Influence of Standardized Procedures on the Reliability of Hip Clinical Assessment.

OBJECTIVE: This study evaluated a standardized and personalized approach to verify the effects of conditions on intrarater and interrater reliability, standard error of measurement, and minimal detectable difference for provocative tests and range-of-motion (ROM) tests used in hip pain assessment: flexion-adduction-internal rotation (FADIR), flexion-abduction-external rotation-extension (FABER), and hip internal rotation with 90° of hip flexion (hip IR). METHODS: Nineteen participants (mean [± SD] age = 24 ± 2 years; 10 women and 9 men) without lower limb or back pain were recruited. Three raters evaluated each participant during 2 testing sessions, 1 day apart. Raters performed the 3 tests in 4 conditions: classic (C), controlled pressure duration (CPD), subject-specific position (SSP), and mixed (M = CPD + SSP). RESULTS: For intrarater reliability, the CPD condition showed the highest intraclass correlation coefficients (ICCs; mean and 95% confidence interval [CI]) for hip IRROM (0.83; 95% CI, 0.53-0.94) and FADIRROM (0.75; 95% CI, 0.60-0.89). The SSP condition showed the highest ICCs for FABERheight (0.71; 95% CI, 0.42-0.87) and FABERROM (0.62; 95% CI, 0.27-0.83). Concerning interrater reliability, the classic condition presented the highest ICCs for FABER variables (height: 0.54; 95% CI, 0.28-0.76; ROM: 0.58; 95% CI, 0.32-0.79) and hip IR ROM (0.72; 95% CI, 0.51-0.87). The CPD condition showed the highest ICC for FADIRROM (0.57; 95% CI, 0.32-0.78). CONCLUSION: In the conditions of this study, CPD showed the highest ICCs for hip IRROM and FADIRROM, and SSP showed the highest ICCs for FABERheight and FABERROM.

Quantification and Reliability of Hip Internal Rotation and the FADIR Test in Supine Position Using a Smartphone Application in an Asymptomatic Population.

OBJECTIVE: The purpose of this study was to quantify and report the intrarater and interrater reliability of hip internal rotation (IR) range of motion supine with the hip and knee at 90° of flexion and for the flexion-adduction-internal rotation (FADIR) test. Hip internal rotation measured in a lying supine position with the hip and knee at 90° of flexion revealed information on hip impairments. To date no simple quantification approach has been presented in this position; therefore, the FADIR test has not been quantified yet. METHODS: Twenty participants (mean ± standard deviation [SD] age, 24.0 ± 2.1 years; 10 women and 10 men) without lower-limb or back pain were recruited. Three raters evaluated each participant during 2 testing sessions, 1 day apart. A built-in smartphone compass application was used to obtain the hip IR range of motion in both procedures. RESULTS: Mean (± SD) supine IR was 51.7° (± 9.7°) and 62.6° (± 11.4°) for men and women, respectively. Concerning the FADIR test, mean values were 41.8° (± 9.64°) and 50.1° (± 8.0°) for men and women, respectively. The mean intrarater and interrater reliability coefficients were 0.80 and 0.72 for hip IR and 0.75 and 0.40 for the FADIR test. The standard error of the mean ranged from 4.8° to 8.3° (minimal detectable difference [MDD], 13.3° to 22.9°) for hip IR and from 4.6° to 10.3° (MDD, 12.8° to 28.6°) for the FADIR test. CONCLUSION: Overall, the smartphone compass application is adequate to quantify hip IR in a lying supine position. However, the poor to moderate interrater reliability in the FADIR test and the size of the MDD values suggest that the FADIR test should be standardized.

Quantification of joint alignment and stability during a single leg stance task in a knee osteoarthritis cohort.

BACKGROUND: Knee osteoarthritis alters joint stability but its kinematics during functional weight-bearing tasks remain unclear. We propose and validate an assessment technique for the quantification of knee alignment and stability in patients during a short single leg stance task. METHODS: Three-dimensional knee kinematics were acquired non-invasively from 31 knee osteoarthritis patients (subdivided as moderate or severe) and 15 asymptomatic individuals during six short single-leg stance tasks. Data of participants achieving ≥3 trials were retained. From flexion-extension signals, a data treatment method compared the average between-trial root-mean-square error (RMSE) across trial triplets, and the average within-trial range of movement (RoM) for two data windows. From secondary knee motions (ab/adduction and int/external rotations, anteroposterior and mediolateral translations), we extracted measures characterizing alignments (mean), largest deviations (maximum, minimum), and extent of micro-adjustments (RoM, length of knee excursion). Their sensitivity to disease and severity was determined using an ANOVA, and between-trial repeatability using ICC2,3. RESULTS: Ninety-four percent of patients achieved ≥3 trials. The retained trial triplet and window reduced the RMSE (2.15 to 1.54) and RoM (4.9° to 1.77°) for flexion-extension. Mean, minimum, and maximum measures were sensitive to disease for anteroposterior translations, and to severity for ab/adduction (P < 0.05). High repeatability was found for those measures (ICC ≥0.84). RoM and length of knee excursion, although sensitive to disease for anteroposterior translations, had lower ICC. CONCLUSION: The proposed technique is feasible and exposed measures of knee alignment sensitive to knee osteoarthritis, for instance, an anterior femoral shift and an increased adduction malalignment with greater severity.

Voltage-dependent-anion-channels (VDACs) in Arabidopsis have a dual localization in the cell but show a distinct role in mitochondria.

In mammals, the Voltage-dependent anion channels (VDACs) are predominant proteins of the outer mitochondrial membrane (OMM) where they contribute to the exchange of small metabolites essential for respiration. They were shown to be as well associated with the plasma membrane (PM) and act as redox enzyme or are involved in ATP release for example. In Arabidopsis, we show that four out of six genomic sequences encode AtVDAC proteins. All four AtVDACs are ubiquitously expressed in the plant but each of them displays a specific expression pattern in root cell types. Using two complementary approaches, we demonstrate conclusively that the four expressed AtVDACs are targeted to both mitochondria and plasma membrane but in differential abundance, AtVDAC3 being the most abundant in PM, and conversely, AtVDAC4 almost exclusively associated with mitochondria. These are the first plant proteins to be shown to reside in both these two membranes. To investigate a putative function of AtVDACs, we analyzed T-DNA insertion lines in each of the corresponding genes. Knock-out mutants for AtVDAC1, AtVDAC2 and AtVDAC4 present slow growth, reduced fertility and yellow spots in leaves when atvdac3 does not show any visible difference compared to wildtype plants. Analyses of atvdac1 and atvdac4 reveal that yellow areas correspond to necrosis and the mitochondria are swollen in these two mutants. All these results suggest that, in spite of a localization in plasma membrane for three of them, AtVDAC1, AtVDAC2 and AtVDAC4 have a main function in mitochondria.

Long-term functional outcome of older adults after a traumatic brain injury.

PURPOSE: To identify factors associated with long-term independence in mobility and self-care activities of daily living of older adults after traumatic brain injury (TBI). PARTICIPANTS: One hundred thirty-six TBI survivors 55 years or older were assessed 2 to 4 years postinjury (mean of 3.2 years). SETTING: Level I or level II trauma centers in Quebec, Canada. MAIN MEASURES: Personal, injury-related, and environmental factors were gathered from hospital records or by telephone interview; a telephone version of the Functional Independence Measure motor scale was collapsed to 4 levels. ANALYSIS: Logistic regression analyses identified factors associated with independence in mobility and self-care. RESULTS: The strongest and most consistent factors associated with independence in mobility and self-care were fewer comorbid conditions, no difficulty of access to home modification services and home support services, male gender, younger age at time of injury, and shorter acute care length of stay. CONCLUSION: Factors associated with long-term functional outcome should be considered in the development of practice guidelines for rehabilitation of older adults who sustained a TBI.

Effects of physiotherapy treatment on knee osteoarthritis gait data using principal component analysis.

BACKGROUND: Interpreting gait data is challenging due to intersubject variability observed in the gait pattern of both normal and pathological populations. The objective of this study was to investigate the impact of using principal component analysis for grouping knee osteoarthritis (OA) patients' gait data in more homogeneous groups when studying the effect of a physiotherapy treatment. METHODS: Three-dimensional (3D) knee kinematic and kinetic data were recorded during the gait of 29 participants diagnosed with knee OA before and after they received 12 weeks of physiotherapy treatment. Principal component analysis was applied to extract groups of knee flexion/extension, adduction/abduction and internal/external rotation angle and moment data. The treatment's effect on parameters of interest was assessed using paired t-tests performed before and after grouping the knee kinematic data. FINDINGS: Increased quadriceps and hamstring strength was observed following treatment (P<0.05). Except for the knee flexion/extension angle, two different groups (G(1) and G(2)) were extracted from the angle and moment data. When pre- and post-treatment analyses were performed considering the groups, participants exhibiting a G(2) knee moment pattern demonstrated a greater first peak flexion moment, lower adduction moment impulse and smaller rotation angle range post-treatment (P<0.05). When pre- and post-treatment comparisons were performed without grouping, the data showed no treatment effect. INTERPRETATION: The results of the present study suggest that the effect of physiotherapy on gait mechanics of knee osteoarthritis patients may be masked or underestimated if kinematic data are not separated into more homogeneous groups when performing pre- and post-treatment comparisons.

Test-retest reliability and minimal clinical change determination for 3-dimensional tibial and femoral accelerations during treadmill walking in knee osteoarthritis patients.

OBJECTIVE: To determine the test-retest reliability and the minimal clinical change determination for accelerometric parameters, estimated by a new accelerometric-based method that estimates 3-dimensional (3D) linear accelerations of the tibia and femur during comfortable and fast walking speeds. DESIGN: Test-retest study. SETTING: Gait laboratory in a research center. PARTICIPANTS: Patients (N=25; 6 men, 19 women) with symptomatic knee osteoarthritis (OA). INTERVENTIONS: Not applicable. MAIN OUTCOMES MEASURES: Subjects attended 2 walking sessions in which accelerometers were rigidly fixed by means of an exoskeleton to the femoral and tibial segments. In both sessions, 3D accelerations were collected for 25 seconds for each of the walking speeds. Mean accelerometric pattern was calculated using 15 gait cycles. From each mean pattern, maximal, minimal, and range values were extracted from the loading phase period. The root mean square (RMS) value was also calculated for every pattern. Relative and absolute reliability were determined using intraclass correlation (ICC) and standard error (SE) of measurement, respectively. Minimal detectable change was calculated for each parameter as the least significant difference. RESULTS: Tibial and femoral accelerations showed reliable values across sessions 1 and 2 with ICCs greater than or equal to .75 for 96% and 88% of the parameters at comfortable and fast speeds, respectively. The SE of measurement ranged from .01 to .05g for the RMS value and from .05 to .35g for maximal, minimum, and range point parameters. CONCLUSIONS: The proposed method is the first to have determined the reliability and the minimal detectable change for tibial and femoral acceleration parameters in knee OA patients during a treadmill walking evaluation. The minimal detectable change determined in this study will be used to determine improvement or deterioration of knee OA patients after rehabilitation.

New accelerometric method to discriminate between asymptomatic subjects and patients with medial knee osteoarthritis during 3-d gait.

This study presents a new method to estimate 3-D linear accelerations at tibial and femoral functional coordinate systems. The method combines the use of 3-D accelerometers, 3-D gyroscopes and reflective markers rigidly fixed on an exoskeleton and, a functional postural calibration method. Marker positions were tracked by a six-camera optoelectronic system (VICON 460, Oxford Metrics). The purpose of this study was to determine if this method could discriminate between medial osteoarthritic and asymptomatic knees during gait. Nine patients with osteoarthritic knees and nine asymptomatic control subjects were included in this study. Eighteen parameters representing maximal, minimal, and range of acceleration values were extracted during the loading and preswing to mid-swing phase periods, and were compared in both groups. Results show good discriminative capacity of the new method. Eight parameters were significantly different between both groups. The proposed method has the potential to be used in comprehending and monitoring gait strategy in patients with osteoarthritic knee.

Automatic classification of asymptomatic and osteoarthritis knee gait patterns using kinematic data features and the nearest neighbor classifier.

The aim of this work is to develop an automatic computer method to distinguish between asymptomatic (AS) and osteoarthritis (OA) knee gait patterns using 3-D ground reaction force (GRF) measurements. GRF features are first extracted from the force vector variations as a function of time and then classified by the nearest neighbor rule. We investigated two different features: the coefficients of a polynomial expansion and the coefficients of a wavelet decomposition. We also analyzed the impact of each GRF component (vertical, anteroposterior, and medial lateral) on classification. The best discrimination rate (91%) was achieved with the wavelet decomposition using the anteroposterior and the medial lateral components. These results demonstrate the validity of the representation and the classifier for automatic classification of AS and OA knee gait patterns. They also highlight the relevance of the anteroposterior and medial lateral force components in gait pattern classification.

Constitutive activation of a plasma membrane H(+)-ATPase prevents abscisic acid-mediated stomatal closure.

Light activates proton (H(+))-ATPases in guard cells, to drive hyperpolarization of the plasma membrane to initiate stomatal opening, allowing diffusion of ambient CO(2) to photosynthetic tissues. Light to darkness transition, high CO(2) levels and the stress hormone abscisic acid (ABA) promote stomatal closing. The overall H(+)-ATPase activity is diminished by ABA treatments, but the significance of this phenomenon in relationship to stomatal closure is still debated. We report two dominant mutations in the OPEN STOMATA2 (OST2) locus of Arabidopsis that completely abolish stomatal response to ABA, but importantly, to a much lesser extent the responses to CO(2) and darkness. The OST2 gene encodes the major plasma membrane H(+)-ATPase AHA1, and both mutations cause constitutive activity of this pump, leading to necrotic lesions. H(+)-ATPases have been traditionally assumed to be general endpoints of all signaling pathways affecting membrane polarization and transport. Our results provide evidence that AHA1 is a distinct component of an ABA-directed signaling pathway, and that dynamic downregulation of this pump during drought is an essential step in membrane depolarization to initiate stomatal closure.

Development of a Tool for Analyzing 3D Knee Kinematic Characteristics of Different Daily Activities.

This study provides a basic understanding of the kinematic characteristics of the knee during different daily activities based on a functional knee analyzer, which allows a three-dimensional evaluation of the knee in motion. The results showed that there was significant difference in knee motion between the patients with knee osteoarthritis (OA) and normal subjects during lunging, squatting and no weight-bearing knee flexion-extension. The data obtained by the knee analyzer was sensitive enough to distinguish young and middle-aged subjects from OA subjects during different daily activities; squatting gave the best results. On the other hand, the OA and elderly subjects had similar knee flexion and adduction angle profiles. This founding may partially explain the increased prevalence of OA in elderly people. The results support the use of functional knee analyzer for biomechanical analysis of daily activities, especially squatting, as a clinical evaluation tool for patients with knee osteoarthritis.

The Arabidopsis genome sequence as a tool for genome analysis in Brassicaceae. A comparison of the Arabidopsis and Capsella rubella genomes.

The annotated Arabidopsis genome sequence was exploited as a tool for carrying out comparative analyses of the Arabidopsis and Capsella rubella genomes. Comparison of a set of random, short C. rubella sequences with the corresponding sequences in Arabidopsis revealed that aligned protein-coding exon sequences differ from aligned intron or intergenic sequences in respect to the degree of sequence identity and the frequency of small insertions/deletions. Molecular-mapped markers and expressed sequence tags derived from Arabidopsis were used for genetic mapping in a population derived from an interspecific cross between Capsella grandiflora and C. rubella. The resulting eight Capsella linkage groups were compared to the sequence maps of the five Arabidopsis chromosomes. Fourteen colinear segments spanning approximately 85% of the Arabidopsis chromosome sequence maps and 92% of the Capsella genetic linkage map were detected. Several fusions and fissions of chromosomal segments as well as large inversions account for the observed arrangement of the 14 colinear blocks in the analyzed genomes. In addition, evidence for small-scale deviations from genome colinearity was found. Colinearity between the Arabidopsis and Capsella genomes is more pronounced than has been previously reported for comparisons between Arabidopsis and different Brassica species.