Forefoot joint damage, pain and disability in rheumatoid arthritis patients with foot complaints: the role of plantar pressure and gait characteristics

New Insight into the Effects of Different Types of Midfoot and Hindfoot Deformities on the Functional Outcomes of Rheumatoid Arthritis Patients

In advanced stages of rheumatoid arthritis (RA), the pattern of joint involvement leads to varied types of foot deformities such as forefoot, midfoot, and hindfoot deformities. We aim to evaluate midfoot and hindfoot deformities and their effect on functional outcomes in RA patients. In this prospective cross-sectional study clinical and radiological evaluations of 100 adult RA patients were studied for midfoot and hindfoot deformities. The RA disease activity, functional disability level, specific foot and ankle assessments, gait speed, and balance tests were assessed. Radiological examinations of the weight-bearing feet in a standing position were done. We found that the most frequent deformity type was the planovalgus foot (24%). There were statistically significant differences between the types of foot deformities and disease duration, disease activity, falls, Tinetti and Berg balance Test, and health assessment questionnaire-disability index. The multivariate regression analysis of independent correlates of falling detected that patients with equinovarus deformity were 2.5 times more liable for falling with 63.5% predictive power. According to the predictive criteria of deformity type for falling, the equinocavovarus type had accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 91%, 84.5%, 98.5%, 99%, and 84%, respectively. We found in RA patients, midfoot and hindfoot deformities cause a significant reduction of functional ability and quality of life. The early detection of foot deformities requires a good awareness of the clinical and radiographic diagnosis of different types of deformities thus reducing the possible functional disabilities via early management by combined orthotic, physiotherapy, and surgical treatments.

Exposure of Undergraduate Nursing Students to Standing Environments: A Longitudinal Study on Plantar Force and Pressure Distribution

BACKGROUND

Understanding the link between plantar force, pressure, and foot discomfort is important for nursing students' well-being, given the prevalence of foot and ankle musculoskeletal disorders among nurses. Assessing these factors can inform tailored self-care interventions, supporting holistic nursing education.

PURPOSE

To assess the plantar force and pressure distribution of third-year nursing students at baseline and after 5 months of exposure to a clinical setting.

METHODS

A prospective cohort study in a Portuguese nursing school measured changes in podiatric profile at 5 months, including peak pressure, maximum force, and contact area.

RESULTS

Elevated mean peak pressure in the heel correlated positively with maximum force and contact area. Negative correlations were found between the contact area and edema. Peak pressure correlated positively with thigh pain, indicating pressure transfer to metatarsal heads.

CONCLUSIONS

The findings underscore the importance of integrating ergonomic education into nursing curricula and raising awareness of self-care interventions.

The causality between rheumatoid arthritis and postural deformities: bidirectional Mendelian randomization study and mediation analysis

Background

To better understand the preventive or therapeutic clinical interventions that may be supported by the association between rheumatoid arthritis (RA) and postural deformities including hallux valgus, flat foot, and scoliosis, this study was conducted using Mendelian randomization (MR) analysis. It aimed to investigate whether RA is causally associated with postural deformities in European populations.

Methods

Summary-level data on RA and postural deformities were obtained from the IEU OpenGWAS project and Finngen database, respectively. LDSC regression analysis was conducted to assess the genetic correlation between these diseases. The inverse variance weighting (IVW) method was employed as the primary approach for two-sample MR analyses to evaluate causality. Supplementary methods included MR-Egger, maximum likelihood, weighted median, and cML-MA. To test for potential horizontal pleiotropy, we performed the MR-Egger intercept test, cML-MA, and secondary analyses after excluding confounders. Additionally, mediation analyses were conducted using two-step MR.

Results

The IVW method revealed RA to be causally associated with hallux valgus (OR 1.132, 95% CI 1.087-1.178, P < 0.001) and flat foot (OR 1.197, 95% CI 1.110-1.291, P < 0.001). Among postural deformities, hallux valgus was causally associated with flat foot (OR 1.823, 95% CI 1.569-2.119, P < 0.001) and scoliosis (OR 1.150, 95% CI 1.027-1.287, P < 0.05). No significant horizontal pleiotropy was detected. Moreover, mediation analyses indicated that hallux valgus mediates the effect of RA on flat foot (mediation effect 0.024, 95% CI 0.005-0.044, P < 0.05), with a mediation proportion of 41.31%.

Conclusion

These findings indicate a potential causal association between genetically predicted RA and both hallux valgus and flat foot. Furthermore, hallux valgus serves as a mediator in the pathway from RA to flat foot. This underscores the importance of early screening and preventive treatment of foot deformities in RA patients. Further research is necessary to determine the applicability of these findings in non-European populations.

Differences and Similarities in the Feet of Metatarsalgia Patients with and without Rheumatoid Arthritis in Remission

Objectives: Metatarsalgia continues to be a problem in patients with rheumatoid arthritis (RA) in remission (remRA), as well as in the non-rheumatic population, with a mechanical origin. Identify and compare clinical, morphological, disability, synovitis (ultrasound), and radiological osteoarticular damage characteristics in two groups of patients with lesser-ray metar-tarsalgia, with remRA, and without RA. Methods: Cross-sectional study with 84 patients with remRA (mRA) and 60 patients without RA (nmRA). The study evaluated five clinical variables (pain, Foot Function Index (FFI), joint mobility, digital deformities, and foot type), a radiological variable (osteoarticular damage), and an ultrasound variable (metatarsal synovitis). The data were analysed using descriptive and correlational techniques. Results: There were no significant differences in sex, age, body mass index (BMI), or degree of pain. Both groups showed a high prevalence of limited joint mobility for the ankle and first metatarsal phalanx (DF1st MTPJ) and digital deformities, with no statistically significant differences. Similarly, there were no differences in lesser-ray synovitis. On the other hand, there were differences in mRA with greater disability and activity limitation (FFI), LDD (lesser-ray digital deformities) stiffness, first-ray deformities, radiological damage, synovitis in 1st MTPJ, and positive Doppler (five patients). Conclusions: Metatarsalgia presents similarities in both populations. Biomechanical factors may influence the symptoms and presence of synovitis in patients with RA in remission. Other characteristics are more frequent in mRA, which could be related to the disease; thus, future research should include both biomechanical and ultrasound exploration of the foot in the valuation of patients in remission.

Do Dynamic Plantar Pressures Differ Based on Sonographic Evidence of Metatarsophalangeal Joint Synovitis in People With Rheumatoid Arthritis?

OBJECTIVE

The metatarsophalangeal joints (MTPJs) are the most common location for synovitis in people with rheumatoid arthritis (RA), yet their association with plantar foot pressures has received very little attention. This study aimed to determine whether plantar pressures differed based on sonographic evidence of MTPJ synovitis in people with RA.

METHOD

Ultrasound was used to assess synovitis (grey scale synovial hypertrophy and power Doppler signal) in MTPJs 1 to 5 using the combined EULAR/Outcome Measures in Rheumatology scoring system. Peak pressure (PP) and pressure time integrals (PTIs) were assessed during barefoot walking for seven plantar foot regions (heel, midfoot, first metatarsal, second metatarsal, third to fifth metatarsals, hallux, lesser toes). Mixed-effects linear regression was used to determine the difference in PP and PTI between MTPJs with none/minimal synovitis and MTPJs with moderate/severe synovitis.

RESULTS

Thirty-five participants with RA were included. Mean age was 66.3 years and mean disease duration was 22.2 years. Participants with sonographic evidence of moderate/severe synovitis at the first MTPJ had reduced PTI at the hallux compared with those with none/minimal synovitis at this joint (P = 0.039). Participants with moderate/severe synovitis at the second MTPJ and fourth MTPJ had reduced PP and reduced PTI at lesser toes compared with those with none/minimal synovitis in these joints (all P ≤ 0.048). No significant differences were observed for synovitis in other joints.

CONCLUSION

These findings may be suggestive of an inverse relationship between plantar pressure and soft tissue pathology, which is consistent with an offloading strategy and reduced use of the toes during propulsion.

Preoperative patient's expectations and clinical outcomes after rheumatoid forefoot deformity reconstruction by joint sacrificing surgery

Objective

To study the clinical and radiologic factors related with overall patient satisfaction of joint scarifying reconstruction on severe rheumatoid forefoot deformity (RFD).

Methods

Forty cases of RFD were retrospectively enrolled. A questionnaire on the factors for patient's expectations and satisfactions of the greater and lesser toes was administered, including repression of relapse in deformity (D), pain reduction (P), improvement in shoe wearing (S), barefoot activity (B), and appearance (A). Overall satisfaction were assessed using the 5-digit-scale. Hallux valgus angle, 1, 2 intermetatarsal angle, and other radiologic parameters were measured. Pearson's correlation and multiple linear regression analyses were used to evaluate the relationships between these factors and overall satisfaction.

Results

Overall satisfaction was 4.0±0.82. Postoperative radiologic parameters were corrected in adequate range. Visual analog scale (VAS) was reduced from 7.2±2.1 to 2.2±1.8. For the greater toe, patient's expectations (D, P, S, B, and A) were 4.2, 4.1, 3.0, 2.5, 2.7 and satisfactions were 4.2, 4.0, 3.4, 3.5, 3.3, respectively. For the lesser toes, patient's expectations (D, P, S, B, and A) were 3.9, 4.1, 3.4, 3.0, 2.8, and satisfactions were 3.4, 4.0, 3.4, 3.6, 2.9, respectively. Satisfactions with P and B, and reduction amounts of VAS were significantly correlated with overall satisfaction.

Conclusion

Although forefoot reconstruction with a joint sacrificing procedure is non-physiological, it could be a good surgical option for severe RFD. Each patient's expectations and satisfactions with this procedure could vary. Thus, it seems important to inform patients preoperatively that expectation could be fulfilled well or less.

Foot Pain and Disability in Women with Rheumatoid Arthritis, Ehlers-Danlos Syndrome and Systemic Lupus Erythematosus: Relationship with Quality of Life

The aim of this work was to investigate the relationship foot pain and foot disability have with HRQoL in groups of women with RA, SLE and EDS, in comparison with a control group. A cross-sectional study was carried out with females with one of these conditions and a control group. The SF-12 questionnaire was used to collect data about quality of life. The type of foot was classified according to the footprint and the foot posture index. A total of 156 patients and 47 controls participated in the study (N = 203). Neither pain nor foot posture were different between groups. The physical and mental components of SF-12 were worse in rheumatoid arthritis and Ehlers-Danlos syndrome patients, and the physical component was worse in systemic lupus erythematosus patients, compared to controls. A significant difference was also observed in the mental component between systemic lupus erythematosus and Ehlers-Danlos syndrome patients, the latter having the lowest values among the groups. We can conclude that women with rheumatoid arthritis, Ehlers-Danlos syndrome, systemic lupus erythematosus and foot pain perceive a worse quality of life. There are no significant changes in foot posture. Pain and health-related quality of life are independent of foot posture.

Orthopaedic Simulation of a Morton's Extension to Test the Effect on Plantar Pressures of Each Metatarsal Head in Patients without Deformity: A Pre-Post-Test Study

BACKGROUND

the area beneath the metatarsal heads is a common location of foot pain, which is often associated with high plantar pressures. The aim of this study was to determine the effect of the application of a Morton's extension on the pressure in the metatarsal bones of the foot using a pressure platform.

METHODS

twenty-five subjects without musculoskeletal pathology were selected for this study, and an experiment was conducted with them as the subjects, before and after application of a Morton's extension. The foot regions were divided into the forefoot (transversely subdivided into six areas corresponding to the first, second, third, fourth, and fifth metatarsal heads, and the hallux), midfoot, and rearfoot, and then the maximum and average pressures exerted at each region were measured before and after placing a Morton's extension.

MAIN FINDINGS

we found a pressure reduction, with a p-value less than (p < 0.05), in the head of the second and third metatarsals in statics and dynamics.

CONCLUSIONS

we can conclude that the Morton's extension produces a variation in plantar pressures on the lesser metatarsals. The application of a Morton's extension may be beneficial for the management of forefoot pathology. This study will help clinicians consider various tools to treat forefoot disorders. NCT05879094 (ClinicalTrial.gov (accessed on 18 May 2023)).

Footwork Pro System Reproducibility of Static and Dynamic Plantar Pressure Indicators

Objective

The purpose of this study was to identify the reproducibility of the Footwork Pro plate in the measurement of static and dynamic plantar pressure in healthy adults.

Methods

We performed a reliability study using a test-retest design. The sample consisted of 49 healthy adults of both sexes, aged 18 to 64. Participants were assessed on the following 2 different occasions: the initial moment and 7 days later. Measurements for the static and dynamic plantar pressure were performed. We used the Student t test for paired data, the concordance correlation coefficient, and bias to estimate reliability.

Results

Plantar pressure values for the static condition (peak plantar pressure, plantar surface contact area, and body mass distribution) and dynamic condition (peak plantar pressure, plantar surface contact area, and contact time) between the first and second measurements did not present statistically significant differences. The concordance correlation coefficients were ≤0.90, and the biases were of low magnitude.

Conclusion

The findings showed that the Footwork Pro system offered clinically acceptable reproducibility to identify static and dynamic plantar pressure and thus may be a reliable tool for this purpose.

The Management of Metatarsalgia in Rheumatoid Arthritis Using Simple Insoles: An Effective Concurrent Treatment to Drug Therapy

BACKGROUND

Metatarsalgia is a common affliction in rheumatoid arthritis (RA), often requiring aggressive pharmacologic treatment that carries associated adverse effects. The aim of this study was to investigate whether simple insoles would have a beneficial effect on forefoot pain, disability, and functional limitation in participants with RA experiencing forefoot pain.

METHOD

A prospective, quasi-experimental, pretest-posttest trial was performed at a rheumatology outpatient clinic. Participants were supplied with a simple insole comprising a valgus pad and a plantar metatarsal pad and covered with a cushioning material. The Foot Function Index (FFI) was self-administered before and 3 months after insole use.

RESULTS

Reductions in forefoot pain (from 56.78 to 42.97) and total (from 41.64 to 33.54) FFI scores were noted. Statistical significance for this reduction was achieved following the t test (P = .002 and P = .0085, respectively). However, although reductions in mean disability and activity limitation scores were recorded (from 50 to 44.85 and from 18 to 14.57, respectively), these did not reach significance (P = .151 and P = .092, respectively) Conclusions: Simple insoles have been shown to be effective in reducing total and forefoot pain FFI scores in patients with RA experiencing metatarsalgia. This treatment offers advantages because these devices can be fabricated simply and cheaply, thus initiating the patient on an effective orthosis therapy immediately in the clinic without having to wait for prolonged periods until custom orthotic devices can be supplied.

Assessment of the functional impact of foot involvement in patients with rheumatoid arthritis

AIM OF THE WORK

We aimed to evaluate the impact of foot involvement in patients with rheumatoid arthritis (RA) using the functional foot index (FFI) and to identify predictive factors of the functional impact of foot abnormalities in RA patients.

PATIENTS AND METHODS

This was a cross-sectional study including patients with RA meeting the criteria of the American College of Rheumatology and the European League Against Rheumatism 2010. The main epidemiological data, results of podoscopic and clinical examination of the foot and ankle, biological tests and radiological findings were collected. The presence of foot pain was assessed by a visual analogic scale (0-10), and the functional impact of foot involvement was assessed based on the validated French version of the FFI.

RESULTS

Fifty RA patients with an average age of 59.3 ± 9.9 years [39-79] were included, and 80% of them had foot involvement. Foot pain was present in 32 patients (64%), most frequently situated in the forefoot (56%). The average FFI score was 33.67 ± 30.53 [0-92.67]. The following factors had a significant association with the FFI score: an occupation soliciting the feet (p = 0.001), disease duration (p = 0.033, r = 0,302), the Health Assessment Questionnaire (p = 0.0001, r = 0,480), body mass index (p = 0.0001, r = 0,654), the presence of podiatric abnormalities (p = 0.0001) and Visual Analog Scale foot pain (p = 0.0001, r = 0,854). A significant association was also found between the FFI score and the presence of a hallux valgus (p = 0.004), a spread of the forefoot (p = 0.029), a claw of the toes (p = 0.002), a triangular forefoot (p = 0.0001), a quintus varus (p = 0.002), flat feet (p = 0.0001) and a valgus of the hindfoot (p = 0.001).

CONCLUSION

Due to the high frequency of foot involvement and its significant functional impact, meticulous examination of the feet and assessment of their functional impact must be one of the parameters for monitoring the disease. Its impact on one's quality of life can be important.

LEVEL OF CLINICAL EVIDENCE

4 (cohort studies, non experimental, observational studies).

Baropodometric Assessment of the Podiatric Profile of Nursing Students in Clinical Settings: A Study Protocol

Introduction

Nursing students are exposed to increased risks of developing foot and ankle disorders due to prolonged standing and walking positions during clinical settings. This can lead to high dropout rates from nursing degree, thus contributing to a future shortage in nursing professionals. This protocol aims to develop a study to understand the influence of prolonged standing and walking positions on nursing students' foot health, and specifically to study the relationship between the podiatric profile (regional force and pressure exerted on the foot) and related signs and symptoms.

Methods and Analysis

A prospective observational cohort study will be conducted with 194 nursing students. Participants will be asked to walk through a baropodometric platform before and after a 5-month clinical training session. Assessment will focus on the change in podiatric profile, namely foot posture and foot function, at 5 months, and changes in foot health at 5 months. The study will start in January 2022 and it's expected to end by June 2022.

Discussion

The study aims to perform an innovative assessment of nursing students' podiatric profile, which will allow for a comprehensive description of foot/ankle changes and their relationship with prolonged standing and walking contexts.

Ethics and Dissemination

The study was approved by The Ethical Committee of the Health Sciences Research Unit: Nursing (UICISA: E), of the Nursing School of Coimbra (ESEnfC), with the approval code nr. P799_07_2021. The study was also recorded in ClinicalTrials.gov on the number NCT05197166. Findings will be used to publish articles in peer-review scientific journals and oral communications and posters at scientific meetings.

Predicting Forefoot-Orthosis Interactions in Rheumatoid Arthritis Using Computational Modelling

Foot orthoses are prescribed to reduce forefoot plantar pressures and pain in people with rheumatoid arthritis. Computational modelling can assess how the orthoses affect internal tissue stresses, but previous studies have focused on a single healthy individual. This study aimed to ascertain whether simplified forefoot models would produce differing biomechanical predictions at the orthotic interface between people with rheumatoid arthritis of varying severity, and in comparison to a healthy control. The forefoot models were developed from magnetic resonance data of 13 participants with rheumatoid arthritis and one healthy individual. Measurements of bony morphology and soft tissue thickness were taken to assess deformity. These were compared to model predictions (99th% shear strain and plantar pressure, max. pressure gradient, volume of soft tissue over 10% shear strain), alongside clinical data including body mass index and Leeds Foot Impact Scale–Impairment/Footwear score (LFIS-IF). The predicted pressure and shear strain for the healthy participant fell at the lower end of the rheumatoid models’ range. Medial first metatarsal head curvature moderately correlated to all model predicted outcomes (0.529 < r < 0.574, 0.040 < p < 0.063). BMI strongly correlated to all model predictions except pressure gradients (0.600 < r < 0.652, p < 0.05). There were no apparent relationships between model predictions and instances of bursae, erosion and synovial hypertrophy or LFIS-IF score. The forefoot models produced differing biomechanical predictions between a healthy individual and participants with rheumatoid arthritis, and between individuals with rheumatoid arthritis. Models capable of predicting subject specific biomechanical orthotic interactions could be used in the future to inform more personalised devices to protect skin and soft tissue health. While the model results did not clearly correlate with all clinical measures, there was a wide range in model predictions and morphological measures across the participants. Thus, the need for assessment of foot orthoses across a population, rather than for one individual, is clear.

Pedobarographic Measurements of Rheumatoid Feet Compared with Clinical Parameters

Objective:

This study aimed to investigate the relationship between plantar pressure pedobarographic measurements and disease activity, radiological abnormalities, and foot indexes in patients with rheumatoid arthritis (RA).

Methods:

Sociodemographics, foot symptoms, anatomical distribution, pain intensity and duration, and podiatry services access data were collected. Disease activity scale of 28 joints (DAS28) was used for the disease activity, and Health Assessment Questionnaire (HAQ) was used for the functional status. Foot function index (FFI) was used to measure the impact of foot pathology on its function. The Modified Larsen scoring was used to assess radiological abnormalities. Pedobarographic measurements were used to analyze foot loading characteristics.

Results:

A total of 104 feet of 52 patients with RA was evaluated. DAS28 scores did not correlate with the plantar pressure values (p>0.05). A significant correlation was found between HAQ scores and right medial midfoot loading pressure (r=0.355; p<0.01). FFI scores were positively correlated with right lateral midfoot loading pressure (r=0.302; p<0.05). No relationship was found between Manchester Foot Pain and Disability Index and plantar loading characteristics. The radiological scores were correlated with left lateral hindfoot plantar pressure (r=0.286; p<0.05).

Conclusions:

Pedobarographic measurements can be considered as a follow-up evaluation tool for the evaluation of all foot parts (forefoot, midfoot, and hindfoot). Rheumatoid feet investigation showed that foot involvement is independent of the disease duration, whereas midfoot plantar pressures are associated with the body mass index. Additionally, DAS28 may fall short as a marker of disease activity because it neglects foot problems.

Comparison between the plantar pressure effects of toe separators and insoles in patients with hallux valgus at a one-month follow-up

BACKGROUND

Various designs of foot orthoses for hallux valgus have been developed to reduce foot pain. The plantar pressure assessment can determine the better intervention. This study aimed to compare the effectiveness of plantar pressure distribution in patients with hallux valgus during walking with toe separator and insole.

METHOD

Patients with hallux valgus were randomized into one of two interventions: prefabricated toe separator or customized insole. The plantar pressure distribution of the participants was measured during walking with the devices after use for one month with an in-shoe measurement system.

RESULTS

Twenty-three participants were analyzed. After 1-month, significant peak pressures and pressure-time integral reductions were observed during walking in the middle forefoot (64.28 kPa and 28.97 kPa s, respectively) and lateral forefoot regions (54.03 kPa and 22.30 kPa s, respectively) after insole use compared with a toe separator.

CONCLUSIONS

After one month of use, the customized insole was more effective in plantar pressure reduction than the toe separator for a hallux deformity.

The effect of pre-fabricated insole on plantar pressure distribution in patients with rheumatoid arthritis

BACKGROUND

Foot deformities result in pain and changes in plantar pressure distribution in rheumatoid arthritis (RA) patients. Medical insoles are commonly prescribed for declining pain and modifying foot pressure distribution in these patients. The purpose of this study was to evaluate the effect of a pre-fabricated insole with metatarsal pad and medial longitudinal arch support on plantar pressure distribution in rheumatoid arthritis patients.

METHODS

Fifteen females with RA participated in this study. All patients received a pair of pre-fabricated insoles that were individually modified using metatarsal pads and medial longitudinal arch supports. Mean peak pressure (kPa), maximum force (N), and contact area (cm²) were calculated for the heel, midfoot, metatarsophalangeal joint, and toe regions using the Pedar-X system immediately and after a month follow-up.

FINDINGS

In the heel and metatarsophalangeal joint regions, maximum pressure and force showed a significant reduction in the follow-up assessment (p < 0.05). The comparison showed a significant increase in maximum pressure and force in the midfoot when participants walked with insole compared to without insole condition (p < 0.001).

INTERPRETATION

Using a pre-fabricated insole with an individually modified metatarsal pad and medial longitudinal arch support could alter rheumatoid arthritis patients' plantar pressures after one month of follow-up. This type of insole is simple and inexpensive and showed a significant effect on decreasing pressures under the metatarsal heads.

Reporting of Research Ethics in Studies Focusing on Foot Health in Patients with Rheumatoid Arthritis - A Systematic Review

Research ethics is a fundamental part of the entire research. Patients with rheumatoid arthritis are sensitive group of research participants because their long-term health problems cause significant changes in their foot health. In foot health research, data are usually collected through a clinical assessment of the foot or questionnaires. However, there is limited evidence of the reported research ethics of empirical studies on foot health in patients with rheumatoid arthritis. Therefore this review aimed to analyze the reported research ethics of peer-reviewed empirical studies focusing on foot health in patients with rheumatoid arthritis as research participants. This systematic review used the Medline/PubMed, CINAHL, and Embase databases. A total of 1,653 records were identified, and 32 articles were included in the final analysis. Reporting research ethics in studies of patients with rheumatoid arthritis is fragmented, focusing predominantly on ethical approval and informed consent and lacking a broader discussion about research ethics.

Effects of rocker radii with two longitudinal bending stiffnesses on plantar pressure distribution in the forefoot

INTRODUCTION

Outsole parameters of the shoe can be adapted to offload regions of pain or region of high pressures. Previous studies already showed reduced plantar pressures in the forefoot due to a proximally placed apex position and higher longitudinal bending stiffness (LBS). The aim of this study was to determine the effect of changes in rocker radii and high LBS on the plantar pressure profile during gait.

METHOD

10 participants walked in seven shoe conditions of which one control shoe and six rocker shoes with small, medium and large rocker radii and low and high longitudinal bending stiffness. Pedar in-shoe plantar pressure measuring system was used to quantify plantar pressures while walking on a treadmill at self-selected walking speed. Peak plantar pressure, maximum mean pressure and force-time integral were analyzed with Generalized Estimated Equation (GEE) and Tukey post hoc correction (α = .05).

RESULTS

Significantly lower plantar pressures were found in the first toe, toes 2-5, distal and proximal forefoot in all rocker shoe conditions as compared to the control shoe. Plantar pressures in the first toe and toes 2-5 were significantly lower in the small radius compared to medium and large radii. For the distal forefoot both small and medium radii significantly reduced plantar pressure compared to large radii. Low LBS reduced plantar pressure at the first toe significantly compared to high LBS independent of the rocker radius. Plantar pressures in the distal forefoot and toes 2-5 were lower in high LBS compared to low LBS.

CONCLUSION

Manipulation of the rocker radius and LBS can effectively reduce peak plantar pressures in the forefoot region during gait. In line with previous studies, we showed that depending on the exact target location for offloading, different combinations of rocker radius and LBS need to be adopted to maximize treatment effects.

Foot Involvement as the First Manifestation in Rheumatoid Arthritis Patients in Lahore

Objective

The objective of this study was to determine the involvement of the foot as the first manifestation in rheumatoid arthritis (RA).

Methods

This study was conducted on 100 patients who presented to the outpatient department of the Rheumatology Department at Fatima Memorial Hospital and College of Medicine and Dentistry in Lahore, Pakistan. The period of this cross-sectional study was three months - from October 2017 to December 2017. One hundred patients aged more than 16 years, who were diagnosed as cases of RA with foot involvement, and with a disease duration of less than two years (to minimize recall bias), were enrolled for the study.

Results

Out of the 100 patients, 20% were male and 80% were female. The mean age of the study population was 41.16 ± 12.343 years. Foot Involvement as the first manifestation was noted in 29 (29%) of the cases. The pattern of foot involvement shows a 59% forefoot involvement, 27% hindfoot involvement, and 14% midfoot involvement. Walking difficulty was most common in forefoot involvement (71.42% of cases), followed by hindfoot involvement (20% of cases), and least common in midfoot involvement (8.57% of cases) (p=0.0001).

Conclusion

Foot involvement as the first manifestation is quite common in RA and should not be ignored, especially in patients with large joint involvement sparing the hands.

The difference of in-shoe plantar pressure between level walking and stair walking in healthy males

Stair walking is more demanding locomotion than level walking and can aggravate discomfort of the foot. The purpose of this study is to analyze plantar pressure distribution and pressure patterns during gait cycle at stair walking compared to level walking. Thirty-five healthy males with 23.4 ± 2 years old were included in this study after examining normality. They performed level walking, stair ascending, and descending in same type of shoes. Measurements of in-shoe plantar pressure including peak pressure, pressure-time integral were done by Pedar-X system, masked 7 regions. Also, pressures in each region throughout the gait cycle were analyzed from each type of walking. Statistical analysis was performed using repeated measure one way analysis of variance. Peak pressure in all regions except for the midfoot was higher during level walking than stair walking. Pressure-time integral in the forefoot, midfoot during stair ascending, and the forefoot during stair descending was higher than level walking. In gait cycle, first peak was produced in the heel and the second peak was produced in the hallux during level walking, whereas during stair ascent, the heel and midfoot were in first peak, and the second peak was in the hallux. During stair descent, the first peak were in the forefoot and the midfoot, and the second peak was in the forefoot. In healthy young male adults, forefoot and midfoot are significant regions in the way that they have higher pressure burdens than other foot regions during stair walking.

Plantar Pressure Evaluation during the Season in Five Basketball Movements

Sports activity is extremely important in the health context, with a clear motivation for its practice. One of the sports that involve more athletes is basketball, where the human body undergoes rapid reactions, emphasizing the contact of the foot with the ground. The main goal of the present study is to evaluate the distribution of plantar pressure in five different basketball movements. Supported by a group of nine volunteer female athletes from a senior basketball team, a data acquisition protocol was defined to identify the changes that occur throughout the sports season. In this study, the maximum values of plantar pressure were evaluated for both feet. The five movements that were defined and studied are all movements that might be performed during the basketball practice period. To guarantee the necessary conditions of data reliability and repeatability, at least seven repetitions were performed for each movement, which occurred at two different moments of the sports season: at the beginning of the competition in November, and at season peak, four months later, in March. Overall, the results obtained did not present statistically significant changes between the two seasons in this study. However, a slight decrease was observed throughout the sporting season for all movements, except for the rebound, where there was a contrary evaluation. Additionally, athletes with a higher level of experience show higher values of plantar pressure than less experienced athletes.

Distribution of erosions in hands and feet at the time for the diagnosis of RA and during 8-year follow-up

Background

Joint destruction in rheumatoid arthritis (RA) is usually evaluated by radiographs of both hands and feet, while the inflammatory status mostly is evaluated by DAS28 which, however, does not include the feet.

Objectives

To investigate the distribution of erosions in hands and feet in early RA over 8 years and its potential clinical implications. Furthermore, the group of patients never showing erosions has been addressed.

Methods

This study comprises 1041 patients from the BARFOT study of patients with early RA. Radiographs of hands and feet were performed at baseline, 1, 2, 5, and 8 years and evaluated by the Sharp van der Heijde scoring (SHS) method (32 joints in the hands and 12 in the feet). Disease activity was measured by DAS28, SR, CRP, and function with HAQ.

Results

In the feet, there were significantly more eroded joints in percent of examined joints than in the hands at all time points. Patients with erosions only in the feet were younger, more often seropositive and smokers. They had significantly lower baseline DAS28, than the patients with erosions only in the hands. The patients without erosions over time were, at diagnosis, significantly younger and less frequently seropositive compared with patients having erosions.

Conclusions

This study highlights the importance of evaluating the feet in patients with RA, both with clinical examinations and with imaging and lends support to the notion that seropositivity and smoking are risk factors for erosive disease. Further studies of patients with nonerosive disease are needed.

Key Points: • Foot problems are common in RA • This study emphasizes the limitations of DAS28 and Sharp van der Heijde score as regards evaluating disease activity and radiographic damage • This study highlights the importance of evaluating the feet in patients with RA with clinical examinations and imaging • This study also points out the need of further studies of patients with non-erosive RA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10067-020-05465-x.

Foot characteristics during walking in 6-14- year-old children

The main purpose of the study was to establish foot characteristics during walking in children. In this cross-sectional study, we recruited 1 284 primary-school students aged 6–14 years (714 boys and 570 girls) randomly selected from five schools in the city of Brno, Czech Republic. Children walked across a pressure platform (EMED-xl; Novel_GmbH, Munich, Germany) to collect the data for both left and right foot during three trials. After the procedure, the software generated several foot characteristic variables: (1) force-time integral, (2) pressure-time integral, (3) contact area, (4) contact time, (5) peak pressure and (6) average pressure for the total foot. Curves for the 5^th, 10^th, 25^th, 50^th, 75^th, 90^th and 95^th percentiles were calculated using the Lambda, Mu and Sigma (LMS) Chartmaker software. Our results showed that boys had longer force-time integral, higher contact area and contact time values, and higher peak plantar pressure, while no significant differences in pressure-time integral and average plantar pressure between sexes were observed. Older boys and girls had higher values in all measured variables. Our results provide for the first-time sex- and age-specific foot characteristics during walking in 6–14-year-old children.

Outcomes and potential mechanism of a protocol to optimize foot orthoses in patients with rheumatoid arthritis

Background

Foot problems are highly prevalent in patients with rheumatoid arthritis. Treatment of foot problems related to rheumatoid arthritis often consists of custom made foot orthoses. One of the assumed working mechanisms of foot orthoses is redistribution of plantar pressure by creating a larger weight bearing area. Overall, the reported treatment effect of foot orthoses on foot pain in rheumatoid arthritis is small to medium. Therefore, we developed a foot orthoses optimization protocol for evaluation and adaptation of foot orthoses by using the feedback of in-shoe plantar pressure measurements. The objectives of the present study were: 1) to evaluate the 3-months outcomes of foot orthoses developed according to the protocol on pain, physical functioning and forefoot plantar pressure in patients with foot problems related to rheumatoid arthritis, and 2) to determine the relationship between change in forefoot plantar pressure and change in pain and physical functioning.

Methods

Forty-five patients with foot problems related to rheumatoid arthritis were included and received foot orthoses developed according to the protocol. Outcome measures were assessed at baseline and after three months of wearing foot orthoses in 38 patients. Change scores and effect sizes (ES) were calculated for pain, physical functioning and plantar pressure. In a subgroup of patients with combined forefoot pain and high plantar pressure, the relationship between change in plantar pressure and change in pain and physical functioning was analyzed.

Results

In the total group of 38 patients, statistically significant changes in pain (ES 0.69), physical functioning (ES 0.82) and forefoot plantar pressure (ES 0.35) were found. In the subgroup (n = 23) no statistically significant relationships were found between change in plantar pressure and change in pain or physical functioning.

Conclusion

Foot orthoses developed according to a protocol for improving the plantar pressure redistribution properties lead to medium to large improvements in pain and physical functioning. The hypothesis that more pressure reduction would lead to better clinical outcomes could not be proven.

Higher body mass index is associated with lower foot health in patients with rheumatoid arthritis: baseline results of the Amsterdam-Foot cohort

Objective: Obesity is highly prevalent in patients with rheumatoid arthritis (RA), with likely impact on weight-bearing foot joints. We explored the associations between body mass index (BMI) and measures of foot health in patients with RA and foot complaints.Method: We examined patients with RA presenting for their first custom-made therapeutic footwear or foot orthoses. Domains of foot health comprised: foot pain, foot-related activity limitations, forefoot plantar pressure, foot synovitis, and foot deformity. In regression analyses, BMI was the independent variable and foot health domains were the dependent variables.Results: The cohort at baseline comprised 230 patients [mean ± sd age 58 ± 13 years, 80% female, mean ± sd disease duration 10 ± 9 years, and median (interquartile range) BMI 26.7 (23.5-30.1) kg/m²]. Small to modest statistically significant associations were found in the majority of the measures studied between a higher BMI and more foot pain, more foot-related activity limitations, higher in-shoe measured forefoot plantar pressure, and the presence of foot synovitis. No relationships were found between BMI and barefoot measured forefoot plantar pressure or foot deformity.Conclusion: BMI is negatively associated with foot health in patients with RA. Although the clinical relevance of our findings for an individual patient is not immediately obvious, future research should consider BMI as a potential therapeutic target to improve foot health.

Surgical Treatment for the Ankle and Foot in Patients with Rheumatoid Arthritis: A Systematic Review

The aim was to identify effective surgical treatments for patients with rheumatoid arthritis in the foot and/or ankle. A systematic review of the literature was conducted via a data search of the PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and PROSPERO databases, from their inception until June 2019. Only non-randomized controlled trials and cohort studies were included in this review. Two of the present authors independently assessed the quality of each study and extracted the relevant data. A quality assessment of all articles was performed using the methodological index for non-randomized studies criteria. In addition, the Newcastle Ottawa scale was used for cohort studies. Thirteen studies met the inclusion criteria (five cohort studies and eight NRCTs). The total population considered was 923 patients (570 patients had RA), with a mean age of 58.8 years. Regarding the risk of bias, both the NRCTs and the cohort studies had a moderate level of quality. Despite the relatively low quality of these studies, surgical treatment for the foot and/or ankle is shown to reduce pain and improve functionality in patients with RA, in the short term (6-12 months).

Effects of forefoot arthroplasty on plantar pressure, pain, gait and disability in rheumatoid arthritis

Objectives: The purpose of this study was to clarify the effect of forefoot arthroplasty on plantar pressure, pain, gait, and disability within 1 year after arthroplasty in patients with RA.Methods: Eleven patients with RA who underwent forefoot arthroplasty completed this quasi-experimental study. Outcome measures were in-shoe plantar pressure, visual analog scale (VAS) for pain, temporal gait parameters, and modified Health Assessment Questionnaire (mHAQ), obtained preoperatively and at 4 and 12 months postoperatively.Results: The average peak plantar pressure under the 2nd metatarsal head decreased at 4 months postoperatively, compared to preoperative values (p < .05) and the decreased plantar pressure was sustained at 12 months postoperatively. Similar changes were observed under the 3rd to 5th metatarsal heads. The median VAS for foot pain decreased from 25 mm preoperatively to 1 mm at 4 months postoperatively and the lower score was sustained at 12 months postoperatively (p < .05). The median mHAQ score remained lower (<1.0) at all measurement points. Regarding gait, there were no significant differences from the preoperative assessment to postoperative follow-up.Conclusion: Plantar pressure and forefoot pain decreased at 4 and 12 months after forefoot arthroplasty in patients with RA. No adverse effects on gait parameters or disability were observed.

Forefoot pathology in relation to plantar pressure distribution in patients with rheumatoid arthritis: A cross-sectional study in the Amsterdam Foot cohort

BACKGROUND

In patients with rheumatoid arthritis (RA), both high and low forefoot plantar pressures have been reported. Better understanding of pathology in the forefoot associated with altered pressure distribution in patients with RA could help to better formulate and specify goals for treatment with foot orthoses or therapeutic footwear.

OBJECTIVES

To investigate the association of plantar pressure with disease activity and deformity in the forefoot in patients with rheumatoid arthritis and forefoot symptoms.

METHODS

A cross sectional study, using data of 172 patients with rheumatoid arthritis and forefoot symptoms, was conducted. Peak pressure (PP) and pressure time integral (PTI) in the forefoot were measured with a pressure platform. Forefoot deformity was assessed using the Platto score. Forefoot disease activity was defined as swelling and/or pain assessed by palpation of the metatarsophalangeal joints. The forefoot was divided in a medial, central and lateral region, in which the following conditions could be present: 1) no pathology, 2) disease activity, 3) deformity or 4) disease activity and deformity. A multilevel analysis was performed using condition per forefoot region as independent variable and PP or PTI in the corresponding region as dependent variable.

RESULTS

Statistically significant higher plantar pressures were found in forefoot regions with deformities (RR 1.2, CI 1.1-1.3, P<0.0001), compared to forefoot regions without forefoot pathology. No significant differences in plantar pressures were found when solely forefoot disease activity was present in forefoot regions.

SIGNIFICANCE

Forefoot deformities are related to higher plantar pressures measured in the corresponding forefoot regions. The absence of an association between local disease activity and plantar pressure might be explained by the low prevalence of metatarsophalangeal joint pain or swelling. Future research with sensitive imaging measures to detect disease activity is recommended to reveal the effect of forefoot disease activity on plantar pressure.

Objectively Assessed Foot and Ankle Characteristics in Patients With Systemic Lupus Erythematosus: A Comparison With Age- and Sex-Matched Controls

OBJECTIVE

To objectively identify foot and ankle characteristics in patients with systemic lupus erythematosus (SLE) compared to age- and sex-matched controls.

METHODS

A total of 54 patients with SLE and 56 control participants attended a study visit designed to comprehensively assess the foot and ankle. Objectively assessed foot characteristics included muscle strength, joint motion, foot posture, foot problems, protective sensation, vibration perception threshold (VPT), ankle brachial index (ABI), plantar pressure, and spatiotemporal gait characteristics. Self-reported measure of foot pain and impairment were also assessed using a 100-mm foot pain visual analog scale. Data were analyzed using regression models. Plantar pressure and gait models were adjusted for walking velocity, body mass index, and foot pain.

RESULTS

Compared to controls, participants with SLE had lower muscle force for plantarflexion, dorsiflexion, inversion, and eversion (all P < 0.001), higher foot posture indices (P = 0.007), higher foot problem scores (P = 0.001), higher VPT (P = 0.001), and more frequent abnormal ABI (odds ratio [OR] 3.13, P = 0.044). Participants with SLE also had lower peak pressure and higher pressure time integrals for all foot regions (all P < 0.001), lower step and stride length, velocity, and cadence, and higher step, swing, stance, and single and double support times compared to controls (all P < 0.001). Compared to controls, participants with SLE also reported greater foot pain (P < 0.001).

CONCLUSION

Patients with SLE experience a wide range of foot symptoms. This study has provided objective evidence of foot and ankle disease in patients with SLE, including reduced muscle strength and altered gait patterns when compared to controls. This highlights the importance of foot health assessments as part of SLE management.

Region-specific foot pain and plantar pressure in people with rheumatoid arthritis: A cross-sectional study

BACKGROUND

It is unclear whether region-specific foot pain may influence plantar pressure in people with established rheumatoid arthritis. The aim was to determine the association between region-specific foot pain and region-specific plantar pressure.

METHODS

Twenty-one people with rheumatoid arthritis and 19 age- and sex-matched controls participated in this study. Self-reported foot pain in the toes, forefoot, midfoot and rearfoot was assessed using foot diagrams. Peak pressure and pressure time integrals for the toes, forefoot, midfoot and rearfoot were calculated using a pressure mat system. Differences in foot pain and pressure between the groups were calculated using appropriate regression models. To determine associations between region-specific pain and pressure, linear regression models were used while adjusting for body mass and participant group.

FINDINGS

Participants with rheumatoid arthritis were primarily elderly female with long disease duration. Compared to controls, participants with rheumatoid arthritis had higher odds of foot pain at the toes (Odds Ratio (OR) = 10.4, P = 0.001), forefoot (OR = 6.3, P = 0.006) and rearfoot (OR = 10.1, P = 0.011). Participants with RA had higher peak pressure at the rearfoot (P = 0.003) and higher pressure time integrals at the forefoot (P = 0.005), midfoot (P = 0.016) and rearfoot (P < 0.001). After adjusting for body mass and participant group, peak pressure was significantly higher at the toes in those with midfoot pain and rearfoot pain.

INTERPRETATION

People with rheumatoid arthritis experience region-wide foot pain and demonstrate differences in pressure distribution compared to people without rheumatoid arthritis. Foot pain at the midfoot and rearfoot is also associated with increases in plantar pressure at the toes.

The effectiveness of therapeutic shoes in patients with rheumatoid arthritis: a systematic review and meta-analysis

The study summarizes the evidence on the effectiveness of therapeutic shoes on foot function, foot pain, physical functioning, health-related quality of life, adherence, adverse events and patient satisfaction in patients with rheumatoid arthritis (RA). Studies investigating the effect of (ready- or custom-made) therapeutic shoes were included. For between-group designs, studies comparing therapeutic shoes versus non-therapeutic shoes were included. A literature search was conducted in The Cochrane Central Registry for Controlled Trials (CENTRAL), PubMed, EMBASE and PEDro up to January 19, 2017. Quantitative data analysis was conducted; when this was not possible qualitative data analysis was performed. Eleven studies were identified. For custom-made shoes, no studies reporting between-group differences were available. Qualitative data-syntheses of the within-group differences resulted in weak evidence for the reduction of foot pain and improvement of physical functioning. For ready-made shoes, one study reported between-group differences, resulting in inconclusive evidence for improvement of foot function. Quantitative data-analyses of within-group differences resulted in a medium to large effect for the reduction of foot pain (SMD 0.60, 95% CI 0.28-0.92; P ≤ 0.001; 184 participants) and a small to medium effect for the improvement of physical functioning (SMD 0.30, 95% CI 0.04-0.56; P = 0.02; 150 participants). Qualitative data-synthesis of within-group differences resulted in weak evidence for improvement of foot function. Within-group results indicate that therapeutic shoes are likely to be effective in patients with RA. Definitive high-quality RCTs are necessary to investigate the between-group effectiveness of therapeutic shoes in patients with RA.

Effect of a thin customized insole on pain and walking ability in rheumatoid arthritis: A randomized study

OBJECTIVE

The aim of the study was to investigate the immediate effects of a thin, easily customizable insole on pain and walking ability in patients with rheumatoid arthritis (RA) who have forefoot pain, and to determine whether the insoles were in use 1 year afterwards.

DESIGN

An experimental, assessor-blinded design was applied to compare the immediate effects when walking with or without insoles in random order. After 1 year, a structured telephone interview was conducted.

PARTICIPANTS

Twenty-one subjects with RA and foot pain in at least one forefoot when walking and in response to the Gänslen test were recruited consecutively from the outpatient clinic and the inpatient ward at a hospital for people with rheumatic disease.

INTERVENTION

Each subject was given a 4-mm thin individually customized insole of a malleable plastic material (CI-Core®) with synthetic textile material on the upper side.

MAIN OUTCOME MEASURES

The 6-min walk test (6MWT) was used to assess the ability to walk, and a 10-cm visual analogue scale to measure the intensity of foot pain induced by walking with and without the insole. A standardized questionnaire with five items was used to determine the use of, and degree of satisfaction with, insoles after 1 year.

RESULTS

The median (interquartile range) foot pain intensity was 19 (15) with and 36 (27) without insoles (p < 0.001; effect size = 0.6). No statistically significant differences in 6MWT were found between the presence or absence of insoles (p = 0.07). After 1 year, 90% of the participants were still using the insoles.

CONCLUSIONS

The use of thin, easily customizable insoles resulted in immediate clinically relevant relief in walking-induced forefoot pain. Most of the patients were still using the insoles after 1 year.

Adaptation and Validation of the Foot Function Index-Revised Short Form into Polish

Purpose

The aim of the present study was to adapt the Foot Function Index-Revised Short Form (FFI-RS) questionnaire into Polish and verify its reliability and validity in a group of patients with rheumatoid arthritis (RA).

Methods

The study included 211 patients suffering from RA. The FFI-RS questionnaire underwent standard linguistic adaptation and its psychometric parameters were investigated. The enrolled participants had been recruited for seven months as a convenient sample from the rheumatological hospital in Śrem (Poland). They represented different sociodemographic characteristics and were characterized as rural and city environments residents.

Results

The mean age of the patients was 58.9 ± 10.2 years. The majority of patients (85%) were female. The average final FFI-RS score was 62.9 ± 15.3. The internal consistency was achieved at a high level of 0.95 in Cronbach's alpha test, with an interclass correlation coefficient ranging between 0.78 and 0.84. A strong correlation was observed between the FFI-RS and Health Assessment Questionnaire-Disability Index (HAQ-DI) questionnaires.

Conclusion

The Polish version of FFI-RS-PL indicator is an important tool for evaluating the functional condition of patients' feet and can be applied in the diagnosis and treatment of Polish-speaking patients suffering from RA.

Footwear interventions for foot pain, function, impairment and disability for people with foot and ankle arthritis: A literature review

OBJECTIVE

To conduct a literature review on the effectiveness of footwear on foot pain, function, impairment and disability for people with foot and ankle arthritis.

METHODS

A search of the electronic databases Scopus, Medline, CINAHL, SportDiscus and the Cochrane Library was undertaken in September 2017. The key inclusion criteria were studies reporting on findings of footwear interventions for people with arthritis with foot pain, function, impairment and/or disability. The Quality Index Tool was used to assess the methodological quality of studies included in the qualitative synthesis. The methodological variation of the included studies was assessed to determine the suitability of meta-analysis and the grading of recommendations, assessment, development and evaluation (GRADE) system. Between and within group effect sizes were calculated using Cohen's d.

RESULTS

1440 studies were identified for screening with 11 studies included in the review. Mean (range) quality scores were 67% (39-96%). The majority of studies investigated rheumatoid arthritis (n = 7), but also included gout (n = 2), and 1st metatarsophalangeal joint osteoarthritis (n = 2). Meta-analysis and GRADE assessment were not deemed appropriated based on methodological variation. Footwear interventions included off-the-shelf footwear, therapeutic footwear and therapeutic footwear with foot orthoses. Key footwear characteristics included cushioning and a wide toe box for rheumatoid arthritis; cushioning, midsole stability and a rocker-sole for gout; and a rocker-sole for 1st metatarsophalangeal joint osteoarthritis. Between group effect sizes for outcomes ranged from 0.01 to 1.26. Footwear interventions were associated with reductions in foot pain, impairment and disability for people with rheumatoid arthritis. Between group differences were more likely to be observed in studies with shorter follow-up periods in people with rheumatoid arthritis (12 weeks). Footwear interventions improved foot pain, function and disability in people with gout and foot pain and function in 1st metatarsophalangeal joint osteoarthritis. Footwear interventions were associated with changes to plantar pressure in people with rheumatoid arthritis, gout and 1st metatarsophalangeal joint osteoarthritis and walking velocity in people with rheumatoid arthritis and gout.

CONCLUSION

Footwear interventions are associated with reductions in foot pain, impairment and disability in people with rheumatoid arthritis, improvements to foot pain, function and disability in people with gout and improvements to foot pain and function in people with 1st metatarsophalangeal joint osteoarthritis. Footwear interventions have been shown to reduce plantar pressure rheumatoid arthritis, gout and 1st metatarsophalangeal joint osteoarthritis and improve walking velocity in rheumatoid arthritis and gout.

Comparison of the effects of forefoot joint-preserving arthroplasty and resection-replacement arthroplasty on walking plantar pressure distribution and patient-based outcomes in patients with rheumatoid arthritis

Purpose

The purpose of this retrospective study is to clarify the difference in plantar pressure distribution during walking and related patient-based outcomes between forefoot joint-preserving arthroplasty and resection-replacement arthroplasty in patients with rheumatoid arthritis (RA).

Methods

Four groups of patients were recruited. Group1 included 22 feet of 11 healthy controls (age 48.6 years), Group2 included 36 feet of 28 RA patients with deformed non-operated feet (age 64.8 years, Disease activity score assessing 28 joints with CRP [DAS28-CRP] 2.3), Group3 included 27 feet of 20 RA patients with metatarsal head resection-replacement arthroplasty (age 60.7 years, post-operative duration 5.6 years, DAS28-CRP 2.4), and Group4 included 34 feet of 29 RA patients with metatarsophalangeal (MTP) joint-preserving arthroplasty (age 64.6 years, post-operative duration 3.2 years, DAS28-CRP 2.3). Patients were cross-sectionally examined by F-SCAN II to evaluate walking plantar pressure, and the self-administered foot evaluation questionnaire (SAFE-Q). Twenty joint-preserving arthroplasty feet were longitudinally examined at both pre- and post-operation.

Results

In the 1^st MTP joint, Group4 showed higher pressure distribution (13.7%) than Group2 (8.0%) and Group3 (6.7%) (P<0.001). In the 2^nd-3^rd MTP joint, Group4 showed lower pressure distribution (9.0%) than Group2 (14.5%) (P<0.001) and Group3 (11.5%) (P<0.05). On longitudinal analysis, Group4 showed increased 1^st MTP joint pressure (8.5% vs. 14.7%; P<0.001) and decreased 2^nd-3^rd MTP joint pressure (15.2% vs. 10.7%; P<0.01) distribution. In the SAFE-Q subscale scores, Group4 showed higher scores than Group3 in pain and pain-related scores (84.1 vs. 71.7; P<0.01) and in shoe-related scores (62.5 vs. 43.1; P<0.01).

Conclusions

Joint-preserving arthroplasty resulted in higher 1^st MTP joint and lower 2^nd-3^rd MTP joint pressures than resection-replacement arthroplasty, which were associated with better patient-based outcomes.

Impact of midfoot and Hindfoot involvement on functional disability in Korean patients with rheumatoid arthritis

Background

Foot involvement in rheumatoid arthritis (RA) patients has been reported to severely affect functional capacity and quality of life. We aimed to determine the impact of midfoot and hindfoot involvement on functional disability in Korean patients with RA.

Methods

We evaluated the RA involvement and deformity of three regions of the foot (forefoot, midfoot and hindfoot) and ankle using conventional radiography in Korean patients with RA. We compared the clinical features between RA patients with and without foot or ankle involvement. Using multivariable logistic regression analyses, the impact of midfoot or hindfoot involvement on functional disability in RA patients was evaluated.

Results

Overall, 120 patients with a median age of 48.0 [interquartile range (IQR), 37–56] years and median disease duration of 58.0 (IQR, 10–89) months were included. The prevalence of foot or ankle RA involvement was 74 (61.7%). The number of patients with forefoot, midfoot, hindfoot and ankle involvement was 32 (43.2%), 24 (32.4%), 46 (62.2%) and 4 (5.4%), respectively. Compared to patients without foot or ankle involvement those with such involvement had greater disease activity and functional disability, more of them were treated with biologic agents, and they had a lower health-related quality of life. After adjusting for potential confounders, hindfoot involvement was associated with a higher degree of functional disability. However, walking difficulty was more associated with midfoot involvement rather than with involvement in other regions.

Conclusions

In Korean patients with RA, hindfoot involvement is associated with functional disability and midfoot involvement affects walking.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1726-7) contains supplementary material, which is available to authorized users.

Plantar plate pathology is associated with erosive disease in the painful forefoot of patients with rheumatoid arthritis

Background

Disease-related foot pathology is recognised to have a significant impact on mobility and functional capacity in the majority of patients with rheumatoid arthritis (RA). The forefoot is widely affected and the metatarsophalangeal (MTP) joints are the most common site of symptoms. The plantar plates are the fibrocartilaginous distal attachments of the plantar fascia inserting into the five proximal phalanges. Together with the transverse metatarsal ligament they prevent splaying of the forefoot and subluxation of the MTP joints. Damage to the plantar plates is a plausible mechanism therefore, through which the forefoot presentation, commonly described as ‘walking on pebbles’, may develop in patients with RA.

The aims of this study were to investigate the relationship between plantar plate pathology and clinical, biomechanical and plain radiography findings in the painful forefoot of patients with RA. Secondly, to compare plantar plate pathology at the symptomatic lesser (2nd-5th) MTP joints in patients with RA, with a group of healthy age and gender matched control subjects without foot pain.

Methods

In 41 patients with RA and ten control subjects the forefoot was imaged using 3T MRI. Intermediate weighted fat-suppressed sagittal and short axis sequences were acquired through the lesser MTP joints. Images were read prospectively by two radiologists and consensus reached. Plantar plate pathology in patients with RA was compared with control subjects. Multivariable multilevel modelling was used to assess the association between plantar plate pathology and the clinical, biomechanical and plain radiography findings.

Results

There were significant differences between control subjects and patients with RA in the presence of plantar plate pathology at the lesser MTP joints. No substantive or statistically significant associations were found between plantar plate pathology and clinical and biomechanical findings. The presence of plantar plate pathology was independently associated with an increase in the odds of erosion (OR = 52.50 [8.38–326.97], p < 0.001).

Conclusion

The distribution of plantar plate pathology at the lesser MTP joints in healthy control subjects differs to that seen in patients with RA who have the consequence of inflammatory disease in the forefoot. Longitudinal follow-up is required to determine the mechanism and presentation of plantar plate pathology in the painful forefoot of patients with RA.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1668-0) contains supplementary material, which is available to authorized users.

Discordance between clinical and imaging criteria: assessment by magnetic resonance imaging of the foot of patients with rheumatoid arthritis

Evaluation of the correlation between disease activity and joint involvement was assessed by MRI in the clinically dominant foot of patients with RA. We conducted a cross-sectional descriptive study of 55 patients with RA, who were subjected to clinical evaluation and MRI assessment. Imaging of the clinically dominant foot was performed, and both the Disease Activity Score 28 (DAS28-CRP) and the Health Assessment Questionnaire-Disability Index (HAQ-DI) were measured. The majority of patients classified as in clinical remission presented some degree of inflammatory activity upon MRI evaluation. Statistical analysis demonstrated no correlation between MRI findings and clinical scores. There is evidence of disease activity on MRI of the clinically dominant foot even in patients classified as in clinical remission according to the DAS28-CRP criteria.

In vitro and in vivo evaluation of anti-arthritic, antioxidant efficacy of fucoidan from Undaria pinnatifida (Harvey) Suringar

Seaweed and their constituents have been traditionally employed for the management of various human pathologic conditions such as edema, urinary disorders and inflammatory anomalies. The current study was performed to investigate the antioxidant and anti-arthritic effects of fucoidan from Undaria pinnatifida. A noteworthy in vitro antioxidant potential at 500μg/ml in 2, 2-diphenyl-1-picrylhydrazyl scavenging assay (80% inhibition), nitrogen oxide inhibition assay (71.83%), hydroxyl scavenging assay (71.92%), iron chelating assay (73.55%) and a substantial ascorbic acid equivalent reducing power (399.35μg/mg ascorbic acid equivalent) and total antioxidant capacity (402.29μg/mg AAE) suggested fucoidan a good antioxidant agent. Down regulation of COX-2 expression in rabbit articular chondrocytes in a dose (0-100μg) and time (0-48h) dependent manner, unveiled its in vitro anti-inflammatory significance. In vivo carrageenan induced inflammatory rat model demonstrated a 68.19% inhibition of inflammation whereas an inflammation inhibition potential of 79.38% was recorded in anti-arthritic complete Freund's adjuvant-induced arthritic rat model. A substantial ameliorating effect on altered hematological and biochemical parameters in arthritic rats was also observed. Therefore, findings of the present study prospects fucoidan as a potential antioxidant that can effectively abrogate oxidative stress, edema and arthritis-mediated inflammation and mechanistic studies are recommended for observed activities.

Battery-Free Smart Sock for Abnormal Relative Plantar Pressure Monitoring

This paper presents a new design of a wearable plantar pressure monitoring system in the form of a smart sock for sensing abnormal relative pressure changes. One advantage of this approach is that with a battery-free design, this system can be powered solely by radio frequency (RF) energy harvested from a radio frequency identification (RFID) reader unit hosted on a smartphone of the wearer. At the same time, this RFID reader can read foot pressure values from an embedded sensor-tag in the sock. A pressure sensing matrix made of conductive fabric and flexible piezo-resistive material is integrated into the sock during the knitting process. Sensed foot pressures are digitized and stored in the memory of a sensor-tag, thus allowing relative foot pressure values to be tracked. The control unit of the smart sock is assembled on a flexible printed circuit board (FPC) that can be strapped to the lower limb and detached easily when it is not in use. Experiments show that the system can operate reliably in both tasks of RF energy harvesting and pressure measurement.

Experiences of mobility for people living with rheumatoid arthritis who are receiving biologic drug therapy: implications for podiatry services

BACKGROUND

Despite significant advancements in new treatment modalities for rheumatoid arthritis with biological therapies, foot complications remain a disabling and common feature of the disease. In this study the aim was to explore and describe the personal experiences of people with rheumatoid arthritis in receipt of biologic treatments in a bid to understand the impact of this form of medication on their mobility.

METHODS

An interpretative phenomenological analysis (IPA) was undertaken to explore in depth the individual experience of rheumatoid disease through personal accounts of the patient journey spanning both 'before' and 'after' the instigation of biologic therapy. A purposive sampling strategy was adopted and in-depth semi structured interviews used to facilitate rich, detailed interview data exploring the lived experiences of individuals undertaking biological therapy and the changes to mobility experienced as a result. Thematic analysis was employed with an IPA framework to identify key meanings, and report patterns within the data.

RESULTS

Five people with rheumatoid arthritis participated in the study. The mean disease duration was 20.2 years (range: 6 -32) and all were being treated with biologic therapies. Four key themes emerged from the data: 1) Life before biologic treatment, depicted in accounts as a negative experience characterised by painful and disabling symptoms and feelings of hopelessness. 2) Life with biologic treatment, often experienced as a life changing transition, restoring function and mobility and offering renewed hope. 3) Sense of self, in which the impact of rheumatoid disease and the subsequent changes arising from biologic therapy reveal a profound impact on feelings of personal identity both pre and post biologic therapy; an effect of footwear on self-image emerges as a dominant sub theme; 4) Unmet footcare needs were evident in the patient narrative, where the unrelenting if diminished impact of foot pain on mobility was viewed in the context of problematic access to foot health services.

CONCLUSION

Whilst the findings from this study mirror those within the existing literature, which report improvements in physical function related to biological therapy, foot problems clearly remained an unremitting feature of life for patients with rheumatoid disease, even when in receipt of biologics.

Discrete sensors distribution for accurate plantar pressure analyses

The aim of this study was to determine the distribution of discrete sensors under the footprint for accurate plantar pressure analyses. For this purpose, two different sensor layouts have been tested and compared, to determine which was the most accurate to monitor plantar pressure with wireless devices in research and/or clinical practice. Ten healthy volunteers participated in the study (age range: 23-58 years). The barycenter of pressures (BoP) determined from the plantar pressure system (W-inshoe®) was compared to the center of pressures (CoP) determined from a force platform (AMTI) in the medial-lateral (ML) and anterior-posterior (AP) directions. Then, the vertical ground reaction force (vGRF) obtained from both W-inshoe® and force platform was compared for both layouts for each subject. The BoP and vGRF determined from the plantar pressure system data showed good correlation (SCC) with those determined from the force platform data, notably for the second sensor organization (ML SCC= 0.95; AP SCC=0.99; vGRF SCC=0.91). The study demonstrates that an adjusted placement of removable sensors is key to accurate plantar pressure analyses. These results are promising for a plantar pressure recording outside clinical or laboratory settings, for long time monitoring, real time feedback or for whatever activity requiring a low-cost system.

Plantar forefoot pressures in psoriatic arthritis-related dactylitis: an exploratory study

Dactylitis is a common feature of psoriatic arthritis (PsA); local physical trauma has been identified as a possible contributing factor. The aim of this study was to explore differences in forefoot plantar pressures in patients with PsA with and without dactylitis and compare to healthy controls. Thirty-six participants were recruited into three groups: group A PsA plus a history of dactylitis; group B PsA, no dactylitis; group C control participants. Forefoot plantar pressures were measured barefoot and in-shoe at the left second and fourth toes and corresponding metatarsophalangeal joints. Temporal and spatial parameters were measured and data from the foot impact scale for rheumatoid arthritis (FIS-RA), EQ5D and health assessment questionnaire (HAQ) were collected. Pressure time integral peak plantar pressure, and contact time barefoot and in-shoe were not significantly different between groups. Temporal and spatial parameters reported no significant differences between groups. ANOVA analysis and subsequent post hoc testing using Games-Howell test yielded significance in FIS-RA scores between both PsA groups versus controls, A p ≤ 0.0001 and PsA group B p < 0.0001 in the FIS-RA impairment and footwear domain, PsA group A p < 0.03 and PsA group B p ≤ 0.05 in the FIS-RA activity and participation domain compared to controls. This is the first exploratory study to investigate forefoot plantar pressures in patients with and without historical dactylitis in PsA. FIS-RA scores indicate PsA patients have significant limitations compared to controls, although a history of dactylitis does not appear to worsen patient reported outcomes.

Changes in foot function, disease activity, and disability after forefoot resection arthroplasty in patients with rheumatoid arthritis

The purpose of this study was to investigate the changes in foot function, disease activity, and disability in patients with RA after resection arthroplasty of the forefoot (arthroplasty). Arthroplasty was performed on 11 patients with RA. All study patients underwent clinical assessment to measure disease activity (Disease Activity Score in 28 Joints-C-reactive protein, DAS28-CRP), disability (Health Assessment Questionnaire-Disability Index, HAQ-DI) and foot function (Foot Function Index, FFI) at the following stages: preoperatively and 1, 3, and 12 months after surgery. Following arthroplasty, foot function improved significantly, as assessed by FFI total and subscales (pain, disability, and limitation of activity) (P<0.001, P<0.001, P<0.001, and P=0.002, respectively). Disease activity was significantly improved in relation to DAS28-CRP and its subscales of number of swollen joints and patient global assessment (PtGA) (P=0.033, P=0.008, and P=0.038, respectively). There was no significant difference in disability, as assessed by the HAQ-DI and its subscale, HAQ-walking (P=0.150 and P=0.597, respectively). Foot function improved significantly after arthroplasty, and was maintained at 12 months postoperatively. Additionally, our study showed that disease activity and its subscale PtGA improved after arthroplasty.

In-shoe plantar pressure measurements for the evaluation and adaptation of foot orthoses in patients with rheumatoid arthritis: A proof of concept study

OBJECTIVES

Improving foot orthoses (FOs) in patients with rheumatoid arthritis (RA) by using in-shoe plantar pressure measurements seems promising. The objectives of this study were to evaluate (1) the outcome on plantar pressure distribution of FOs that were adapted using in-shoe plantar pressure measurements according to a protocol and (2) the protocol feasibility.

METHODS

Forty-five RA patients with foot problems were included in this observational proof-of concept study. FOs were custom-made by a podiatrist according to usual care. Regions of Interest (ROIs) for plantar pressure reduction were selected. According to a protocol, usual care FOs were evaluated using in-shoe plantar pressure measurements and, if necessary, adapted. Plantar pressure-time integrals at the ROIs were compared between the following conditions: (1) no-FO versus usual care FO and (2) usual care FO versus adapted FO. Semi-structured interviews were held with patients and podiatrists to evaluate the feasibility of the protocol.

RESULTS

Adapted FOs were developed in 70% of the patients. In these patients, usual care FOs showed a mean 9% reduction in pressure-time integral at forefoot ROIs compared to no-FOs (p=0.01). FO adaptation led to an additional mean 3% reduction in pressure-time integral (p=0.05). The protocol was considered feasible by patients. Podiatrists considered the protocol more useful to achieve individual rather than general treatment goals. A final protocol was proposed.

CONCLUSIONS

Using in-shoe plantar pressure measurements for adapting foot orthoses for patients with RA leads to a small additional plantar pressure reduction in the forefoot. Further research on the clinical relevance of this outcome is required.

Effectiveness of insole use in rheumatoid feet: a randomized controlled trial

OBJECTIVES

To assess the effectiveness of foot orthoses with regard to pain, function, quality of life, and global perceived effect in patients with rheumatoid arthritis (RA).

METHOD

A double-blind randomized controlled trial (RCT) was carried out. Eighty women with RA were randomly assigned to an experimental group (EG) or a control group (CG). The EG used an insole with metatarsal and medial arch supports and the CG used a flat insole for 6 months. Evaluations performed at baseline and after 45, 90, and 180 days by a blinded assessor were: foot pain while walking and at rest, function, quality of life, and global perceived effect with treatment.

RESULTS

The groups were homogeneous for all parameters at baseline. A statistically significant improvement (p < 0.001) was found in the EG regarding pain while walking (mean difference: -2.2 for the right foot and -2.1 for the left foot) and at rest (mean difference: -0.3 for the right foot and -0.5 for the left foot) in comparison to CG. There were no differences in any other observed measures. The time of insole use correlated with foot pain and function in the EG.

CONCLUSIONS

Foot orthoses with metatarsal and medial arch supports decreases pain during walking and at rest in both feet in patients with RA. Time of insole use correlated with improvements in pain and function.

Are Pressure Time Integral and Cumulative Plantar Stress Related to First Metatarsophalangeal Joint Pain? Results From a Community-Based Study

OBJECTIVE

To examine the relationship between plantar stress over a step, cumulative plantar stress over a day, and first metatarsophalangeal (MTP) joint pain among older adults.

METHODS

Plantar stress and first MTP pain were assessed within the Multicenter Osteoarthritis Study. All included participants were asked if they had pain, aching, or stiffness at the first MTP joint on most days for the past 30 days. Pressure time integral (PTI) was quantified as participants walked on a pedobarograph, and mean steps per day were obtained using an accelerometer. Cumulative plantar stress was calculated as the product of regional PTI and mean steps per day. Quintiles of hallucal and second metatarsal PTI and cumulative plantar stress were generated. The relationship between predictors and the odds ratio of first MTP pain was assessed using a logistic regression model.

RESULTS

Feet in the quintile with the lowest hallux PTI had 2.14 times increased odds of first MTP pain (95% confidence interval [95% CI] 1.42-3.25, P < 0.01). Feet in the quintile with the lowest second metatarsal PTI had 1.50 times increased odds of first MTP pain (95% CI 1.01-2.23, P = 0.042). Cumulative plantar stress was unassociated with first MTP pain.

CONCLUSION

Lower PTI was modestly associated with increased prevalence of frequent first MTP pain at both the hallux and second metatarsal. Lower plantar loading may indicate the presence of an antalgic gait strategy and may reflect an attempt at pain avoidance. The lack of association with cumulative plantar stress may suggest that patients do not limit their walking as a pain-avoidance mechanism.