kinematics and plantar loading and contribute to injury risk. Ankle bracing is commonly used in sport to prevent these injuries, but no researchers have examined the effects of ankle bracing on plantar loading.

OBJECTIVE

To evaluate the effects of ankle braces on plantar loading during athletic tasks.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 36 participants (11 men, 25 women; age = 23.1 ± 2.5 years, height = 1.72 ± 0.09 m, mass = 66.3 ± 14.7 kg) were recruited for this study.

INTERVENTION(S)

Participants completed walking, running, and cutting tasks in 3 bracing conditions: no brace, lace-up ankle-support brace, and semirigid brace.

MAIN OUTCOME MEASURE(S)

We analyzed the plantar-loading variables of contact area, maximum force, and force-time integral for 2 midfoot and 3 forefoot regions and assessed the displacement of the center of pressure. A 3 × 3 mixed-model repeated-measures analysis of variance was used to determine the effects of brace and foot type (α = .05).

RESULTS

Foot type affected force measures in the middle (P range = .003-.047) and the medial side of the foot (P range = .004-.04) in all tasks. Brace type affected contact area in the medial midfoot during walking (P = .005) and cutting (P = .01) tasks, maximum force in the medial and lateral midfoot during all tasks (P < .001), and force-time integral in the medial midfoot during all tasks (P < .001). Portions of the center-of-pressure displacement were affected by brace wear in both the medial-lateral and anterior-posterior directions (P range = .001-.049).

CONCLUSIONS

Ankle braces can be worn to redistribute plantar loading. Additional research should be done to evaluate their effectiveness in injury prevention.

SUBTALAR JOINT IN NEUTRAL AND RELAXED POSITIONS FOR EVALUATION OF MEDIAL LONGITUDINAL ARCH

OBJECTIVE

The medial longitudinal arch is the main structure of load bearing and shock absorption of the foot. The evaluation of medial longitudinal arch, such as the navicular height, the medial longitudinal arch angle and the Feiss line should be performed with the subtalar joint in the neutral and relaxed position. Our study analyzed the correlation between the measurements of the subtalar joint in neutral and relaxed positions during the evaluation tests of the medial longitudinal arch.

METHODS

This is a cross-sectional study, in which 51 healthy volunteers (102 feet; 36 women; 28 ± 5 years, 1.66 ± 0.10 m; 24.5 ± 4.5 kg/m2) had their navicular height, medial longitudinal arch angle and Feiss line measured in the neutral and relaxed positions. The correlation between the measures was evaluated using Pearson's test.

RESULTS

A strong correlation of the 102 feet Feiss line measurements between neutral and relaxed positions (r = 0.81) was observed, and a moderate correlation between the medial longitudinal arch angle (r = 0.78) and between navicular height in neutral and relaxed positions (r = 0.76).

CONCLUSION

The measurements of the longitudinal medial arch between the neutral and relaxed positions are strongly correlated. Therefore, it is not necessary to measure the medial longitudinal arch in both neutral and relaxed positions. Level of Evidence II, Diagnostic Studies - Investigating a diagnostic test.

Relationship between dynamic foot-ground contact area and balance impairments in adolescents with down syndrome

PURPOSE

Down Syndrome (DS) is characterized by intellectual disability, hypotonia, and joint laxity. Physical disability can be an additional problem and manifests as reduced lower limb muscle strength and impaired balance. The objectives of this study were to characterize DS dynamic foot-ground contact area and to study its relationship with balance impairment among adolescents with DS.

METHODS

Twenty-eight children and adolescents with DS and 28 non-DS adolescents/children were matched for age and sex. The Oxford Ankle Foot Questionnaire (parents' version) was used to measure disability related to ankle/foot problems in all subjects. A pressure-sensitive mat was used to assess the contact area and arch index. Also, a Biodex balance system was used for measuring postural stability.

RESULTS

There were significant differences between both groups in all domains of the Oxford Ankle Foot Questionnaire, overall contact area, and arch index (p < 0.05). Overall postural stability index was significantly decreased in subjects with DS (p < 0.05). There was a nonsignificant correlation between contact area and postural stability (p > 0.05).

CONCLUSION

Adolescents with DS exhibited larger mid-foot and forefoot contact areas with respect to non-DS matched children. Impairment of balance in adolescents with DS is a multifactorial problem not related to changes in the foot contact area.

Assessment of quadriceps angle in children aged between 2 and 8 years

Aim:

The quadriceps angle is the angle between the line drawn from the spina iliaca anterior superior to the midpoint of the patella, and the line drawn from the midpoint of the patella to the tuberositas tibiae. It is important for lower extremity posture. The aim of this study was to determine the normative quadriceps angle value by measurement, and to assess the probable effect of factors such as measurement position, age, sex, and presence of pes planus on these values.

Material and Methods:

A total of 599 children consisting of 296 (49.4%) girls and 303 (50.6%) boys aged between 2 and 8 years, were included in the study. The children were divided into three groups by age as 2–4 years, 4–6 years, and 6–8-years. After the children’s demographic data were collected, the quadriceps angle was measured using an electronic goniometer. Pes planus was assessed by drawing the Feiss line.

Results:

In bilateral measurement, it was found that the quadriceps angle decreased with age both in the supine and standing positions (p<0.05). It was observed that sex and presence of pes planus had no effect on the quadriceps angle independent from measurement positions (p>0.05). A low negative correlation was found between body mass index and the quadriceps angle in both measurement positions (p<0.05).

Conclusion:

It was found that positional changes and weight bearing on limbs did not cause any change in knee position in healthy children. We consider that the decrease in quadriceps angle in this age group is due to growth rate asymmetry between the femur shaft and pelvic diameter.

Associations between biomechanical and clinical/anthropometrical factors and running-related injuries among recreational runners: a 52-week prospective cohort study

BACKGROUND

The purpose of this exploratory study was to investigate whether runners with certain biomechanical or clinical/anthropometrical characteristics sustain more running-related injuries than runners with other biomechanical or clinical/anthropometrical characteristics.

METHODS

The study was designed as a prospective cohort with 52-weeks follow-up. A total of 224 injury-free, recreational runners were recruited from the Gothenburg Half Marathon and tested at baseline. The primary exposure variables were biomechanical and clinical/anthropometrical measures, including strength, lower extremity kinematics, joint range of motion, muscle flexibility, and trigger points. The primary outcome measure was any running-related injury diagnosed by a medical practitioner. Cumulative risk difference was used as measure of association. A shared frailty approach was used with legs as the unit of interest. A total of 448 legs were included in the analyses.

RESULTS

The cumulative injury incidence proportion for legs was 29.0% (95%CI = 24.0%; 34.8%). A few biomechanical and clinical/anthropometrical factors influence the number of running-related injuries sustained in recreational runners. Runners with a late timing of maximal eversion sustained 20.7% (95%CI = 1.3; 40.0) more injuries, and runners with weak abductors in relation to adductors sustained 17.3% (95%CI = 0.8; 33.7) more injuries, compared with the corresponding reference group.

CONCLUSIONS

More injuries are likely to occur in runners with late timing of maximal eversion or weak hip abductors in relation to hip adductors.

Feet deformities and their close association with postural stability deficits in children aged 10-15 years

BACKGROUND

Children and young people make up an age group most vulnerable to falls. Various stability disorders may become instrumental in sustaining more frequent falls and resultant fractures. Correct morphological structure impacts overall efficiency of the foot, as well as offers significant diagnostic potential. Even minor foot disorders may affect the entire bio kinematic chain, also impacting the foot's motility. Structural alterations within a foot may also impair balance in the standing position, and contribute to more frequent injuries. The study aimed to assess the relationship between feet deformities and postural stability deficits in schoolchildren prone to sustain accidental falls.

METHODS

The study involved 200 children (101 girls and 99 boys) aged 10-15 years, randomly selected from primary schools. A 2D podoscan was used to assess the plantar part of the foot, while stabilometric examination was aided by the FreeMed dynamometric platform.

RESULTS

Correlation between respective variables was reflected by Spearman's rank coefficient. The subjects' age negatively correlated with the COP range of movement along the Y axis, and the COP surface area, while their BMI negatively correlated with the COP trajectory's length. Step regression analysis indicated that the width of the left foot, the left foot Wejsflog index, the left foot Clark's angle, the hallux valgus angle were the essential predictors of stabilometric variables in girls. In boys, though, predictive value was associated with Clarke's angle of the left and right foot, Wejsflog index of the right foot, and the width of both the left and right foot.

CONCLUSIONS

There is a statistically significant correlation between morphological variables of the foot and postural stability. When assessing the key variables of the foot and their interrelationship with postural stability, the Clarke's angle, Wejsflog index, hallux valgus angle, and foot width, should be granted due prominence in the girls. As regards the boys, the following variables were established as predictive in assessing postural stability: Clarke's angle, Wejsflog index, and foot width.

Relationships between the foot posture Index and static as well as dynamic rear foot and arch variables

Clinicians, podiatrists and researchers have been quantifying foot posture and movement in various speed conditions and populations. Common variables to assess foot posture/movement are the Foot Posture Index (FPI-6), Achilles tendon angle (β), rear foot angle (γ) and longitudinal arch angle (LAA). These variables were frequently used in clinical and biomechanical settings. This study aimed to determine the relationship between the biomechanical variables (β, γ & LAA) in static and dynamic conditions and the clinically used FPI-6 and their redundancy. Forty participants performed bipedal standing, over ground walking and running trials. Manual assessment data (FPI-6), kinematic data and ground reaction forces were collected. Discrete biomechanical variables (β, γ & LAA) were calculated at various time points (e.g. heel strike). A Principal Component Analysis (PCA) was performed to quantify the contribution of each variable to the overall variance in the data set. Spearman correlations were used to assess the relationship between the sub-measures of the FPI-6 and the biomechanical variables. Two major components were found that explained 85.2% of the overall variance, consisting of LAA and β variables, respectively. Only LAA variables showed significant, but moderate correlations (r < -0.6) with the fifth sub-measurement of the FPI-6. The LAA and β describe independent movements, which dominate foot posture/movement in static and dynamic conditions. The FPI-6 sub-measurements did not closely reflect static nor dynamic behavior of the rear and mid foot. The FPI-6 and biomechanical variables may not be used interchangeably for screening or grouping individuals according to their foot posture/movement.

Can short-term effectiveness of anti-pronation taping predict the long-term outcomes of customized foot orthoses: developing predictors to identify characteristics of patients with plantar heel pain likely to benefit from customized foot orthoses

Background

Foot orthoses are widely used to manage plantar heel pain (PHP). However, the evidence concerning the effect of foot orthoses on PHP is not conclusive. The study aims to identify the characteristics of patients with PHP likely to achieve a positive outcome after customized foot orthoses and to verify the concept that patients who respond positively to anti-pronation taping would achieve a positive prognosis after wearing foot orthoses for six months.

Methods

This is a prospective observational cohort study. Seventy-four patients with PHP underwent a baseline examination and received anti-pronation taping to their painful feet. The taping effects on pain and function were assessed at the 7-day follow-up visit. Then, all patients received an intervention for their PHP with customized foot orthoses for six months. Outcome was assessed with a numeric pain rating scale, the patient-specific functional scale, the foot function index, and the global rating of perceived change. Significant reduction of pain, increase of function, and perception of a meaningful improvement were considered a positive response.

Results

Of 74 patients, 49 had a positive response to the customized foot orthosis treatment. Five predictors were identified: (1) the average pain intensity decreased by over 1.5 points with taping, (2) the range of ankle plantarflexion > 54 degrees, (3) the strength of ankle plantarflexors on the symptomatic side was equal to or stronger than that on the other side, (4) the range of hip internal rotation < 39 degrees, and (5) the range of hip external rotation > 45 degrees. The presence of three or more predictors increased the rate of achieving positive outcome from 66 to 89%.

Conclusions

The predictors of customized foot orthosis outcome in patients with PHP are related to several physical measures of a lower extremity. Findings of the study can be used to screen and select patients with PHP for foot orthosis intervention. Moreover, patients who respond positively to anti-pronation taping would also benefit from the customized foot orthoses. However, since there was no control group in the current study, it is inappropriate to draw conclusions about the effectiveness of the foot orthoses treatment.

Trial registration

The trial was retrospectively registered with the Australian and New Zealand Clinical Trials Registry (ACTRN 12617000119392).

Effect of toe dorsiflexion on the regional distribution of plantar fascia shear wave velocity

BACKGROUND

The plantar fascia is exposed to repetitive tensile stress induced by cyclic loads associated with daily activities, such as walking and running. Due to overuse or abnormal foot alignment, insertional and distal (i.e., mid-substance) regions within the plantar fascia may exhibit microtears, which leads to plantar fasciopathy. Ultrasound shear wave elastography is an imaging technique to measure shear wave velocity propagating through biological tissues, considered herein as an index of tensile stress. This study aimed to quantify the effect of toe dorsiflexion on the regional distribution of plantar fascia shear wave velocity.

METHODS

Shear wave velocity of the plantar fascia was measured in the insertional and distal regions using ultrasound shear wave elastography in sixteen healthy participants (7 males and 9 females). The measurements were performed while the toes were maintained in neutral or dorsiflexed positions.

FINDINGS

When considering the insertional region, there was no significant difference in shear wave velocity between neutral toe position [mean (SEM): 5.4 (0.6) m/s] and dorsiflexed toe position [5.5 (0.5) m/s] (P = 0.88; effect size = 0.05). When considering the distal region, there was a significant difference in shear wave velocity between the neutral position [7.8 (0.4) m/s] and dorsiflexed position [9.9 (0.3) m/s] (P = 0.002; effect size = 0.88). The difference in shear wave velocity between the insertional and distal regions showed a large effect size for either neutral (P = 0.010; effect size = 0.75) or dorsiflexed toe position (P = 0.003; effect size = 0.86).

INTERPRETATION

In contrast to clinical beliefs, these findings suggest that toe dorsiflexion induces non-homogeneous changes in tensile stress within the plantar fascia.

Use of high speed stereo radiography to assess the foot orthoses effectiveness in controlling midfoot posture during walking: A pilot study

BACKGROUND

The intent of this pilot study was to determine the feasibility of using high-speed stereo radiography (HSSR) to assess the effectiveness of footwear and foot orthoses in controlling the change in the position of the midfoot during walking in individuals with a flexible pes planus foot type.

METHODS

Four individuals (1 female; 3 male) with a mean age of 25 years (range 22-29) and a bilateral flexible pes planus foot type participated in the study. The HSSR system was used to measure 3-dimensional changes in the longitudinal arch angle (LAA) with each participant walking barefoot, shoe only and shoes with orthoses.

RESULTS

The HSSR system was found to be highly effective in measuring the change in the position of the midfoot, as measured using the LAA, when wearing footwear with or without foot orthoses. Based on an assessment of mean values, three out of the four participants demonstrated a change in the LAA as a result of using either shoes only or shoes with orthoses. The methodology used in this pilot study for assessing the effect of footwear and foot orthoses on the posture of the midfoot was highly effective with no side-effects noted by any of the study participants.

CONCLUSIONS

Future studies using the HSSR will require modifications to participant inclusion criteria as well as alterations to the data collection methodology. The HSSR system used in this study is feasible for use in larger cohort studies assessing footwear and foot orthosis effectiveness with the described modifications.

Development of a clinical prediction rule to identify patients with plantar heel pain likely to benefit from biomechanical anti-pronation taping: A prospective cohort study

OBJECTIVES

To develop a clinical prediction rule (CPR) to identify patients with plantar heel pain (PHP) likely to benefit from biomechanical anti-pronation taping (BAPT).

DESIGN

A prospective cohort study.

SETTING

An outpatient rehabilitation department in a general hospital.

PARTICIPANTS

Seventy-five patients with PHP.

MAIN OUTCOME MEASURES

After completing a series of physical examinations, all patients received BAPT and were evaluated with a numeric rating scale for pain intensity, the patient-specific functional scale and foot function index (FFI) for function, and the global rating of change for perceived improvement.

RESULTS

Twenty-eight patients achieved a successful outcome. A CPR with 6 significant variables was identified by a multivariate logistic regression: FFI score less than 33.3, hip adduction angle of the most affected side was greater than the contralateral side, ankle plantarflexors and hip abductors on the most affected side were not weaker than those on the contralateral side, ankle invertors on the most affected side were weaker than the contralateral side, and having more than 2 painful sites in the low back and lower extremity regions. If 5 or more of the 6 predictors were presented, the probability of success increased from 37% to 80%.

CONCLUSIONS

A CPR has been developed to identify patients with PHP likely to benefit from BAPT.

Do Structural Changes of the Foot Influence Plantar Pressure Patterns During Various Stages of Pregnancy and Postpartum?

BACKGROUND

The foot of a pregnant woman undergoes morphological changes with the advancement of pregnancy. It is important to understand the structural changes of the foot during pregnancy and postpartum because any such change may alter the plantar pressure pattern and the entire foot biomechanics.

METHOD

Primigravidae with a gestational age of 12 weeks or less, aged between 18 and 35 years were included in the study. They were prospectively studied across 5 time periods during pregnancy and postpartum. The measures recorded were length, width, navicular height, truncated foot length and normalized navicular height, truncated ratio of the foot, and the static plantar pressure pattern. Repeated-measures ANOVA was done to analyze the changes across various time periods.

RESULTS

All the foot parameters, except foot length and truncated foot length, showed significant differences across various time periods of pregnancy and postpartum (P < .001). It was found that the static plantar pressures also varied significantly (P ≤ .001).The maximum pressure was recorded at the hindfoot of the dominant leg.

CONCLUSION

The feet of pregnant women tend to get pronated as pregnancy advances but do not reach baseline values even at 6 weeks postpartum. Pregnant women tend to bear more weight on the dominant foot with an increased static hindfoot pressure as pregnancy progresses.

LEVELS OF EVIDENCE

Prognostic study, Level I: Prospective.

An Investigation of Structure, Flexibility, and Function Variables that Discriminate Asymptomatic Foot Types

It has been suggested that foot type considers not only foot structure (high, normal, low arch), but also function (overpronation, normal, oversupination) and flexibility (reduced, normal, excessive). Therefore, this study used canonical regression analyses to assess which variables of foot structure, function, and flexibility can accurately discriminate between clinical foot type classifications. The feet of 61 asymptomatic, healthy adults (18–77 years) were classified as cavus (N = 24), rectus (N = 54), or planus (N = 44) using standard clinical measures. Custom jigs assessed foot structure and flexibility. Foot function was assessed using an emed-x plantar pressure measuring device. Canonical regression analyses were applied separately to extract essential structure, flexibility, and function variables. A third canonical regression analysis was performed on the extracted variables to identify a combined model. The initial combined model included 30 extracted variables; however 5 terminal variables (malleolar valgus index, arch height index while sitting, first metatarsophalangeal joint laxity while standing, pressure-time integral and maximum contact area of medial arch) were able to correctly predict 80.7% of foot types. These remaining variables focused on specific foot characteristics (hindfoot alignment, arch height, midfoot mechanics, Windlass mechanism) that could be essential to discriminating foot type.

Differences in Pes Planus and Pes Cavus subtalar eversion/inversion before and after prolonged running, using a two-dimensional digital analysis

In sports, there is a constant discussion about the hyper-pronation and supination of the foot during loading and its relation to injuries or discomfort. The purpose of the present study was to investigate the possible differences in the subtalar joint in the midstance phase of running, between individuals with Pes Planus and Pes Cavus, after 5 min and 45 min of running. Thirty-four subjects, meeting the requirements for Pes Planus (30 feet) and Pes Cavus (35 feet), according to the criteria for Medial Longitudinal Arch-angle, were included in the study. The calcaneal vertical angle, representing the eversion/inversion of the subtalar joint, was measured using with two-dimensional digital analysis and Dartfish Software with the subjects running barefoot on a treadmill, before and after 45 min of outside running wearing shoes. Both individuals with Pes Cavus and Pes Planus showed a significant increase in the calcaneal eversion (P<0.05) after 45 min of running. Between the groups, there was a significantly greater eversion of the Pes Planus, on the right foot, after 45 min of running (P<0.05) compared to the Pes Cavus. The effect of fatigue evident in the present study suggests that further biomechanical research should be considered when exposing the foot to the repetitive nature of running, conditions most likely responsible for the overrepresented overuse injuries among runners.

Evaluation of the relationship between the static measurement of transverse arch flexibility of the forefoot and gait parameters in healthy subjects

[Purpose] To investigate the relationship between the static measurement of the transverse arch of the forefoot, using a 3-dimensional (3D) foot scanner, and kinetics and kinematics of gait parameters in the sagittal plane. [Subjects and Methods] Twenty healthy subjects participated in this study. The transverse arch of the forefoot was measured under three conditions as follows: condition 1, sitting; condition 2, standing; and condition 3, foot forward and lower leg tilting anteriorly to the maximum position with heel contact. Gait parameters were recorded using a 3D motion analysis system and force plate. Correlation coefficients between TAF for each comparison of conditions and gait parameters were calculated using the Spearman correlation analysis. [Results] Rates of the transverse arch of the forefoot width and height between condition 2 and condition 3 were significantly correlated with the anterior and posterior component of ground reaction forces, the hip joint extension angle, and the ankle plantar flexion moment. [Conclusion] Our study’s findings indicated that increased stiffness of the transverse arch of the forefoot was related to the increase in ankle plantar moment, and decreased stiffness of the transverse arch of the forefoot was related to the increase in hip joint extension angle during gait.

Plantar Pressure Detection with Fiber Bragg Gratings Sensing System

In this paper, a novel fiber-optic sensing system based on fiber Bragg gratings (FBGs) to measure foot plantar pressure is proposed. This study first explores the Pedar-X insole foot pressure types of the adult-size chart and then defines six measurement areas to effectively identify four foot types: neutral foot, cavus foot, supinated foot and flat foot. The plantar pressure signals are detected by only six FBGs, which are embedded in silicone rubber. The performance of the fiber optic sensing is examined and compared with a digital pressure plate of i-Step P1000 with 1024 barometric sensors. In the experiment, there are 11 participants with different foot types to participate in the test. The Pearson correlation coefficient, which is determined from the measured results of the homemade fiber-optic plantar pressure system and i-Step P1000 plantar pressure plate, reaches up to 0.671 (p < 0.01). According to the measured results from the plantar pressure data, the proposed fiber optic sensing system can successfully identify the four different foot types. Measurements of this study have demonstrated the feasibility of the proposed system so that it can be an alternative for plantar pressure detection systems.

The use of a static measure to predict foot posture at midstance during walking

Previous studies have successfully used the longitudinal arch angle (LAA) to assess foot posture, but the measurement consistency and ability of the LAA to predict dynamic foot posture during activity in a variety of foot types have not been evaluated. The purpose of this study was to determine the reliability of the LAA as well as if the clinical method of assessing the LAA could be used to predict the LAA at midstance during walking for supinated, normal, and pronated foot types. The Arch Height Ratio was used to select 35 participants with 12 supinated, 46 normal, and 12 pronated feet. A standard goniometer was used to measure the LAA (CLINIC_LAA) on both feet while standing. Both feet were then filmed using a high speed camera while walking on a treadmill. The LAA was determined by the angle formed by two lines drawn between the markers placed on the first metatatarsal and medial malleolus with the apex the navicular tuberosity. The LAA in midstance (WALK_LAA) was determined using the mean of five walking trials. The reliability of the CLINIC_LAA assessed on both feet by two raters over two days were excellent. There was no difference between the left and right foot for the CLINIC_LAA. The Pearson correlation between CLINIC_LAA and WALK_LAA for all 70 feet was r=0.96 (r²=0.92). The results indicate the LAA is highly predictive of foot posture at midstance in walking explaining over 90% of the variance for a wide range of foot types.

Pathophysiology of juvenile idiopathic arthritis induced pes planovalgus in static and walking condition: a functional view using 3D gait analysis

BACKGROUND

Patients suffering from juvenile idiopathic arthritis (JIA) frequently have affected ankle joints, which can lead to foot deformities such as pes planovalgus (JIA-PPV). Usually, JIA-PPV is diagnosed by examining the foot in non-weightbearing or in weightbearing, static condition. However, functional limitations typically appear during dynamic use in daily activities such as walking. The aim of this study was to quantify the pathophysiology of JIA-PPV in both static and dynamic condition, i.e. in upright standing and during the stance phase of walking using three-dimensional (3d) gait analysis.

METHODS

Eleven JIA patients (age = 12y) with at least one affected ankle joint and fixed pes planovalgus (≥5°) were compared to healthy controls (CG) (n = 14, age = 11y). Kinematic and kinetic data were obtained in barefoot standing and walking condition (1.1-1.3 m/s) with an 8-camera 3d motion analysis system including two force-plates and one pressure distribution plate. All participants were prepared using reflecting markers according to the Oxford Foot and Plug-in-Gait Model. Results were compared using the Mann-Whitney-U-test and Wilcoxon signed-rank test (p < 0.05).

RESULTS

In comparison to CG, JIA-PPV had an excessive hindfoot/tibia eversion (p < 0.001) and a forefoot/hindfoot supination (p < 0.001) in both static and walking condition. JIA-PPV showed a greater hindfoot/tibia eversion during walking (midstance) compared to standing (p = 0.021) in contrast to CG. The arch index, measured by plantar pressure distribution, indicates a reduced arch height in JIA-PPV (p = 0.007). Patients had a lower maximum dorsiflexion of hindfoot/tibia (p = 0.001) and a lower plantarflexion of forefoot/hindfoot (p = 0.028), both when standing and walking. The kinetic results showed lower maximum ankle dorsiflexion moments (p < 0.037) as well as generated ankle power (p = 0.086) in JIA-PPV.

CONCLUSIONS

The pathophysiology of JIA-PPV during walking indicated that excessive hindfoot eversion produces accessory symptoms such as a reduced arch height, increased forefoot supination and reduced propulsion effect of the ankle. Muscular and coordinative insufficiency caused by arthritis can lead to the observed increased hindfoot eversion from static to dynamic condition. Conventional static or passive foot examination techniques probably underestimate deformity in JIA pes planovalgus. 3d gait analysis might be helpful in early diagnosis of this condition, especially in JIA patients with affected ankle joints.

Dynamic in-vivo assessment of navicular drop while running in barefoot, minimalist, and motion control footwear conditions

Running-related injuries are common and previous research has suggested that the magnitude and/or rate of pronation may contribute to the development of these injuries. Accurately and directly measuring pronation can be challenging, and therefore previous research has often relied on navicular drop (under both static and dynamic conditions) as an indirect assessment of pronation. The objectives of this study were to use dynamic, biplane X-ray imaging to assess the effects of three footwear conditions (barefoot, minimalist shoes, motion control shoes) on the magnitude and rate of navicular drop during running, and to determine the association between static and dynamic measures of navicular drop. Twelve healthy distance runners participated in this study. The magnitude and rate of navicular drop were determined by tracking the 3D position of the navicular from biplane radiographic images acquired at 60Hz during the stance phase of overground running. Static assessments of navicular drop and foot posture were also recorded in each subject. Footwear condition was not found to have a significant effect on the magnitude of navicular drop (p=0.22), but motion control shoes had a slower navicular drop rate than running barefoot (p=0.05) or in minimalist shoes (p=0.05). In an exploratory analysis, static assessments of navicular drop and foot posture were found to be poor predictors of dynamic navicular drop in all footwear conditions (p>0.18).

Flexibility of the transverse arch of the forefoot

PURPOSE

To measure the percentage of the transverse arch length (%TAL) in 2 positions using a 3-dimensional motion capture system to determine the flexibility of the transverse arch of the forefoot.

METHODS

19 men and 10 women with no lower extremity injury or deformity were included. The %TAL of the left foot was measured using a digital caliper in the standing position and the lower leg maximum anterior tilting (LMAT) position. The difference in the %TAL between the 2 positions (δ%TAL) was calculated. 10 markers were mounted on skin over each metatarsal head and base of the left foot. Motion was captured using a 3-dimensional motion capture system. Coordinates of each marker were manually digitised. The percentage of the transverse arch height (%TAH) and angle between the first and fifth metatarsals (M1M5) were calculated, and differences in each forefoot parameter in the 2 positions were defined as δ%TAL, δ%TAH, δM1M5, and the fore foot flexibility magnitude (FFM) was calculated. Subjects were divided into 3 groups based on their δ%TAL: <25th percentile (hypo-flexibility group, n=7), >26th percentile to <74th percentile (control group, n=15), and >75th percentile (hyperflexibility group, n=7). The 3 groups were compared in terms of the δ%TAL. δ%TAH, δM1M5, and FFM.

RESULTS

The δ%TAL correlated with δM1M5 (r=0.61, p<0.001) and FFM (r=0.60, p=0.001). For the δM1M5, the hyper-flexibility group differed significantly from other groups (p=0.01). For the FFM, the hyperflexibility group differed significantly from the hypoflexibility group (p=0.02).

CONCLUSION

Measurement of the %TAL in both the standing and LMAT positions provides a simple and quantitative method of assessing the flexibility of the transverse arch of the forefoot.

The association of foot arch posture and prior history of shoulder or elbow surgery in elite-level baseball pitchers

STUDY DESIGN

Case-control.

OBJECTIVES

The specific aim of this study was to examine the association between abnormal foot arch postures and a history of shoulder or elbow surgery in baseball pitchers.

BACKGROUND

Pitching a baseball generates forces throughout the musculoskeletal structures of the upper and lower limbs. Structures such as the longitudinal arch of the foot are adaptable to stresses over time. Repeated pitching-related stresses may contribute to acquiring abnormal foot arch postures. Inversely, congenitally abnormal foot arch posture may lead to altered stresses of the upper limb during pitching.

METHODS

A convenience sample of 77 pitchers was recruited from a Division I university team and a professional baseball franchise. Subjects who had a history of shoulder or elbow surgery to the pitching arm were classified as cases. Subjects who met the criteria for classification of pes planus or pes cavus based on longitudinal arch angle were classified as having abnormal foot arch posture. Odds ratios were calculated to examine the association between abnormal foot arch posture and pitching-arm injury requiring surgery.

RESULTS

Twenty-three subjects were classified as cases. The odds of being a case were 3.4 (95% confidence interval: 1.2, 9.6; P = .02) times greater for subjects with abnormal foot arch posture and 2.9 (95% confidence interval: 1.0, 8.1; P = .04) times greater for subjects with abnormal foot posture on the lunge leg.

CONCLUSION

Abnormal foot arch posture and a surgical history in the pitching shoulder or elbow may be associated. Because the foot and its arches are adaptable and change over time, the pathomechanics of this association should be further explored.

Normative values for the foot posture index between right and left foot: a descriptive study

BACKGROUND

The foot posture index (FPI) is a commonly used method to quantify standing foot posture. No normative data have, however, been presented to establish the range of a normal difference and asymmetrical differences between FPI score in the right foot and in the left foot.

PURPOSE

The purpose of the present study was to establish normative values for the difference between the FPI scores across the two feet.

METHODS

Among 930 healthy adults, FPI score was quantified in both feet. Difference between the two feet was calculated as FPI score on the right foot minus the FPI score on the left foot. Based on a normal distribution of the differences, asymmetry was defined as values below or above one standard deviation (SD) from the mean. Severe asymmetry was below and above ±2SD from the mean. Normal difference was defined as the range between ±1SD.

RESULTS

A reference range for normal difference in FPI score between left foot and right foot was -2 to +2. Asymmetry scores ranged from -2 to -4 and +2 to +4, while severe asymmetry was <-4 and >4.

CONCLUSION

Normative values for the difference between FPI scores in right foot and left foot have been presented from a large sample of healthy adults. These normative values can be used to identify a normal difference or an asymmetrical difference in foot posture across feet in one individual.

Effects of kinesiotaping on foot posture in participants with pronated foot: a quasi-randomised, double-blind study

OBJECTIVE

To investigate whether kinesiotaping improves excessive foot pronation compared with sham kinesiotaping.

DESIGN

Quasi-randomised, double-blind study.

SETTING

One primary care centre.

PARTICIPANTS

One hundred and thirty participants were screened for inclusion. Sixty-eight participants with pronated feet [Foot Posture Index (FPI)≥ 6] were enrolled, and the follow-up rate was 100%.

INTERVENTIONS

Participants were allocated into one of two groups: an experimental kinesiotaping group (KT1) and a sham taping group (KT2). Measures were collected by a blinded assessor at baseline, and 1 minute, 10 minutes, 60 minutes and 24 hours after taping.

MAIN OUTCOME MEASURES

The primary outcome was total FPI score, and the secondary outcome was rear-foot FPI score.

RESULTS

There were no significant differences in total FPI score between kinesiotaping and sham taping at any time point. Similarly, there were no significant differences in rear-foot FPI score, apart from at 60-minute follow-up when the difference between groups was significant (P=0.04) but the effect size was very small (0.85 points on the rear-foot FPI score between -6 and +6).

CONCLUSIONS

Kinesiotaping does not correct foot pronation compared with sham kinesiotaping in people with pronated feet.

No association between q-angle and foot posture with running-related injuries: a 10 week prospective follow-up study

BACKGROUND/PURPOSE

There is a paucity of knowledge on the association between different foot posture quantified by Foot Posture Index (FPI) and Quadriceps angle (Q-angle) with development of running-related injuries. Earlier studies investigating these associations did not include an objective measure of the amount of running performed. Therefore, the purpose of this study was to investigate if kilometers to running-related injury (RRI) differ among novice runners with different foot postures and Q-angles when running in a neutral running shoe.

METHODS

A 10 week study was conducted including healthy, novice runners. At baseline foot posture was evaluated using the foot posture index (FPI) and the Q-angle was measured. Based on the FPI and Q-angle, right and left feet / knees of the runners were categorized into exposure groups. All participants received a Global Positioning System watch to allow them to quantify running volume and were instructed to run a minimum of two times per week in a conventional, neutral running shoe. The outcome was RRI.

RESULTS

Fifty nine novice runners of mixed gender were included. Of these, 13 sustained a running-related injury. No significant difference in cumulative relative risk between persons with pronated feet and neutral feet was found after 125 km of running (Cumulative relative risk = 1.65 [0.65; 4.17], p = 0.29). Similarly, no difference was found between low and neutral Q-angle (Cumulative relative risk = 1.25 [0.49; 3.23], p = 0.63).

CONCLUSION

Static foot posture as quantified by FPI and knee alignment as quantified by Q-angle do not seem to affect the risk of injury among novice runners taking up a running regimen wearing a conventional neutral running shoe. These results should be interpreted with caution due to a small sample size.

LEVEL OF EVIDENCE

2a.