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James Woodburn

Publications and source records attributed to James Woodburn.

11 recordsLinked to original sources
PubMed2006

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 < or =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 degrees Vs -85.7 degrees). 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.

Adult↗
PubMed2006

Regionalised centre of pressure analysis in patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis patients alter their gait pattern to compensate for painful foot symptoms. The centre of pressure may be a useful indicator of these altered loading patterns. Our purpose was to undertake a comparison of the regionalised duration and velocity of the centre of pressure between rheumatoid arthritis patients with foot impairments and healthy able-bodied adults. METHODS: The progression of the centre of pressure through the foot, heel, midfoot, forefoot and toe regions was measured using an EMED-ST pressure platform. Patients walked at self selected cadence. Variables analysed were the average and maximum velocity and the duration of the centre of pressure (as % stance). RESULTS: In comparison with able-bodied adults, rheumatoid arthritis patients had a statistically significant decrease in the average velocity of the centre of pressure in the total foot (P<0.001), heel (P=0.001) and midfoot (P<0.001) regions. The maximum velocity of the centre of pressure was slower in rheumatoid arthritis patients in only the midfoot region (P=0.002). During stance, the duration of the centre of pressure was longer in the midfoot (P<0.001) and shorter in the forefoot (P=0.001) in the rheumatoid arthritis patients. INTERPRETATION: Alteration of the foot loading patterns in patients with rheumatoid arthritis can be characterised by changes to the centre of pressure patterns. Off-loading the painful and deformed forefoot was a characteristic feature in this patient cohort.

Adult↗
PubMed2006

A framework for evaluating image segmentation algorithms.

The purpose of this paper is to describe a framework for evaluating image segmentation algorithms. Image segmentation consists of object recognition and delineation. For evaluating segmentation methods, three factors-precision (reliability), accuracy (validity), and efficiency (viability)-need to be considered for both recognition and delineation. To assess precision, we need to choose a figure of merit, repeat segmentation considering all sources of variation, and determine variations in figure of merit via statistical analysis. It is impossible usually to establish true segmentation. Hence, to assess accuracy, we need to choose a surrogate of true segmentation and proceed as for precision. In determining accuracy, it may be important to consider different 'landmark' areas of the structure to be segmented depending on the application. To assess efficiency, both the computational and the user time required for algorithm training and for algorithm execution should be measured and analyzed. Precision, accuracy, and efficiency factors have an influence on one another. It is difficult to improve one factor without affecting others. Segmentation methods must be compared based on all three factors, as illustrated in an example wherein two methods are compared in a particular application domain. The weight given to each factor depends on application.

Algorithms↗
PubMed2005

Development of a foot impact scale for rheumatoid arthritis.

OBJECTIVE: To develop a new foot impact scale to assess foot status in rheumatoid arthritis (RA) using established qualitative methodology and the latest item response techniques (Rasch analysis). METHODS: Foot problems in RA were explored by conducting qualitative interviews that were then used to generate items for a new foot impact scale. Further validation was undertaken following postal surveys and Rasch analysis. RESULTS: Analysis of the first postal survey (n = 192 responses) produced a 63-item binary response, 4-subscale instrument. The 4 subscales covered the domains impairment, activities, participation, and footwear. Following test-retest postal surveys and additional analysis, the instrument was reduced to a 2 subscale, 51-item questionnaire covering the domains of impairments/shoes and activities/participation. Initial results of these subscales indicate good psychometric properties, external validity, and test-retest reliability. CONCLUSION: A foot impact scale to assess the impact of RA and to measure the effect of interventions has been developed. The 2 scales comprising the instrument demonstrate good psychometric properties.

Adult↗
PubMed2005

Selectively attenuating soft tissues close to sites of inflammation in the peritalar region of patients with rheumatoid arthritis leads to development of pes planovalgus.

OBJECTIVE: To compare the 3-dimensional (3D) orientation of the tibiotalar, tibiocalcaneal, and intertarsal joints in cadaveric specimens following structural weakening to predetermined ligaments in the peritalar region and medial ankle tendons under axial loads and simulated calcaneal valgus deformity. METHODS: Eight fresh-frozen, unembalmed human lower leg and foot specimens were placed in a materials testing machine. The mid-stance period of gait was simulated and the 3D orientation of the tibiotalar, tibiocalcaneal, and intertarsal joints was measured using an electromagnetic motion analysis system. Specimens were then axially loaded at 840 N for 5400 cycles with the calcaneus in its initial orientation and under simulated valgus conditions using a heel wedge following attenuation (multiple stab incisions) of selected ligaments (tibionavicular, anterior tibiotalar and tibiocalcaneal portions of the medial deltoid ligament, the inferior calcaneonavicular ligament, and the superomedial calcaneonavicular ligament) or tendons (tibialis posterior, flexor digitorum longus, and flexor hallucis longus). The joint orientation measurements were then repeated and compared with baseline intact measurements. RESULTS: Pes planovalgus was observed in 6/8 specimens following testing. The tibiotalar, tibiocalcaneal, talonavicular, and calcaneocuboid joints were more dorsiflexed, everted, and externally rotated following either ligament or tendon compromise. The changes in orientation were small but showed consistent patterns with the smallest changes (typically < 1 degrees ) for the transverse plane and largest (up to 3.5 degrees ) for the frontal plane. The magnitude of change was similar for the tibiotalar and tibiocalcaneal joints, largest for the talonavicular joint, and smallest for the calcaneocuboid joint for both ligament and tendon compromise. The orientation of the talocalcaneal joint was more plantarflexed and everted relative to baseline, for both the ligament and tendon compromise with < 1 degrees of change in orientation about the transverse plane. Under simulated valgus heel conditions, joint orientation was further increased especially about the frontal plane in the direction of eversion. The smallest changes were noted for the calcaneocuboid joint (approximately 1 degrees ), similar change (approximately 2-3 degrees ) for the tibiotalar, tibiocalcaneal and talocalcaneal joints, and the largest changes (> 3 degrees ) for the talonavicular joint. There were no observed differences in the magnitude of change between ligament or tendon condition. CONCLUSION: Selective attenuation to either the ligaments supporting the tibiotalar, talocalcaneal, and talonavicular joints or the medial ankle tendons followed by cyclic loading results in small but important changes in the orientation of the tarsal bones consistent with the development of pes planovalgus.

Ankle Joint↗
PubMed2004

Multisegment foot motion during gait: proof of concept in rheumatoid arthritis.

OBJECTIVE: To test a multisegment foot model for kinematic analysis during barefoot walking in patients with well established rheumatoid arthritis (RA) and foot impairments. METHODS: Five healthy adult subjects and 11 RA patients with advanced disease were studied. Foot impairments were assessed using standardized outcomes and clinical examination techniques. A 6-camera 60 Hz video-based motion analysis system was used to measure motion of the shank, rearfoot, forefoot, and hallux segments and the vertical displacement of the navicular. Face validity and estimates of repeatability were determined. Motion patterns were calculated and comparisons were made between healthy subjects and patients with RA. Relationships between clinical impairment and abnormal motion were determined through inspection of individual RA cases. RESULTS: Across the motion variables, the within-day and between-day coefficient of multiple correlation values ranged from 0.677 to 0.982 for the healthy subjects and 0.830 to 0.981 for RA patients. Based on previous studies, motion parameters for the healthy subjects showed excellent face validity. In RA patients, there was reduced range of motion across all segments and all planes of motion, which was consistent with joint stiffness. In the RA patients, rearfoot motion was shifted towards eversion and external rotation and peak values for these variables were increased, on average, by 7 degrees and 11 degrees, respectively. Forefoot range of motion was reduced in all 3 planes (between 31% and 53%), but the maximum and minimum angles were comparable to normal. The navicular height, during full foot contact, was on average 3 mm lower in the RA patients in comparison to normal. The hallux was less extended in the RA subjects in comparison to normal (21 degrees vs 33 degrees) during the terminal stance phase. Individual cases showed abnormal patterns of motion consistent with their clinical impairments, especially those with predominant forefoot pain or pes planovalgus. CONCLUSION: In RA, multisegment foot models may provide a more complete description of foot motion abnormalities where pathology presents at multiple joints, leading to complex and varied patterns of impairment. This technique may be useful to evaluate functional changes in the foot and to help plan and assess logical, structurally based corrective interventions.

Adult↗
PubMed2003

Changes in 3D joint kinematics support the continuous use of orthoses in the management of painful rearfoot deformity in rheumatoid arthritis.

OBJECTIVE: To evaluate the efficacy of custom foot orthoses for the management of painful rearfoot valgus in patients with rheumatoid arthritis (RA). METHODS: Patients were randomized to receive custom-manufactured rigid carbon graphite foot orthoses (RA-orthosis) or enter a control group (RA-control) receiving no orthotic intervention. Three-dimensional (3D) kinematics were measured at the ankle joint complex (AJC) using an electromagnetic tracking (EMT) system under barefoot, shod, and orthosis walking conditions. Previously established normal 3D kinematic data were used to descriptively compare motion patterns in both RA groups and statistical analyses were performed on integrals of motion-time for each axis of rotation from data collected at baseline, 3, 6, 12, 18, 24, and 30 months. RESULTS: Compared with healthy control subjects, all patients with RA demonstrated excessive subtalar joint eversion motion through the stance phase of gait (p < 0.0001) coupled with excessive internal leg rotation (p < 0.0001). Custom-manufactured orthoses significantly reduced eversion through stance (p = 0.009) and re-established equilibrium of motion relative to neutral joint position. Correcting the frontal plane component of the deformity did not lead to a significant reduction in internal leg rotation (p = 0.294). The devices had no effect on tibiotalar dorsiflexion/plantarflexion (p = 0.960). Prospectively, the rigid orthoses maintained and then improved the reduction in cumulative subtalar eversion motion (p < 0.0001). Minimal changes in cumulative subtalar component eversion and internal leg rotation were recorded for both RA groups when walking barefoot but the effect was significantly less for the RA-control group. From 12 months onwards, internal leg rotation started to decrease, suggesting re-coupling of motion, but the overall motion pattern remained abnormal in comparison with normal reference values. CONCLUSION: These results support the continuous use of custom-manufactured foot orthoses to correct deformity and optimize AJC function in RA patients with early painful deformity of the rearfoot.

Arthritis, Rheumatoid↗
PubMed2002

The geometric architecture of the subtalar and midtarsal joints in rheumatoid arthritis based on magnetic resonance imaging.

OBJECTIVE: To compare in vivo the 3-dimensional (3-D) geometric architecture of the subtalar and midtarsal joints in normal and rheumatoid arthritic (RA) feet, using magnetic resonance imaging (MRI) analysis. METHODS: MRI was performed on 23 patients with RA, all of whom had disease activity in the subtalar and/or midtarsal joints. Image processing techniques were used to create 3-D reconstructions of the calcaneus (C), cuboid (c), navicular (N), and talus (T) bones. Twenty-four standard architectural parameters were measured from the reconstructions and were compared with data from 10 normal subjects. These parameters defined both 3-D distance and angular relationships among the 4 bones studied. Pattern classification techniques were used to establish a geometric architecture foot profile for the RA patients. The degree of individual patient fit to the new RA foot profile and to profiles for normal, pes planus, and pes cavus foot types was derived. Logistic regression was used to examine the relationship of foot architecture to inflammatory disease characteristics and physical examination variables. RESULTS: Subtalar or midtarsal pain was reported by all 23 patients, and 22 of the 23 patients presented with >/=1 clinical feature of pes planovalgus deformity. In 21 patients, ultrasonography revealed synovitis at >/=1 tarsal joint or surrounding tendon. In the RA group, the normalized distances between the geometric centroids were significantly closer for bone pairs Cc and cT and significantly distracted for bone pair CN compared with the distances in normal subjects. In RA patients (versus normal subjects), the angles subtended at the bone centroids were significantly decreased in 3 bone groups (CNc, TCN, and TNc) and significantly increased in 3 bone groups (CcN, CcT, NTc). The angles formed between the major principal axes of bone pairs CT and cT were significantly increased in RA patients compared with those in normal subjects. Pattern classification defined 11 RA feet as having normal structure and 12 as having abnormal structure. However, the abnormal feet did not fit consistently with structures defined for RA, pes planus, or pes cavus foot types. Logistic regression demonstrated that subtalar joint synovitis was the only predictive factor for abnormal subtalar and midtarsal architecture (odds ratio 19.2, 95% confidence interval 1.77-200.0). CONCLUSION: This unique 3-D MRI-based technique successfully quantified the effects of RA on the geometric architecture of the foot and the patient-specific nature of these changes. This technique can be used to provide logical therapy for correction.

Adult↗
PubMed2002

A randomized controlled trial of foot orthoses in rheumatoid arthritis.

OBJECTIVE: To investigate the clinical effectiveness of early foot orthosis intervention for painful correctable valgus deformity of the rearfoot in rheumatoid arthritis (RA). METHODS: Patients with RA were randomized to receive custom manufactured rigid foot orthoses under podiatry supervision (n = 50) or enter a control group (n = 48). The control group received foot orthoses only when prescribed under normal medical care. Foot pain and disability, using the Foot Function Index (FFI), along with disease activity, tolerance, and adverse reactions, were serially measured over 30 mo continuous treatment. RESULTS: The group assigned foot orthoses demonstrated an immediate clinical improvement, the effect peaking at 12 mo. At 30 mo the FFI total score was reduced by 23.1% from baseline in the intervention group. Area under the curve analysis showed a statistically significant reduction in FFI scores for total score (p = 0.026), foot pain (p = 0.014), and foot disability (p = 0.016) when intervention was compared to control scores. There were no confounding effects from differences between groups for disease activity or pharmacological or other management strategies. Most patients (96%) used their orthoses and most found them comfortable (97%), although minor adverse reactions, such as tender spots, blisters, and callus, were reported in 30% of patients in the early stages of treatment and persisted in 12% for 30 mo. CONCLUSION: Custom designed foot orthoses used continuously over a 30 mo treatment period resulted in a reduction in foot pain by 19.1%, foot disability by 30.8%, and functional limitation by 13.5%. Clinical effectiveness might be enhanced by their use in the early stages of rearfoot pain and deformity.

Adult↗