Foot morphologic characteristics and risk of exercise-related injury

The effect of movement system impairment-based classification treatment compared to routine physiotherapy on pain, disability, alignment, and movement impairments in individuals with tibiofemoral rotation syndrome: a randomized controlled trial

BACKGROUND

Knee pain is a common musculoskeletal problem. Lower extremity movement impairments could alter stresses in different planes and contribute to knee pain. Classifying these impairments may be helpful in the diagnosis and treatment of knee problems. Movement system impairment (MSI)-based classification is a system to evaluate movement impairments. Trials that involve this classification are limited. Therefore, it will be of interest to examine the effect of movement system impairment-based classification treatment compared to routine physiotherapy in individuals with tibiofemoral rotation syndrome.

METHODS

Twenty-two individuals with knee pain aged 18-40 years (2 males, 20 females) diagnosed with tibiofemoral rotation (TFR) syndrome were included. After initial evaluation, individuals were randomly assigned into two treatment groups (MSI-based treatment and routine physiotherapy). Both treatment groups contained 8 treatment sessions over 4 weeks. Alignment and movement impairments data form, a numeric rating scale (NRS), and the Kujala Disability Questionnaire were assessed at baseline and after a four-week intervention. Independent samples t-test and Mann-Whitney U test were used for quantitative variables, and Fisher's exact test was employed for qualitative variables to compare the groups. One-way Analysis of variance (ANOVA) and paired samples t-test were utilized to within-group changes of quantitative variables, and qualitative variables were analyzed with the McNemar test.

RESULTS

The results showed that pain intensity and disability significantly decreased within and between groups after intervention (P > 0.05). There were also statistically significant differences between treatment groups for 3 out of 6 alignment and movement impairments (PS-FAdd/IR, Step down-Add/Valgus, and STS-Add/Valgus) (P > 0.05). Within-group differences for alignment and movement impairments were significant only for the MSI-based treatment group (P > 0.05).

CONCLUSIONS

The findings suggest that a specific MSI-based treatment, considering a homogenous group of individuals with knee pain, may contribute to pain, disability, and alignment and movement impairments improvement. Therefore, it is important to notice the classification-based treatment for individuals with knee pain.

TRIAL REGISTRATION NUMBER (TRN) AND DATE OF REGISTRATION

The trial was registered at the ( https://www.irct.ir ), (IRCT20210505051181N3) on 17/7/2021.

Changes in gait pattern and quality of life of adolescents with flexible flat foot after Calcaneal Lengthening Osteotomy

BACKGROUND

Calcaneal Lengthening Osteotomy is a surgical technique to correct flexible flat foot deformities in patients who did not show any change in their symptoms after conservative treatment. In this study, the effects of CLO on the kinematic and kinetic changes of gait was analyzed and the clinical and quality of life improvements in children treated by CLO for moderate to severe symptomatic flexible flat foot deformities were assessed.

METHODS

Participants were seven adolescents (13 feet) with symptomatic FFF who underwent during 2019-2022 and seven (10 feet) healthy children as control group. Three items were evaluated in each foot before and after surgery including: 1. Clinical examination 2.quality of life (using Pediatric Quality of Life Inventory version 4 questionnaire) 3. Gait analysis (Vicon motion systems, Oxford metrics Inc., UK). Also, the kinetic and kinematic analysis between patients and healthy groups were compared.

RESULTS

Kinematic results of control was significantly better than FFF group. Ankle range of motion(32.94 ± 13.39 compared to 32.94 ± 13.39,P-Value:0.01),foot progression angle (-9.26 ± 7.67 compared to -16.07 ± 9.00,P-Value:0.01),and internal rotation of ankle was higher in control group compared to FFF. FFF patients demonstrated improvement in kinematic results after CLO surgery. Foot progression angle was improved after surgery (-11.31 ± 6.07 compared to -16.19 ± 7.06, P-value:0.00), maximum plantar flexion decreased after CLO surgery due to achil tendon procedure during CLO surgery. Kinetic results of FFF patients showed significant increase in ankle Power in coronal and transverse plane, Also knee and hip power showed similar results.Quality of life parameters showed significant improve in all parameters (Physical,Social, emotional and school function), Also ADKE and ADKF improved after surgery.

CONCLUSION

CLO surgery significantly improved patients' quality of life of patients with symptomatic FFF. Also, kinetic results showed improvement in some parameters of gait results after CLO surgery. Thus, our study suggested CLO surgery as an excellent surgical option for symptomatic FFF.

Is Subtle Cavovarus a Problem for Athletes?

Cavovarus or high-arched foot is a common foot deformity that occurs due to the disruption of the foot-driven equilibrium between the first metatarsal, fifth metatarsal, and the heel. This imbalance leads to an increase in the foot's normal plantar concavity. Cavovarus deformity ranges from a mild and flexible malalignment to a fixed, complex, and severe deformation. Subtle cavovarus foot, the mild form of the cavus foot, was first described by Manoli and colleagues.

Using Wearable Inertial Sensors to Monitor Effectiveness of Different Types of Customized Orthoses during CrossFit® Training

BACKGROUND

Dynamic balance plays a key role in high-impact sports, such as CrossFit, where athletes are required to maintain balance in various weightlifting exercises. The loss of balance in these sport-specific movements may not only affect athlete performance, but also increase the risk of injuries.

OBJECTIVES

The aim of the study is to achieve greater insight into the balance and athlete position during the CrossFit training by means of inertial sensors, with a particular focus on the role of different custom foot orthoses (CFOs) in order to detect correlations with the role of the cavus foot.

METHODS

A total of 42 CrossFit^® athletes, aged 25 to 42 years, were enrolled in this study. One-way ANOVA tests with post-hoc analysis of variance were used to compare foot posture groups and effects of different types of customized foot orthoses.

RESULTS

When comparing the effects of CFOs with the respective balance basal level during the pistol squat exercise, we observed a significant (p = 0.0001) decrease in the sway area, antero-posterior displacement (APD) and medio-lateral displacement (MLD) compared to the basal using both types of CFOs.

CONCLUSION

No significant positive effects of CFOs were observed in some static tests. On the contrary, positive effects of CFOs and, in particular, postural insoles, are relevant to dynamic balance.

Effect of Hamstring Tightness and Fatigue on Dynamic Stability and Agility in Physically Active Young Men

Hamstring extensibility has been defined as a factor to diminished dynamic stability and therefore increased risk of injury. The purpose of this study was to analyse the effects of hamstring tightness and fatigue on dynamic stability and agility. Nineteen participants were divided between the normal extensibility group (NEG) (n = 9, 82.2° ± 12.4°) and hamstrings tightness group (HTG) (n = 10, 64° ± 4.9°) using the passive straight leg raise test. To analyse dynamic stability and agility, they performed the modified Star Excursion Balance Test (mSEBT) and Dynamic Postural Stability Index (DPSI), and hexagon agility test, respectively, before and after a fatigue protocol. A two-way repeated measures ANOVA was used to determine differences among conditions: NEG vs. HTG, and rested vs. fatigued. HTG showed a significantly lower reach in the anterior direction in the mSEBT in pre- and post-fatigue than NEG. Participants in the NEG showed poor stability after landing in the mediolateral direction on DPSI post-fatigue. No significant changes were found in agility related with the group nor fatigue state. Participants with hamstring extensibility reduction has no differences in dynamic stability after landing nor agility after fatigue test, but significantly affects reaching distances during one-leg balance. As a conclusion, a reduction in range of motion in HTG was observed, but no other effects were observed on performance and dynamic stability after a local fatigue protocol depending on hamstring extensibility.

Prevention of Lower Extremity Musculoskeletal Injuries in Tactical and First Responder Populations: A Systematic Review and Meta-Analysis of Randomized Trials From 1955 to 2020

ABSTRACT

Sinnott, AM, Krajewski, KT, LaGoy, AD, Beckner, ME, Proessl, F, Canino, MC, Nindl, BC, Turner, RL, Lovalekar, MT, Connaboy, C, and Flanagan, SD. Prevention of lower extremity musculoskeletal injuries in tactical and first responder populations: A systematic review and meta-analysis of randomized trials from 1955 to 2020. J Strength Cond Res 37(1): 239-252, 2023-Lower extremity musculoskeletal injuries (LEMSIs) impose a significant burden on tactical and first responder populations. To determine the effectiveness of LEMSI prevention strategies, we performed a systematic review and meta-analysis of randomized controlled trials published in English from 1955 to 2020 (PROSPERO: CRD42018081799). MEDLINE, EMBASE, Cochrane, CINAHL, ProQuest, and DTIC databases were searched for trials that assigned military service members, police, firefighters, or paramedics to LEMSI prevention interventions with a minimum surveillance period of 12 weeks. Evidence was synthesized as odds ratios (OR) for LEMSI occurrence between individuals assigned to interventions and those assigned to standard activities. Risk of bias was assessed with the Cochrane Risk of Bias tool 2.0. Random-effects meta-analyses were conducted for (a) physical training and (b) footwear modifications to reduce LEMSI and (c) footwear modifications to reduce stress fractures specifically. Certainty in the body of evidence was determined with the GRADE approach. Of 28,499 records, 18 trials comprised of more than 11,000 subjects were synthesized. Interventions included physical training (8, N = 6,838), footwear modifications (8, N = 3,792), nutritional supplementation (1, N = 324), and training modifications (1, N = 350). Overall risk of bias was generally moderate ( N = 7 of 18) or high ( N = 9 of 18). Physical training (OR = 0.87, 95% CI [0.71, 1.08], p = 0.22, I 2 = 58.4%) and footwear modification (OR = 1.13, 95% CI [0.85, 1.49], p = 0.42, I 2 = 0.0%) did not reduce LEMSI or stress fractures (OR = 0.76, 95% CI [0.45, 1.28], p = 0.30, I 2 = 70.7%). Our results indicate that there is weak evidence to support current LEMSI prevention strategies. Future efforts will benefit from longer surveillance periods, assessment of women and nonmilitary populations, improved methodological rigor, and a greater breadth of approaches.

Agreement between clinical measures to classify foot posture in asymptomatic adults

BACKGROUND

Various clinical measures of static foot posture have been developed and used. However, consensus among clinical measures to classify foot posture remains to be established. Therefore, this study aimed to determine the level of agreement as a reliability component between two common clinical methods in asymptomatic adults: the normalised navicular height truncated (NNHt) and the Foot Posture Index-6 (FPI-6).

METHODS

The NNHt and FPI-6 were conducted on 102 asymptomatic adults. The measurement sequence was randomly arranged for each participant. Weighted Kappa (K_w) was used to determine the agreement between the methods.

RESULTS

Both the NNHt and FPI-6 achieved similar foot posture distributions: approximately 40-50% of the participants had a normal foot, approximately 40% had a pronated foot and approximately 10-20% had a supinated foot. The agreement between the methods to classify foot posture was excellent (K_w = 0.84).

CONCLUSIONS

The present study found excellent agreement between two commonly used clinical measures. This finding highlights the NNHt and FPI-6 consensus for foot posture classification in asymptomatic adults.

Effects of Foot-Core Training on Foot-Ankle Kinematics and Running Kinetics in Runners: Secondary Outcomes From a Randomized Controlled Trial

This study investigated the effectiveness of an 8-week foot-core exercise training program on foot-ankle kinematics during running and also on running kinetics (impact loads), with particular interest in biomechanical outcomes considered risk factors for running-related injuries in recreational runners. A single-blind, randomized, controlled trial was conducted with 87 recreational runners randomly allocated to either the control (CG) or intervention (IG) group and assessed at baseline and after 8 weeks. The IG underwent foot-core training 3 times/week, while the CG followed a placebo lower-limb stretching protocol. The participants ran on a force-instrumented treadmill at a self-selected speed while foot-segment motion was captured simultaneously with kinetic measurements. After the intervention, there were statistically significant changed in foot biomechanics, such as: IG participants strike the ground with a more inverted calcaneus and a less dorsiflexed midfoot than those in the CG; at midstance, ran with a less plantarflexed and more adducted forefoot and a more abducted hallux; and at push-off, ran with a less dorsiflexed midfoot and a less adducted and more dorsiflexed hallux. The IG runners also had significantly decreased medial longitudinal arch excursion (p = 0.024) and increased rearfoot inversion (p = 0.037). The 8-week foot-core exercise program had no effect on impact (p = 0.129) and breaking forces (p = 0.934) or on vertical loading rate (p = 0.537), but it was positively effective in changing foot-ankle kinematic patterns.”

A Retrospective Study of Foot Biomechanics and Injury History in Varsity Football Athletes at the U.S. Naval Academy

INTRODUCTION

The six-item Foot Posture Index (FPI-6) was previously developed as an assessment tool to measure the posture of the foot across multiple segments and planes. It was derived from a criterion-based observational assessment of six components of each foot during static standing. The association between abnormal foot posture and musculoskeletal injuries remains unclear and is in of need further exploration.

HYPOTHESIS/PURPOSE

The purpose of this study was to assess the association between foot biomechanics and self-reported history of musculoskeletal pain or injury.

STUDY DESIGN

Retrospective, cross-sectional study of collegiate football players at the U.S. Naval Academy.

MATERIALS AND METHODS

For each athlete, data were recorded on height, weight, self-reported history of pain or injury, and foot posture, which was measured using a FPI-6 with each item measuring the degree of pronation/supination. The primary outcome was each athlete's maximum deviation from neutral posture across the six-item index (FPImax). The prespecified primary analysis used generalized linear models to measure the association between FPImax and self-report history of pain or injury. Exploratory analyses measured the association using penalized regression (L1-norm) and a type of tree-based ensemble known as extreme gradient boosting (XGBoost).

RESULTS

Data were collected on 101 athletes, 99 of whom had sufficient body mass index (BMI) data to be included for analysis. Among the 99 athletes, higher FPImax was associated with a prior history of musculoskeletal pain (odds ratio [OR] 1.15, 95% confidence interval [CI] 0.97 to 1.35), although the sample size was too small for the association to be significant with 95% CI (P = .107). FPImax was not associated with a history of knee injury/pain (OR 0.98, 95% CI 0.83 to 1.15, P = .792), nor with a history of ankle/foot injury or pain (OR 1.04, 95% CI 0.90 to 1.21, P = .599). From the L1-penalized model, the FPI components with the strongest linear associations were the L6, R2, R1-squared, and FPImax. From the XGBoost model, the most important variables were FPItotal, BMI, R1, and R2.

CONCLUSIONS

The U.S. Naval Academy football players whose foot postures deviated from neutral were more likely to have reported a previous history of musculoskeletal pain. However, this deviation from normal was not strongly associated with a specific history of pain or injury to the knee, ankle, or foot.

CLINICAL RELEVANCE

The information ascertained from this study could be used to better inform clinicians about the value of the FPI in predicting or mitigating injuries for varsity football athletes.

Immediate effect of prefabricated and UCBL foot orthoses on alignment of midfoot and forefoot in young people with symptomatic flexible flatfoot: A radiographic evaluation

BACKGROUND

Radiographic imaging has been considered the gold standard in evaluating the skeletal alignment of the foot in static weightbearing. The effects of foot orthoses on the alignment of foot bones have been mostly evaluated using lateral view x-rays. The posterior-anterior view has not been investigated extensively.

OBJECTIVES

To investigate the effects of 2 foot orthoses: University of California Biomechanics Laboratory Orthosis (UCBL) and a prefabricated orthosis (P-FFO) on the alignment of foot bones on anterior-posterior x-rays in young people with symptomatic flexible flatfoot (SFF).

STUDY DESIGN

This is a randomized, crossover study.

METHODS

Fifteen participants (mean [SD], 23.67 ± 2 years) with SFF were randomly imaged in 3 different conditions: shoes only, shoes + P-FFO, and shoes + UCBL. The talonavicular coverage, the first and the second talometatarsal angles, the intermetatarsal angle, and the cuboid abduction angle (CAA) were measured on weightbearing, anterior-posterior x-ray images for each condition.

RESULTS

Both orthotic designs demonstrated a significant reduction in the talonavicular coverage, the first and the second talometatarsal angles, and the CAA compared with the shoe-only condition (P < .001). The talonavicular coverage angle reduced by ∼11% using P-FFO compared with UCBL (P < .005). No significant differences were observed for other angles between the 2 orthotic conditions.

CONCLUSIONS

Both orthotic conditions improved the talonavicular coverage, first and the second talometatarsal angle, and CAA in young people with SFF. The walls of the UCBL orthosis did not result in further correction of the talonavicular coverage angle compared with the prefabricated FFO design.

Predicting Postoperative Sagittal Plane Alignment of the Foot Using Intraoperative Simulated Weightbearing Lateral Imaging During Flatfoot Reconstructive Surgery: A Short-Term Retrospective Analysis

The sagittal plane relationship of the hindfoot and midfoot joints is a primary determinant of proper alignment in flatfoot reconstructive surgery as assessed both clinically and on postoperative weightbearing (WB) lateral radiographs. The traditional approach to intraoperative radiographic imaging allows for accurate assessment of fixation placement but only a crude evaluation of final sagittal plane alignment. Surgeons employ various methods in an attempt to load the foot during lateral imaging. Skepticism exists regarding the ability of simulated WB fluoroscopy to predict the final outcome, and evidence is lacking to support this practice. A retrospective investigation was performed assessing the correlation of Meary's angle, calcaneal inclination angle, and calcaneal-1^st metatarsal angle as demonstrated on intraoperative simulated WB lateral foot imaging to 10- week postoperative full WB lateral radiographs. A consistent simulated WB imaging protocol was used with 46 consecutive cases of flatfoot reconstruction in this analysis of secular trends. The average change in Meary's angle between intraoperative simulated WB and postoperative full WB was -1.09° with 89% of cases within ±5°. The average change in calcaneal-1^st metatarsal angle between intraoperative simulated WB and full WB was -2.61° with 85% of cases within ±5°. The average change in calcaneal inclination angle between intraoperative simulated WB and full WB was -2.62° with 88% of cases within ±5°. These findings confirm the clinical utility of intraoperative simulated WB lateral imaging as a useful tool in predicting the postoperative sagittal plane alignment of the midfoot and rearfoot in patients undergoing flatfoot reconstructive surgery.

The Subtle Cavovarus Foot Deformity: The Nonneurologic Form of Cavus Foot Deformity

Conditions of ankle instability, peroneal tendon tears, and stress fractures of the lateral metatarsals are commonly encountered in a clinical foot and ankle practice. Evaluation of the supporting foot structure is critical to prevent failure of index procedures. The prominence of the subtle cavus foot is now a recognized entity and must be properly diagnosed and addressed surgically.

Stabilization of postural sway on a sideward slope using cuboid support insoles

[Purpose] The purpose of this study was to elucidate whether insoles alter postural sway on a sideward slope rather than on level ground. [Participants and Methods] This study involved 20 flat-footed individuals and 20 normal-footed individuals. The postural sway was determined based on the total length of the locus and the body sway area, which were measured using the Zebris system. The participants were divided into three groups: the BMZ insoles, Superfeet insoles, and no insole groups. These insoles were worn by the participants with their normal shoes worn daily. [Results] The total length of the locus of the BMZ group was significantly lower than those of the Superfeet and no-insole groups. The body sway area did not significantly differ based on the insole condition. [Conclusion] BMZ insoles improve postural sway in both normal-footed and flat-footed individuals on a sideward slope.

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.

Effect of 5-day dry immersion on the human foot morphology evaluated by computer plantography and soft tissues stiffness measuring

16 participants have been subjected to Dry Immersion model (DI) for 5 days. DI reproduces the space flight factors such as lack of support, mechanical and axial unloading, physical inactivity, elimination of vertical vascular gradient. Long-term bed rest is also associated with similar factors, so the results of the study may be useful for clinical medicine. Computer plantography and measuring the stiffness of the soft tissues of the foot and superficial muscles of the shin (mm. tibialis anterior and peroneus longus) were performed twice before DI exposure, on the 2nd and 4th days of DI exposure, as well as on the 2nd day of the recovery period. DI exposure effects the parameters under study in two ways: by raising the longitudinal arch and by flattening the transverse arch, which is accompanied by a decrease in the soft tissues stiffness of the foot and superficial muscles of the shin. The work reveals the phenomenon of compensating the longitudinal arch state by changing the characteristics that reflect the transverse arch state. The results of the study for the first time demonstrate the correlation of the foot morphological characteristics with a decrease in stiffness of mm. peroneus longus and tibialis anterior.

Does Arch Stiffness Influence Running Spatiotemporal Parameters? An Analysis of the Relationship between Influencing Factors on Running Performance

This study aimed to determine the influence of arch stiffness on running spatiotemporal parameters at a common speed for a wide range of endurance runners (i.e., 12 km·h⁻¹). In total, 97 runners, 52 men and 45 women, completed a treadmill running protocol at 12 km·h⁻¹. Spatiotemporal parameters were measured using the OptoGait system, and foot structure was assessed by determining arch stiffness. Since between-sex differences were found in anthropometric and foot structure variables, data analysis was conducted separately for men and women, and body mass and height were considered as covariates. For both sexes, a k-means cluster analysis grouped participants according to arch stiffness, by obtaining a group of low-arch stiffness (LAS group) and a group of high-arch stiffness (HAS group), with significant differences in arch stiffness (p < 0.001, for both men and women). No significant differences between LAS and HAS groups were found in running spatiotemporal parameters, regardless of sex (p ≥ 0.05). For both sexes, the partial correlation analysis reported no significant correlations (p ≥ 0.05) between foot structure variables and running spatiotemporal parameters. The results obtained show no differences in spatiotemporal gait characteristics during running at submaximal velocity between runners with low-arch stiffness and those with high-arch stiffness, regardless of sex. These findings may have important implications for clinicians and coaches by adding more evidence to the debate about the use of static foot classification measures when characterizing the foot and its biomechanics during running.

Relationships Between Arch Height Flexibility and Medial-Lateral Ground Reaction Forces in Rearfoot and Forefoot Strike Runners

Higher medial-lateral forces have been reported in individuals with stiffer foot arches. However, this was in a small sample of military personnel who ran with a rearfoot strike pattern. Therefore, our purpose was to investigate whether runners, both rearfoot and forefoot strikers, show different associations between medial-lateral forces and arch stiffness. A group of 118 runners (80 rearfoot strikers and 38 forefoot strikers) were recruited. Ground reaction force data were collected during running on an instrumented treadmill. Arch flexibility was assessed as the difference in arch height from sitting to standing positions, and participants were classified into stiff/flexible groups. Group comparisons were performed for the ratio of medial:vertical and lateral:vertical impulses. In rearfoot strikers, runners with stiff arches demonstrated significantly higher medial:vertical impulse ratios (P = .036). Forefoot strikers also demonstrated higher proportions of medial forces; however, the mean difference did not reach statistical significance (P = .084). No differences were detected in the proportion of lateral forces between arch flexibility groups. Consistent with previous findings in military personnel, our results indicate that recreational runners with stiffer arches have a higher proportion of medial forces. Therefore, increasing foot flexibility may increase the ability to attenuate medial forces.

Prediction of the Longitudinal Arch Angle During Running for Various Foot Strike Patterns Using a Static Longitudinal Arch Angle Measurement

BACKGROUND

The medial longitudinal arch angle (LAA) of the foot has been used as an index of high and low arches. The LAA during the support phase of running (LAArun), which may be related to lower-limb injuries, is commonly predicted from the LAA at standing (LAAstand). However, it is not known whether this prediction is valid for all of the foot contact patterns. The purpose of this study was to verify whether prediction of the LAArun from the LAAstand is valid for different foot strike patterns.

METHODS

The 26 participants were divided into a rearfoot strike group (n = 15) and a nonrearfoot strike group (n = 11). The LAA was obtained by measuring the angle formed between the line from the navicular bone to the medial malleolus and the line from the navicular bone to the first metatarsal head. The LAAstand and the minimum value of the LAArun, when the arch is most collapsed, were measured using a motion capture system.

RESULTS

There were no significant differences in the LAAstand, the LAArun, and the difference (LAAstand - LAArun) between the two groups. In both groups, a very strong and significant correlation was found between the LAAstand and the LAArun. Furthermore, a nearly identical equation for predicting the LAArun from the LAAstand was derived for the two groups.

CONCLUSIONS

The LAArun can be predicted from the LAAstand for any foot strike pattern with almost the same equation.

The Application of Forensic Podiatry to Clinical Practice

The practice of the clinical podiatrist traditionally focuses on the diagnosis and treatment of conditions of the foot, ankle, and related structures of the leg. Clinical podiatrists are expected to be mindful of "the principles and applications of scientific enquiry." This includes the evaluation of treatment efficacy and the research process. In contrast, the forensic podiatrist specializes in the analysis of foot-, ankle-, and gait-related evidence in the context of the criminal justice system. Although forensic podiatry is a separate, specialized field, many aspects of this discipline can be useful in the clinical treatment and management of foot and ankle problems. The authors, who are forensic podiatrists, contend that the clinical podiatrist can gain significant insights from the field of forensic podiatry. This article aims to provide clinical podiatrists with an overview of the principles and methods that have been tested and applied by forensic podiatrists in their practice, and suggests that the clinical practice of the nonforensic foot practitioner may benefit from such knowledge.

Can an insole for obese individuals maintain the arch of the foot against repeated hyper loading?

BACKGROUND

Insoles are often applied as preventive therapy of flatfoot deformity, but the therapeutic effects on obese individuals are still controversial. We aimed to investigate the effect of insole use on time-dependent changes in the foot arch during a repeated-loading simulation designed to represent 20,000 contiguous steps in individuals with a BMI value in the range of 30-40 kg/m2.

METHODS

Eighteen cadaveric feet were randomly divided into the following three groups: normal, obese, and insole. Ten thousand cyclic loadings of 500 N (normal group) or 1000 N (obese and insole groups) were applied to the feet. We measured time-dependent change in arch height and calculated the bony arch index (BAI), arch flexibility, and energy absorption.

RESULTS

The normal group maintained more than 0.21 BAI, which is the diagnostic criterion for a normal arch, throughout the 10,000 cycles; however, BAI was less than 0.21 at 1000 cycles in the obese group (mean, 0.203; 95% confidence interval [CI] 0.196-0.209) and at 6000 cycles in the insole group (mean, 0.200; 95% CI, 0.191-0.209). Although there was a significant time-dependent decrease in flexibility and energy absorption in both the obese and insole groups (P < 0.001), the difference between 1 and 10,000 cycles were significantly smaller in the insole group than in the obese group (P = 0.024).

CONCLUSIONS

Use of insoles for obese individuals may help to slow time-dependent foot structural changes. However, the effect was not enough to maintain the foot structure against repeated hyper loadings.

The relationship between foot arch flexibility and medial-lateral ground reaction force distribution

BACKGROUND

Overuse running injury susceptibility has previously been associated with the magnitude and slope of ground reaction force profiles, most often in the vertical axis. However, despite the implications of excessive pronation and supination on injury susceptibility, very little research has examined the factors that might affect distribution of force in the medial-lateral directions.

RESEARCH QUESTION

The purpose of this study was to consider how foot structure, specifically arch flexibility, affects the distribution of ground reaction force between the medial-lateral and vertical planes of motion.

METHODS

Twenty-five participants were classified as having stiff or flexible arches, and three dimensional kinetic data were gathered while the volunteers ran at 7 mph on an instrumented treadmill. A mixed-effects ANOVA was used to analyze the effect of arch flexibility type on distribution of ground reaction force impulse in the medial and lateral directions.

RESULTS

The results suggest that individuals with relatively stiff arches experience a greater proportion of ground reaction force in the medial-lateral plane of motion, as compared with those with more flexible arches (p = 0.03). Further, the results suggest that most individuals, regardless of foot structure, experience greater impulse of force in the lateral than in the medial direction (p < 0.01).

SIGNIFICANCE

Considering previously explored relationships between ground reaction force, foot pronation/supination, and chronic running injuries, the results of this study suggest that arch flexibility could be used as a criterion for assessing injury susceptibility. Further, conclusions drawn from this study add to the discussion on the pros and cons of training or using devices to increase or restrict arch flexibility while running.

Pathology and management of flexible flat foot in children

We describe the pathology and treatment of flexible flat foot in children. The flexible flat foot is seen in the overly flexible foot and usually involves hypermobility of the subtalar joint. It typically occurs in childhood and may continue to adulthood. The arch develops spontaneously during the first decade of life in most children and comes within the normal range observed in adult feet. We prescribed orthoses for the treatment of flexible flat foot patients. Lateral weight-bearing radiographs and ultrasonography were helpful for the evaluation of the flat foot. Bleck recommended the UCBL shoe insert in cases of flexible flat foot if the standing or lateral rentgenogram demonstrates a talar plantar flexion angle (TPF) of 45° or greater. Bordelon suggested that cases of flexible flat foot should be treated if the standing or lateral roentgenogram demonstrates a Meary's talo-1st metatarsal angle (T1-MTA) of -15°or greater. However, the radiograph of a young child's foot poses some difficulties in making an accurate evaluation, because of the radiolucent cartilage zone. In this situation, a sagittal image obtained by ultrasonography has proved to be a powerful aid to evaluate the type of the flat foot. We classified the flat foot into three types: talo-navicular sag (T-N sag), naviculo-cuneiform sag (NC sag) and talo-navicular and naviculo-cuneiform sag (Mixed sag) following the criteria of Tachdjian. We recommended the NC sag and Mixed sag groups to be treated by using orthoses, while we kept a status of watchful waiting for the T-N sag group. However, we should consider the increasing complaints of children and their parents during the orthotic treatment. A through discussion between the parents of patients and the pediatric orthopedic doctors is necessary before orthotic treatment is started.

Forefoot transverse arch height asymmetry is associated with foot injuries in athletes participating in college track events

[Purpose] The association between foot injuries and foot alignment, including the transverse arch height (TAH) and asymmetry, was examined in athletes participating in college track events. [Participants and Methods] This study included 55 male athletes participating in a college track and field club. Data including demographic information and the incidence of foot injuries within a year prior to participation in this study were obtained via questionnaires. TAH and the medial longitudinal arch height during 10 and 90% loading, leg-heel alignment, and the heel angle were measured before calculating the asymmetry of each alignment parameter measured. Participants were categorized into an injury or a normal group. Unpaired t-tests were used to perform between-group comparisons for each alignment parameter measured and asymmetry. Additionally, logistic regression analysis was performed to identify factors associated with foot injuries after adjustment for demographic data. [Results] TAH asymmetry during 10 and 90% loading was significantly greater in the injury group. Further logistic regression analysis performed showed that only TAH asymmetry during 90% loading was significantly associated with foot injuries after adjustment for demographic data. [Conclusion] With regard to track events, a greater asymmetry of forefoot TAH in a weight-bearing position was observed to be associated with foot injuries.

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.

Foot posture is associated with plantar pressure during gait: A comparison of normal, planus and cavus feet

BACKGROUND

Variations in foot posture, such as pes planus (low medial longitudinal arch) or pes cavus (high medial longitudinal arch) are associated with some lower limb injuries. However, the mechanism that links foot posture to injury is not clear. Research question The aim of this study was to compare plantar pressure between healthy individuals with normal, planus or cavus feet.

METHODS

Ninety-two healthy volunteers (aged 18 to 45) were classified as either normal (n = 35), pes planus (n = 31) or pes cavus (n = 26) based on the Foot Posture Index, Arch Index and normalised navicular height truncated. Barefoot walking trials were conducted using an emed^®-x400 plantar pressure system (Novel GmbH, Munich, Germany). An 11 region mask was used that included the medial heel, lateral heel, midfoot, 1st, 2nd, 3rd, 4th and 5th metatarsophalangeal joints, hallux, 2nd toe, and the 3rd, 4th and 5th toes. Peak pressure, pressure-time integral, maximum force, force-time integral and contact area were calculated for each region. One way analyses of variance and effect sizes were used to compare the three foot posture groups.

RESULTS

Overall, the largest differences were between the planus and cavus foot groups in forefoot pressure and force. In particular, peak pressures at the 4th and 5th MTPJs in the planus foot group were lower compared to the normal and cavus foot groups, and displayed the largest effect sizes. Significance This study confirms that foot posture does influence plantar pressures, and that each foot posture classification displays unique plantar pressure characteristics.

Utility outcome assessment of pes planus deformity

BACKGROUND

Despite being a common condition, there are no objective measures in the literature to reflect the burden of pes planus on affected individuals. Our primary objective was to evaluate this burden by recruiting a sample from the general population using validated utility outcome measures.

METHODS

Participants were recruited online and filled a questionnaire to help measure the health burden of pes planus. Three recognized utility outcome scores were used to compare the health burden of monocular blindness, binocular blindness, and pes planus. These included the standard gamble (SG), time trade-off (TTO), and visual analogue score (VAS). Paired t test, independent t test, and linear regression were used for statistical analysis.

RESULTS

Ninety-two participants were included in the final analysis. The utility outcome scores (VAS, TTO, SG) for pes planus were 73±17, 0.90±0.08, and 0.88±0.12, respectively. The linear regression analysis showed that age was inversely proportional to the time trade-off. However, race, educational level, and income were not significant predictors of utility outcome score for pes planus.

CONCLUSIONS

This study shows that the perceived burden of living with pes planus is comparable to living with some debilitating conditions. Our participants were willing to sacrifice 3.6 years of life, and have a procedure with a theoretical 12% mortality risk to attain perfect health.

Musculoskeletal training injury prevention in the U.S. Army: Evolution of the science and the public health approach

Injuries cause more morbidity among soldiers in the U.S. Army than any other health condition. Over two-thirds of U.S. soldiers' injuries occur gradually from cumulative micro-traumatic damage to the musculoskeletal system as a result of physical training activities. Paradoxically, the very physical training activities required to improve soldier performance also result in injury. Determining the amounts and types of physical training that maximize performance while minimizing injuries requires scientific evidence. This evidence must be incorporated into a framework that ensures scientific gaps are addressed and prevention efforts are evaluated. The five-step public health approach has proven to be an effective construct for Army public health to organize and build an injury prevention program. Steps include: 1) surveillance to define the magnitude of the problem, 2) research and field investigations to identify causes and risk factors, 3) intervention trials and systematic reviews to determine what works to address leading risk factors, 4) program and policy implementation to execute prevention, and 5) program evaluation to assess effectiveness. Dissemination is also needed to ensure availability of scientific lessons learned. Although the steps may not be conducted in order, the capability to perform each step is necessary to sustain a successful program and make progress toward injury control and prevention. As with many U.S. public health successes (e.g., seatbelts, smoking cessation), the full process can take decades. As described in this paper, the U.S. Army uses the public health approach to assure that, as the science evolves, it is translated into effective prevention.

Centre of pressure characteristics in normal, planus and cavus feet

Background

The aim of this study was to compare centre of pressure (COP) characteristics between healthy adults with normal, planus or cavus feet who were allocated to groups based on reliable foot posture measurement techniques.

Methods

Ninety-two healthy adult participants (aged 18 to 45) were recruited and classified as either normal (n = 35), pes planus (n = 31) or pes cavus (n = 26) based on Foot Posture Index, Arch Index and normalised navicular height truncated measurements. Barefoot walking trials were conducted using an emed^®-x 400 plantar pressure system (Novel GmbH, Munich, Germany). Average, maximum, minimum and range (difference between maximum and minimum) values were calculated for COP velocity and lateral-medial force index during loading response, midstance, terminal stance and pre-swing phases of stance. The COP excursion index was also calculated. One-way analyses of variance were used to compare the three foot posture groups.

Results

The cavus foot exhibited the slowest average and minimum COP velocity during terminal stance, but this pattern was reversed during pre-swing, when the cavus foot exhibited the fastest maximum COP velocity. The planus foot exhibited the smallest lateral medial force index range during terminal stance. There were no differences between the groups for COP excursion index.

Conclusion

These findings indicate that there are differences in COP characteristics between foot postures, which may represent different mechanisms for generating force to facilitate forward progression of the body during the propulsive phases of gait.

Short-term effects of sports taping on navicular height, navicular drop and peak plantar pressure in healthy elite athletes: A within-subject comparison

Medial tibial stress syndrome (MTSS) is one of the most common exercise-induced leg pain. The navicular drop (ND) was identified as a risk factor for MTSS. This study aimed to evaluate the short-term effects of sports taping applied to the supporting lower leg during sitting, standing, walking, and jogging to restrict the ND in healthy elite athletes.Twenty-four healthy elite athletes without a history of exercise-induced pain or injuries in the lower limbs participated in this study (median age: 21.00 years; 1st--3rd quartiles; 19.25-22.00). The 4 taping conditions were used: rigid taping (RT), kinesiology taping (KT), placebo taping (PT), and non-taping (NT). The order of taping techniques was randomly assigned. Normalized navicular height (NH), ND, and normalized ND evaluated using 3-dimensional motion analysis, and normalized peak plantar pressure (PP) were compared in 4 taping conditions during sitting, standing, walking, and jogging.During sitting, the normalized NH of RT is higher than that of NT, KT, and PT (χ = 17.30, P = .001), while during jogging, the normalized NH of RT is higher than that of NT and PT (χ = 10.55, P = .014). The normalized peak PP of NT is higher than that of PT (χ = 8.871, P = .031) in the lateral midfoot region.This study showed the RT technique maintained NH during sitting and jogging, and the RT technique could be an effective preventive and treatment strategy for MTSS.

Association of bilateral flat feet with knee pain and disability in patients with knee osteoarthritis: A cross-sectional study

This cross-sectional study examined the relationship of flat feet with knee pain, disability, and physical performance in patients with knee osteoarthritis (OA). Orthopedic clinic participants (n = 95; age 61-91 years; 68.4% women) with Kellgren-Lawrence (K/L) grade ≥1 in the medial compartment underwent evaluation of navicular height and foot length for flat feet. Knee pain intensity, disability, and physical performance were evaluated using the Japanese Knee Osteoarthritis Measure, 10-m walk, timed up and go, and five-repetition chair stand tests. Of the 95 enrolled patients, 24 (25.3%) had bilateral flat feet, and significantly higher knee pain compared to patients with no flat feet (11.3 ± 8.23 points vs. 6.58 ± 6.37 points; p = 0.043). A ordinal logistic regression analysis showed that bilateral flat feet were significantly associated with increased knee pain (proportional odds ratio: 5.48, 95% confidence interval: 1.96, 15.3; p = 0.001) compared with no flat feet, adjusted for age, sex, body mass index, and tibiofemoral joint K/L grade, which is consistent across various different cutoffs of the definition of flat feet. Physical performance was similar between patients with and without bilateral flat feet. The presence of unilateral flat feet was not significantly associated with any outcome measures. These findings indicate that bilateral, but not unilateral, flat feet are associated with worse knee pain. A prospective study investigating a causal relationship between bilateral flat feet posture and knee pain as well as disability would be of particular interest to verify the potential adverse effect of altered foot posture. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2490-2498, 2017.

Foot structure is significantly associated to subtalar joint kinetics and mechanical energetics

INTRODUCTION/AIM

Foot structure has been implicated as a risk factor of numerous overuse injuries, however, the mechanism linking foot structure and the development of soft-tissue overuse injuries are not well understood. The aim of this study was to identify factors that could predict foot function during walking.

METHODS

A total of eleven variables (including measures of foot structure, anthropometry and spatiotemporal gait characteristics) were investigated for their predictive ability on identifying kinematic, kinetic and energetic components of the foot. Three-dimensional motion capture and force data were collected at preferred walking speed on an instrumented treadmill. Mechanical measures were subsequently assessed using a custom multi-segment foot model in Opensim. Factors with significant univariate associations were entered into multiple linear regression models to identify a group of factors independently associated with the mechanical measures.

RESULTS

Although no model could be created for any of the kinematic measures analysed, approximately 46% and 37% of the variance in the kinetic and energetic measures were associated with three or two factors respectively. Arch-height ratio, foot length and step width were associated with peak subtalar joint (STJ) moment, while greater STJ negative work was correlated to a low arch-height ratio and greater foot mobility.

CONCLUSION

The models presented in this study suggest that the soft-tissue structures of a flat-arched, mobile foot are at a greater risk of injury as they have greater requirements to absorb energy and generate larger forces. However, as these associations are only moderate, other measures may also have an influence.

Characteristics of the Foot Static Alignment and the Plantar Pressure Associated with Fifth Metatarsal Stress Fracture History in Male Soccer Players: a Case-Control Study

BACKGROUND

There is a large amount of information regarding risk factors for fifth metatarsal stress fractures; however, there are few studies involving large numbers of subjects. This study aimed to compare the static foot alignment and distribution of foot pressure of athletes with and without a history of fifth metatarsal stress fractures.

METHODS

The study participants comprised 335 collegiate male soccer players. Twenty-nine with a history of fifth metatarsal stress fractures were in the fracture group and 306 were in the control group (with subgroups as follows: 30 in the fracture foot group and 28 in the non-fracture group). We measured the foot length, arch height, weight-bearing leg-heel alignment, non-weight-bearing leg-heel alignment, forefoot angle relative to the rearfoot, forefoot angle relative to the horizontal axis, and foot pressure.

RESULTS

The non-weight-bearing leg-heel alignment was significantly smaller and the forefoot angle relative to the rearfoot was significantly greater in the fracture foot group than in the control foot group (P = 0.049 and P = 0.038, respectively). With regard to plantar pressure, there were no significant differences among the groups. Midfield players had significantly higher rates of fifth metatarsal stress fracture in their histories, whereas defenders had significantly lower rates (chi-square = 13.2, P < 0.05). There were no significant differences in the frequency of fifth metatarsal stress fractures according to the type of foot (kicking foot vs. pivoting foot) or the severity of ankle sprain.

CONCLUSIONS

Playing the midfield position and having an everted rearfoot and inverted forefoot alignment were associated with fifth metatarsal stress fractures. This information may be helpful for preventing fifth metatarsal stress fracture recurrence. More detailed load evaluations and a prospective study are needed in the future.

Flat Foot in a Random Population and its Impact on Quality of Life and Functionality

INTRODUCTION

Flat foot is a common deformity in adults. It is characterized by medial rotation and plantar flexion of the talus, eversion of the calcaneus, collapsed medial arch and abduction of the forefoot.

AIM

The aim of this study was to determine the prevalence of flat foot and its impact on quality of life, dependence, foot pain, disability and functional limitation among random population of 40-year-old and above.

MATERIALS AND METHODS

A cross-sectional study in a random population sample from Cambre (A Coruña-Spain) (n=835) was performed (α =0.05; Precision=±3.4%). The diagnosis of flat foot was stablished by the study of the footprint obtained with a pedograph. Anthropometric variables were studied, Charlson's Comorbidity Index, function and state of foot (Foot Function Index (FFI), Foot Health Status Questionnaire (FHSQ)), quality of life (SF-36), and dependence for activities of daily living (Barthel and Lawton index). A logistic and linear multiple regression analysis was performed.

RESULTS

The prevalence of flat foot was 26.62%. Patients with flat foot were significantly older (65.73±11.04 vs 61.03±11.45-year-old), showed a higher comorbidity index (0.92±1.49 vs 0.50±0.98), had a greater BMI (31.45±5.55 vs 28.40±4.17) and greater foot size (25.16±1.66 vs 24.82±1.65). The presence of flat foot diminishes the quality of life, as measured by the FHSQ, and foot function, measured by the FFI. The presence of flat foot does not alter the physical and mental dimension of the SF-36 or the degree of dependence.

CONCLUSION

Flat foot was associated with age, Charlson's Comorbidity Index, BMI and foot size. The SF-36, Barthel and Lawton questionnaires remained unaltered by the presence of flat foot. The FHSQ and FFI questionnaires did prove to be sensitive to the presence of flat foot in a significant manner.

The relationship between arch height and foot length: Implications for size grading

OBJECTIVE

Medial longitudinal Arch Height is synonymous with classifying foot type and conversely foot function. Detailed knowledge of foot anthropometry is essential in the development of ergonomically sound footwear. Current Footwear design incorporates a direct proportionate scaling of instep dimensions with those of foot length. The objective of this paper is to investigate if a direct proportional relationship exists between human arch height parameters and foot length in subjects with normal foot posture.

METHOD

A healthy convenience sample of 62 volunteers was recruited to participate in this observational study. All subjects were screened for normal foot health and posture. Each subject's foot dimensions were scanned and measured using a 3D Foot Scanner. From this foot length and arch height parameters were obtained. Normalised ratios of arch height with respect to foot length were also calculated. The arch height parameters and the normalised arch ratios were used interchangeably as the dependent variables with the foot length parameters used as the independent variable for Simple Linear Regression and Correlation.

RESULTS

Analysis of foot length measures demonstrated poor correlation with all arch height parameters.

CONCLUSION

No significant relationships between arch height and foot length were found. The predictive value of the relationship was found to be poor. This holds significant implications for the current method of proportionate scaling of footwear in terms of fit and function to the midfoot region for a normative population.

Does foot placement affect the reliability of static foot posture measurements?

BACKGROUND

Previous studies have reported conflicting results on whether different foot placements in standing can affect static measurements of foot posture. We sought to determine whether three measurements of static foot posture could be consistently measured in three different foot placements while standing.

METHODS

Twenty individuals, 12 women and eight men, with a mean age of 24.8 years consented to participate. Two raters assessed the dorsal arch height, midfoot width, and heel width of each foot while the participant stood in the following three foot placements: a standardized placement, a participant-determined placement after marching in place, and a rater-determined foot placement based on observation of the participant's angle of gait and base of support while walking.

RESULTS

All three measurements of static foot posture were shown to have high levels of intrarater and interrater reliability. Significant differences in the measurements of dorsal arch height, midfoot width, and heel width were found among all three of the foot placements. There were no differences between the two raters for any of the three measurements of foot posture.

CONCLUSIONS

Based on these findings, we recommend that clinicians perform measurements of static foot posture using the same standing foot placement between sessions to ensure a high level of measurement consistency.

Effects of body mass index on foot posture alignment and core stability in a healthy adult population

Foot biomechanics and core stability (CS) play significant roles in the quality of standing and walking. Minor alterations in body composition may influence base support or CS strategies. The aim of this study was to investigate the effect of the body mass index (BMI) on the foot posture index (FPI) and CS in a healthy adult population. A total of 39 healthy adult subjects with a mean age of 24.3±6.4 years and over-weight BMI values between 25 and 29.9 kg/m2 (27.43±6.1 kg/m2) participated in this study. Foot biomechanics were analyzed using the FPI. CS was assessed using a plank test with a time-to-failure trial. The Spearman correlation coefficient indicated a significant correlation between BMI and both the FPI (r=0.504, P=0.001) and CS (r= -0.34, P=0.036). Present study concluded that an overweight BMI influences foot posture alignment and body stability. Consequently, BMI should be considered during rehabilitation management for lower extremity injuries and body balance.

Musculoskeletal Lower Limb Injury Risk in Army Populations

Injuries are common within military populations, with high incidence rates well established in the literature. Injuries cause a substantial number of working days lost, a significant cost through compensation claims and an increased risk of attrition. In an effort to address this, a considerable amount of research has gone into identifying the most prevalent types of injury and their associated risk factors. Collective evidence suggests that training and equipment contribute to a large proportion of the injuries sustained. In particular, the large loads borne by soldiers, the high intensity training programs and the influence of footwear have been identified as significant causative factors of lower limb injury in military populations. A number of preventative strategies have been developed within military bodies around the world to address these issues. The relative success of these strategies is highly variable; however, with advancements in technology, new approaches will become available and existing strategies may become more effective.

Foot orthotics for low back pain: The state of our understanding and recommendations for future research

PURPOSE

The purpose of the article is to evaluate the literature on the use of foot orthotics for low back pain and to make specific recommendations for future research.

METHODS

Database searches were conducted using PubMed, EBSCO, GALE, Google Scholar, and clinicaltrials.gov. The biomedical literature was reviewed to determine the current state of knowledge on the benefits of foot orthotics for low back pain related to biomechanical mechanisms and clinical outcomes.

RESULTS

It may be argued that foot orthotics are experimental, investigational, or unproven for low back pain due to lack of sufficient evidence for their clinical effectiveness. This conclusion is based upon lack of high quality randomized controlled trials (RCTs). However, there is extensive research on biomechanical mechanisms underlying the benefits of orthotics that may be used to address this gap. Additionally, promising pilot studies are beginning to emerge in the literature and ongoing large-scale RCTs are addressing effects of foot orthotics on chronic low back pain.

CONCLUSIONS

Based upon the critical evaluation of the current research on foot orthotics related to biomechanical mechanisms and clinical outcomes, recommendations for future research to address the evidence-practice gaps on the use of foot orthotics for low back pain are presented.

Consistency of Lower-Body Dimensions Using Surface Landmarks and Simple Measurement Tools

Caia, J, Weiss, LW, Chiu, LZF, Schilling, BK, and Paquette, MR. Consistency of lower-body dimensions using surface landmarks and simple measurement tools. J Strength Cond Res 30(9): 2600-2608, 2016-Body dimensions may influence various types of physical performance. This study was designed to establish the reliability and precision of bilateral lower-body dimensions using surface anatomic landmarks and either sliding calipers or goniometry. Fifty university students (25 men and 25 women) were measured on 2 separate occasions separated by 48 or 72 hours. A small digital caliper was used to acquire longitudinal dimensions of the feet, whereas a larger broad-blade caliper was used to measure lower-limb, hip, and pelvic dimensions. Quadriceps angle (Q-angle) was determined through surface goniometry. Data for all foot and lower-limb dimensions were both reliable and precise (intraclass correlation coefficient (ICC) ≥0.72, SEM 0.1-0.5 cm). Measures of Q-angle were also reliable and precise (ICC ≥0.85, SEM 0.2-0.4°). Findings from this investigation demonstrate that lower-body dimensions may be reliably and precisely measured through simple practical tests, when surface anatomic landmarks and standardized procedures are used. Although intertester reliability remains to be established, meticulous adherence to specific measurement protocols is likely to yield viable output for lower-body dimensions when more sophisticated methods are unavailable or inappropriate.

Mountaineering-induced bilateral plantar paresthesia

CONTEXT

Flat feet (pes planus) have been implicated in multiple musculoskeletal complaints, which are often exacerbated by lack of appropriate arch support or intense exercise.

OBJECTIVE

To investigate the efficacy of osteopathic manipulative treatment (OMT) on a patient (K.K.H.) with mountaineering-induced bilateral plantar paresthesia and to assess the association of pes planus with paresthesia in members of the mountaineering expedition party that accompanied the patient.

METHODS

A patient history and physical examination of the musculoskeletal system were performed. The hindfoot, midfoot, forefoot, big toe, and distal toes were evaluated for neurologic function, specifically pin, vibration, 10-g weight sensitivity, and 2-point discrimination during the 4-month treatment period. To determine if OMT could augment recovery, the patient volunteered to use the contralateral leg as a control, with no OMT performed on the sacrum or lower back. To determine if pes planus was associated with mountaineering-induced paresthesia, a sit-to-stand navicular drop test was performed on members of the expedition party.

RESULTS

Osteopathic manipulative treatment improved fibular head motion and muscular flexibility and released fascial restrictions of the soleus, hamstring, popliteus, and gastrocnemius. The patient's perception of stiffness, pain, and overall well-being improved with OMT. However, OMT did not shorten the duration of paresthesia. Of the 9 expedition members, 2 experienced paresthesia. Average navicular drop on standing was 5.1 mm for participants with no paresthesia vs 8.9 mm for participants with paresthesia (t test, P<.01; Mann-Whitney rank sum test, P=.06).

CONCLUSION

These preliminary findings suggest that weakened arches may contribute to mountaineering-induced plantar paresthesia. Early diagnosis of pes planus and treatment with orthotics (which may prevent neuropathies)--or, less ideally, OMT after extreme exercise--should be sought to relieve tension and discomfort.

Painful Flexible Flatfoot

Flatfoot is commonly encountered by pediatric orthopedic surgeons and pediatricians. A paucity of literature exists on how to define a flatfoot. The absence of the medial arch with a valgus hindfoot is the hallmark of this pathology. Flatfoot can be flexible or rigid. This review focuses on the diagnosis and treatment of the flexible flatfoot. Most flatfeet are flexible and clinically asymptomatic, and warrant little intervention. If feet are symptomatic, treatment is needed. Most patients who require treatment improve with foot orthotics and exercises. Only feet resistant to conservative modalities are deemed surgical candidates. The presence of a tight heel cord is often found in patients who fail conservative management.

Selected static foot assessments do not predict medial longitudinal arch motion during running

Background

Static assessments of the foot are commonly advocated within the running community to classify the foot with a view to recommending the appropriate type of running shoe. The aim of this work was to determine whether selected static foot assessment could predict medial longitudinal arch (MLA) motion during running.

Methods

Fifteen physically active males (27 ± 5 years, 1.77 ± 0.04 m, 80 ± 10 kg) participated in the study. Foot Posture Index (FPI-6), MLA angle and rearfoot angle were measured in a relaxed standing position. MLA motion was calculated using the position of retro-reflective markers tracked by a VICON motion analysis system, while participants ran barefoot on a treadmill at a self-selected pace (2.8 ± 0.5 m.s⁻¹). Bivariate linear regression was used to determine whether the static measures predicted MLA deformation and MLA angles at initial contact, midsupport and toe off.

Results

All three foot classification measures were significant predictors of MLA angle at initial contact, midsupport and toe off (p < .05) explaining 41–90 % of the variance. None of the static foot classification measures were significant predictors of MLA deformation during the stance phase of running.

Conclusion

Selected static foot measures did not predict dynamic MLA deformation during running. Given that MLA deformation has theoretically been linked to running injuries, the clinical relevance of predicting MLA angle at discrete time points during the stance phase of running is questioned. These findings also question the validity of the selected static foot classification measures when looking to characterise the foot during running. This indicates that alternative means of assessing the foot to inform footwear selection are required.

Electronic supplementary material

The online version of this article (doi:10.1186/s13047-015-0113-6) contains supplementary material, which is available to authorized users.

The effect of various degrees of foot posture on standing balance in a healthy adult population

PURPOSE

Foot biomechanics plays a significant role in the quality of standing and walking. It has been believed that even minor biomechanical alterations in the foot support surface may influence strategies to maintain body standing balance. Hence, the aim of this study was to investigate the role of various degrees of foot posture on static and dynamic standing balance components in a healthy adult population.

SUBJECTS AND METHODS

A convenience sample of 41 healthy adult subjects with a mean age of 24.3 ± 6.4 years and a body mass index (BMI) of 29 kg/m(2) participated in this study. On the basis of foot posture index (FPI), the participants were allocated into either group A or B. Group A included 16 subjects with an FPI range of 6-11 whereas group B included 25 subjects with an FPI range of 0-5. Standing balance components were analyzed using computerized dynamic posturography (CDP) by the Modified Clinical Test of Sensory Interaction on Balance (mCTSIB) and the limit of stability (LOS).

RESULTS

Spearman's correlation coefficient showed a significant correlation between the standing dynamic balance and FPI in group B but not in group A. Moreover, it also showed no significant correlation between the standing static balance component and FPI in either group A or B.

CONCLUSION

This study concluded that higher degrees of FPI might have an effect on standing dynamic balance in healthy subjects. These components may require extra attention during the preventive aspects of rehabilitation.

Foot posture and function have only minor effects on knee function during barefoot walking in healthy individuals

BACKGROUND

Foot posture has been postulated as a risk factor for overuse injuries of the knee, however the link between foot posture and knee joint function is unclear. The aims of this study were to: (i) compare knee adduction moment and knee joint rotations between normal, planus and cavus foot posture groups, and (ii) to determine the relationship between rearfoot and midfoot joint rotations and knee adduction moment magnitude.

METHODS

Rotation of the knee, rearfoot and midfoot was evaluated in 97 healthy adults that were classified as normal (n=37), cavus (n=30) or planus (n=30) for the Foot Posture Index, Arch Index and normalised navicular height. One way analyses of variance were used to compare tri-planar knee joint rotation, knee adduction moment peak variables and knee adduction angular impulse between foot posture groups. Pearson's correlation coefficient was used to investigate the association between rearfoot and midfoot joint rotation during initial contact phase and the magnitude of 1st knee adduction moment peak.

FINDINGS

The planus group displayed significantly greater external rotation angle at heel contact compared to both normal and cavus groups. The planus groups also displayed greater extension at heel contact and sagittal plane flexion range of motion during propulsion and early swing compared to the cavus group. Otherwise, differences between groups were characterised by small effect sizes. There was no association between rearfoot or midfoot joint rotations and knee adduction moment.

INTERPRETATION

These findings suggest that in healthy individuals, foot posture and foot joint rotations do not substantially influence knee joint rotations and knee adduction moment while walking at a comfortable pace.

Foot posture is associated with kinematics of the foot during gait: A comparison of normal, planus and cavus feet

Variations in foot posture are associated with the development of some lower limb injuries. However, the mechanisms underlying this relationship are unclear. The objective of this study was to compare foot kinematics between normal, pes cavus and pes planus foot posture groups using a multi-segment foot model. Ninety-seven healthy adults, aged 18-47 were classified as either normal (n=37), pes cavus (n=30) or pes planus (n=30) based on normative data for the Foot Posture Index, Arch Index and normalised navicular height. A five segment foot model was used to measure tri-planar motion of the rearfoot, midfoot, medial forefoot, lateral forefoot and hallux during barefoot walking at a self-selected speed. Angle at heel contact, peak angle, time to peak angle and range of motion was measured for each segment. One way ANOVAs with post-hoc analyses of mean differences were used to compare foot posture groups. The pes cavus group demonstrated a distinctive pattern of motion compared to the normal and pes planus foot posture groups. Effect sizes of significant mean differences were large and comparable to similar studies. Three key differences in overall foot function were observed between the groups: (i) altered frontal and transverse plane angles of the rearfoot in the pes cavus foot; (ii) Less midfoot motion in the pes cavus foot during initial contact and midstance; and (iii) reduced midfoot frontal plane ROM in the pes planus foot during pre-swing. These findings indicate that foot posture does influence motion of the foot.

Height of the foot longitudinal arch and anterior cruciate ligament injuries

OBJECTIVE:

To evaluate the association between the height of the medial longitudinal arch of the foot and non-contact injuries of the anterior cruciate ligament.

METHODS:

One hundred and five patients were included in this case-control study. The case group consisted of 52 patients with non-contact injury of the anterior cruciate ligament. Fifty-three individuals with no history of symptoms regarding to feet or knees comprised the control group. An anthropometric assessment of the bony arch index was performed, which consisted of measuring the ratio of the height between the navicular bone to the ground and the distance from the most posterior support point of the calcaneus to the first metatarsal-phalangeal joint. Gender, height, weight, body mass index and the frequency of sports practice were also evaluated.

RESULTS:

Subjects in the case group had significantly higher medial longitudinal arches than individuals in the control group.

CONCLUSION:

Individuals with rupture of the anterior cruciate ligament had higher arches than the corresponding controls, suggesting an association between a high medial longitudinal arch of the foot and injury of the anterior cruciate ligament. Level of Evidence III, Case-Control Study