Good Inter-session Reliability Research Articles

Original article: Validity and reliability of gait metrics derived from researcher-placed and self-placed wearable inertial sensors

To compare the inter-session placement reliability for researcher-placed and self-placed sensors, and to evaluate the validity and reliability of waveforms and discrete variables from researcher-placed and self-placed sensors following a previously described alignment correction algorithm. Fourteen healthy, pain-free participants underwent gait analysis over two data collection sessions. Participants self-placed an inertial sensor on their left tibia and a researcher placed one on their right tibia, before completing 10 overground walking trials. Following an axis correction from a principal component analysis-based algorithm, validity and reliability were assessed within and between days for each sensor placement type through Euclidean distances, waveforms, and discrete outcomes. The placement location of researcher-placed sensors exhibited good inter-session reliability (ICC = 0.85) in comparison to self-placed sensors (ICC = 0.55). Similarly, waveforms from researcher-placed sensors exhibited excellent validity across all variables (CMC ≥ 0.90), while self-placed sensors saw high validity for most axes with reductions in validity for mediolateral acceleration and frontal plane angular velocity. Discrete outcomes saw good to excellent reliability across both sensor placement types. A simple alignment correction algorithm for inertial sensor gait data demonstrated good to excellent validity and reliability in self-placed sensors with no additional data or measures. This method can be used to align sensors easily and effectively despite sensor placement errors during straight, level walking to improve 3D gait data outcomes in data collected with self-placed sensors.

Test-retest reliability of wireless inertial-sensor derived measurements of knee joint kinematics.

Advances in sensor technology have provided an opportunity to measure gait characteristics using body-worn inertial measurement units (IMUs). Whilst research investigating the validity of IMUs in reporting gait characteristics is extensive, research investigating the reliability of IMUs is limited. This study aimed to investigate the inter-session reliability of wireless IMU derived measures of gait (i.e., knee angle, range of motion) taking multiple test administrators into account. Fifteen healthy volunteers (43 ± 15 years) completed two visits. Within each visit, participants were required to perform two sets of 6 gait trials (6-metre walk tests). IMUs were placed on the participant in 7 locations on the lower limbs and waist. A different test administrator (n = 3) applied the IMUs at each set. At visit 2, this procedure was repeated with the same test administrators as visit 1. Kinematic measures of maximum angle (Knee_Max), minimum angle (Knee_Min), and range of motion (RoM) are reported for the left and right knee. The intraclass correlation coefficients (ICC), standard error of measurement (SEM) and minimum detectable change (MDC) are reported to determine IMU reliability. The results confirmed moderate to good inter-session reliability across all features (0.73-0.87). SEM values ranged from 1.21-3.32° and MDC values ranged from 3.37 - 9.21°. Therefore, IMUs appear to be a reliable method to determine inter-session gait characteristics across multiple test administrators.

Reliability and agreement of a dynamic quadriceps incremental test for the assessment of neuromuscular function

The quadriceps-intermittent-fatigue (QIF) test assesses knee extensors strength, endurance and performance fatigability in isometric condition. We aimed to assess reliability and agreement for this test in dynamic conditions and with the use of transcranial magnetic stimulation. On two separate sessions, 20 young adults (25 ± 4 yr, 10 women) performed stages of 100 knee extensors concentric contractions at 120°/s (60° range-of-motion) with 10% increments of the initial maximal concentric torque until exhaustion. Performance fatigability across the test was quantified as maximal isometric and concentric torque loss, and its mechanisms were investigated through the responses to transcranial magnetic and electrical stimulations. Reliability and agreement were assessed using ANOVAs, coefficients of variation (CVs) and intra-class correlation coefficients (ICCs) with 95% CI. Good inter-session reliability and high agreement were found for number of contractions [489 ± 75 vs. 503 ± 95; P = 0.20; ICC = 0.85 (0.66; 0.94); CV = 5% (3; 7)] and total work [11,285 ± 4,932 vs. 11,792 ± 5838 Nm.s; P = 0.20; ICC = 0.95 (0.87; 0.98); CV = 8% (5; 11)]. Poor reliability but high agreement were observed for isometric [–33 ± 6 vs. −31 ± 7%; P = 0.13; ICC = 0.47 (0.05; 0.75); CV = 6% (4;8)] and concentric [−20 ± 11% vs. −19 ± 9%; P = 0.82; ICC = 0.26 (−0.22; 0.63); CV = 9% (6; 12)] torque loss. The dynamic QIF test represents a promising tool for neuromuscular evaluation in isokinetic mode.

Dermal thickness and echogenicity using DermaScan C high frequency ultrasound: Methodology and reliability testing in people with and without primary lymphoedema.

DermaScan C high frequency ultrasound was investigated for image capture and analysis of dermal measures in people with and without primary lymphoedema. Three repeated images were taken at six sites in people without lymphoedema (NLO). Intra-rater reliability was assessed by taking three sets of measures on images from 10 people and inter-session reliability by capturing three images, lifting the probe from the skin in between. Methods were adjusted, and repeated images from four sites were taken in people with primary lymphoedema (PLO) and reliability re-assessed. Intra-rater reliability in NLO and PLO for echogenicity measures were excellent (NLO ICC(3,1) : .989; PLO .997) across all sites and specific to each site (calf: ICC(3,1) : .989; and foot: ICC(3,1) : .999, respectively). Inter-session reliability was moderate for NLO (ICC(3,1) : .727), improving after method modifications for PLO (ICC(3,1) : .916). When investigated by site, inter-session reliability was good in the foot (ICC(3,1) : .811) and moderate in the calf (ICC(3,1) : .616). Mean thickness analysed by site resulted in good inter-session reliability only in the foot (ICC(3,1) .838). Intra-rater reliability was excellent using the DermaScan C for dermal measures in people with primary lymphoedema. Inter-session reliability required particular attention to method and gain settings.

Reliability of Change of Direction and Agility Assessments in Youth Soccer Players.

Considering the vast physical and neural developments experienced throughout adolescence, the reliability of physical performance may vary in youth populations. This study aimed to examine the reliability of change of direction (COD) and agility tests in youth soccer players. Altogether, 86 youth soccer players, aged 13.6 ± 2.0 years, volunteered to participate. Data were collected from a modified 505 COD test (m505COD) and the Y-sprint drill in both pre-planned (Y-SprintPRE) and reactive (Y-SprintREACT) conditions during 2 sessions, 7 days apart. Anthropometric data including body mass, standing stature, and sitting height were also collected. COD and agility tests demonstrated good reliability (ICC = 0.81–0.91; CV = 1.2–2.0; d = 0.00–0.31; p < 0.01) for our entire sample. However, we observed a small negative relationship between age and intersession differences for the Y-SprintPRE (r = −0.28; p = 0.04), and moderate negative relationships between both age (r = −0.41; p < 0.01), and maturity offset (r = −0.39; p < 0.01) for the Y-SprintREACT. Although the COD and agility tests adopted within this study possess good intersession reliability, we observed greater intersession differences for younger and less mature individuals. We suggest that while COD and agility tests may provide meaningful objective data for monitoring the development of youth soccer players, these tests should be used with caution when evaluating younger, more immature athletes.

Reproducibility of amygdala activation in facial emotion processing at 7T

Despite its importance as the prime method for non-invasive assessment of human brain function, functional MRI (fMRI) was repeatedly challenged with regards to the validity of the fMRI-derived brain activation maps. Amygdala fMRI was particularly targeted, as the amygdala’s anatomical position in the ventral brain combined with strong magnetic field inhomogeneities and proximity to large vessels pose considerable obstacles for robust activation mapping.In this high-resolution study performed at ultra-high field (7T) fMRI, we aimed at (1) investigating systematic replicability of amygdala group-level activation in response to an established emotion processing task by varying task instruction and acquisition parameters and (2) testing for intra- and intersession reliability.At group-level, our results show statistically significant activation in bilateral amygdala and fusiform gyrus for each of the runs acquired. In addition, while fusiform gyrus activations are consistent across runs and sessions, amygdala activation levels show habituation effects across runs. This amygdala habituation effect is replicated in a session repeated two weeks later. Varying task instruction between matching emotions and matching persons does not change amygdala activation strength. Also, comparing two acquisition protocols with repetition times of either 700 ​ms or 1400 ​ms did not result in statistically significant differences of activation levels.Regarding within-subject reliability of amygdala activation, despite considerable variance in individual habituation patterns, we report fair to good inter-session reliability for the first run and excellent reliability for averages over runs.We conclude that high-resolution fMRI at 7T allows for robust mapping of amygdala activation in a broad range of variations. Our results of amygdala 7T fMRI are suitable to inform methodology and may encourage future studies to continue using emotion discrimination paradigms in clinical and non-clinical applications.

The validity and reliability of the Vail Sport Test™ as a measure of performance following anterior cruciate ligament reconstruction

ObjectivesTo determine the validity and inter-session reliability of the Vail Sport Test™. DesignCohort study-exploratory methodological research design. SettingClinical Research Laboratory. ParticipantsForty-eight participants who underwent ACL-R. Main outcome measureParticipants performance on the Vail Sport Test™ was graded by an experienced rater in real-time, and simultaneously recorded by a three-dimensional (3D) motion capture system. Construct validity was assessed using the reference standards of the camera system and the IKDC short form. To determine the between-day reliability, a subset of participants returned to repeat the test. ResultsThere were no significant difference between the scores collected in real-time and from the kinematic data on the involved limb (p = 0.222). There was a significant difference for the uninvolved limb (p = 0.015). There was no significant difference between the scores collected in real time and those of the IKDC (p = 0.885). Good inter-session reliability (ICC = 0.787) was found for the involved limb. ConclusionThe results of this study showed good reliability and partially support the validity of the Vail Sport Test as a measure of readiness to return to play.

Intra-session and inter-session reliability of electromyography in leg extension during maximum voluntary isometric contractions of quadriceps: The effect of knee angle

Numerous factors can influence the reliability of the signal obtained by electromyography EMG among which the type of contraction is practically fundamental. This study aimed to investigate intra- and inter-session reliability of EMG for maximal voluntary isometric contraction (MVIC) of the knee extensors at different joint angles. Nine healthy male students from the Faculty of Sport and Physical Education voluntarily joined the experiment. Main characteristics of the subjects were: age 23±1 years, body weight 80.8±7.8 kg and body height 182±7 cm. EMG signal from three surface heads of quadriceps femoris was recorded - vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF). Subjects had to perform 3 MVIC as fast as possible, as strong as possible at 6 different knee joint angles on 2 occasions separated by 7-8 days. The intra-class coefficient of correlation (ICC) was used to identify relative intra- and inter-session reliability, while standard error of measurement (SEM) was used to calculate the absolute reliability of each tested muscle. All muscles showed high intra-session reliability (ICC=0.488-0.988 and SEM=1.38-11.35). VL showed good inter-session reliability for most of the conditions (ICC=0.603-0.948), VM for two knee angles (ICC120°=0.764 and ICC130°=0.788), RF was not reliable for any knee angle. This study indicates that RF does not need to be used in EMG testing in leg extension MVIC due to lack of reliability between two sessions, and If EMG RMS from VL and VM will be tested, knee angle of 120° should be used for the testing.

Reliability of Noncontact Pachymetry after Laser In Situ Keratomileusis

To assess the repeatability and reproducibility of central corneal thickness (CCT) measurements obtained by combined scanning-slit/Placido-disc topography (Orbscan II; Bausch & Lomb, Rochester, NY) after laser in situ keratomileusis (LASIK) and to compare the results with another noncontact method, specular microscopy (SP-2000P; Topcon, Tokyo, Japan). To analyze intrasession repeatability, one examiner measured 22 postmyopic LASIK eyes 10 times successively in the shortest time possible, using both devices randomly. To study intersession reproducibility, the same operator obtained measurements from another 50 eyes with stable refraction in two consecutive visits at the same time of the day between 6 and 9 months after myopic LASIK. Any association between residual stromal bed thickness and measurement variability was recorded and evaluated. For intrasession repeatability, Orbscan II and Topcon SP-2000P CCT measurements showed a repeatability of 20.2 (4.3%) and 12.8 (2.6%) microm, respectively. Both devices yielded excellent intraclass correlation coefficients (ICC; 0.98 and 0.99, respectively). For intersession reproducibility, no difference in CCT measurements was found. The coefficient of intersession reproducibility were 6.7% (29.5 microm) for Orbscan II and 4.3% (19.5 microm) for Topcon SP-2000P CCT measurements. The ICCs (0.95 and 0.96, respectively) indicated good intersession reliability. Repeatability and reproducibility with both devices were unrelated to stromal bed thickness. Both noncontact pachymeters provide repeatable CCT measurements in transparent postmyopic LASIK corneas after the early postoperative period. Intersession variations in CCT of more than 29 microm with the Orbscan II and 19 microm with the Topcon SP-2000P may reflect true corneal change. These estimates should help investigators and clinicians differentiate actual CCT modification from measurement variability.

Repeatability and Reproducibility of Posterior Corneal Curvature Measurements by Combined Scanning-Slit and Placido-Disc Topography after LASIK

To assess the repeatability and reproducibility of posterior corneal curvature (PCC) measurements made by combined scanning-slit/Placido-disc topography (Orbscan II) after LASIK. Experimental instrument validation study. We recruited 22 consecutive postmyopic LASIK patients for the repeatability study and another 50 consecutive postmyopic LASIK patients for the reproducibility study. To analyze intrasession repeatability, 1 examiner measured 22 postmyopic LASIK eyes 10 times successively in the shortest time possible. To study intersession reproducibility, the same operator obtained measurements from another 50 eyes with stable refraction in 2 consecutive visits at the same time of the day between 6 and 9 months after myopic LASIK. We explored any association between residual stromal bed thickness and measurement variability. Orbscan II scanning-slit PCC data, precision, within-subject coefficient of variation (CV(w)), limits of agreement (LoA), and intraclass correlation coefficient (ICC). For intrasession repeatability, precision was 0.067 mm (best-fit sphere [BFS]), 0.110 diopters (D; power within 5 mm), 0.158 D (power within 3 mm), and 0.46 (eccentricity). Repeatability was high for PCC BFS and power measurements within 3-mm and 5-mm zones (CV(w) ranged from 0.5%-1.2%) but poor for eccentricity data (CV(w), 31.6%). Correspondingly, ICCs ranged from 0.89 to 0.98 for PCC BFS and power, and the ICC was 0.20 for PCC eccentricity values. For intersession reproducibility, on average, no difference in PCC measurements could be found, indicating that when there is variability, it is due to random factors. The width of the 95% LoA between sessions was clinically acceptable for BFS (0.25 mm) and power (0.4 D [within 5 mm] and 0.6 D [within 3 mm]). Similarly, ICCs indicated good intersession reliability for BFS and power (0.98, 0.96, and 0.85 for BFS, power within 5 mm, and power within 3 mm, respectively) but poor reliability for eccentricity (0.59). Repeatability and reproducibility were unrelated to stromal bed thickness. Orbscan II provides reliable post-LASIK PCC data for symmetrical parameters (BFS and power), independent of the residual stromal bed thickness, but is unreliable for measurements that are radially asymmetrical (eccentricity). Orbscan II is useful for monitoring the PCC after LASIK once the early postoperative period is over.

Test–retest reliability of balance tests in children with cerebral palsy

To investigate intrasession and intersession reliability of balance tests in children with or without disabilities, 50 children without disabilities (ND) and 36 children with cerebral palsy (CP) aged from 5 to 12 years were tested. Intrasession reliability of postural stability of the Smart Balance Master System and one-leg standing test were assessed in both groups and intersession reliability of the Smart Balance Master System and balance subtest of the Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) were assessed in ND children. Intersession reliability of the postural stability test in ND children, obtained using the Smart Balance Master System, was of moderate to good reliability in centre target (CT), sway vision (SV), eyes open and sway surface (EOSS), and sway vision and sway surface (SVSS; ICC 0.72 to 0.84). In children with CP, intrasession reliability was high in CT (ICC 1). One-leg standing tests in both groups also had moderate to good intersession reliability (ICC 0.56 to 0.99). Agreement of failure score of lateral rhythmic shifting (LRS) at 1 second and 2 seconds pace was 85% and 93% respectively in ND children. Within the balance subtest of BOTMP, only two items had 100% agreement. Results suggest that postural stability tests in four conditions (CT, SV, EOSS, and SVSS), LRS, one-leg standing, and walking on a line are reliable and can be used to monitor balance control in ND children. Postural stability in CT condition and one-leg standing test are reliable in children with CP. Further study is needed to establish more reliable balance tests for children with CP.

Reliability of individual differences in initial sensitivity and acute tolerance to nitrous oxide hypothermia

On average, the hypothermia exhibited by rats receiving 60% nitrous oxide (N 2O) eventually abates despite the continued inhalation of the drug (i.e., acute tolerance develops). However, large individual differences occur in both the magnitude of hypothermia achieved and the degree of acute tolerance that develops. To determine whether the degree of temperature loss and subsequent recovery during N 2O administration are reliable characteristics of an individual, we measured intraperitoneal temperature via telemetry in 77 Long–Evans rats that each received 60% N 2O for 5 h during two sessions separated by 14 days. Good intersession reliability (Pearson's r) was observed for simple change and adjusted change scores for both initial N 2O temperature sensitivity (.61≤ r≤.62), and acute tolerance development (.46≤ r≤.52). In a separate experiment, three groups of rats were selected based on their individual body temperature patterns during an initial N 2O administration: (1) insensitive to N 2O hypothermia ( n=8); (2) marked hypothermia followed by acute tolerance development ( n=6); and (3) marked hypothermia followed by little acute tolerance development ( n=6). When retested 10 days later, each group exhibited a body temperature profile similar to that observed during the initial N 2O exposure. Thus, the temperature profile observed during a rat's initial exposure to 60% N 2O reflects a reproducible response for that animal.

Test‐retest reliability of balance tests in children with cerebral palsy

To investigate intrasession and intersession reliability of balance tests in children with or without disabilities, 50 children without disabilities (ND) and 36 children with cerebral palsy (CP) aged from 5 to 12 years were tested. Intrasession reliability of postural stability of the Smart Balance Master System and one‐leg standing test were assessed in both groups and intersession reliability of the Smart Balance Master System and balance subtest of the Bruininks‐Oseretsky Test of Motor Proficiency (BOTMP) were assessed in ND children. Intersession reliability of the postural stability test in ND children, obtained using the Smart Balance Master System, was of moderate to good reliability in centre target (CT), sway vision (SV), eyes open and sway surface (EOSS), and sway vision and sway surface (SVSS; ICC 0.72 to 0.84). In children with CP, intrasession reliability was high in CT (ICC 1). One‐leg standing tests in both groups also had moderate to good intersession reliability (ICC 0.56 to 0.99). Agreement of failure score of lateral rhythmic shifting (LRS) at 1 second and 2 seconds pace was 85% and 93% respectively in ND children. Within the balance subtest of BOTMP, only two items had 100% agreement. Results suggest that postural stability tests in four conditions (CT, SV, EOSS, and SVSS), LRS, one‐leg standing, and walking on a line are reliable and can be used to monitor balance control in ND children. Postural stability in CT condition and one‐leg standing test are reliable in children with CP. Further study is needed to establish more reliable balance tests for children with CP.