Gait in children with achondroplasia - a cross-sectional study on joint kinematics and kinetics.

BACKGROUND: Children with achondroplasia have extreme short stature due to short limbs, as well as several other clinical features that may affect their gait. The purpose of this cross-sectional study was to provide a detailed description of gait in children with achondroplasia compared to age-matched controls. METHODS: Between the years 2007 and 2010, 16 children with achondroplasia [mean age 9.6 years (range 5-16; six female)] with no previous history of orthopaedic lower limb surgery and 19 age-matched controls conducted three-dimensional (3D) gait analysis at one occasion. The gait analysis rendered pelvis and lower limb joint kinematics and kinetics, and time and distance data. Descriptive statistics, independent samples t-tests, and Fisher's exact test were used to describe the cohort including gait data and participant characteristics. RESULTS: Children with achondroplasia had kinematic gait pattern deviations in all three planes, especially in the sagittal plane, when compared to the control group. Peak anterior pelvic tilt and peak ankle dorsiflexion were found to be increased. Increased knee flexion was noted at initial contact and again at terminal stance. During stance, children with achondroplasia had a higher peak hip abduction angle and a higher peak knee varus angle in the frontal plane. In the sagittal plane, kinetic gait pattern deviations were found at the hip, knee, and ankle, consistent with a flexion pattern. Compared to the control group, children with achondroplasia walked with reduced walking speed and step length, and increased cadence. There was no difference in walking speed when leg length was taken into account. Normalised step length and normalised cadence, on the other hand, were found to be increased in children with achondroplasia. CONCLUSIONS: The observed gait characteristics in children with achondroplasia are related to anatomical attributes and strategies to increase step length, and hence walking speed.

Neurodevelopmental difficulties in children with idiopathic clubfoot.

AIM: To evaluate neurodevelopmental difficulties in children with idiopathic clubfoot. METHOD: A cross-sectional study of 106 children (29 females, 77 males; aged 8-10y) with idiopathic clubfoot and 109 age-, sex-, and residential area-parallelized children from the general population. Neurodevelopmental difficulties were assessed using the parent-report Five to Fifteen (FTF) questionnaire. Group differences were analysed for FTF domains, subdomains, and items. The 90th centile cut-off of the general population on FTF and the parent-based disease-specific instrument (DSI) were used to evaluate clinical relevance of neurodevelopmental symptoms in idiopathic clubfoot. RESULTS: Modest group differences were found for several FTF domains (motor skills, perception, and language) and subdomains (gross and fine motor skills, relation in space, comprehensive and expressive language skills). Thirty-one per cent of the children with idiopathic clubfoot scored in the clinically significant range on 2 or more FTF domains. DSI scores were lower in this subgroup. INTERPRETATION: Findings indicate a moderate and selective increase of neurodevelopmental difficulties in children with idiopathic clubfoot as a whole, especially in the areas of motor skills, perception, and language. Idiopathic clubfoot with marked neurodevelopmental symptoms are associated with less satisfaction of the clubfoot treatment. Our results recommend awareness of neurodevelopmental difficulties in the assessment and treatment of idiopathic clubfoot. WHAT THIS PAPER ADDS: A substantial minority of children with idiopathic clubfoot show neurodevelopmental difficulties. Children with idiopathic clubfoot might present additional difficulties in motor skills, perception, and language. Children with idiopathic clubfoot and marked neurodevelopmental symptoms show poorer parent-reported clubfoot treatment satisfaction. Neurodevelopmental difficulties should be considered in clinical practice of idiopathic clubfoot.

Neurodevelopmental difficulties negatively affect health-related quality of life in children with idiopathic clubfoot.

AIM: To study health-related quality of life (HRQoL) in children with idiopathic clubfoot (IC) and the influence of sex, clubfoot laterality and neurodevelopmental difficulties (NDD) on HRQoL. METHODS: A cross-sectional questionnaire-based study in Stockholm and Skåne Counties, Sweden, of 106 children with IC born 2004-2007 (mean 9.4 ± 0.6 years) and a general population sample of 109 schoolchildren (mean 9.5 ± 0.6 years). The children and their caregivers answered the EQ-5D-Y (Youth) and Five to Fifteen questionnaires to operationalise HRQoL and NDD, respectively. RESULTS: No reduced HRQoL on the EQ-5D-Y dimensions were reported by 51% of the children with IC, and 71% in the general population sample, with significant more problems in the IC sample regarding 'mobility', 'doing usual activities' and 'having pain or discomfort', despite similar overall health status. Neither sex nor clubfoot laterality affected HRQoL. Children with IC and NDD combined reported more problems in three out of five dimensions and lower overall health status compared with children with IC alone. CONCLUSION: Despite similar overall health status, children with IC had more HRQoL problems compared with the general population, being associated with coexisting NDD but not sex or clubfoot laterality.

Younger age is associated with greater pain expression among patients with knee or hip osteoarthritis scheduled for a joint arthroplasty.

BACKGROUND: This study describes how patients with knee or hip osteoarthritis (OA), scheduled for arthroplasty, characterize their pain qualitatively and quantitatively and investigates whether differences exist in pain expression between younger and older patients, and between men and women. METHODS: One hundred eight patients scheduled for a joint arthroplasty completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) or Hip Disability and Osteoarthritis Outcome Score (HOOS) and a health-related quality of life question. Pain was assessed using the visual analogue scale (VAS), KOOS/HOOS and the Pain-o-Meter (POM) consisting of 12 sensory and 11 affective words (POM-Words). Frequency of analgesics use was assessed and preoperative radiographs were graded. ANOVA was used to test differences in pain expression with age (< 65 vs. ≥65 years), sex, and affected joint as independent factors. RESULTS: Patients < 65 years of age used more affective words (POM) and words with higher affective intensity (median scores 8 (3-39), 5.5 (2-27) respectively), than older patients, despite having less radiographically advanced OA. They also reported more symptoms (KOOS/HOOS) than older patients. However, pain ratings, as measured by VAS and KOOS/HOOS pain, did not differ between younger and older adults. Women reported more frequent analgesics use (45.7 and 26.5% respectively) and rated their pain higher than men (mean POM-VAS = 42 (SD 24) and 31 (SD 19); respectively). No differences existed between sexes for sensory or affective POM-Words, or radiographic grade of OA. With age and sex as independent factors, a significant difference between knee and hip OA remained for sensory POM-words intensity scores. CONCLUSIONS: Younger adults scheduled for arthroplasty expressed pain using more affective words and words with higher intensity and had less radiographically advanced OA than older adults. However, VAS and KOOS/HOOS pain subscales could not distinguish the difference in pain expression. Thus, the POM may be a valuable tool for assessment of pain.

Gross Motor Skills in Children With Idiopathic Clubfoot and the Association Between Gross Motor Skills, Foot Involvement, Gait, and Foot Motion.

BACKGROUND: Little is known regarding gross motor skills (GMS) in children with idiopathic clubfoot (IC). This study describes GMS, specifically foot involvement and asymmetries, and analyses the association between GMS, gait, and foot status in children with IC. METHODS: Gross motor tasks and gait were analyzed in children with IC and typically developed (TD) children. GMS were assessed using videotapes and the Clubfoot Assessment Protocol (CAP). The Gait Deviation Index (GDI) and GDI-Kinetic were calculated from gait analyses. Children were divided into bilateral, unilateral clubfoot, or TD groups. To analyze asymmetries, feet within each group were further classified into superior or inferior foot, depending on their CAP scores. Correlations identified associations between CAP and GDI, GDI-Kinetic, passive foot motion, and Dimeglio Classification Scores at birth in the clubfeet. RESULTS: In total, 75 children (mean age, 5 years) were enrolled (bilateral n=22, unilateral clubfoot n=25, TD=28). Children with clubfeet demonstrated significantly lower GMS, gait, and foot motion compared with TD children. One leg standing and hopping deviated in 84% and 91%, respectively, in at least one foot in children with clubfoot. Gross motor asymmetries were evident in both children with bilateral and unilateral involvement. In children with unilateral clubfoot, contralateral feet showed few deviations in GMS compared with TD; however, differences existed in gait and foot motion. The association between GMS and gait, foot motion, and initial foot status varied between poor and moderate. CONCLUSIONS: Gross motor deficits and asymmetries are present in children with both bilateral and unilateral IC. Development of GMS of the contralateral foot mirrors that of TD children, but modifies to the clubfoot in gait and foot motion. The weak association with gait, foot motion, and initial clubfoot severity indicates that gross motor measurements represent a different outcome entity in clubfoot treatment. We therefore, recommend gross motor task evaluation for children with IC. LEVEL OF EVIDENCE: Level II-prognostic studies.

Changes of and interrelationships between performance-based function and gait and patient-reported function 1 year after total hip arthroplasty.

BACKGROUND: The aim of this prospective study is to evaluate the degree of improvement in, and interrelationships between, performance-based function, gait, and patient-reported function 1 year after total hip arthroplasty (THA) in patients with primary hip osteoarthritis (OA). MATERIALS AND METHODS: Thirty-four patients with hip OA, with a mean age of 67 years (standard deviation, SD 9 years), and 25 age- and gender-matched healthy controls performed three performance-based functional tests, instrumented three-dimensional gait analysis, and completed the Hip disability and Osteoarthritis Outcome Score prior to and 1 year after THA. Effect sizes with 95 % confidence intervals were calculated as measures of the magnitude of improvement in performance after surgery. RESULTS: Performance-based function displayed large improvements 1 year after THA. Overall gait patterns, quantified using a kinematic and a kinetic gait index, respectively, revealed moderate improvements in kinematics of the operated limb and kinetics of the contralateral limb. Patient-reported function displayed the largest improvement after surgery. CONCLUSIONS: The findings of this study suggest that objectively measured improvements in performance-based function and gait are not in line with patient-reported functional improvements, highlighting the importance of using both subjective and objective methods for evaluating function following THA. LEVEL OF EVIDENCE: III.

Improved knee biomechanics among patients reporting a good outcome in knee-related quality of life one year after total knee arthroplasty.

BACKGROUND: It is not well understood why one in five patients report poor outcomes following knee arthroplasty. This study evaluated changes in knee biomechanics, and perceived pain among patients reporting either a good or a poor outcome in knee-related quality of life after total knee arthroplasty. METHODS: Twenty-eight patients (mean age 66 (SD 7) years) were included in this prospective study. Within one month of knee arthroplasty and one year after surgery, patients underwent three-dimensional (3D) gait analysis, completed the Knee Injury and Osteoarthritis Outcome Score (KOOS), and rated perceived pain using a visual analogue scale. A "good outcome" was defined as a change greater than the minimally detectable change in the KOOS knee-related quality of life, and a "poor outcome" was defined as change below the minimally detectable change. Nineteen patients (68%) were classified as having a good outcome. Groups were analyzed separately and knee biomechanics were compared using a two-way repeated measures ANOVA. Differences in pain between groups were evaluated using Mann Whitney U test. RESULTS: Patients classified as having a good outcome improved significantly in most knee gait biomechanical outcomes including increased knee flexion-extension range, reduced peak varus angle, increased peak flexion moment, and reduced peak valgus moment. The good outcome group also displayed a significant increase in walking speed, a reduction (normalization) of stance phase duration (% of gait cycle) and increased passive knee extension. Whereas, the only change in knee biomechanics, one year after surgery, for patients classified as having a poor outcome was a significant reduction in peak varus angle. No differences in pain postoperatively were found between groups. CONCLUSION: Patients reporting a good outcome in knee-related quality of life improved in knee biomechanics during gait, while patients reporting a poor outcome, despite similar reduction in pain, remained unchanged in knee biomechanics one year after total knee arthroplasty. With regards to surgeon-controlled biomechanical factors, surgery may most successfully address frontal plane knee alignment. However, achieving a good outcome in patient-reported knee-related quality of life may be related to dynamic improvements in the sagittal plane.

Deficits in functional performance and gait one year after total knee arthroplasty despite improved self-reported function.

PURPOSE: The current literature lacks sufficient information about improvements in gait patterns and function after total knee arthroplasty (TKA) and whether patients return to full function. This study evaluated change in gait, performance-based function, and self-reported function 1 year after TKA in patients with symptomatic knee osteoarthritis and how these aspects interrelate. METHODS: A total of 28 patients (64 % female) with knee osteoarthritis, with a mean age of 66 (±7) years, and 25 age- and gender-matched controls participated in this prospective cohort study. Three-dimensional gait analysis generated comprehensive measures of kinematic and kinetic gait deviations, respectively. Participants completed the Five Times Sit-to-Stand (5STS) test, and the self-reported questionnaire Knee Injury and Osteoarthritis Outcome Score (KOOS), at baseline prior to surgery and 1 year after TKA. RESULTS: Kinetic gait deviations of both the operated and non-operated limb persisted in patients with knee osteoarthritis at 1 year after surgery, while kinematic gait patterns were comparable to controls. Performance on the 5STS and KOOS scores in patients with knee osteoarthritis improved significantly 1 year after surgery (effect size 0.5-1.5), but did not reach the level of controls. Ten patients with knee osteoarthritis (36 %) exceeded the minimally detectable change on the 5STS. CONCLUSION: Measures of overall gait patterns and the 5STS revealed improvements in function 1 year after TKA, but were not restored to the level of healthy controls. Based on change in 5STS performance, we identified patients with substantial improvements in gait patterns. Self-reported measures of function could not detect differences between patients improving in 5STS performance and those who did not. These findings highlight the use of the 5STS in clinical practice since improvement on this test seems to follow the reduction in gait pattern deviations. LEVEL OF EVIDENCE: II.

Gait in 5-year-old children with idiopathic clubfoot: A cohort study of 59 children, focusing on foot involvement and the contralateral foot.

Background and purpose - Idiopathic clubfoot can be bilateral or unilateral; however, most studies of gait have assessed clubfoot cases as one uniform group. The contralateral foot in children with unilateral clubfoot has shown deviations in pedobarographic measurements, but it is seldom included in studies of gait. We evaluated gait in children with idiopathic clubfoot, concentrating on foot involvement. Patients and methods - Three-dimensional gait analyses of 59 children, mean age 5.4 years, with bilateral (n = 30) or unilateral (n = 29) idiopathic clubfoot were stratified into groups of bilateral, unilateral, or contralateral feet. Age-matched controls (n = 28) were evaluated for comparison. Gait assessment included: (1) discrete kinematic and kinetic parameters, and (2) gait deviation index for kinematics (GDI) and kinetics (GDI-k). Results - No differences in gait were found between bilateral and unilateral idiopathic clubfoot, but both groups deviated when compared to controls. Compared to control feet, contralateral feet showed no deviations in discrete gait parameters, but discrepancies were evident in relation to unilateral clubfoot, causing gait asymmetries in children with unilateral involvement. However, all groups deviated significantly from control feet according to GDI and GDI-k. Interpretation - Bilateral and unilateral idiopathic clubfoot cases show the same persistent deviations in gait, mainly regarding reduced plantarflexion. Nevertheless, knowledge of foot involvement is important as children with unilateral clubfoot show gait asymmetries, which might give an impression of poorer deviations. The results of GDI/GDI-k indicate global gait adaptations of the contralateral foot, so the foot should preferably not be used as a reference for gait.

Ankle arthritis predicts polyarticular disease course and unfavourable outcome in children with juvenile idiopathic arthritis.

OBJECTIVES: To evaluate the occurrence, clinical characteristics and prognostic factors associated with ankle arthritis in children with juvenile idiopathic arthritis (JIA). METHODS: 440 children with JIA were followed for eight years in a prospective Nordic population-based cohort study. Data on remission was available for 427 of these children. Occurrence of clinically assessed ankle arthritis was analysed in relation to JIA category, clinical characteristics and remission data eight years after disease onset. RESULTS: In 440 children with JIA, 251 (57%) experienced ankle arthritis during the first eight years of disease. Ankle arthritis was least common in the persistent oligoarticular category (25%) and most common in children with extended oligoarticular (83%) and polyarticular RF-negative (85%) JIA. Children who developed ankle arthritis during the first year of disease were younger at disease onset (median age 4.9 (IQR 2.1-8.8) vs. 6.6 (IQR 2.8-10.1) years, p<0.003) and had more cumulative affected joints at 8-year follow-up (median involved joints 10 (IQR 6-16) vs. 3 (IQR 2-9), p<0.001). The odds ratio for not achieving remission eight years after disease onset, if the ankle joint was involved during the first year of disease was 2.0 (95 % CI:1.3-3.0, p<0.001). Hind-, mid- and forefoot involvements were more common compared to patients without ankle arthritis. CONCLUSIONS: In this Nordic population-based 8-year follow-up study, occurrence of ankle arthritis during the first year was associated with an unfavourable disease outcome. We suggest that ankle arthritis should be recognised in the assessment of prognosis and choice of treatment strategy in JIA.

Psychometric properties of the Knee injury and Osteoarthritis Outcome Score for Children (KOOS-Child) in children with knee disorders.

BACKGROUND: The Knee injury and Osteoarthritis Outcome Score (KOOS) is a self-administered valid and reliable questionnaire for adults with joint injury or degenerative disease. Recent data indicate a lack of comprehensibility when this is used with children. Thus, a preliminary KOOS-Child was developed. This study aims to evaluate psychometric properties of the final KOOS-Child when used in children with knee disorders. METHODS: 115 children (boys/girls 51/64, 7-16 years) with knee disorders were recruited. All children (n=115) completed the KOOS-Child, the Child-Health Assessment Questionnaire (CHAQ) and the EQ-5D-Youth version (EQ-5D-Y) at baseline to evaluate construct validity. Two additional administrations (1-3 weeks and 3 months) were performed for analyses of reliability (internal consistency and test-retest; n=72) and responsiveness (n=91). An anchor-based approach was used to evaluate responsiveness and interpretability. RESULTS: After item reduction, the final KOOS-Child consists of 39 items divided into five subscales. No floor or ceiling effects (≤15%) were found. An exploratory factor analysis on subscale level demonstrated that items in all subscales except for Symptoms loaded on one factor (Eigenvalues 3.1-5.5, Symptom: 2 factors, Eigenvalue >1). Sufficient homogeneity was found for all subscales (Cronbach's α = 0.80-0.90) except for the Symptoms subscale (α = 0.59). Test-retest reliability was substantial to excellent for all subscales (Intraclass Correlation Coefficient 0.78-0.91, Smallest Detectable Change (SDC)ind 14.6-22.6, SDCgroup 1.7-2.7). Construct validity was confirmed, and greater effect sizes were seen in those reporting improved clinical status. Minimal important changes greater than the SDCs were found for patients reporting to be better and much better. CONCLUSIONS: The final KOOS-Child demonstrates good psychometric properties and supports the use of the KOOS-Child when evaluating children with knee disorders.

Development of the Knee Injury and Osteoarthritis Outcome Score for children (KOOS-Child): comprehensibility and content validity.

BACKGROUND AND PURPOSE: The Knee Injury and Osteoarthritis Outcome Score (KOOS) is distinguished from other knee-specific measures by the inclusion of separate scales for evaluation of activities of daily living, sports and recreation function, and knee-related quality of life, with presentation of separate subscale scores as a profile. However, its applicability in children has not been established. In this study, we examined how well the KOOS could be understood in a cohort of children with knee injury, with a view to preparing a pediatric version (KOOS-Child). MATERIAL AND METHODS: A trained researcher conducted cognitive interviews with 34 Swedish children who had symptomatic knee injuries (either primary or repeated). They were 10-16 years of age, and were selected to allow for equal group representation of age and sex. All the interviews were recorded. 4 researchers analyzed the data and modified the original KOOS questionnaire. RESULTS: Many children (n =14) had difficulty in tracking items based on the time frame and an equivalent number of children had trouble in understanding several terms. Mapping errors resulted from misinterpretation of items and from design issues related to the item such as double-barreled format. Most children understood how to use the 5-point Likert response scale. Many children found the instructions confusing from both a lexical and a formatting point of view. Overall, most children found that several items were irrelevant. INTERPRETATION: The original KOOS is not well understood by children. Modifications related to comprehension, mapping of responses, and jargon in the KOOS were made based on qualitative feedback from the children.

Reliability and reference values of two clinical measurements of dynamic and static knee position in healthy children.

PURPOSE: The purposes of this study were to evaluate reliability of the Single-limb mini squat test (a dynamic measure of medio-lateral knee position) and the Quadriceps-angle (Q-angle) (a static measure of medio-lateral knee position), present paediatric reference values of the Q-angle, and evaluate the association between the tests. METHODS: Two hundred and forty-six healthy children (9-16 years) were included (intra/inter-rater reliability for Q-angle (n = 37/85) and for Single-limb mini squat test (n = 33/28)). Dynamic medio-lateral knee position was assessed by the Single-limb mini squat test. Static medio-lateral knee position was evaluated by the Q-angle. RESULTS: The reliability of the Single-limb mini squat test was found to be moderate (kappa 0.48-0.57, 95% CI 0.16-0.85, 76-79% agreement). Fair to moderate reliability (ICC 0.35-0.42, 95% CI 0.11-0.66, SEM 1.4°-1.9°, n.s.) of the Q-angle measurements was found. Reference values for the Q-angle (mean 13.5° (1.9)-15.3° (2.8)) varies with age and gender. No associations were found between dynamic and static measures. CONCLUSIONS: The Single-limb mini squat test showed a moderate reliability and the Q-angle showed a fair to moderate reliability. A difference found for age and gender was lower than 5° and may not be clinical significant. No association were found between the two tests, indicating dynamic and static knee position being two different concepts. In a clinical perspective, we suggest that the Single-limb mini squat test is a contribution to the available tool box for evaluation of dynamic medio-lateral knee position in children, although the Q-angle may not be used before more research has been done justifying its use.

A qualitative study examining the validity and comprehensibility of physical activity items: developed and tested in children with juvenile idiopathic arthritis.

BACKGROUND: Not all physical activity (PA) questionnaires (PAQ) gather information regarding PA intensity, duration, and modes and only a few were developed specifically for children. We assessed children's comprehensibility of items derived from two published PAQs used in children along with three items designed to ascertain PA intensity in order to assess comprehensibility of items and identify response errors. We modified items to create a new PAQ for children (ASCeND). We hypothesized that children would have comprehension difficulties with some original PAQ items and that ASCeND would be easier to comprehend, and would improve recall and reporting of PA. METHODS: For this qualitative study, we recruited 30 Swedish children [ages 10-16 years; mean age = 13.0 (SD = 1.8)]; median disease activity score = 4.5 (IQR 2.2-9.0); median disease duration = 5.0 (IQR 2.6-10.8) with juvenile idiopathic arthritis (JIA) from a children's hospital-based rheumatology clinic. We conducted cognitive interviews to identify children's comprehension of PAQ items. Interviews were audiotaped, transcribed, and independently analyzed. In phase one, 10 children were interviewed and items modified based on feedback. In phase two, an additional 20 children were interviewed to gather more feedback and further refine the modified items, to create the ASCeND. RESULTS: The median interview time was 41 min (IQR 36-56). In phase one, 219 comments were generated regarding directions for recording PA duration, and transportation use, walking, dancing, weight-bearing exercise and cardio fitness. Based on feedback we modified the survey layout, clarified directions and collapsed or defined items to reduce redundancy. In phase two, 95 comments were generated. Most comments related to aerobic fitness and strenuous PA. Children had difficulty recalling total walking and other activities per day. Children used the weather on a particular day, sports practice, or gym schedules to recall time performing activities. The most comments regarding comprehension were generated about the 3-item PA intensity survey, suggesting children had problems responding to intensity items. CONCLUSIONS: The newer layout facilitated recall of directions or efficiency in answering items. The 3-item intensity survey was difficult to answer. Sports-specific items helped children more accurately recall the amount of daily PA. The ASCeND appeared to be easy to answer and to comprehend.

The centre of mass trajectory is a sensitive and responsive measure of functional compensations in individuals with knee osteoarthritis performing the five times sit-to-stand test.

This study aimed to evaluate whether the trajectory of the body's Centre of Mass (CoM) is a sensitive and responsive measure of functional compensations in individuals with knee osteoarthritis (OA) performing the Five Times Sit-to-Stand test (5STS). This prospective study included 21 individuals with OA and 21 age- and gender-matched controls. Motion analysis data was collected while participants performed the 5STS, one month prior and one year after total knee arthroplasty (TKA). Pain was evaluated using a visual analogue scale. Repeated measures ANOVAs were used to evaluate (1) differences in the area under the curve (AUC) of CoM trajectories, and (2) the effect of number of sit-to-stand cycles on the AUC. Preoperatively, individuals with OA displayed a larger contralateral shift (p = 0.009) and forward displacement of the CoM (p < 0.004) than controls. Postoperatively, CoM trajectories of OA individuals were not statistically different from controls. However, upon comparison of specific cycles, OA individuals displayed a larger forward displacement during the final cycle. Pain was significantly reduced postoperatively (p = 0.001). The CoM trajectory appears to be a sensitive and responsive measure of functional compensations. The increased contralateral shift of the CoM represents a strategy to reduce pain by unloading the affected knee. Postoperatively, when pain was substantially reduced, OA individuals were comparable to controls. The increased forward CoM displacement characterises a strategy to reduce muscular effort by reducing the required knee extension moment. Postoperatively, OA individuals were comparable to controls in all cycles but the last, possibly suggesting residual muscle weakness.

The impact of symptomatic knee osteoarthritis on overall gait pattern deviations and its association with performance-based measures and patient-reported outcomes.

BACKGROUND: Limited knowledge exists regarding the impact of symptomatic knee osteoarthritis (OA) on the overall gait pattern; and whether gait deviations are associated with performance-based measures (PBMs) and patient-reported outcomes (PROs). This cross-sectional study evaluated overall gait patterns in patients with knee OA using the Gait Deviation Index for kinematics (GDI) and kinetics (GDI-kinetic), and explored associations between gait deviations, PBMs, and PROs. METHODS: Forty patients with knee OA and 25 age and gender-matched controls underwent three-dimensional gait analysis. Participants performed the Timed Up and Go (TUG), Five Times Sit-to-Stand (5STS), and Single Limb Mini Squat (SLMS) tests and completed a disease-specific PRO. Associations between gait deviations, PBMs, and PROs were assessed by Pearson's correlation and multiple linear regression. RESULTS: Patients with OA demonstrated significantly lower GDI and GDI-kinetic scores of the OA and contralateral limbs compared to controls; with GDI-kinetic scores on the contralateral limb more impacted than the OA limb. On the contralateral limb, GDI-kinetic score significantly correlated with TUG (r=-0.42) and 5STS (r=-0.33), while on the OA limb with TUG (r=-0.68), 5STS (r=-0.38), SLMS (r=-0.38), activities of daily living (r=0.35) and Knee-related Quality of Life (r=0.35). No significant associations existed between kinematic GDI scores, PBMs and PROs. CONCLUSION: The overall gait pattern, as represented by GDI and GDI-kinetic scores, in patients with symptomatic knee OA is affected both on the painful OA limb and the contralateral limb. The GDI and GDI-kinetic scores provide different information regarding function that is not revealed by PBMs or PROs.

Effect of Intraarticular Corticosteroid Foot Injections on Walking Function in Children With Juvenile Idiopathic Arthritis.

OBJECTIVE: To evaluate gait dynamics and self-reported foot-related disability before and after treatment with intraarticular corticosteroid injections (IACI) in children with juvenile idiopathic arthritis (JIA) and foot involvement, and determined whether children with polyarticular and oligoarticular disease responded similarly to IACI treatment. METHODS: Forty-three children (35 girls and 8 boys) with JIA were consecutively recruited (mean ± SD age 11.1 ± 4.2 years, mean disease duration 4.5 ± 3.6 years). Sixty-five percent were diagnosed with polyarthritis. All children received IACI treatment for ankle and/or foot joint synovitis. Fifty-eight percent received additional injections in the knee and/or hip joint. Forty healthy children, matched by age and sex, comprised the control group. Gait dynamics and foot-related disability were assessed before IACI treatment and at 3 weeks and 3 months following the injections. RESULTS: Foot-related disability and inflammatory joint symptoms improved following treatment. Gait dynamics were compromised before treatment and did not improve following treatment (mean ± SD nondimensional walking speed 0.49 ± 0.05 in the control group; 0.44 ± 0.07 in the JIA group pretreatment; 0.43 ± 0.10 in the JIA group 3 weeks following treatment; and 0.43 ± 0.07 in the JIA group 3 months following treatment) (P = 0.001 in controls versus pretreatment JIA group, P = 0.45 JIA over time). Mean ± SD ankle power was 3.81 ± 0.67 in the control group; 3.01 ± 1.19 in the JIA group pretreatment; 3.19 ± 1.30 in the JIA group 3 weeks after treatment; and 3.22 ± 1.03 in the JIA group 3 months after treatment (P < 0.001 in controls versus pretreatment JIA group, P = 0.51 JIA over time). The ankle power to hip power ratio was reduced (P = 0.01 in controls versus pretreatment JIA group), indicating a power shift from the ankles to the hips, which was more prominent in children with polyarthritis. CONCLUSION: As a result of IACI treatment, improvements were found in self-reported foot-related disability and inflammatory joint symptoms, but gait dynamics were unchanged. Children with polyarticular disease and those with greater self-reported walking difficulties prior to IACI treatment demonstrated worse outcomes, and children in these groups should be monitored carefully after treatment.

Assessment of arm movements during gait in stroke - the Arm Posture Score.

The purpose of the study was to apply the Arm Posture Score (APS) to a stroke population, since comprehensive measures to quantify arm swing in the affected and non-affected arms during gait are lacking. A further aim was to investigate how gait speed and upper limb function estimated by clinical measures are related to the APS in the stroke group. The APS is the summarized root mean square deviation (RMSD) from normal, based on kinematics. Four arm movements (sagittal and frontal planes) as well as six arm movements (incorporating transversal plane) were included in the calculation of APS, referred to as APS4 and APS6, respectively. The study population consisted of 25 persons with stroke and 25 age- and gender-matched controls. The APS measures were significantly different between the affected and non-affected arms, as well as between the affected arm and the non-dominant arm of the controls (p≤0.001). Spasticity significantly influenced both APS measures, while speed only had a significant effect on the APS4. The APS measures correlated significantly to clinical measures of upper limb function. Both APS measures seem to be useful indices to quantify and discriminate between impaired and normal arm swing during gait after stroke. The variability of rotational arm movements needs to be studied further before considering the additional value of the APS6 over the APS4. When interpreting the APS, complementary kinematics should be taken into account, as the single value of the APS gives no information about the direction of the deviation.

Gait deviations in individuals with inflammatory joint diseases and osteoarthritis and the usage of three-dimensional gait analysis.

This chapter describes three-dimensional gait analysis and common gait deviations in adults with rheumatoid arthritis (RA) and osteoarthritis (OA). Furthermore, we describe changes in gait deviations following surgical and non-surgical interventions. Gait analysis is used to define gait deviations and to evaluate varying surgical approaches, types of surgeries and non-pharmacologic interventions. Most studies examine gait in adults with knee OA. Limitations of existing studies include small samples, poor selection of controls, sample heterogenecity, lack of baseline gait assessments and inconsistency in measurement. Across studies, time and distance parameters are generally used to provide a global measure of gait deviations. Individuals with RA and OA in the lower extremities exhibit reduced walking speed/cadence and decreased motion and moments in relation to healthy subjects. Future research should include larger sample sizes, the use of proper controls, pre- and post-assessments and identify gait abnormalities early in the disease process to minimise long-term consequences.

Analytical decomposition can help to interpret ankle joint moment-angle relationship.

Moment-angle relationship (dynamic joint stiffness)--the relationship between changes in joint moment and changes in joint angle--is useful for demonstrating interaction of kinematics and kinetics during gait. However, the individual contributors of dynamic joint stiffness are not well studied and understood, which has thus far limited its clinical application. In this study, ankle dynamic joint stiffness was analyzed and decomposed into three components in thirty able-bodied children during the stance phase of the gait. To verify the accuracy of the decomposition, the sum of decomposed components was compared to stiffness computed from experimental data, and good to very good agreement was found. Component 1, the term associated with changes in ground reaction force moment, was the dominant contribution to ankle dynamic joint stiffness. Retrospective data from eight children with juvenile idiopathic arthritis and idiopathic toe-walking was examined to explore the potential utility of analytical decomposition in pathological gait. Compared to controls, component 1 was the source of highest deviation in both pathological groups. Specifically, ankle dynamic joint stiffness differences can be further identified via two sub-components of component 1 which are based on magnitudes and rates of change of the ground reaction force and of its moment arm, and differences between the two patient groups and controls were most evident and interpretable here. Findings of the current study indicate that analytical decomposition can help identify the individual contributors to joint stiffness and clarify the sources of differences in patient groups.