Intersession Reliability Research Articles

Test–retest reliability of subjective supra-threshold scaling of multiple pressure-pain sensations among healthy individuals: a study using hydraulic pressure algometry

Background: Supra-threshold scaling of multiple pressure-pain sensations involves delivery of varied stimulus intensities, either via stimulus-dependent or response-dependent manner, and recording of subjective pain ratings by participants. The focus of this study was to determine the intra- and inter-session reliability of pain intensity and pain unpleasantness ratings related to pressure-pain thresholds (PPTs) of just noticeable pain (JNP), weak pain (WP) and moderate pain (MP) among healthy individuals.Methods: Fourteen healthy participants (eight women, six men) participated in three sessions of testing at varied intervals over the course of 72 h. In session one, a multiple random staircase method using hydraulic pressure algometry was used to measure PPT of JNP, WP and MP on thumbnail bed. In session 2, ratings of pain intensity and pain unpleasantness were recorded when stimuli at levels corresponding to PPT of JNP, WP and MP were repeatedly applied before and after 20 min of no intervention.Results: Interclass correlation coefficient (ICC) values for pain ratings of JNP, WP and MP in intra-session reliability were 0.810, 0.826 and 0.881, respectively, whereas the values were 0.817, 0.792 and 0.910, respectively, for inter-session reliability. ICC values for pain unpleasantness were also highly consistent and repeatable. Temporal summation of pain intensity and pain unpleasantness were not related to the repeated application of pressure stimuli.Conclusions: The findings indicate that the pain intensity and pain unpleasantness ratings for stimuli at levels equal to the thresholds of JNP, WP and MP have good intra- and inter-session reliability.Significance: This study showed that both pain intensity and pain unpleasantness of JNP, WP and MP have good intra- and inter-session reliability and agreement. Furthermore, the temporal summation of pain or unpleasantness is not related to repeated application of pressure stimuli.Abbreviations: JNP: Just noticeable pain; WP: Weak pain; MP: Moderate pain; PPTs: pressure-pain thresholds; HPA: Hydraulic pressure algometry; MRSM: multiple random staircase method

The validity and reliability of the Swaymeter for postural sway measurement in typically developing children aged between 7–12 years

BackgroundThe Swaymeter is a simple devicefor measuring postural sway. It consists of a 40-cm-long rod with a vertically mounted pen at the end of the rod that measures the displacement of the body at waist level. Research questionThis device could be an effective tool for measuring postural sway in children. However, the validity and reliability of the Swaymeter in children has not been evaluated. In this study, we aimed to evaluate the validity and reliability of the Swaymeter in typically developing children aged 7–12 years. MethodThe Swaymeter procedure was randomly measured in quiet bipedal stance under 4 conditions: eyes open and eyes closed on the floor, eyes open and eyes closed on foam, 30 s were performed in each condition. There were 15 children participated in the validity study. The postural sway was measured concurrently with the motion capture system with two reflective markers on the top of the pen and 12th thoracic vertebra level in three trials with four testing conditions. Additionally, 36 children participated in test-retest reliability. Three measurements were performed on the same day and one week later. ResultsSwaymeter had a moderate to good correlation with motion capture system (r = 0.637–0.979). The test-retest reliability of the Swaymeter showed moderate to good reliability for immediate test-retest (ICC = 0.51–0.87). However, inter-session reliability revealed moderate to good reliability except for the AP variable that showed low reliability. Good to excellent reliability was found in sway area variable (ICCs between 0.74 and 0.92) for all measurements. SignificancePostural sway measure by Swaymeter was valid and reliable in typically developing children aged 7–12 years and suitable for applying to assess postural sway in typically developing children.

The effect of transcranial magnetic stimulation test intensity on the amplitude, variability and reliability of motor evoked potentials

High degrees of variability reported in Transcranial magnetic stimulation (TMS) assessment of corticospinal excitability (CSE) highlight the need to investigate its reliability as an assessment tool. This study investigated the effect of TMS test intensity on the amplitude, variability and test-retest reliability of motor evoked potentials (MEP). Twenty-five MEPs were recorded at 105%, 120%, 135%, 150% and 165% of resting motor threshold across three sessions in twelve participants. Repeated measures analysis of variance (RM-ANOVA), recruitment curve gradients and standardised z-value SDs were utilized to investigate the effect of TMS test intensity on MEP amplitude and variability. Test-retest reliability of MEP amplitude was assessed using RM-ANOVA and intraclass correlations (ICC). RM-ANOVA reported MEP amplitude significantly increased between 105–120% and 120–135% with non-significant increases thereafter. Recruitment curve gradients reduced as TMS test intensity increased. Standardised z-value SDs reported MEP amplitude variability reduced as TMS test intensity increased with the only significant reduction occurring between 120% and 135%. RM-ANOVA reported no significant effect of time on MEP amplitude, indicating agreement between sessions. ICCs indicated significant intra- and inter-session reliability for all TMS test intensities except for 105%. The only significant reduction in variability and final significant increase in MEP amplitude occurred between the same TMS test intensities. Reduced variability and increased reliability at higher TMS test intensities validate the use of higher TMS test intensities to assess changes in CSE in future research. To increase accuracy in capturing true changes in CSE we recommend assessing changes in CSE across a range of TMS test intensities.

Short Term Test-Retest Reliability of Contralateral Inhibition of Distortion Product Otoacoustic Emissions.

Background and ObjectivesStrength of medial olivocochlear reflex can be measured reliably using contralateral inhibition of distortion product otoacoustic emissions (DPOAEs) when its fine structure is considered. However, measurement of fine structure of DPOAE is difficult with clinical equipment. Thus, this study investigated the clinically relevant test-retest reliability of contralateral inhibition of DPOAEs.Subjects and MethodsTwenty-six young adults with normal hearing sensitivity participated. DPOAEs were recorded at 27 discrete f2 frequencies between 800 Hz and 8,000 Hz at frequency resolution of 8 points per octave with and without contralateral white noise presented at 50 dB SPL. To check for short term inter-session reliability, contralateral inhibition of DPOAEs were recorded in three sessions, two recording sessions on first day separated by 30 minutes and third time after one week of the first session. Within each session, DPOAEs were recorded twice in single probe-fit condition to test for intra-session reliability.ResultsCronbach’s alpha was calculated having poor reliability (α≤ 0.7) of contralateral inhibition of DPOAEs in both intra-session and inter-session conditions for most of the tested frequencies. 95% confidence intervals of contralateral inhibition magnitude also showed large variability.ConclusionsThe current results showed that though DPOAE amplitudes were highly reliable across sessions, amount of inhibition of DPOAEs was not reliable when DPOAEs were measured at discrete frequencies. These findings are concurrent with the literature.

Comfort assessment of running footwear: Does assessment type affect inter-session reliability?

Assessing comfort of running footwear reliably is challenging. The purpose of this study was to compare the intra-rater reliability between different assessment types, to calculate intra-individual reliability scores and to evaluate the effect of rater selection based on individual reliability scores on group level reliability. Three assessment types: ranking, Visual Analogue Scale (VAS), and Likert Scale (LS) were provided twice in six separate sessions among 30 participants, who assessed comfort of five shoes after treadmill running. Spearman's rho provided an evaluation of inter-session relative reliability and typical error as a measure of absolute reliability for each assessment type. Ranking (r = 0.70, 95% confidence interval [CI] 0.61–0.78) yielded the highest relative reliability for overall comfort, followed by VAS (r = 0.67, 95% CI 0.56–0.75) and LS (r = 0.63, 95% CI 0.52–0.72), with large-scale overlaps of CIs between assessment types. The same order of assessment types was found for the percentage of reliable raters (r ≥ 0.7) with 60% in ranking scale, 47% in VAS and 37% in LS. Forming subgroups corresponding to the intra-individual reliability substantially increased group level reliabilities. Based on measures of relative reliability, an extreme reduction in resolution as provided by the ranking from pairwise comparisons seems to be a valuable tool in footwear comfort assessments if assessment time is of minor importance. No preference can be provided for the two investigated rating scales. Besides the assessment type, a selection of the best raters in additional reliability checks seems to be a prerequisite for further comfort-related studies.

Difference in medial gastrocnemius mechanical properties between paretic and non-paretic legs in children with unilateral cerebral palsy

Children with spastic unilateral cerebral palsy (CP) present very early in childhood alterations in gastrocnemius muscle structural and mechanical properties that can be non-invasively investigated through 2D ultrasonography (US). To gain knowledge about spastic muscle properties during ankle mobilization, the purpose of this study was to assess gastrocnemius medialis (GM) muscle passive stiffness and strain during ankle mobilization in both paretic and non-paretic legs in children with unilateral CP. Thirteen children (6- to 12-year-old) with unilateral spastic CP, participated in two sessions of measurements with a one-week interval. Children were installed prone on an isokinetic dynamometer while their ankle was passively mobilized from 25° plantarflexion to maximal dorsiflexion at 2°/s. EMG activity was monitored to ensure complete relaxation. Displacement of the musculo-tendinous junction (MTJ) was recorded with US during mobilization and was synchonized with passive torque. GM stiffness was then calculated as the slope of the torque/MTJ displacement relationship. GM strain was calculated as the GM excursion divided by GM resting length (measured at neutral position with simple US tape method). Inter-session reliability was assessed with the measurement of coefficient of variation (CV) between both experimental sessions. GM stiffness was higher for the paretic leg than for the non-paretic one (4.2 vs. 3 Nm/cm; P = 0.025). When considered on the same angular range (i.e. −25° plantarflexion to maximal dorsiflexion angle on paretic leg), GM strain was similar between both legs ( P = 0.43). Inter-session reliability of GM stiffness (9.75% ≤ CV ≤ 10.67%), strain (CV ≤ 9.97%) and length (CV ≤ 7.5%) were good. Spastic GM muscle lengthening during ankle mobilization was characterized by an increased stretch resistance when compared to non-paretic muscle despite similar passive GM strain between both legs. This may be due to altered spastic GM growth during childhood, characterized by reduced GM paretic length.

Difference in medial gastrocnemius mechanical properties between paretic and non-paretic legs in children with unilateral cerebral palsy

Children with spastic unilateral cerebral palsy (CP) present very early in childhood alterations in gastrocnemius muscle structural and mechanical properties that can be non-invasively investigated through 2D ultrasonography (US). To gain knowledge about spastic muscle properties during ankle mobilization, the purpose of this study was to assess gastrocnemius medialis (GM) muscle passive stiffness and strain during ankle mobilization in both paretic and non-paretic legs in children with unilateral CP. Thirteen children (6- to 12-year-old) with unilateral spastic CP, participated in two sessions of measurements with a one-week interval. Children were installed prone on an isokinetic dynamometer while their ankle was passively mobilized from 25° plantarflexion to maximal dorsiflexion at 2°/s. EMG activity was monitored to ensure complete relaxation. Displacement of the musculo-tendinous junction (MTJ) was recorded with US during mobilization and was synchonized with passive torque. GM stiffness was then calculated as the slope of the torque/MTJ displacement relationship. GM strain was calculated as the GM excursion divided by GM resting length (measured at neutral position with simple US tape method). Inter-session reliability was assessed with the measurement of coefficient of variation (CV) between both experimental sessions. GM stiffness was higher for the paretic leg than for the non-paretic one (4.2 vs. 3 Nm/cm; P = 0.025). When considered on the same angular range (i.e. −25° plantarflexion to maximal dorsiflexion angle on paretic leg), GM strain was similar between both legs ( P = 0.43). Inter-session reliability of GM stiffness (9.75% ≤ CV ≤ 10.67%), strain (CV ≤ 9.97%) and length (CV ≤ 7.5%) were good. Spastic GM muscle lengthening during ankle mobilization was characterized by an increased stretch resistance when compared to non-paretic muscle despite similar passive GM strain between both legs. This may be due to altered spastic GM growth during childhood, characterized by reduced GM paretic length.

Test-retest reliability of clitoral blood flow measurements using color Doppler ultrasonography at rest and after a pelvic floor contraction task in healthy adult women.

Test-retest reliability assessment of the dorsal clitoral artery's blood flow at rest and after muscle activation has never been documented. If this outcome measure is to be used in conditions impeding vascularity, it requires a psychometric evaluation. The aim of this study was to assess the inter-session test-retest reliability of clitoral blood flow in healthy women using color Doppler ultrasonography at rest and after a pelvic floor muscle (PFM) contraction task. Two assessment sessions were conducted using a clinical ultrasound system. Clitoral blood flow measurements were repeated at rest and after a PFM contraction task. Measurements of the peak systolic velocity (PSV), time-averaged maximum velocity (TAMX), end-diastolic velocity (EDV), pulsatility index (PI), and resistance index (RI) were taken. The test-retest reliability was assessed using paired t-test, intraclass correlation coefficient (ICC), and Bland-Altman plots. For reliability at rest, ICC values were 0.95 for PSV, 0.87 for TAMX, and 0.67 for both PI and RI. The variability between measurements, as per Bland-Altman plots, was small for PSV, TAMX, and RI and acceptable for PI. For reliability after the PFM contractions task, ICC values were 0.85 for PSV, 0.77 for TAMX, 0.79 for PI, and 0.81 for RI. The variability between measurements was small for PSV and RI and acceptable for TAMX and PI. EDV parameter did not perform as well in both conditions. Assessment of the clitoral blood flow with color Doppler ultrasound is reliable at rest and after a PFM contraction task.

Investigating the Intersession Reliability of Dynamic Brain-State Properties.

Dynamic functional connectivity metrics have much to offer to the neuroscience of individual differences of cognition. Yet, despite the recent expansion in dynamic connectivity research, limited resources have been devoted to the study of the reliability of these connectivity measures. To address this, resting-state functional magnetic resonance imaging data from 100 Human Connectome Project subjects were compared across 2 scan days. Brain states (i.e., patterns of coactivity across regions) were identified by classifying each time frame using k means clustering. This was done with and without global signal regression (GSR). Multiple gauges of reliability indicated consistency in the brain-state properties across days and GSR attenuated the reliability of the brain states. Changes in the brain-state properties across the course of the scan were investigated as well. The results demonstrate that summary metrics describing the clustering of individual time frames have adequate test/retest reliability, and thus, these patterns of brain activation may hold promise for individual-difference research.

Validity of the Kinect and Myo armband in a serious game for assessing upper limb movement

A cost-effective, easily-accessible neuro-motor rehabilitation solution is proposed that can determine the range of motion and the kinematic ability of participants. A serious game comprising four-scenarios are developed in which the players control an avatar that mirrors the rotations of the upper-limb joints through multi-channel-input devices (Kinect, Myo, FootPedal). Administered functional reach tests (FRT) challenge the player to interact with a 3D-environment while standing or sitting and using the FootPedal which simulates the action of walking whilst body movement is measured concurrently. The FRT’s complexity level is adapted using a Monte Carlo Tree Search algorithm which determines a virtual object’s position based on the proved ability of the user. Twenty-three volunteers were recruited to play the game in 45-min sessions. The data show that the system has a more positive impact on players performance and is more motivating than formal therapy. The visual representation of the trajectory of the objects is shown to increase the perception of the participants voluntary/involuntary upper extremity movement, and the results show a comparable inter-session reliability (acceptable-good) over two repeated sessions. A high Pearson correlation demonstrates the validity of using Kinect and Myo devices in assessing upper-limb rehabilitation, and the timing and the clinically relevant movement data have a higher accuracy when the devices are paired.

Reliability of the Star Excursion Balance Test and Two New Similar Protocols to Measure Trunk Postural Control

BackgroundAlthough the Star Excursion Balance test (SEBT) has shown a good intrasession reliability, the intersession reliability of this test has not been deeply studied. Furthermore, there is an evident high influence of the lower limbs in the performance of the SEBT, so even if it has been used to measure core stability, it is possibly not the most suitable measurement. Objective(1) To assess the absolute and relative between-session reliability of the SEBT and 2 novel variations of this test to assess trunk postural control while sitting, ie, the Star Excursion Sitting Test (SEST) and the Star Excursion Timing Test (SETT); and (2) to analyze the relationships between these 3 test scores. DesignCorrelational and reliability test–retest study. SettingControlled laboratory environment. ParticipantsTwenty-seven physically active men (age: 24.54 ± 3.05 years). MethodRelative and absolute reliability of the SEBT, SEST, and SETT were calculated through the intraclass correlation coefficient (ICC) and standard error of measurement (SEM), respectively. A Pearson correlation analysis was carried out between the variables of the 3 tests. Main Outcome MeasuresMaximum normalized reach distances were assessed for different SEBT and SEST directions. In addition, composite indexes were calculated for SEBT, SEST, and SETT. ResultsThe SEBT (dominant leg: ICC = 0.87 [0.73-0.94], SEM = 2.12 [1.66-2.93]; nondominant leg: ICC = 0.74 [0.50-0.87], SEM = 3.23 [2.54-4.45]), SEST (ICC = 0.85 [0.68-0.92], SEM = 1.27 [1.03-1.80]), and SETT (ICC = 0.61 [0.30-0.80], SEM = 2.31 [1.82-3.17]) composite indexes showed moderate-to-high 1-month reliability. A learning effect was detected for some SEBT and SEST directions and for SEST and SETT composite indexes. No significant correlations were found between SEBT and its 2 variations (r ≤ .366; P > .05). A significant correlation was found between the SEST and SETT composite indexes (r = .520; P > .01). ConclusionsSEBT, SEST, and SETT are reliable field protocols to measure postural control. However, whereas the SEBT assesses postural control in single-leg stance, SEST and SETT provide trunk postural control measures with lower influence of the lower-limbs. Level of EvidenceIII

S99. Reliability of surface electromiography measures for latissimus dorsi, femoral biceps and paraspinal muscles in persons with low back pain

Eighty percent of the population have experienced at least one episode of low back pain (LBP) in their lifetime and approximately 13–19% of adults complain of suffering LBP associated to lifting loads. Latissimus dorsi (LD), femoral biceps (FB) and the paraspinal muscles (PS), have an important role in the stability of the lumbosacral spine. It has been observed that during daily life activities the muscles show different electromyographic responses, depending on factors such as the health condition in which they are studied and the posture in which the measurement is made, among others.The surface electromyography (sEMG) is a non-invasive method that assesses muscle activation and provides relevant information that helps to understand the motor control in people with idiopathic chronic LBP; however, there are no reports in literature about the sEMG reliability during lifting a load for the above-mentioned muscles in people with chronic LBP. Objective: to determine the inter-session reliability of the sEMG for LD, FB and PS muscles, during lifting a load in people with chronic LBP. There were included 10 people (7 women and 3 men) with chronic LBP, between 18 and 40 years (32 ± 4.1) and body mass index 27.4 ± 6.04. The sEMG activity of the LD, FB and PS muscles was assessed while lifting a load in a symmetrical bipedal position in two sessions, with five days between each assessment. The Root mean square (RMS) amplitude and the latency were calculated. The inter-session reliability was assessed through Intraclass Correlation Coefficient (ICC) 2,1 and Bland–Altman analysis. Surface EMG measurements presented moderate to good reliability in latency measures for all assessed muscles (ICC 0.49–0.77 for LD, 0.46–0.56 for FB and 0.59–074 for PS muscles) and displayed moderate to excellent reliability for the RMS amplitude (ICC values 0.46–0.8 for LD; 0.42–0.55 for FB and 0.43–0.68 for PS muscles). Bland–Altman analysis showed a mean value of the difference close to zero and limits of agreement between 2 and 4 ms. The sEMG is a reliable tool that can be useful to evaluate muscle activation during a functional activity, in order to help to understand the muscle activation patterns in people with idiopathic chronic LBP.

The Reliability of Polyvinylidene Fluoride Sensor for Intra- and Intersession Measurements.

A new nasal sensor has been designed using Polyvinylidene fluoride (PVDF) film using its piezoelectric property to measure nasal patency. The aim of this study is to determine the intra- and intersession reliability of the new PVDF nasal sensor measurement of unilateral and combined nasal parameters in a group of healthy subjects. Two identical nasal sensors: for right nostril (RN) and left nostril (LN) were designed using piezoelectric natured PVDF films. Twenty subjects were studied. To evaluate the repeatability, total three sets of PVDF sensor measurements were recorded, two sets were taken 5min apart during same session without repositioning the PVDF nasal sensors and two more sets were taken during 1h apart successively, by repositioning the PVDF nasal sensor. Intraclass correlation coefficients (ICC) of PVDF sensor measurements for intra- and intersession showed a high and greater repeatability over time for all the combined (mean) and unilateral (RN and LN) values. In both healthy and patients, ICC values for both intra- and intersession measurements were ≥ 0.80 confirming strong reliability and also almost all of the coefficients of variation for the same parameters were low (below 10%). PVDF sensor measurements showed good intra- and intersession repeatability and can be recommended for the objective monitoring of nasal patency during diagnosis and follow-up of conditions.

High Reliability of Cone Cell Measurements With Adaptive Optics Scanning Laser Ophthalmoscopy in a Simulated Real-Life Clinical Setting.

The authors evaluated adaptive optics scanning laser ophthalmoscopy (AO-SLO) in a simulated real-life clinical setting to identify factors that impact its reliability in this setting. For this prospective study, macular cones were imaged in five healthy eyes using an AO-SLO prototype machine. Multilevel mixed-effect regression was used to compare the cone densities across different analysis parameters. Intergrader, intragrader, interphotographer, and intersession reliabilities were determined with intraclass correlation coefficients (ICCs). Cone densities in the largest measurement window size, 150 μm × 150 μm, were most consistent. Image quality strongly impacted cone analysis. Intragrader and intergrader ICCs were 0.99 and 0.98, respectively. Intersession and interphotographer reliability both had an ICC of 0.72. Larger measurement window sizes and higher image quality improve the reliability of cone density measurement. Although there were excellent intergrader and intragrader reliabilities, intersession and interphotographer reliabilities were not as robust. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:228-235.].

Effect of knee angle on neuromuscular assessment of plantar flexor muscles: A reliability study.

IntroductionThis study aimed to determine the intra- and inter-session reliability of neuromuscular assessment of plantar flexor (PF) muscles at three knee angles.MethodsTwelve young adults were tested for three knee angles (90°, 30° and 0°) and at three time points separated by 1 hour (intra-session) and 7 days (inter-session). Electrical (H reflex, M wave) and mechanical (evoked and maximal voluntary torque, activation level) parameters were measured on the PF muscles. Intraclass correlation coefficients (ICC) and coefficients of variation were calculated to determine intra- and inter-session reliability.ResultsThe mechanical measurements presented excellent (ICC>0.75) intra- and inter-session reliabilities regardless of the knee angle considered. The reliability of electrical measurements was better for the 90° knee angle compared to the 0° and 30° angles.ConclusionsChanges in the knee angle may influence the reliability of neuromuscular assessments, which indicates the importance of considering the knee angle to collect consistent outcomes on the PF muscles.

The minimal number of TMS trials required for the reliable assessment of corticospinal excitability, short interval intracortical inhibition, and intracortical facilitation

Transcranial magnetic stimulation (TMS)-induced motor evoked potentials (MEPs) are frequently used to assess corticospinal and intercortical activities. Trial to trial variance of the potentials is commonly observed, and averages of multiple MEPs are usually reported. Multiple trials have resources implications and are not compatible with some experimental protocols. This study investigated the minimum number of MEPs required to reliably assess corticospinal excitability (CSE), short interval intracortical inhibition (SICI) and intercortical facilitation (ICF), within and between sessions. Fifteen healthy volunteers received 35 single-pulse TMS for CSE assessments and 35 paired-pulse TMS for SICI and ICF measurements. Intra- and intersession reliability were examined using intra-class correlation coefficient tests, and stability of the measures was assessed using a general equation estimation analysis. Coefficients of variation were used to probe the effects of inter-individual variability on reliability results. All analyses were carried out on cumulative averages. The optimal number of trials to ensure “excellent” intra and inter-session reliability with low inter-individual variability and the highest level of stability was found to be 20 for CSE and 26 for SICI assessments. Although 30 consecutive trials produced highly reliable ICF measures within a session, inter-session reliability was not significant across 35 trials. These findings have significant implications for improving time efficiency of TMS experiments without compromising intra- or intersession reliability.

Inter-session reliability of short-interval intracortical inhibition measured by threshold tracking TMS

Paired-pulse transcranial magnetic stimulation (TMS) using fixed test stimuli suffers from marked variability of the motor evoked potential (MEP) amplitude. Threshold tracking TMS (TT-TMS) was introduced to overcome this problem. The aim of this work was to describe the absolute and relative reliability of short-interval intracortical inhibition (SICI) using TT-TMS. Cortical excitability studies were performed on twenty-six healthy subjects over three sessions (two recordings on the same day and one seven days apart), with MEPs recorded over abductor pollicis brevis. Reliability was established by calculating the standard error of the measurements (SEm), minimal detectable change (MDC) and intraclass correlation coefficient (ICC). Resting motor threshold and averaged SICI presented the lowest SEm and highest ICCs. SICI at 1 ms showed a higher SEm than SICI at 3 ms, suggesting different physiological processes, but averaging SICI over a number of intervals greatly increases the reproducibility. The variability was lower for tests undertaken at the same time of day seven days apart compared to tests performed on the same day, and in both instances the ICC for averaged SICI was ≥0.81. The MDC in averaged SICI was reduced from 6.7% to 2% if the number of subjects was increased from one to eleven. In conclusion, averaged SICI is the most reproducible variable across paired-pulse TT-TMS measures, showing an excellent ICC. It is recommended that, in longitudinal studies, testing be performed at the same time of day and that changes in cortical excitability should be measured and averaged over a number of interstimulus intervals to minimise variability.

Three-dimensional assessment of squats and drop jumps using the Microsoft Xbox One Kinect: Reliability and validity

ABSTRACTThe Microsoft Xbox One Kinect™ (Kinect V2) contains a depth camera that can be used to manually identify anatomical landmark positions in three-dimensions independent of the standard skeletal tracking, and therefore has potential for low-cost, time-efficient three-dimensional movement analysis (3DMA). This study examined inter-session reliability and concurrent validity of the Kinect V2 for the assessment of coronal and sagittal plane kinematics for the trunk, hip and knee during single leg squats (SLS) and drop vertical jumps (DVJ). Thirty young, healthy participants (age = 23 ± 5yrs, male/female = 15/15) performed a SLS and DVJ protocol that was recorded concurrently by the Kinect V2 and 3DMA during two sessions, one week apart. The Kinect V2 demonstrated good to excellent reliability for all SLS and DVJ variables (ICC ≥ 0.73). Concurrent validity ranged from poor to excellent (ICC = 0.02 to 0.98) during the SLS task, although trunk, hip and knee flexion and two-dimensional measures of knee abduction and frontal plane projection angle all demonstrated good to excellent validity (ICC ≥ 0.80). Concurrent validity for the DVJ task was typically worse, with only two variables exceeding ICC = 0.75 (trunk and hip flexion). These findings indicate that the Kinect V2 may have potential for large-scale screening for ACL injury risk, however future prospective research is required.

Reliability of Near-Infrared Spectroscopy for Measuring Intermittent Handgrip Contractions in Sport Climbers.

Baláš, J, Kodejška, J, Krupková, D, Hannsmann, J, and Fryer, S. Reliability of near-infrared spectroscopy for measuring intermittent handgrip contractions in sport climbers. J Strength Cond Res 32(2): 494-501, 2018-The use of near-infrared spectroscopy (NIRS) to investigate muscle oxygenation changes during physical tasks such as rock climbing has rapidly increased within recent years; yet, there is no known measure of reliability. The current study aimed to determine intersession reliability and minimal detectable change (MDC) of continuous wave NIRS parameters during intermittent handgrip contractions in rock climbers. Thirty-two sport climbers were tested for exhaustive intermittent handgrip exercise (8-second contraction-2-second relief) at 60% of maximal voluntary contraction on 3 separate days. During each visit, continuous wave NIRS was used to determine tissue saturation index (TSI) as the measure of tissue oxygenation in the flexor digitorum profundus. To assess the intersession reliability, the intraclass correlation coefficient (ICC), SEM, coefficient of variation (CV), and MDC were used. Mean deoxygenation during the contractions provided reliable results ([INCREMENT] TSI; first trial -8.9 ± 2.9%, second trial -8.8 ± 2.7%, and third trial -8.4 ± 2.6%; ICC = 0.692; SEM = 1.5%; CV = 17.2%; MDC = 4.2%). Mean muscle reoxygenation during the relief periods was similarly reliable ([INCREMENT] TSI; first trial 9.0 ± 3.1%, second trial 8.8 ± 2.9%, and third trial 8.5 ± 2.7%; ICC = 0.672; SEM = 1.7%; CV = 19.0%, MDC = 4.7%). As such, continuous wave NIRS provides a reliable measure of deoxygenation and reoxygenation during intermittent contractions to failure in the forearm flexors of rock climbers. Differences exceeding ∼4.5% for [INCREMENT] TSI during contraction and relief periods should be considered meaningful.

The Reliability of Parkour Skills Assessment.

The aim of the study was to determine the reliability of parkour skills assessment in field conditions. Twenty young men completed three trials of a parkour obstacle course on two separate days. The tested group consisted of 10 beginners (age 16 ± 1 years, body mass = 65 ± 12 kg, height = 177 ± 7 cm) and 10 advanced traceurs (age 18 ± 2 years, body mass = 68 ± 14 kg, height = 178 ± 6 cm). The performance was video-recorded and subsequently analyzed by three raters (total score 0–45). Median and percentiles were used to characterize results from all sessions by all raters. Inter-rater, intra-session and inter-session reliability were assessed using Krippendorff’s α for ordinal data. The Mann-Whitney test was used to assess the differences between beginners and advanced traceurs. Advanced traceurs obtained a total score from 41 to 44 whilst beginners achieved 27 to 33 points. Krippendorff’s α for total score ranged from 0.910 to 0.916 between raters, 0.828 to 0.874 between trials, and from 0.839 to 0.924 between days. The proposed parkour course differentiated two different ability levels and the skills assessment demonstrated excellent reliability between raters, trials, and days.