The impact of rheumatoid arthritis on foot function in the early stages of disease: a clinical case series

BACKGROUND Foot involvement occurs early in rheumatoid arthritis but the extent to which this impacts on the structure and function leading to impairment and foot related disability is unknown. The purpose of this study was to compare clinical disease activity, impairment, disability, and foot function in normal and early rheumatoid arthritis (RA) feet using standardised clinical measures and 3D gait analysis. METHODS Twelve RA patients with disease duration ≤2 years and 12 able-bodied adults matched for age and sex underwent 3D gait analysis to measure foot function. Disease impact was measured using the Leeds Foot impact Scale (LFIS) along with standard clinical measures of disease activity, pain and foot deformity. For this small sample, the mean differences between the groups and associated confidence intervals were calculated using the t distribution RESULTS Moderate-to-high foot impairment and related disability were detected amongst the RA patients. In comparison with age- and sex-matched controls, the patients with early RA walked slower (1.05 m/s Vs 1.30 m/s) and had a longer double-support phase (19.3% Vs 15.8%). In terminal stance, the heel rise angle was reduced in the patients in comparison with normal (-78.9° Vs -85.7°). Medial arch height was lower and peak eversion in stance greater in the RA patients. The peak ankle plantarflexion power profile was lower in the patients in comparison with the controls (3.4 W/kg Vs 4.6 W/kg). Pressure analysis indicated that the RA patients had a reduced lesser toe contact area (7.6 cm2 Vs 8.1 cm2), elevated peak forefoot pressure (672 kPa Vs 553 kPa) and a larger mid-foot contact area (24.6 cm2 Vs 19.4 cm2). CONCLUSION Analysis detected small but clinically important changes in foot function in a small cohort of RA patients with disease duration <2 years. These were accompanied by active joint disease and impairment and disability

Mass Customization of Foot Orthosis for Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an inflammatory disease, which can cause pain, stiffness, and swelling in the joints of hands and feet. The foot is a major site for RA involvement and a major source of disability resulting from this disease. This paper introduces research which aims to create a mass customisation process for customised orthoses for patients with RA. 3D laser scanning, and gait analysis will be used to generate the orthosis geometry and rapid manufacturing, namely the selective laser sintering (SLS) process, will be used to produce the orthoses. The SLS process enables the incorporation of compositional functional elements, such as locally adjusted stiffness or flexibility, into the orthosis design. The process involved two central elements. The first was a literature survey to identify orthotic design rules for foot impairments in RA. This survey will form a platform for the design rule development and will be complemented by data obtained from two patient trials. The second is a virtual three-segment foot model, created in Anybody dynamics modelling software which can be motivated by data measured from patients using 3D motion capture and force plate systems. Once the measured data has been applied to the model, a virtual insole can be used to simulate the effects of various features in the orthosis. Considerable variation was noted in the literature for types of material, design and methods of orthotic construction. Pressure redistribution using cushioning materials was consistently mapped to painful deformed joints. Orthoses with contoured surfaces, either custom- or mass produced in thermoplastic materials of varying stiffness and density were mapped to joint motion control and deformity prevention. The paper will also describe applying patient gait data to the Anybody model, and then altering the gait pattern by applying the insole model. Future work will also be discussed.Mechanical Engineerin

Dynamic plantar loading index detects altered foot function in individuals with rheumatoid arthritis but not changes due to orthotic use

Background Altered foot function is common in individuals with rheumatoid arthritis. Plantar pressure distributions during gait are regularly assessed in this patient group; however, the association between frequently reported magnitude-based pressure variables and clinical outcomes has not been clearly established. Recently, a novel approach to the analysis of plantar pressure distributions throughout stance phase, the dynamic plantar loading index, has been proposed. This study aimed to assess the utility of this index for measuring foot function in individuals with rheumatoid arthritis.Methods Barefoot plantar pressures during gait were measured in 63 patients with rheumatoid arthritis and 51 matched controls. Additionally, 15 individuals with rheumatoid arthritis had in-shoe plantar pressures measured whilst walking in standardized footwear for two conditions: shoes-only; and shoes with prescribed custom foot orthoses. The dynamic plantar loading index was determined for all participants and conditions. Patient and control groups were compared for significant differences as were the shod and orthosis conditions.Findings The patient group was found to have a mean index of 0.19, significantly lower than the control group's index of 0.32 (p > 0.001, 95% CI [0.054, 0.197]). No significant differences were found between the shoe-only and shoe plus orthosis conditions. The loading index was found to correlate with clinical measures of structural deformity.Interpretation The dynamic plantar loading index may be a useful tool for researchers and clinicians looking to objectively assess dynamic foot function in patients with rheumatoid arthritis; however, it may be unresponsive to changes caused by orthotic interventions in this patient group.</p

155?Sex-related differences in muscle co-activation in individuals with knee osteoarthritis

Background: Sex-related differences in muscle function have been well established in healthy individuals. In individuals with knee osteoarthritis (KOA), impairments in muscle function such as muscle weakness and high muscle co-activation have also been demonstrated. Muscle dysfunction has been shown to be a strong contributor to poor physical function and low health-related quality of life in patients with KOA. The purpose of this study was, therefore, to analyse sex and osteoarthritis-related differences in muscle function, to establish to what extent both sex and disease status contribute to muscle dysfunction.Methods: Muscle co-activation was assessed in 77 symptomatic KOA participants (62.5±8.1yrs; 48/29 women/men) and 18 age-matched asymptomatic controls (62.5±10.4yrs; 9/9 women/men), using electromyography (EMG) during a series of walking, stair ascent and descent and sit-to-walk activities. EMG was recorded from 7 sites medial/lateral gastrocnemius, biceps femoris, semitendinosus, vastus lateralis/medialis and normalised to maximal voluntary contraction. Normalised EMG was used to calculate hamstrings-quadriceps and medial-lateral muscle co-activation as (antagonist/agonist) *(antagonist+agonist). The stance phase of walking was split into pre-stance (150ms prior to initial contact), loading (0-15% of stance), early-stance (15-40%), mid-stance (40-60%), late-stance (60-100%) and overall-stance (0-100%). Stairs negotiation was also split into transition (stance phase on the floor) and continuous (stance phase on the second step of the staircase). All participants provided written informed consent and the study was approved by Research Ethics committees (HLS12/86, 13/ws/0146). Independent samples T-tests were performed to assess the differences between KOA and controls. Linear regressions were performed to investigate the relationship between muscle function, sex and disease status, and Bonferroni corrected for multiple comparisons.Results: Individuals with KOA were weaker than controls (P < 0.007). Overall there were very few differences in muscle co-activation between KOA and controls. Women were weaker than men (P ⩽ 0.002) and had higher hamstrings-quadriceps and medial-lateral muscle co-activation across all activities of daily living. In multiple regression analyses sex and muscle weakness, but not age or disease status, predicted high muscle co-activation.Conclusion: High muscle co-activation was associated with female sex and muscle weakness regardless of disease status and age. It has previously been suggested that muscle co-activation acts as a compensatory mechanism for muscle weakness, accommodating for the diminished force generating capabilities to maintain a certain level of function and movement activation patterns. This suggests that muscle weakness may be the main contributing factor for high muscle co-activation which is thought to increase joint loads with detrimental effects on cartilage and joint integrity. This may explain high muscle co-activation in women with muscle weakness and increased risk of incidence and progression of KOA in women

Age Determination of Pheasants (Phasianus Colchicus) using Discriminant Analysis

Most gallinaceous birds can be identified as juveniles or adults using the outermost primaries (P9 and P10) which are retained until after the first breeding season and are often identifiable by colour and wear. The pheasant Phasianus colchicus, however, moults all ten primary feathers during its post-juvenile moult so alternative techniques are required. To date the method most widely used on live birds is measurement of the shaft diameter of the proximal primary feather, P1, which is replaced first before the bird is fully-grown. Using a known-age sample of 752 free-living pheasants, this study presents a discriminant function analysis using proximal primary feather measurements and other morphological characteristics to achieve a greater level of accuracy of ageing. Ageing accuracy was high, especially for males, at over 95%. The model was less accurate for females, with 83% and 94% respectively for the two year groups. When our model was applied to an independent data set of unknown-age birds 85% were classified. Less than 3% could not be aged accurately and the remainder were unclassified due to missing measurements. Our model offers a reliable method of ageing pheasants, both live and dead, however researchers are cautioned to potential year, origin (stock) and site effects

Investigating Mountain Watershed Headwater‐To‐Groundwater Connections, Water Sources, and Storage Selection Behavior With Dynamic‐Flux Particle Tracking

Climate change will impact mountain watershed streamflow both directly—with changing precipitation amounts and variability—and indirectly—through temperature shifts altering snowpack, melt, and evapotranspiration. To understand how these complex processes will affect ecosystem functioning and water resources, we need tools to distinguish connections between water sources (rain/snowmelt), groundwater storage, and exit fluxes (streamflow/evapotranspiration), and to determine how these connections change seasonally and as climate shifts. Here, we develop novel watershed-scale approaches to understand water source, storage, and exit flux connections using a dynamic-flux particle tracking model (EcoSLIM) applied in California's Cosumnes Watershed, which connects the Sierra Nevada and Central Valley. This work develops new visualizations and applications to provide mechanistic understanding that underpins the interpretation of isotopic field data at watershed scales to distinguish sources, flow paths, residence times, and storage selection. In our simulations, streamflow comes primarily from snow-derived water while evapotranspiration generally comes from rain. Most streamflow starts above 1,000&nbsp;m while evapotranspiration is sourced relatively evenly across the watershed and is generally younger than streamflow. Modeled streamflow consists primarily of water sourced from precipitation in the previous 5&nbsp;years but before the current water year, while ET consists primarily of water from precipitation in the current water year. ET, and to a lesser extent streamflow, are both younger than water in groundwater storage. However, snowmelt-derived streamflow preferentially discharges older water from snow-derived storage. Dynamic-flux particle tracking and new approaches presented here enable novel model-tracer comparisons in large-scale watersheds to better understand watershed behavior in a changing climate

Let me Google that for you:a time series analysis of seasonality in internet search trends for terms related to foot and ankle pain

BACKGROUND: The analysis of internet search traffic may present the opportunity to gain insights into general trends and patterns in information seeking behaviour related to medical conditions at a population level. For prevalent and widespread problems such as foot and ankle pain, this information has the potential to improve our understanding of seasonality and trends within these conditions and their treatments, and may act as a useful proxy for their true incidence/prevalence characteristics. This study aimed to explore seasonal effects, general trends and relative popularity of internet search terms related to foot and ankle pain over the past decade. METHODS: We used the Google Trends tool to obtain relative search engine traffic for terms relating to foot and ankle pain and common treatments from Google search and affiliated pages for major northern and southern hemisphere English speaking nations. Analysis of overall trends and seasonality including summer/winter differences was carried out on these terms. RESULTS: Searches relating to general foot pain were on average 3.4 times more common than those relating to ankle pain, and twice as common as searches relating to heel pain. Distinct seasonal effects were seen in the northern hemisphere, with large increases in search volumes in the summer months compared to winter for foot (p = 0.004, 95 % CI [22.2–32.1]), ankle (p = 0.0078, 95 % CI [20.9–35.5]), and heel pain (p = 0.004, 95 % CI [29.1–45.6]). These seasonal effects were reflected by data from Australia, with the exception of ankle pain. Annual seasonal effects for treatment options were limited to terms related to foot surgery and ankle orthoses (p = 0.031, 95 % CI [3.5–20.9]; p = 0.004, 95 % CI [7.6–25.2] respectively), again increasing in the summer months. CONCLUSIONS: A number of general trends and annual seasonal effects were found in time series internet search data for terms relating to foot and ankle pain. This data may provide insights into these conditions at population levels. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13047-015-0074-9) contains supplementary material, which is available to authorized users

Metatarsophalangeal joint pain in psoriatic arthritis: a cross-sectional study

Methods. Thirty-four consecutive patients with PsA (mean age 45.3 years, 65% female, mean disease duration 9.9 years) and 22 control participants (mean age 37.9 years, 64% female) underwent clinical and US examination to determine the presence of pain, swelling, synovitis, erosions, effusions and submetatarsal bursae at the MTP joints. Mean barefoot peak plantar pressures were determined at each MTP joint. Levels of pain, US-determined pathology and peak pressures were compared between groups. Binary logistic regression was used to identify demographic, clinical examination-derived, US-derived and plantar pressure predictors of pain at the MTP joints in the PsA group. Results. The presence of pain, deformity, synovitis, erosions (P &amp;lt; 0.001) and submetatarsal bursae and peak plantar pressure at MTP 3 (P &amp;lt; 0.05) were significantly higher in the PsA group. MTP joint pain in PsA was independently predicted by high BMI, female gender and the presence of joint subluxation, synovitis and erosion. Conclusion. These results suggest local inflammatory and structural factors, together with systemic factors (gender, BMI), are predominantly responsible for painful MTP joints in PsA, with no clear role for plantar pressure characteristics

'Choosing shoes': a preliminary study into the challenges facing clinicians in assessing footwear for rheumatoid patients

Background: Footwear has been accepted as a therapeutic intervention for the foot affected by rheumatoid arthritis (RA). Evidence relating to the objective assessment of footwear in patients with RA is limited. The aims of this study were to identify current footwear styles, footwear characteristics, and factors that influence footwear choice experienced by patients with RA. Methods: Eighty patients with RA were recruited from rheumatology clinics during the summer months. Clinical characteristics, global function, and foot impairment and disability measures were recorded. Current footwear, footwear characteristics and the factors associated with choice of footwear were identified. Suitability of footwear was recorded using pre-determined criteria for assessing footwear type, based on a previous study of foot pain. Results: The patients had longstanding RA with moderate-to severe disability and impairment. The foot and ankle assessment demonstrated a low-arch profile with both forefoot and rearfoot structural deformities. Over 50% of shoes worn by patients were opentype footwear. More than 70% of patients’ footwear was defined as being poor. Poor footwear characteristics such as heel rigidity and sole hardness were observed. Patients reported comfort (17%) and fit (14%) as important factors in choosing their own footwear. Only five percent (5%) of patients wore therapeutic footwear. Conclusions: The majority of patients with RA wear footwear that has been previously described as poor. Future work needs to aim to define and justify the specific features of footwear that may be of benefit to foot health for people with RA