Foot posture, foot function and low back pain: the Framingham Foot Study

Electromyographic Analysis of Large Muscle Activity in Progressive Collapsing Foot Deformity

BACKGROUND

There are various deformities described in the spectrum of Progressive Collapsing Foot Deformity (PCFD) which not only have adverse effects on the foot but also on the entire lower limb. Early lower limb muscular fatigue and pain during exertion is the most common complaint of patients with PCFD. Surface electromyography (sEMG) provides an accurate assessment of muscle activity. In this study, we aim to compare the activities of quadriceps, hamstrings, and gastrosoleus muscle groups of adult patients with PCFD with normal lower limbs and correlate the radiological parameters and functional effects of PCFD with the activities.

METHODS

Thirty patients with bilateral PCFD and 30 controls underwent weight-bearing anteroposterior (AP), lateral, and hindfoot alignment radiographs of the foot. Radiographic parameters of PCFD were assessed. Surface electromyography was used to assess the quadriceps, hamstrings, and gastrosoleus activities, and this was compared between the 2 groups and correlated with radiological measurements of PCFD. Tegner activity questionnaire was used to assess the functional effects of collapsed arch.

RESULTS

Electrical activities of all muscle groups were significantly higher in cases than controls. Meary's angle and hindfoot moment arm had significant correlations with hamstring activity (P = .013) and gastrosoleus activity (P = .027), respectively. Tegner scores of cases were significantly lower than those of controls (P = .041).

CONCLUSIONS

The PCFD causes an increase in activity of large muscles of the affected lower limb which act on joints other than those in the foot. This finding may be due to several compensatory mechanisms that counteract the deforming forces. This may be a cause for the frequent complaint, early fatigue, and hence functional impairment. However, most radiological parameters did not correlate with muscle activities and larger study size may be required for further association.

LEVELS OF EVIDENCE

Diagnostic: Level 3.

Inter-rater reliability and test-retest reliability of the foot posture index (FPI-6) for assessing static foot posture in elderly female patients with knee osteoarthritis and its association with quadriceps muscle tone and stiffness

Objective

1. To assess the Inter-rater reliability and test-retest reliability of FPI-6 total score and individual scores in static foot posture evaluation among elderly female patients with knee osteoarthritis (KOA), aiming to establish the reliability of the FPI-6 scale. 2. To investigate the disparity between dominant and non-dominant quadriceps characteristics in elderly female KOA patients, as well as explore the correlation between quadriceps characteristics and abnormal foot posture, thereby offering novel insights for the prevention and treatment of KOA.

Methods

The study enrolled a total of 80 lower legs of 40 participants (all female) with unilateral or bilateral KOA, who were assessed by two raters at three different time points. The inter-rater and test-retest reliability of the FPI-6 was evaluated using the intra-class correlation coefficient (ICC), while the absolute reliability of FPI-6 was examined using the standard error of measurement (SEM), minimum detectable change (MDC), and Bland-Altman analysis. The internal consistency of FPI-6 was assessed using Spearman's correlation coefficient. Additionally, MyotonPRO was employed to assess quadriceps muscle tone and stiffness in all participants, and the association between quadriceps muscle tone/stiffness and the total score of FPI-6 was analyzed.

Result

Our study found excellent inter-rater and test-retest reliability (ICC values of 0.923 and 0.931, respectively) for the FPI-6 total score, as well as good to excellent reliability (ICC values ranging from 0.680 to 0.863 and 0.739-0.883) for individual items. The SEM and MDC values for the total score of FPI-6 among our study inter-rater were 0.78 and 2.15, respectively. and the SEM and MDC values for the test-retest total score of FPI-6 were found to be 0.76 and 2.11, respectively. Furthermore, the SEM and MDC values between inter-rater and test-retest across six individual items ranged from 0.30 to 0.56 and from 0.84 to 1.56. The Bland-Altman plots and respective 95% LOA showed no evidence of systematic bias. In terms of the mechanical properties of the quadriceps on both sides, the muscle tone and stiffness of rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) were significantly higher in the non-dominant leg compared to the dominant leg. Additionally, in the non-dominant leg, there was a significant positive correlation between the muscle tone and stiffness of VM, VL, RF and the total score of FPI-6. However, in the dominant leg, only VM's muscle tone and stiffness showed a significant positive correlation with the total score of FPI-6.

Conclusion

The reliability of the FPI-6 total score and its six individual items was good to excellent. Our findings offer a straightforward and dependable approach for researchers to assess foot posture in elderly female patients with KOA. Furthermore, we observed significantly greater quadriceps tension and stiffness in the non-dominant leg compared to the dominant leg. The FPI-6 total score exhibited a significant correlation with changes in quadriceps muscle performance among KOA patients. These observations regarding the relationship between changes in quadriceps muscle performance and foot posture in elderly female KOA patients may provide novel insights for disease prevention, treatment, and rehabilitation.

Development and feasibility of a function-based preventive intervention for lifestyle-related disorders

BACKGROUND

The enormous effect of lifestyle-related disorders on health of the global population warrants the development of preventive interventions. Focusing on musculoskeletal health and physical activity may be a way to encourage necessary lifestyle changes by making them more concrete and understandable. The aims of the current study were to develop a function-based preventive intervention aimed at lifestyle-related disorders in physically inactive 40-year-old people and to investigate the feasibility of the intervention. The feasibility study aimed to solve practical and logistical challenges and to develop the intervention based on the experiences of participants and involved clinical personnel according to defined criteria.

METHODS

Development of the standardised functional examination was based on literature-validated tests and clinical reasoning. Development of a risk profile was based on the functional examination and similar profiles which have already proved feasible. The feasibility of the functional examination and risk profile, together with function-based lifestyle counselling was tested on 27 participants in a pilot study with two physiotherapist examinations over a four-month period. Practical results and feedback from participants and collaborating personnel were examined.

RESULTS

The functional examination consists of 20 established tests not requiring specialised equipment or training which were deemed relevant for a middle-aged population and a sub-maximal ergometer test. The risk profile consists of seven functional dimensions: cardiovascular fitness, strength in upper extremity, lower extremity and trunk, mobility, balance and posture, and three non-functional dimensions: weight, self-assessed physical activity and pain. Each dimension contains at least two measures. The participants appreciated the intervention and found it motivating for making lifestyle changes. They found the tests and risk profile understandable and could see them as tools to help achieve concrete goals. The examination required 60-75 min for one physiotherapist. The recruitment rate was low and recruited participants were highly motivated to making lifestyle changes.

CONCLUSION

This project developed a functional test battery and risk profile aimed at inactive 40-year-olds which fulfilled our feasibility criteria. Functional screening and lifestyle counselling were found to be of value to a sub-group of inactive 40-year-olds who were already motivated to improve their health situations.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05535296 first posted on 10/09/2022.

Effects of physical interventions on pain and disability in chronic low back pain with pronated feet: a systematic review and meta-analysis

BACKGROUND

A link between pronated feet (PF) and chronic low back pain (CLBP) has been reported in the literature. However, physical interventions (PI) like physiotherapy and orthotics mainly target the lower back, neglecting the broader biomechanical impacts of PF that affect the feet, ankles, and overall posture. Currently, there is a lack of comprehensive meta-analyses or systematic reviews on this subject.

OBJECTIVES

This systematic review with a meta-analysis aimed to evaluate the effects of PI on pain and disability in patients having CLBP with PF.

METHODS

From inception until October 15, 2023, Medline/PubMed, Web of Science, and Scopus databases were searched using the desired keywords for randomized control trials (RCTs). The quality of the RCTs was evaluated using the PEDro scale and risk of bias tool.

RESULTS

Four studies involving 268 patients were identified, two compared custom-made foot orthoses to non-biomechanical foot insoles, while the other two used exercises. The meta-analysis included four studies for pain and three for disability. The results showed a significant change in pain [-2.43 (95% CI -2.73 to -2.13, p < .001)] and disability of -6.69 (95% CI -8.04 to -5.33, p < .001)].

CONCLUSIONS

This systematic review and meta-analysis of four RCTs elucidates that PI, specifically targeting PF, significantly alleviate pain and reduce disability in patients having CLBP with PF. These findings advocate for integrating foot-based PI within the treatment protocols for patients suffering from CLBP accompanied by PF.

Integration of Osteopathic Manipulative Treatment for Patients with Chronic Pain

The Five Models of Osteopathic Medicine offers guidance on creating a treatment plan that includes OMT for patients with chronic pain. Using OMT on one body region or system has numerous downstream effects and can influence multiple models. This paper describes this therapeutic modality.

Increased ankle pain after total knee arthroplasty is associated with a preoperative lateralized gait and talar tilt, but not with ankle laxity or the range of motion of the subtalar joint

Aims

Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity.

Methods

Patients who underwent TKA from September 2020 to September 2021 were prospectively included. Inclusion criteria were primary end-stage osteoarthritis (Kellgren-Lawrence stage IV) of the knee. Exclusion criteria were missed follow-up visit, post-traumatic pathologies of the foot, and neurological disorders. Radiological angles measured included the mTFA, hindfoot alignment view angle, and TT. The Foot Function Index (FFI) score was assessed. Gait analyses were conducted to measure mediolateral changes of the gait line and ankle laxity was tested using an ankle arthrometer. All parameters were acquired one week pre- and three months postoperatively.

Results

A total of 69 patients (varus n = 45; valgus n = 24) underwent TKA and completed the postoperative follow-up visit. Of these, 16 patients (23.2%) reported the onset or progression of ankle symptoms. Varus patients with increased ankle symptoms after TKA had a significantly higher pre- and postoperative TT. Valgus patients with ankle symptoms after TKA showed a pathologically lateralized gait line which could not be corrected through TKA. Patients who reported increased ankle pain neither had a decreased ROM of the subtalar joint nor increased ankle laxity following TKA. The preoperative mTFA did not correlate with the postoperative FFI (r = 0.037; p = 0.759).

Conclusion

Approximately one-quarter of the patients developed ankle pain after TKA. If patients complain about ankle symptoms after TKA, standing radiographs of the ankle and a gait analysis could help in detecting a malaligned TT or a pathological gait.

The Effectiveness of Video-Based Game Exercise Therapy Applications in Pes Planus Rehabilitation: Protocol for a Randomized Controlled Trial

BACKGROUND

Pes planus is one of the most common foot deformities. Although there are many studies on the effectiveness of various exercise methods in pes planus rehabilitation, the number of studies on video-based game exercise therapy applications is very limited.

OBJECTIVE

This study aims to evaluate the effectiveness of 2 video-based game exercise therapies and structured exercise practices in pes planus rehabilitation.

METHODS

This study is a 3-arm, parallel-group, single-blinded randomized controlled trial. The study will include 69 patients with flexible pes planus aged between 18 and 25 years who attend the orthopedics and traumatology clinic and meet the inclusion criteria. The primary outcomes are measures of navicular drop and pedobarographic analysis before and after the intervention, and the secondary outcomes include balance, femoral anteversion, and lower extremity muscle strength. Participants will be evaluated with a navicular drop test for medial longitudinal arch height, a pedobarographic analysis system for plantar pressure analysis, a Craig test for femoral anteversion, the Becure Balance System for balance measurement, and a myometer device for lower extremity muscle strength measurement. Participants will be randomly assigned to a structured exercise group, an exergame group, or a serious game group according to their order of arrival. The structured exercise group will use a short foot exercise, a towel-picking exercise, and various walking and balance exercises. Patients in the serious play group will play the lower extremity games in the Becure Balance System. Patients in the exergame group will play balance games on the Nintendo Wii game console. All participants will participate in 18 exercise sessions (3 days a week for 6 weeks). After the treatment, the initial measurements will be repeated.

RESULTS

The study started in January 2023. It is expected to be completed in June 2024.

CONCLUSIONS

This study will be the first randomized controlled study to evaluate the effectiveness of 2 different video-based game exercise therapy applications in pes planus rehabilitation. Through this study, the use of video-based game exercise therapy in pes planus rehabilitation, together with the developing technology, will be a guide. In addition, a new exercise protocol, including serious game exercises, will be added to the literature. In the future, it is expected that our study on the development of different game systems, especially for the ankle, will provide pioneering feedback.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05679219; https://clinicaltrials.gov/study/NCT05679219.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/51772.

Hallux Limitus Influence on Plantar Pressure Variations during the Gait Cycle: A Case-Control Study

BACKGROUND

Hallux limitus is a common foot disorder whose incidence has increased in the school-age population. Hallux limitus is characterized by musculoskeletal alteration that involves the metatarsophalangeal joint causing structural disorders in different anatomical areas of the locomotor system, affecting gait patterns. The aim of this study was to analyze dynamic plantar pressures in a school-aged population both with functional hallux and without.

METHODS

A full sample of 100 subjects (50 male and 50 female) 7 to 12 years old was included. The subjects were identified in two groups: the case group (50 subjects characterized as having hallux limitus, 22 male and 28 female) and control group (50 subjects characterized as not having hallux limitus, 28 male and 22 female). Measurements were obtained while subjects walked barefoot in a relaxed manner along a baropodometric platform. The hallux limitus test was realized in a seated position to sort subjects out into an established study group. The variables checked in the research were the surface area supported by each lower limb, the maximum peak pressure of each lower limb, the maximum mean pressure of each lower limb, the body weight on the hallux of each foot, the body weight on the first metatarsal head of each foot, the body weight at the second metatarsal head of each foot, the body weight at the third and fourth metatarsal head of each foot, the body weight at the head of the fifth metatarsal of each foot, the body weight at the midfoot of each foot, and the body weight at the heel of each foot.

RESULTS

Non-significant results were obtained in the variable of pressure peaks between both study groups; the highest pressures were found in the hallux with a p-value of 0.127 and in the first metatarsal head with a p-value 0.354 in subjects with hallux limitus. A non-significant result with a p-value of 0.156 was obtained at the second metatarsal head in healthy subjects. However, significant results were observed for third and fourth metatarsal head pressure in healthy subjects with a p-value of 0.031 and regarding rearfoot pressure in subjects with functional hallux limitus with a p-value of 0.023.

CONCLUSIONS

School-age subjects with hallux limitus during gait exhibit more average peak plantar pressure in the heel and less peak average plantar pressure in the third and fourth metatarsal head as compared to healthy children aged between 7 and 12 years old.

Plantar pressure distribution in the evaluation and differentiation of flatfeet

BACKGROUND

Although foot diseases are common, only a few studies have detailed the biomechanical and anatomical components of each disorder. The most reliable diagnostic tool for flatfoot is X-ray radiography. Achieving a similar accurate and objective diagnosis using another assessment tool, such as plantar pressure measurements, can be more convenient in clinical practice.

RESEARCH QUESTION

To identify foot plantar pressure characteristics that primarily detect flatfoot based on X-ray, which addresses the use of such assessments for flatfoot diagnosis. In addition, to compare between the normal foot, flatfoot with positive Foot Posture Index-6 (FPI), and flatfoot with positive FPI and radiographic measures.

METHODS

Sixty-two feet were examined from healthy female subjects aged 20.38 ± 1.10 years. According to the results of FPI and X-ray, each sample was assigned to one of the three groups (normal: negative FPI; FPI+: FPI ≥ +6; X-ray and FPI+: Arch Angle ≥ 165°, CP ≤ 12.3° and FPI ≥ +6) and compared using plantar pressure variables.

RESULTS

As per normal group compared to X-ray and FPI+ group, there was a significant difference in the surface area (P-value: 0.01, 95 % CI: -26.58 to -3.62), force (P-value: 0.04, 95 % CI: -10.37 to -0.09), and pressure (P-value: 0.01, 95 % CI: -56.78 to -6.35) in the medial foot. Similarly, the arch index among the normal group and the X-ray and FPI+ group showed significant differences (Static AI; P-value: 0.003, 95 % CI: -0.21 to -0.04).

CONCLUSION

There was a significant difference in plantar pressure between the normal feet and flatfeet with positive FPI and X-ray in the medial foot area.

SIGNIFICANCE

To attain a consensus among diagnostic approaches to identify flatfoot, the combined comparison of observational, foot pressure, and radiographic methods that have shown considerable reliability can be useful for clinical practice.

The effects of short foot exercises to treat flat foot deformity: A systematic review

BACKGROUND

Studies on the effects of performing short foot exercises (SFEs) on the medial longitudinal arch (MLA) have been inconclusive.

OBJECTIVE

This study aimed to conduct a systematic review of the effects of SFEs.

METHODS

'SFE' and 'intrinsic foot muscle' were keywords used to search for randomized controlled trials. One researcher screened relevant articles based on their titles and abstracts, and two independent researchers closely read the texts, accepting nine studies for inclusion. Outcomes, intervention duration, frequency, and the number of interventions were investigated.

RESULTS

Of 299 potential studies identified, the titles and abstracts of 211 studies were reviewed, and 192 were excluded. The full texts of 21 studies were obtained and evaluated according to inclusion and exclusion criteria. Nine studies met the inclusion criteria. Six studies concerning the MLA were identified, with four reporting MLA improvement. There was no consensus concerning the number and frequency of SFEs performed, and the mechanism of MLA improvement was unclear. MLA improvement was observed in participants who undertook ⩾ 5 weeks of interventions.

CONCLUSIONS

The results suggest that performing SFEs for ⩾ 5 weeks is effective in improving the MLA. Randomized controlled trials with details concerning the number and frequency of treatments are required.

Are Static Foot Posture Measures Related to Static and Dynamic Plantar Pressure Parameters?

BACKGROUND

A few studies have investigated the relationship between foot posture measures and plantar pressure parameters, but no study has investigated the correlation of foot posture measures with all primary parameters consisting of contact area (CA), maximum force (MF), and peak pressure (PP). We aimed to determine the relationship of the Foot Posture Index-6 (FPI-6) and navicular drop (ND) with plantar pressure parameters during static standing and preferred walking.

METHODS

Seventy people were included. Navicular drop and the FPI-6 were used to assess foot posture. Plantar pressure parameters including CA, MF, and PP were recorded by a pressure-sensitive mat during barefoot standing and barefoot walking at preferred speed. All assessments were repeated three times and averaged. Pearson correlation coefficients below 0.300 were accepted as negligible and higher ones were interpreted.

RESULTS

Navicular drop was moderately correlated with dynamic CA under the midfoot and second metatarsal; also, the FPI-6 was moderately correlated with dynamic CA under the midfoot (0.500 < r < 0.700). The other interpreted correlations were poor (0.300 < r < 0.500). Both measures were correlated with dynamic CA under the second and third metatarsals; dynamic CA and MF under the midfoot; and static CA, MF, and PP under the first metatarsal and hallux (P < .01). Navicular drop was also correlated with dynamic MF under the first metatarsal and dynamic CA under the fourth metatarsal (P < .01). Furthermore, ND was correlated with static CA and PP under the second metatarsal and static PP under the fifth metatarsal (P < .01). The FPI-6 was also correlated with dynamic MF and PP under the hallux (P < .01).

CONCLUSIONS

The correlations between foot posture measures and plantar pressure variables are poor to moderate. The measures may be useful in the clinical assessment of medial forefoot problems related to prolonged standing and midfoot complaints related to high force during walking. Furthermore, the FPI-6 may provide valuable data regarding hallux complaints related to the high loads during walking.

Toward improved understanding of foot shape, foot posture, and foot biomechanics during running: A narrative review

The current narrative review has explored known associations between foot shape, foot posture, and foot conditions during running. The artificial intelligence was found to be a useful metric of foot posture but was less useful in developing and obese individuals. Care should be taken when using the foot posture index to associate pronation with injury risk, and the Achilles tendon and longitudinal arch angles are required to elucidate the risk. The statistical shape modeling (SSM) may derive learnt information from population-based inference and fill in missing data from personalized information. Bone shapes and tissue morphology have been associated with pathology, gender, age, and height and may develop rapid population-specific foot classifiers. Based on this review, future studies are suggested for 1) tracking the internal multi-segmental foot motion and mapping the biplanar 2D motion to 3D shape motion using the SSM; 2) implementing multivariate machine learning or convolutional neural network to address nonlinear correlations in foot mechanics with shape or posture; 3) standardizing wearable data for rapid prediction of instant mechanics, load accumulation, injury risks and adaptation in foot tissue and bones, and correlation with shapes; 4) analyzing dynamic shape and posture via marker-less and real-time techniques under real-life scenarios for precise evaluation of clinical foot conditions and performance-fit footwear development.

Reliability and validity of Foot Posture Index (FPI-6) for evaluating foot posture in participants with low back pain

Previous studies have demonstrated that Foot Posture Index (FPI-6) is a valid and moderately reliable tool to evaluate foot posture. However, data about reliability and validity of FPI-6 in the assessment of foot posture in people with low back pain (LBP) is lacking. To investigate reliability and validity of FPI-6 in the assessment of foot posture in people with LBP. Thirty volunteers with LBP, aged 20-64 years, were recruited for the research and assessed by two raters. The data measured by different raters on the same day were used to calculate the inter-rater reliability. The data measured by the same rater on different dates were used to calculate the test-retest reliability. The reliability of FPI-6 was tested with intraclass correlation coefficient (ICC), and absolute reliability with standard error of measurement (SEM), minimal detectable change (MDC) and Bland-Altman analysis. The validity of FPI-6 was tested with Exploratory Factor Analysis (EFA) and Spearman's correlation coefficients. The FPI-6 indicated excellent inter-rater and test-retest reliability in the evaluation of foot posture in people with LBP (ICC = 0.97 and 0.95). The agreement for inter-rater and test-retest was excellent based on the SEM (SEM = 0.12) and MDC value (MDC = 0.33). Bland-Altman plots showed that there was no significant systematic bias for the agreement on the ground of low mean difference (< 1). The EFA suggested that the fit indices were considered acceptable according to the Kaiser-Meyer-Olkin (KMO) value (KMO = 0.620) and Bartlett's sphericity test (P < 0.01). There was a statistically significant positive correlation between each item and total score of FPI-6 because the Spearman's correlation coefficient of six items were all > 0.3 (P < 0.01). The inter-rater and test-retest reliability and validity of FPI-6 on people with LBP were proved reliable. It might be considered a reliable and valid adjunctive tool to detect possible changes of foot posture after interventions in patients with LBP.

Arch volume：a new method for medial longitudinal arch measurement

BACKGROUND

As a flexible and elastic structure, the dynamic morphometry of medial longitudinal arch remains to be an unresolved Issue for clinic. Here we introduce a new measurement named arch volume to describe the morphological changes of the medial longitudinal arch during weight-bearing and compare with present method for measuring MLA.

METHODS

64 healthy participants were enrolled. And the dynamic arch morphology was measured under four weight bearing status with navicular height, arch area and arch volume, respectively.

RESULTS

With the increase of weight loading, the flattening or slightly deformation of medial longitudinal arch was observed by all method (p<0.05). However, as a 3D indicator, arch volume not only showed higher sensitivity than other method, but also provide visualization of MLA during loading changing.

CONCLUSIONS

Compared with navicular height and arch area, arch volume has a significant advantage in describing arch morphological changes under different weight bearing status.

Balance and Posture in Children and Adolescents: A Cross-Sectional Study

Balance and posture are two topics that have been extensively studied, although with some conflicting findings. Therefore, the aim of this work is to analyze the relationship between the postural angles of the spine in the sagittal plane and the stable static balance. A cross-sectional study was conducted with children and adolescents from schools in northern Portugal in 2019. An online questionnaire was used to characterize the sample and analyze back pain. Spinal postural angle assessment (pelvic, lumbar, and thoracic) was performed using the Spinal Mouse^®, while stabilometry assessment was performed using Namrol^® Podoprint^®. Statistical significance was set as α = 0.05. The results showed that girls have better balance variables. There is a weak correlation between the anthropometric variables with stabilometry variables and the postural angles. This correlation is mostly negative, except for the thoracic spine with anthropometric variables and the lumbar spine with BMI. The results showed that postural angles of the spine are poor predictors of the stabilometric variables. Concerning back pain, increasing the postural angle of the thoracic spine increases the odds ratio of manifestation of back pain by 3%.

Correction of severe valgus osteoarthritis by total knee arthroplasty is associated with increased postoperative ankle symptoms

PURPOSE

The aim of this study was to assess the mid-term clinical outcome of the ankle joint after total knee arthroplasty (TKA) in high-grade valgus osteoarthritis.

METHODS

In this case-control study, n = 36 patients with a preoperative mechanical tibiofemoral angle (mTFA) ≥ 15° who underwent TKA between December 2002 and December 2012 were included. The control group (mTFA < 15°) of n = 60 patients was created using case matching. Radiological [mechanical tibiofemoral angle (mTFA) and ankle joint orientation to the ground (G-AJLO)] and clinical parameters [Foot Function Index (FFI), Knee Society Score, Forgotten Joint Score, and Range of Motion (ROM)] were analysed. The mean follow-up time was 59 months (IQR [56, 62]).

RESULTS

The degree of correcting the mTFA by TKA significantly correlated with the postoperative FFI (R = 0.95, p < 0.05), although the knee and ankle joint lines were corrected to neutral orientations. A cut-off value of 16.5° [AUC 0.912 (0.85-0.975 95% CI), sensitivity = 0.8, specificity = 0.895] was calculated, above which the odds ratio (OR) for developing ankle symptoms increased vastly [OR 34.0 (9.10-127.02 95% CI)]. ROM restrictions of the subtalar joint displayed a strong significant correlation with the FFI (R = 0.74, p < 0.05), demonstrating that decreased ROM of the subtalar joint was associated with aggravated outcomes of the ankle joint.

CONCLUSIONS

In this study, higher degrees of leg axis correction in TKA were associated with increased postoperative ankle symptoms. When TKA is performed in excessive valgus knee osteoarthritis, surgeons should be aware that this might trigger the onset or progression of ankle symptoms, particularly in cases of a stiff subtalar joint.

LEVEL OF EVIDENCE

III.

Bony Procedures for Correction of the Flexible Pediatric Flatfoot Deformity

The pediatric flexible flatfoot is a common foot shape that is most often asymptomatic and may be a physiologic variant of normal. Surgery is only indicated when nonoperative interventions have failed to resolve symptoms. The goal of surgery is to alleviate symptoms by improving hindfoot alignment and restoring the medial arch while preserving joint mobility. This article focuses on the common bony techniques for surgical correction of the pediatric flexible flatfoot that has failed nonoperative management, including calcaneal, midfoot, and supramalleolar osteotomies and distal tibial hemiepiphyseodesis.

A Case-Control Study of the Effects of Chronic Low Back Pain in Spatiotemporal Gait Parameters

Chronic low back pain and biomechanical walking imbalances are closely related. It is relevant to identify if there are alterations in spatiotemporal gait patterns in subjects with CLBP (cases) versus healthy subjects (controls) to plan training interventions of motor control gait patterns, and thus allowing normal physical activity of the individual. This study is intended to identify if spatiotemporal alterations occur in the gait cycle in CLBP subjects (cases) compared with a control group (healthy patients) analyzed with an OptoGait LED sensors gait program. Method: A total of n = 147 participants: n = 75 cases (CLBP) and n = 72 healthy controls subjects were studied with OptoGait gait program. Results: Significant differences were found between the two groups and both feet in foot stride, for the differences of the total stride and contact, for gait cadence and total stride length of the gait cycle (p < 0.05). Conclusions: CLBP may alter some normal gait patterns measured by OptoGait; this finding presents imbalances in gait cycle as an underlying factor. The gait is part of daily life of any individual and it is an important physical activity in relation to the maintenance of an optimal state of health. In addition, future studies are deemed necessary.

The Prevalence and Factors Associated with Low Back Pain Among People with Flat Feet

Background

A positive relationship between flat feet and low back pain (LBP) has not gained consensus in literature. The aim of this study was to determine the prevalence and factors associated with low back pain (acute and chronic) among individuals with flat feet.

Methods

In 2018, a cross-sectional study was conducted at a national festival in Saudi Arabia, and 1798 adult visitors were invited to participate in face-to-face interviews. Participants' characteristics were stratified by the type of foot and they were questioned on acute low back pain (ALBP) or chronic low back pain (CLBP). The odds ratio (OR) were presented as a measure of this association, followed by a multivariate analysis.

Results

The prevalence of LBP among participants with flat feet was 65.9%, among whom 51.6% suffered ALBP and 48.4% suffered from CLBP. Flat feet increased the chances of having ALBP by 3.28 times and CLBP by 4.5 times. After stratification, ALBP and CLBP were both significantly higher among all participants with flat feet in comparison with their counter groups. Multivariate analyses showed that females were more likely to complain of ALBP. Participants who did no physical activity were more likely to complain of ALBP. Female participants and older participants were more likely to complain of ALBP and CLBP.

Conclusion

Flat feet are associated with both ALBP and CLBP. Significant factors of low back pain also included sex, age, occupation, and physical activity.

Effects of Orthotic Insoles on Gait Kinematics and Low-Back Pain in Patients with Mild Leg Length Discrepancy

BACKGROUND

Mild leg length discrepancy increases biomechanical asymmetry during gait, which leads to low-back pain. Orthotic insoles with a directly integrated heel lift were used to reduce this asymmetry and thus the associated low-back pain. The aim of this study was to analyze the biomechanical adaptations of the locomotor apparatus during gait and the subjective pain ratings before and after the establishment of orthotic insole use.

METHODS

Eight patients with mild leg length discrepancy (≤2.0 cm) underwent three-dimensional biomechanical analysis while walking before and after 3 weeks of orthotic insole use. Low-back pain was assessed separately before both measurement sessions using a visual analog scale.

RESULTS

Analysis of the kinematic parameters highlighted individual adaptations. The symmetry index of Dingwell indicated that orthotic insoles had no significant effect on the kinematic gait parameters and an unpredictable effect across patients. Orthotic insole use significantly and systematically (in all of the patients) reduced low-back pain (P < .05), which was correlated with changes in ankle kinematics (P = .02, r = 0.80).

CONCLUSIONS

The effects of orthotic insoles on gait symmetry are unpredictable and specific to each patient's individual manner of biomechanical compensation. The reduction in low-back pain seems to be associated with the improved ankle kinematics during gait.

Custom-Made Foot Orthoses as Non-Specific Chronic Low Back Pain and Pronated Foot Treatment

Excessive foot pronation has been reported as being related to chronic low back pain symptoms and risk factors in sports-specific pathologies. Compensating custom-made foot orthotics treatment has not been entirely explored as an effective therapy for chronic low back pain (CLBP). This study aims to observe the effects of custom-made foot orthoses, in subjects with foot pronation suffering from CLBP. A total of 101 patients with nonspecific CLBP and a pronated foot posture index (FPI) were studied. They were randomized in two groups: an experimental one (n = 53) used custom-made foot orthotics, and the control group (n = 48) were treated with non-biomechanical effect orthoses. The CLBP was measured using the Oswestry Disability Index (ODI) Questionnaire and a visual analogue scale (VAS), both for lower back pain. The symptoms were evaluated twice, at first when the subject was included in the study, and later, after 4 weeks of treatment. The analysis of outcomes showed a significant decrease in CLBP in the custom-made foot orthoses participants group (p < 0.001 ODI; p < 0.001 VAS). These findings suggest that controlling excessive foot pronation by using custom-made foot orthoses may significantly contribute to improving CLBP.

A Self-Contained 3D Biomechanical Analysis Lab for Complete Automatic Spine and Full Skeleton Assessment of Posture, Gait and Run

Quantitative functional assessment of Posture and Motion Analysis of the entire skeleton and spine is highly desirable. Nonetheless, in most studies focused on posture and movement biomechanics, the spine is only grossly depicted because of its required level of complexity. Approaches integrating pressure measurement devices with stereophotogrammetric systems have been presented in the literature, but spine biomechanics studies have rarely been linked to baropodometry. A new multi-sensor system called GOALS-E.G.G. (Global Opto-electronic Approach for Locomotion and Spine-Expert Gait Guru), integrating a fully genlock-synched baropodometric treadmill with a stereophotogrammetric device, is introduced to overcome the above-described limitations. The GOALS-EGG extends the features of a complete 3D parametric biomechanical skeleton model, developed in an original way for static 3D posture analysis, to kinematic and kinetic analysis of movement, gait and run. By integrating baropodometric data, the model allows the estimation of lower limb net-joint forces, torques and muscle power. Net forces and torques are also assessed at intervertebral levels. All the elaborations are completely automatised up to the mean behaviour extraction for both posture and cyclic-repetitive tasks, allowing the clinician/researcher to perform, per each patient, multiple postural/movement tests and compare them in a unified statistically reliable framework.

Ankle Angle Prediction Using a Footwear Pressure Sensor and a Machine Learning Technique

Ankle injuries may adversely increase the risk of injury to the joints of the lower extremity and can lead to various impairments in workplaces. The purpose of this study was to predict the ankle angles by developing a footwear pressure sensor and utilizing a machine learning technique. The footwear sensor was composed of six FSRs (force sensing resistors), a microcontroller and a Bluetooth LE chipset in a flexible substrate. Twenty-six subjects were tested in squat and stoop motions, which are common positions utilized when lifting objects from the floor and pose distinct risks to the lifter. The kNN (k-nearest neighbor) machine learning algorithm was used to create a representative model to predict the ankle angles. For the validation, a commercial IMU (inertial measurement unit) sensor system was used. The results showed that the proposed footwear pressure sensor could predict the ankle angles at more than 93% accuracy for squat and 87% accuracy for stoop motions. This study confirmed that the proposed plantar sensor system is a promising tool for the prediction of ankle angles and thus may be used to prevent potential injuries while lifting objects in workplaces.

Foot pronation affects pelvic motion during the loading response phase of gait

BACKGROUND

Increased foot pronation during walking has been associated with low back pain. This association may be due to the impact of increased pronation on pelvic motion.

OBJECTIVE

To investigate the effects of increased bilateral foot pronation on pelvic kinematic in frontal and transverse planes during the loading response phase of gait.

METHODS

Pelvic, hip, and foot angular positions of 20 participants were collected while they walked at fast speed wearing flat and medially inclined insoles inserted in the shoes. Pelvic motion in frontal and transverse planes was analyzed during the loading response phase. Foot eversion-inversion was analyzed during the complete stance phase to verify the insoles effectiveness in inducing increased pronation and to exclude excessive pronators.

RESULTS

Inclined insoles were effective in inducing increased foot pronation. Pelvic and hip motion were altered in the increased pronation condition compared to the control condition. In the frontal plane, mean pelvic position was more inclined to the contralateral side (mean difference [MD]: 0.54°; 95%CI: 0.23, 0.86) and its range of motion (ROM) was reduced (MD: 0.50°; 95%CI: 0.20, 0.79). In the transverse plane, mean pelvic position was less rotated toward the contralateral leg (MD: 1.03°; 95%CI: 0.65, 1.60) without changes in ROM (MD: 0.04°; 95%CI: -0.17, 0.25). The hip was more internally rotated (MD: 1.37°; 95%CI: 0.76, 1.98) without changes in ROM (MD: 0.10°; 95%CI: -1.02, 1.23).

CONCLUSION

Increased bilateral foot pronation changes pelvic motion during walking and should be assessed, as a contributing factor to possible pelvic and lower back disorders.

Are Biomechanical Features of the Foot and Ankle Related to Lumbopelvic Motor Control?

BACKGROUND

Any pathomechanical change in the foot or ankle is expected to cause adverse biomechanical effects on the lumbopelvic region. However, no objective data can be found in the literature regarding the effects of musculus transversus abdominis (mTrA) and musculus lumbar multifidus (mLM), which are effective muscles in lumbopelvic motor control, or regarding the extent of their effects.

METHODS

Sixty-four healthy young adults were assessed by a physiotherapist (C.K.) experienced in treating feet and a radiologist (Y.D.) specialized in muscular imaging. In the determination of biomechanical properties of the foot, the navicular drop test (NDT), Foot Posture Index (FPI), pedobarographic plantar pressure analysis, and isokinetic strength dynamometer measurements were used in determining the strength of the muscles around the ankle. Ultrasonographic imaging was used to determine mTrA and mLM thicknesses.

RESULTS

Significant correlation was found between NDT results and mTrA and mLM thicknesses (P < .05) and between FPI results and mTrA thicknesses (P < .05). As the peak pressure of the foot medial line increased, mTrA and mLM thicknesses decreased (P < .05). Although dorsiflexion muscle strength was also effective, mTrA and mLM thicknesses were found to increase especially as plantarflexion muscle strength increased (P < .05).

CONCLUSIONS

These results show that the biomechanical and musculoskeletal properties of the foot-ankle are associated with lumbopelvic stability.

Semi-automatic measurements of foot morphological parameters from 3D plantar foot scans

Background

Foot healthcare research is focusing increasingly on personalized orthotic and prosthetic devices to address patient-specific morphology and ailments. Customization requires advanced 3D image processing tools to assess foot and leg geometrical parameters and alterations. The aim of this study is to present a new software for the measurement of the foot shape from 3D scans of the foot plantar surface.

Methods

A Kinect-based scanning device was used to acquire the 3D foot shape of 44 healthy subjects. A software was developed in Matlab to measure the foot main morphological parameters from foot scans. Principal Component Analysis was used to orientate the foot scans with respect to the same reference system. Accuracy, via percentage errors and Bland-Altman plots, and correlation of the software-based foot parameters were assessed against manual measurements. A normalized Arch Volume Index (nAVI) was proposed and correlated to the traditional Arch Index. Test-retest Intraclass Correlation Coefficient was used to assess the inter-session repeatability of foot measurements.

Results

The average percentage error between software and manual measurements was 1.2 ± 0.8% for foot length, 9.1 ± 3.7% for foot width, 22.3 ± 13.5% for arch height and 23.1 ± 12.7% for arch depth. Very strong correlations were observed for foot length (R = 0.97) and foot width (R = 0.83), and strong correlations for arch height (R = 0.62) and arch depth (R = 0.74). nAVI was negatively correlated to the Arch Index (R = -0.54). A small difference was found between software and manual measurements of foot length (Δ = 0.92 mm), a software overestimation of foot width (Δ = 8.6 mm) and underestimation of arch height (Δ = -1.4%) and arch depth (Δ = -11%). Moderate to excellent repeatability was observed for all measurements (0.67–0.99).

Conclusions

The present software appears capable to estimate the foot main morphological parameters without the need for skin markers or for identification of anatomical landmarks. Moreover, measurements are not affected by the foot orientation on the scanning device. The good accuracy and repeatability of measurements make the software a potentially useful operator-independent tool for the assessment of foot morphological alterations and for orthotics customization. nAVI may be used for a more realistic classification of foot types when 3D foot images are available.

The effects of shoes and insoles for low back pain: a systematic review and meta-analysis of randomized controlled trials

The aim of this review was to examine the effects of shoes and insoles on low back pain (LBP). Seven electronic databases were searched from their inception to May 2020. The methodological quality of the 14 included studies was assessed by PEDro scale. Quality of evidence was assessed using GRADE. Moderate evidence on the disability questionnaire score (SMD, 0.52; 95% CI, 0.28 to 0.77; P < 0.001) and pain score (SMD, 0.61; 95% CI, 0.36 to 0.85; P < 0.001) of the custom-made orthotics for chronic LBP compared with no orthotics/insoles intervention was found. Meta-analysis results also showed moderate evidence on the disability questionnaire score (SMD, 0.44; 95% CI, 0.05 to 0.82; P =0.03) in patients who wore unstable shoes compared with regular shoes. Pain and life quality scores showed low-quality evidence of unstable shoes for chronic LBP. Custom-made orthotics and unstable shoes can be recommended to patients as a management option of chronic LBP.

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

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

Factors affecting foot posture in young adults: a cross sectional study

OBJECTIVE

Age, Body Mass Index (BMI) and flexibility are factors affecting foot posture, which is poorly understood in young adults. The objective of this study is to discover the relationships among these factors.

METHODS

252 healthy participants (106 males, 146 females) between the ages of 18 and 25 were selected. BMI and the Foot Posture Index - 6 item version (FPI-6) were assessed, a Beighton score was obtained for each participant, and a lunge test was conducted.

RESULTS

Pronated feet (indicated by an FPI-6 score of 6+ (had a weak positive correlation with Beighton score (r=0.25, p= 0.05, 95% CI [0.01 to 0.47]) and a weak negative correlation with BMI (r=0.31, p = 0.01, 95% CI [-0.52 to -0.07]). Females had a higher prevalence of pronated feet (81.75%) than males (18.75%).

CONCLUSION

There is a mild relationship between ligament laxity and foot pronation, and females are more prone to have pronated feet than males. No correlation was found between body weight and pronated feet.

Association between constitution, medical history, axiography and postural control in women aged between 21 to 30 years

The aim of this study was to determine association between constitutional, medical history and axiographic parameters with postural control parameters. Overall, 106 healthy female subjects aged between 21 and 30 years were measured. Data collection was carried out by completing a questionnaire on constitutional parameters, illnesses, accidents and medical/orthodontic therapies, as well as by axio- and posturographic measurements. Data were analyzed using correlations, pair comparisons and group comparisons. The significance level was set at p ≤ 0.05. The statistical evaluation showed significant correlations between sporting exercise and body sway in the sagittal direction (p ≤ 0.03), the BMI and the load on the forefoot/rear foot (p ≤ 0.01), the mouth opening and the load on the forefoot/rearfoot (p ≤ 0.01) and the presence of a deviation with the load on the left/right foot (p ≤ 0.01). The physical condition as well as the temporo-mandibular system are associated with the postural control in young women. Therefore, a holistic diagnosis and therapy will be supported by the present outcomes.

Baropodometric evaluation of foot load distribution during gait in the group of professionally active nurses

OBJECTIVES

Nurses are extremely exposed to musculoskeletal overloads. Prolonged standing postural balance distributions, functional deficits and pain may affect the symmetry of the load on the feet. The study aimed to assess the distribution of foot load during gait among nurses.

METHODS

The sample of this prospective and observational study consisted of 37 female nurses with mean age of 39 years. The Nordic Musculoskeletal Questionnaire (NMQ) was used to evaluate musculoskeletal disturbances and baropodometric gait analysis (BGA) was performed to register distribution of foot load during gait.

RESULTS

We showed that 68% of nurses declare that they know the principles of workplace ergonomics, but only 14% comply with them. NMQ results indicate that as many as 73% of the respondents feel ailments in the "lower back" area. An asymmetry was observed in the load of IV-V of the metatarsal head between the left and right foot (P = .000) and in the load of the left and right lateral part of the heel (P = .028) in the BGA test. Correlations between ailments occurring in the neck area and loading of the lateral arch of the right foot (P = .032) were found. Moreover, the load in this area correlated positively with the occurrence of "lower back" pain (P = .045).

CONCLUSIONS

Nurses have asymmetric distribution of foot load during gait, which results in a discrepancy between the loads on the three main support points of the foot and which may affect nurses' work productivity.

Effects of selective strengthening of tibialis posterior and stretching of iliopsoas on navicular drop, dynamic balance, and lower limb muscle activity in pronated feet: A randomized clinical trial

Objectives: Flexibility and strength are compromised in pronated feet, which could in turn lead to alteration of the dynamic balance and muscle activity in the lower extremities. This study aimed to analyze the effects of selective tibialis posterior strengthening and iliopsoas stretching on navicular drop, dynamic balance, and lower limb muscle activity in young adults with pronated feet. Methods: Twenty-eight participants with pronated feet were randomly assigned to either the stretching and strengthening group (n = 14) or the conventional exercise group (n = 14). The stretching and strengthening group performed tibialis posterior strengthening exercises and iliopsoas stretching three times a week for 6 weeks in addition to the conventional towel curl exercises. The conventional exercise group performed towel curl exercises only. Navicular drop, dynamic balance, and lower limb muscle activity were assessed at baseline and post-intervention. A mixed model analysis of variance was performed to test the study hypothesis. Results: Significant group effects for the activity of tibialis anterior (p = 0.003) and abductor hallucis muscle (p = 0.010), as well as for the posterolateral (p = 0.036) and composite reach scores (p = 0.018), were detected. Significant group × time interactions were observed for naviculardrop (p < 0.001), all dynamic balance components (p < 0.001), and the activity of tibialis anterior (p < 0.001) and abductor hallucis (p < 0.001). Conclusions: This study demonstrated that inclusion of selective tibialis posterior strengthening and iliopsoas stretching in addition to the conventional towel curl exercise program could improve important clinical outcomes, such as navicular drop, muscle activity, and dynamic balance in flatfeet.

The clinical measure of forefoot-shank alignment partially reflects mechanical properties of the midfoot joint complex

BACKGROUND

The clinical measure of forefoot-shank alignment (FSA) predicts the amount of foot pronation during weight-bearing tasks. This may be mediated by a relationship between FSA and the mechanical resistance of the midfoot joint complex (MFJC) to forefoot inversion, which is a component of weight-bearing foot pronation.

OBJECTIVE

To investigate if the clinical measure of FSA is associated with MFJC mechanical resistance to inversion.

DESIGN

Cross-sectional observational study.

METHOD

Forty-six healthy individuals (27 males; 19 females) with mean age of 26.4 years (SD 5.3) participated in this study. FSA was measured with photographs. The resistance torque of the MFJC against inversion was measured with a specially designed device. Mean torque, mean torque normalized by body mass, and joint resting position were calculated as variables related to MFJC mechanical resistance. Correlation analyses were carried out to test the association between each MFJC resistance variable and the FSA (α = 0.05).

RESULTS

/findings: There were significant moderate correlations of FSA with mean torque (r = -0.44, p = 0.002), mean normalized torque (r = -0.42, p = 0.004) and resting position (r = 0.39, p = 0.007). The clinical measure of FSA is associated to the mechanical resistance of the MFJC: (a) the greater the FSA, the smaller the resistance torques; (b) the greater the FSA, the more inverted the forefoot resting position.

CONCLUSIONS

These results showed that the clinical measure of FSA is moderately related to mechanical properties of the MFJC.

Effects of the Short Foot Exercise With Neuromuscular Electrical Stimulation on Navicular Height in Flexible Flatfoot in Thailand: A Randomized Controlled Trial

OBJECTIVES

Flatfoot, or low medial longitudinal arch, contributes to back and lower extremity injuries and is caused by weak abductor hallucis (AbdH) muscles. The purpose of this study was to investigate the effects of short foot exercise (SFE) alone or with neuromuscular electrical stimulation (NMES) on navicular height, the cross-sectional area (CSA) of the AbdH muscle, and AbdH muscle activity in flexible flatfoot.

METHODS

Thirty-six otherwise healthy people with flexible flatfoot were randomly assigned to a group that received SFE with placebo NMES treatment (the control group) or a group that received both SFE and NMES treatment (the experimental group). Each group received 4 weeks of treatment (SFE alone or SFE with NMES). Navicular height, the CSA of the AbdH muscle, and AbdH muscle activity were assessed before and after the intervention.

RESULTS

No significant differences were found in navicular height or the CSA of the AbdH muscle between the control and experimental groups, while AbdH muscle activity showed a statistically significant difference between the groups (SFE=73.9±11.0% of maximal voluntary isometric contraction [MVIC]; SFE with NMES=81.4±8.3% of MVIC; p<0.05). Moreover, the CSA of the AbdH muscle showed a statistically significant increase after treatment in the SFE with NMES group (pre-treatment=218.6±53.2 mm2; post-treatment=256.9±70.5 mm2; p<0.05).

CONCLUSIONS

SFE with NMES was more effective than SFE alone in increasing AbdH muscle activity. Therefore, SFE with NMES should be recommended to correct or prevent abnormalities in people with flexible flatfoot by a physiotherapist or medical care team.

Evaluating the Medial Longitudinal Arch of the Foot: Correlations, Reliability, and Accuracy in People With a Low Arch

BACKGROUND

The medial longitudinal arch of the foot is a variable structure, and a decrease in its height could affect several functions and increase the risk of injuries in the lower limbs. There are many different techniques for evaluating it.

OBJECTIVE

The objective of this study was to evaluate the correlations of the Navicular Drop Test, several footprint parameters, and the Foot Posture Index-6 in people with a low medial longitudinal arch. Intrarater reliability and interrater reliability were also estimated.

DESIGN

This was a repeated-measures, observational descriptive study.

METHODS

Seventy-one participants (53.5% women; mean age = 24.13 years; SD = 3.41) were included. All of the parameters were collected from the dominant foot. The correlation coefficients were calculated. The reliability was also calculated using the intraclass correlation coefficient, 95% CI, and kappa coefficient.

RESULTS

Statistically significant correlations were obtained between the Navicular Drop Test and the footprint parameters, with r absolute values ranging from 0.722 to 0.788. The Navicular Drop Test and the Foot Posture Index-6 showed an excellent correlation (Spearman correlation coefficient = 0.8), and good correlations (Spearman correlation coefficient = |0.663-0.703|) were obtained between the footprint parameters and the Foot Posture Index-6. Excellent intrarater reliability and interrater reliability were obtained for all of the parameters.

LIMITATIONS

Radiographic parameters, the gold standard for evaluating the medial longitudinal arch height, were not used. In addition, the results of this research cannot be generalized to people with normal and high medial longitudinal arches.

CONCLUSIONS

In participants with a low medial longitudinal arch, the Navicular Drop Test showed significant correlations with footprint parameters; correlations were good for the arch angle and Chippaux-Smirnak Index, and excellent for the Staheli Index. The Foot Posture Index-6 showed an excellent correlation with the Navicular Drop Test and a good correlation with the footprint parameters evaluated. All of the parameters showed high reliability.

Effects of foot pronation on the lower limb sagittal plane biomechanics during gait

BACKGROUND

Increased foot pronation may compromise ankle plantarflexion moment during the stance phase of gait, which may overload knee and hip.

RESEARCH QUESTION

This study investigated the influence of increased foot pronation on lower limbs angular displacement, internal moments and power in the sagittal plane and ground reaction force and center of pressure displacement during the stance phase of gait.

METHODS

Kinematic and kinetic data of 22 participants (10 women and 12 men) were collected while they walked wearing flat (control condition) and laterally wedged sandals to induce foot pronation (inclined condition). We used principal component analysis for data reduction and dependent t-test to compare differences between conditions with α = 0.05.

RESULTS

The inclined condition increased forefoot range of motion (p < 0.001; effect size = 0.73); increased ankle plantarflexion angle (p < 0.001; effect size = 0.96); reduced ankle plantarflexion moment in mid and terminal stance phases and delayed and increased ankle plantarflexion moment in late stance (p < 0.001; effect size = 0.72); increased range of ankle power during late stance (p = 0.006; effect size = 0.56); reduced knee range of moment (p < 0.001; effect size = 0.76); increased range of knee power in early stance and reduced knee power generation in late stance (p = 0.005; effect size = 0.56); reduced the anterior displacement of the center of pressure (p < 0.001; effect size = 0.82) and increased the ground reaction force in the anterior direction (p = 0.003; effect size = 0.60).

SIGNIFICANCE

Increased foot pronation compromises lower limb mechanics in the sagittal plane during the stance phase of gait. These findings are explained by the fact that foot pronation increases foot segments flexibility and compromises foot lever arm function during the stance of gait.

Foot Arch Height and Quality of Life in Adults: A Strobe Observational Study

Background: Variations in the foot structure related with the high or low arch are identified common lower limb conditions, and it is supposed to be the effect on the quality of life (QoL) associated to foot health in adults. Here we aimed to determine the relationships between relatively high and low feet arches and QoL. Methods: A cross-sectional study was carried out. Among 138 adults enrolled in the study, 66 had a high arch, 21 had a low arch, and 51 were within the normal range. Changes related to the foot structure were analyzed using Area Calc version 2.6 software, and data obtained using the Foot-Health-Status-Questionnaire (FHSQ), whose domains were compared between foot arch groups by means of the one-way analysis of variance (ANOVA). Results: The results of the FHSQ comparison between the three groups within the sample population did not show any statistically significant difference (p > 0.05) for any domains of specific foot (pain, function, general health and footwear) and general (general health, physical activity, social function and vigor) health-related QoL. Conclusions: Specific foot and general health-related QoL did not seem to be influenced by the foot arch height between high, normal and low feet arches heights. Nevertheless, further studies with higher sample sizes and matched-paired groups should be carried out.

Physical therapist decision-making in managing plantar heel pain: cases from a pragmatic randomized clinical trial

INTRODUCTION

Plantar heel pain (PHP) is a common condition managed by physical therapists that can, at times, be difficult to treat. Management of PHP is complicated by a variety of pathoanatomic features associated with PHP in addition to several treatment approaches with varying efficacy. Although clinical guidelines and clinical trial data support a general approach to management, the current literature is limited in case-specific descriptions of PHP management that addresses unique combinations of pathoanatomical, physical, and psychosocial factors that are associated with PHP. Purpose: The purpose of this case series is to describe physical therapist decision-making of individualized multimodal treatment for PHP cases presenting with varied clinical presentations. Treatment incorporated clinical guidelines and recent evidence including a combination of manual therapy, patient education, stretching, resistance training, and neurodynamic interventions. A common clinical decision-making framework was used to progress individualized treatment from a focus on symptom modulation initially to increased load tolerance of involved tissues and graded activity. In each case, patients met their individual goals and demonstrated clinically meaningful improvements in pain, function, and global rating of change that were maintained at the 1-2-year follow-up. Implications: This case series provides details of physical therapist management of a variety of PHP clinical presentations that can be used to complement clinical practice guidelines in the management of PHP.

The influence of foot hyperpronation on pelvic biomechanics during stance phase of the gait: A biomechanical simulation study

Despite the theoretical link between foot hyperpronation and biomechanical dysfunction of the pelvis, the literature lacks evidence that confirms this assumption in truly hyperpronated feet subjects during gait. Changes in the kinematic pattern of the pelvic segment were assessed in 15 persons with hyperpronated feet and compared to a control group of 15 persons with normally aligned feet during the stance phase of gait based on biomechanical musculoskeletal simulation. Kinematic and kinetic data were collected while participants walked at a comfortable self-selected speed. A generic OpenSim musculoskeletal model with 23 degrees of freedom and 92 muscles was scaled for each participant. OpenSim inverse kinematic analysis was applied to calculate segment angles in the sagittal, frontal and horizontal planes. Principal component analysis was employed as a data reduction technique, as well as a computational tool to obtain principal component scores. Independent-sample t-test was used to detect group differences. The difference between groups in scores for the first principal component in the sagittal plane was statistically significant (p = 0.01; effect size = 1.06), but differences between principal component scores in the frontal and horizontal planes were not significant. The hyperpronation group had greater anterior pelvic tilt during 20%–80% of the stance phase. In conclusion, in persons with hyperpronation we studied the role of the pelvic segment was mainly to maintain postural balance in the sagittal plane by increasing anterior pelvic inclination. Since anterior pelvic tilt may be associated with low back symptoms, the evaluation of foot posture should be considered in assessing the patients with low back and pelvic dysfunction.

Low back pain and disability in individuals with plantar heel pain

BACKGROUND

Lack of response to plantar heel pain (PHP) treatment may be related to unmanaged low back pain (LBP) and low back dysfunction, but a relationship between LBP and PHP has not been established. The purpose of this investigation was to compare the prevalence of LBP among individuals with and without PHP and to assess the association between low back disability and foot/ankle function.

METHODS

A cross-sectional study compared the prevalence and likelihood of LBP in individuals with (n=27) and without (n=27) PHP matched to age, sex, BMI, foot posture, and foot mobility. In individuals with PHP, correlations were examined between foot/ankle function using the foot and ankle ability measure (FAAM), low back disability using the Oswestry low back disability questionnaire (OSW), duration of PHP symptoms, body mass index (BMI), and age.

RESULTS

A greater percentage of individuals with PHP had LBP (74% versus 37% of controls, odds ratio=5.2, P=0.009) and higher levels of low back disability (17% higher OSW score than controls, P<0.001). In individuals with PHP, FAAM scores were correlated with OSW scores (ρ=-0.463, P=0.015), but not with duration of PHP symptoms, BMI, or age (P>0.150).

CONCLUSIONS

Individuals with PHP had a greater prevalence of LBP and higher low back disability that was correlated to reduced foot and ankle function. Treatment to address both local and proximal impairments, including impairments related to LBP, may be warranted to improve the management of PHP.

Association between hyper-pronated foot and the degree of severity of disability in patients with non-specific low back pain

BACKGROUND

It has been established that Hyper-pronation of the foot may lead to postural changes in the lower limbs, with a resultant pelvic ante-version, and a subsequent risk of development of low back pain. However, the association between the presence of a hyper-pronated foot and the severity of disability in low back pain is currently not known.

OBJECTIVES

The purpose of this study was to examine whether the presence of a hyper-pronated foot has any impact on the degree of severity of disability (functional status) in patients with non-specific low back pain.

METHODS

An observational study was conducted in an outpatient setting, where patients diagnosed as having non-specific low back pain were included. The degree of severity of disability was measured using the Modified Oswestry Low Back Pain Disability Questionnaire, and the foot hyper-pronation was assessed with the execution of the Navicular Drop test. Descriptive statistics and Linear regression analyses were conducted.

RESULTS

Of the 71 patients included, 14 demonstrated having a unilateral hyper-pronation of the foot. The mean scores for the functional status and hyper-pronation of the foot were 37.15 (SD = 10.40) and 6.06 (SD = 3.42) respectively. An association was not found between the severity of disability and the presence of foot hyper-pronation (B = .87, p = .78).

CONCLUSIONS

Hyper-pronation of the foot could lead to the development of non-specific low back pain, but the degree of severity of the disability is not influenced by the presence of a hyper-pronated foot. The alterations in lower limb mechanics leading to back pain are a complex issue, and thus needs further research.

Foot Pain in Relation to Ipsilateral and Contralateral Lower-Extremity Pain in a Population-Based Study

BACKGROUND

Clinical observations note that foot pain can be linked to contralateral pain at the knee or hip, yet we are unaware of any community-based studies that have investigated the sidedness of pain. Because clinic-based patient samples are often different from the general population, the purpose of this study was to determine whether knee or hip pain is more prevalent with contralateral foot pain than with ipsilateral foot pain in a population-based cohort.

METHODS

Framingham Foot Study participants (2002-2008) with information on foot, knee, and hip pain were included in this cross-sectional analysis. Foot pain was queried as pain, aching, or stiffness on most days. Using a manikin diagram, participants indicated whether they had experienced pain, aching, or stiffness at the hip or knee and specified the side of any reported pain. Sex-specific multinomial logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals for the association of foot pain with knee and hip pain, adjusting for age and body mass index.

RESULTS

In the 2,181 participants, the mean ± SD age was 64 ± 9 years; 56% were women, and the mean body mass index was 28.6. For men and women, bilateral foot pain was associated with increased odds of knee pain on any side (ORs = 2-3; P < .02). Men with foot pain were more likely to have ipsilateral hip pain (ORs = 2-4; P<.03), whereas women with bilateral foot pain were more likely to have hip pain on any side (OR = 2-3; P < .02).

CONCLUSIONS

Bilateral foot pain was associated with increased odds of knee and hip pain in men and women. For ipsilateral foot and hip pain, men had a stronger effect compared with women.

Alterations in thoracolumbosacral movement when pain causing lameness has been improved by diagnostic analgesia

Lameness, thoracolumbosacral pain and reduced range of motion (ROM) often coexist; better understanding of their relationship is needed. The objectives were to determine if thoracolumbosacral movement of horses changes when pain causing lameness is improved by diagnostic analgesia. We hypothesised that reduction of lameness will increase ROM of the thoracolumbosacral region. Thirteen horses with different types of hind limb lameness were trotted in straight lines and lunged on a 10m diameter circle on left and right reins before and after lameness was subjectively substantially improved by diagnostic analgesia. Inertial sensor data were collected from the withers, thirteenth (T13) and eighteenth thoracic (T18) vertebrae, third lumbar (L3) vertebra, tubera sacrale (TS), left and right tubera coxae. ROM of flexion-extension, axial rotation, lateral bending, dorsoventral, lateral-lateral motion and vertical movement symmetry were quantified at each thoracolumbar site. Hiphike difference (HHD), maximum difference (MaxDiff) and minimum difference (MinDiff) for the pelvic sensors were measured. Percentage changes for before and after diagnostic analgesia were calculated; mean±standard deviation (SD) or median [interquartile range] were determined. Associations between the change in pelvic versus thoracolumbar movement symmetry after each local analgesic technique were tested. After resolution of lameness, HHD decreased by 7% [68%] (P=0.006). The MinDiff decreased significantly by 33% [61%] (P=0.01), 45±13% (P=0.005) and 52±23% (P=0.04), for TS, L3 and T18, respectively. There was significantly increased ROM in flexion-extension at T13, in axial rotation at T13, T18, L3 and in lateral-lateral ROM at L3. Thoracolumbosacral asymmetry and reduced ROM associated with lameness were both altered immediately by improvement in lameness using diagnostic analgesia.

Metatarsal Shape and Foot Type: A Geometric Morphometric Analysis

Planus and cavus foot types have been associated with an increased risk of pain and disability. Improving our understanding of the geometric differences between bones in different foot types may provide insights into injury risk profiles and have implications for the design of musculoskeletal and finite-element models. In this study, we performed a geometric morphometric analysis on the geometry of metatarsal bones from 65 feet, segmented from computed tomography (CT) scans. These were categorized into four foot types: pes cavus, neutrally aligned, asymptomatic pes planus, and symptomatic pes planus. Generalized procrustes analysis (GPA) followed by permutation tests was used to determine significant shape differences associated with foot type and sex, and principal component analysis was used to find the modes of variation for each metatarsal. Significant shape differences were found between foot types for all the metatarsals (p < 0.01), most notably in the case of the second metatarsal which showed significant pairwise differences across all the foot types. Analysis of the principal components of variation showed pes cavus bones to have reduced cross-sectional areas in the sagittal and frontal planes. The first (p = 0.02) and fourth metatarsals (p = 0.003) were found to have significant sex-based differences, with first metatarsals from females shown to have reduced width, and fourth metatarsals from females shown to have reduced frontal and sagittal plane cross-sectional areas. Overall, these findings suggest that metatarsal bones have distinct morphological characteristics that are associated with foot type and sex, with implications for our understanding of anatomy and numerical modeling of the foot.

The Effect of Walking Speed on Foot Kinematics is Modified When Increased Pronation is Induced

BACKGROUND

The relation between walking speed and foot kinematics during gait is not well established, and neither is it clear whether this relation is modified in the presence of factors expected to increase pronation (eg, abnormal foot alignment). Understanding how foot kinematics is affected by walking speed under varying conditions could contribute to our understanding of stresses to the musculoskeletal system during walking. We evaluated the effect of walking speed on foot kinematics in the frontal plane during gait and determined whether this effect is modified by using medially inclined insoles that force the foot into increased pronation.

METHODS

Twenty-six healthy young adults were assessed while walking on a treadmill wearing flat insoles and wearing medially inclined insoles. Foot kinematics in the frontal plane was measured with a three-dimensional motion analysis system. Data were analyzed during the stance phase of gait.

RESULTS

There was no main effect of speed on average calcaneal position. However, there was a significant insole type × walking speed interaction effect. In the flat insole condition, increased walking speed was associated with a less inverted average calcaneal position (or greater magnitudes of eversion), whereas in the inclined insole condition, higher speeds were associated with a less everted average calcaneal position (or increased magnitudes of inversion).

CONCLUSIONS

The magnitude of foot eversion increases at faster gait speeds under typical conditions. In the presence of factors that induce excessive pronation, however, this effect is reversed. Results suggest that individuals use greater active control of foot motion at faster speeds in the presence of excessive pronation to improve push-off efficiency. Potential clinical consequences of this functional strategy are discussed.

Analysis of Difference in Center-of-Pressure Positions Between Experts and Novices During Asymmetric Lifting

Although numerous studies have analyzed the relationship between manual material handling (MMH) and the forces acting on the lumbar spine, the difference in the MMH between experts and novices through the analysis of measured data has not been well studied. The purpose of this paper was to analyze the difference in the MMH positions between ten skilled experts working at a freight transport company (Group 1) and five unskilled novices without any experience (Group 2) during asymmetric lifting. All the human subjects performed asymmetric lifting experiments with closed eyes; the experiments involved moving loads (6 and 18 kg) to the left side. Time series data of the vertical ground reaction force were measured, using a Wii Balance Board, and then, the center-of-pressure (CoP) trajectories were calculated. The balance board was used for the measurement, because it was reliable, inexpensive, and portable and provided good repeatability even on rough surfaces, and all the information pertaining to the load and worker under various conditions was captured without any omissions. Under the 18 kg load condition, the CoP positions for Group 2 were located on the same side during left asymmetric lifting; however, those for Group 1 were located on the opposite side during left asymmetric lifting ([Formula: see text]). Furthermore, under the 6 kg load condition, the load weight influenced asymmetric lifting for most subjects of Group 2 such that the CoP positions were located on the opposite side ([Formula: see text]). Based on the simulation and electromyography measurement results, we inferred that the difference in the CoP positions between the two different groups could be attributed to the difference in the hip positions. Most skilled experts position their hips in such a way that their CoP trajectories move toward the opposite side during left asymmetric lifting. Although the skillful characteristics of experts may be responsible for the lightening of the burden on the waist during asymmetric lifting, there are still two points that this paper does not clarify: the relationship between the experts' adjustment of the hip position and the load of the weight, and the influence of an imbalance of the CoP position on the forces acting on the lumbar spine.