Within-day Reliability Research Articles

An observational study to evaluate the within-day reliability and concurrent validity of 2-minute walk test (2MWT) and 10-metere walk test (10MWT) in health individuals wearing a mask

Background Exercise tests are widely used to prescribe exercises for patients with cardiorespiratory conditions and assess impact of treatments. The 2-minute walk test (2MWT) and 10-metre walk test (10MWT) are common assessments of functional exercise capacity. The COVID-19 pandemic resulted in people wearing masks (commonly surgical masks) to reduce infection. However, the validity and reliability of 2MWT and 10MWT wearing a mask is unknown and further research is required. Aim To assess the within-day reliability and concurrent validity of the 2MWT and 10MWT in healthy individuals wearing a surgical mask. Design and Setting Observational study, in a university setting Methods All participants completed three tests of 2MWT and 10MWT wearing a surgical mask (on one day) and one test without a mask (on a separate day) within one week. Oxygen saturation and heart rate were measured using pulse oximetry and the Borg scale assessed dyspnoea. Statistical analyses included: intraclass correlation coefficients (ICC) for within-day reliability of mask-wearing during three tests and Pearson’s coefficient for concurrent validity correlated tests with a surgical mask and without a mask (the gold standard). Results 15 people, mean (standard deviation) age 26 (2) years were included. The 2MWT and 10MWT (with mask) had excellent within-day reliability (ICC =0.823, 0.920 respectively). Both the 2MWT and 10MWT with and without a mask were highly correlated (r = 0.815, 0.943 respectively, p<0.01). Conclusions The results showed excellent within-day reliability and concurrent validity of 2MWT and 10MWT with a surgical mask in healthy individuals. Further research in clinical populations is needed.

Measurement properties of the incremental step test for people with chronic obstructive pulmonary disease: a cross-sectional study

ObjectivesThe new incremental step test (IST) is a field test that was developed for people with chronic obstructive pulmonary disease (COPD), based on the characteristics of the incremental shuttle walk...

Doppler Ultrasound-Based Leg Blood Flow Assessment During Single-Leg Knee-Extensor Exercise in an Uncontrolled Setting.

Doppler ultrasound has revolutionized the assessment of organ blood flow and is widely used in research and clinical settings. While Doppler ultrasound-based assessment of contracting leg muscle blood flow is common in human studies, the reliability of this method requires further investigation. Therefore, this study aimed to investigate the within-day test-retest, between-day test-retest, and inter-rater reliability of Doppler ultrasound for assessing leg blood flow during rest and graded single-leg knee-extensions (0 W, 6 W, 12 W, and 18 W), with the ultrasound probe being removed between measurements. The study included thirty healthy subjects (age: 33 ± 9.3, male/female: 14/16) who visited the laboratory on two different experimental days separated by 10 days. The study did not control for major confounders such as nutritional state, time of day, or hormonal status. Across different exercise intensities, the results demonstrated high within-day reliability with a coefficient of variation (CV) ranging from 4.0% to 4.3%, acceptable between-day reliability with a CV ranging from 10.1% to 20.2%, and inter-rater reliability with a CV ranging from 17.9% to 26.8%. Therefore, in a real-life clinical scenario where controlling various environmental factors is challenging, Doppler ultrasound can be used to determine leg blood flow during submaximal single-leg knee-extensor exercise with high within-day reliability and acceptable between-day reliability when performed by the same sonographer.

Reliability of ultrasonography to measure cervical multifidus, semispinalis cervicis and longus colli muscles dimensions in patients with unilateral cervical disc herniation: An observational cross-sectional test-retest study

BackgroundUltrasonography (US) has been suggested to assess the morphology and function of cervical muscles; but little is known about the reliability of the US measures in patients with cervical disc herniation (CDH). The purpose of this study was to evaluate within-day inter and intra-rater and between-day intra-rater reliability of US to measure dimensions of deep cervical muscles in patients with unilateral CDH. MethodsThirty patients with unilateral CDH participated. Anterior-posterior and lateral dimension of longus colli (LC), multifidus (MF) and semispinalis cervicis (SC) were measured using B-mode ultrasound. The measurements were repeated by rater A 1 h (for within-day reliability) and one week (for between-day reliability) later. For inter-rater reliability, rater B performed all muscles measurements like rater A. ResultsWithin-day reliability measurement for all muscles was good to excellent with IntraClass Correlation Coefficients (ICC) ranging from 0.82 to 0.96, standard error of measurement (SEM) from 0.18 to 0.46 and minimal detectable changes (MDC) from 0.43 to 1.09. Between-day reliability was good for all muscle dimensions with ICC ranging from 0.75 to 0.89, SEM from 0.30 to 0.64 and MDC from 0.71 to 1.52. Inter-rater reliability was also good with ICC ranging from 0.75 to 0.89, SEM from 0.34 to 0.65 and MDC from 0.81 to 1.55. ConclusionsUS was demonstrated to have high within-day inter and intra-rater and between-day intra-rater reliability to measure muscles dimensions in patients with unilateral CDH. It can be used to assess deep cervical muscles or to monitor the effects of interventions.

Feasibility of a kinect-based system in assessing physical function of the elderly for home-based care

BackgroundWith concerns about accurate diagnosis through telehealth, the Kinect sensor offers a reliable solution for movement analysis. However, there is a lack of practical research investigating the suitability of a Kinect-based system as a functional fitness assessment tool in homecare settings. Hence, the objective of this study was to evaluate the feasibility of using a Kinect-based system to assess physical function changes in the elderly.MethodsThe study consisted of two phases. Phase one involved 35 young healthy adults, evaluating the reliability and validity of a Kinect-based fitness evaluation compared to traditional physical examination using the intraclass correlation coefficient (ICC). Phase two involved 665 elderly subjects, examining the correlation between the Kinect-based fitness evaluation and physical examination through Pearson’s correlation coefficients. A Kinect sensor (Microsoft Xbox One Kinect V2) with customized software was employed to capture and compute the movement of joint centers. Both groups performed seven functional assessments simultaneously monitored by a physical therapist and the Kinect system. System usability and user satisfaction were assessed using the System Usability Scale (SUS) and Questionnaire for User Interface Satisfaction (QUIS), respectively.ResultsKinect-based system showed overall moderate to excellent within-day reliability (ICC = 0.633-1.0) and between-day reliability (ICC = 0.686-1.0). The overall agreement between the two devices was highly correlated (r ≧ 0.7) for all functional assessment tests in young healthy adults. The Kinect-based system also showed a high correlation with physical examination for the functional assessments (r = 0.858–0.988) except functional reach (r = 0.484) and walking speed(r = 0.493). The users’ satisfaction with the system was excellent (SUS score = 84.4 ± 18.5; QUIS score = 6.5–6.7).ConclusionsThe reliability and validity of Kinect for assessing functional performance are generally favorable. Nonetheless, caution is advised when employing Kinect for tasks involving depth changes, such as functional reach and walking speed tests for their moderate validity. However, Kinect’s fundamental motion detection capabilities demonstrate its potential for future applications in telerehabilitation in different healthcare settings.

Measuring upper limb active joint position sense: Introducing a new clinical tool - The Upper Limb Proprioception Reaching Test

BackgroundProprioception is our sense of body awareness, including the sub-category of active joint position sense (AJPS). AJPS is fundamental to joint stability and movement coordination. Despite its importance, there remain few confident ways to measure upper limb AJPS in a clinic. ObjectiveTo assess a new AJPS clinical tool, the Upper Limb Proprioception Reaching Test (PRO-Reach; seven targets), for discriminant validity, intra-rater and absolute reliability. DesignCross-sectional measurement study. MethodsSeventy-five healthy participants took part in a single session with 2 consecutive evaluations (E1 and E2) (within-day reliability). Twenty participants were randomly selected to perform a dominant shoulder fatigue protocol (discriminant validity), whereafter a third evaluation was repeated (E3). The PRO-Reach was analyzed with paired t tests (discriminant validity), intra-class correlation coefficients (ICCs) and minimal detectable change [MDC]) (intra-rater: within-day and between-trial relative and absolute reliability). ResultsThe PRO-Reach supports moderate (mostly superior targets) to excellent (mostly inferior targets) reliability. Between-trial ICCs (T1/T2/T3) varied between 0.72 and 0.90, and within-day (E1/E2) ICCs between 0.45 and 0.72, with associated MDC95 values (3.9–5.0 cm). The overall scores (seven targets) supported the strongest within-day reliability (ICC = 0.77). The inferior targets demonstrated the highest between-trial and within-day reliability (ICCs = 0.90 and 0.72). A fatigue effect was found with the superior and superior-lateral targets (P < .05). ConclusionsThe inferior targets and overall scores demonstrate the strongest reliability. The use of the PRO-Reach tool may be suitable for clinical use upon further psychometric testing amongst pathological populations. Level of evidenceLevel III cross-sectional study.

Reliability of laser-Doppler flowmetry derived measurements of forearm and calf cutaneous vasodilation during gradual local heating in young adults.

Evaluate reliability of laser-Doppler flowmetry derived cutaneous vasodilation on the upper and lower limbs during gradual local heating. In twenty-eight young adults (21 (SD 3) years, 14 females), absolute cutaneous vascular conductance (CVCabs) and CVC normalized to maximum vasodilation at 44 °C (%CVCmax) were assessed at two adjacent sites on each of the forearm and calf during gradual local skin heating (33-42 °C at 1 °C·5 min-1) for two identical trials (~1 week apart). Responses were assessed for baseline, the steady-state heating plateau at 42 °C and the span (i.e. plateau-baseline). Between-day reliability was characterized as measurement consistency across trials. Within-day reliability was characterized as within-limb measurement consistency across adjacent skin sites. Between- and within-day absolute reliability (coefficient of variation) generally improved with heating, from poor (>25 %) at baseline to good (<10 %) for %CVCmax and moderate (10-25 %) for CVCabs for plateau and span. However, relative reliability (intraclass correlation coefficient) was generally not acceptable (≤0.70) for any condition. Responses were generally consistent for females and males and there were no major forearm and calf differences. Consistency of CVC estimates improved during gradual local heating with negligible limb and sex differences, which are important considerations for experimental design and interpretation.

Reliability of Gallon-Jug Shelf-Transfer Power Equations in Older Women.

Ly, A, Strand, KL, Courtney, KJ, Barry, SS, Liscano, JA, Trebotich, TL, Martin-Diala, C, Martin, E, and Signorile, JF. Reliability of gallon-jug shelf-transfer test power equations in older women. J Strength Cond Res 37(5): 1124-1130, 2023-This study examined the test-retest reliability of the gallon-jug shelf-transfer (GJST) test as a measure of upper-body functional power in older women. Although the validity of the predictive equations for power during the GJST test has been established, for the test to be viable in either a laboratory or clinical environment, between-day and within-day reliability must be established. Thirty-four independently living older women (mean ± SD : 75.0 ± 6.4 years) performed 2 sets of 3 repetitions of the GJST test on 2 days separated by at least 48 hours. Using the established predictive equations, the values for peak power and average power were then computed. Statistical analyses to assess reliability included intraclass correlation coefficient, coefficient of variation (CV), SEM , minimal detectable change (MDC), and Cronbach's α values. Furthermore, Bland-Altman plots evaluated the agreement between the tests. Intraclass correlation coefficient (>0.91, p < 0 001), CV (<8.1%), SEM (<5.94 W), MDC (<14 W), and Cronbach's α (>0.95) indicated excellent reliability. The lines of equality for all Bland-Altman plots fell within the 95% confidence interval of the mean difference, implying that there were no significant differences between tests. Furthermore, bias values were small (<11.15 W), and the limits of agreement (LOA) were within an acceptable range. Based on our statistical analyses, the GJST test is a highly reliable assessment for determining object transfer power for healthy older women.

B-Mode Ultrasonography Is a Reliable and Valid Alternative to Magnetic Resonance Imaging for Measuring Patellar Tendon Cross-Sectional Area.

This study investigated the validity and reliability of measuring patellar tendon (PT) cross-sectional area (CSA) using magnetic resonance imaging (MRI) and ultrasound (US) imaging. Nineteen healthy participants (10 women, 9 men) participated in three imaging sessions of the PT, once via MRI and twice via US, with image acquisition conducted by two raters, one experienced (rater 2) and one inexperienced (rater 1). All PT segmentations were analyzed by both raters. The validity of US-derived estimates of PT CSA against MRI estimates was analyzed using linear regression. Within-day reliability of US and MRI measurements and between-day reliability of US measurements were quantified using typical error (TE) and intra-class correlation coefficients (ICC3,1). There was good agreement between US- and MRI-derived estimations of PT CSA (standard errors of the estimate of 3.3 mm2 for rater 1 and 2.6 mm2 for rater 2; Pearson's r=0.97 and 0.98 for raters 1 and 2, respectively). Within-session reliability for estimations of total PT CSA from US and MRI were excellent (ICC3,1 >0.95, coefficient of variation [CV] <4.1%, TE=1.3-3.6 mm2. Between-day reliability for US was excellent (ICC3,1 >0.97, CV <2.7%, TE=1.6-2.3 mm2), with little difference between raters. These findings suggest that MRI and US both provide reliable estimates of PT CSA and that US can provide a valid measure of PT CSA.

Reliability and Validity of Computerized Adventitious Respiratory Sounds in People with Bronchiectasis.

Background: Computerized adventitious respiratory sounds (ARS), such as crackles and wheezes, have been poorly explored in bronchiectasis, especially their measurement properties. This study aimed to test the reliability and validity of ARS in bronchiectasis. Methods: Respiratory sounds were recorded twice at 4 chest locations on 2 assessment sessions (7 days apart) in people with bronchiectasis and daily sputum expectoration. The total number of crackles, number of wheezes and wheeze occupation rate (%) were the parameters extracted. Results: 28 participants (9 men; 62 ± 12 y) were included. Total number of crackles and wheezes showed moderate within-day (ICC 0.87, 95% CI 0.74−0.94; ICC 0.86, 95% CI 0.71−0.93) and between-day reliability (ICC 0.70, 95% CI 0.43−0.86; ICC 0.78, 95% CI 0.56−0.90) considering all chest locations and both respiratory phases; wheeze occupation rate showed moderate within-day reliability (ICC 0.86, 95% CI 0.71−0.93), but poor between-day reliability (ICC 0.71, 95% CI 0.33−0.87). Bland−Altman plots revealed no systematic bias, but wide limits of agreement, particularly in the between-days analysis. All ARS parameters correlated moderately with the amount of daily sputum expectoration (r > 0.4; p < 0.05). No other significant correlations were observed. Conclusion: ARS presented moderate reliability and were correlated with the daily sputum expectoration in bronchiectasis. The use of sequential measurements may be an option to achieve greater accuracy when ARS are used to monitor or assess the effects of physiotherapy interventions in this population.

Reliability of TMS measurements using conventional hand-hold method with different numbers of stimuli for tibialis anterior muscle in healthy adults.

Objective: The objective of this study was to determine the reliability of corticomotor excitability measurements using the conventional hand-hold transcranial magnetic stimulation (TMS) method for the tibialis anterior (TA) muscle in healthy adults and the number of stimuli required for reliable assessment.Methods: Forty healthy adults participated in three repeated sessions of corticomotor excitability assessment in terms of resting motor threshold (rMT), slope of recruitment curve (RC), peak motor evoked potential amplitude (pMEP), and MEP latency using conventional TMS method. The first two sessions were conducted with a rest interval of 1 h, and the last session was conducted 7–10 days afterward. With the exception of rMT, the other three outcomes measure elicited with the block of first 3–10 stimuli were analyzed respectively. The within-day (session 1 vs. 2) and between-day (session 1 vs. 3) reliability for all four outcome measures were assessed using intraclass correlation coefficient (ICC), standard error of measurement, and minimum detectable difference at 95% confidence interval.Results: Good to excellent within-day and between-day reliability was found for TMS-induced outcome measures examined using 10 stimuli (ICC ≥ 0.823), except in pMEP, which showed between-day reliability at moderate level (ICC = 0.730). The number of three stimuli was adequate to achieve minimum acceptable within-day reliability for all TMS-induced parameters and between-day reliability for MEP latency. With regard to between-day reliability of RC slope and pMEP, at least seven and nine stimuli were recommended respectively.Conclusion: Our findings indicated the high reliability of corticomotor excitability measurement by TMS with adequate number of stimuli for the TA muscle in healthy adults. This result should be interpreted with caveats for the specific methodological choices, equipment setting, and the characteristics of the sample in the current study.Clinical Trial Registration: http://www.chictr.org.cn, identifier ChiCTR2100045141.

Within-day Reliability Of Electromyography Normalization With Standard Isometric Contraction In Patients With Knee Osteoarthritis

Within-day Reliability Of Electromyography Normalization With Standard Isometric Contraction In Patients With Knee Osteoarthritis

Measuring the Reliability of Postural Sway Measurements for a Static Standing Task: The Effect of Age

Background: A force plate is used to determine the ability to balance ability. However, only some medical centers or laboratories are equipped with force plates because they are costly so a low-cost force plate is required for home care or health care institutes. Few studies compare the reliability of postural sway measurements in terms of age. This study proposes a low-cost force plate to select reliable parameters to evaluate postural sway. Objectives: To determine the intra-rater reliability of a novel force plate and the effect of age difference on the intra-rater test-retest reliability for the center of pressure (COP). Methods: Forty participants were enrolled for this study: 20 youths and 20 older adults. Participants stood on a custom-made and low-cost force plate with eyes opened and eyes closed to measure COP-related parameters. The within-day test-retest reliability was measured at two sessions on the same day and the between-days reliability was measured on two different days. The COP-related parameters include the average velocity of COP, the average velocity in the antero-posterior and medio-lateral directions, the mean distance of COP and the mean distance in the antero-posterior and medio-lateral directions. An intra-class correlation coefficient test with one-way random model was performed to determine the reliability of different variables within-days and between-days. The results were presented in single measurement of intraclass correlation coefficient (ICC), the standard error of measurements, and the minimal detectable changes of each COP-related parameters. Results: The novel low-cost force plate demonstrates excellent reliability in terms of the COP velocity related parameters for within- and between-day measurements. The ICC of COP distance related parameters were good to excellent reliability for between-day measurements (range: 0.43–0.84). Older adults demonstrated excellent reliability in terms of the mean distance for antero-posterior and the results were better than those for younger participants for the eyes-opened and eyes-closed conditions. The reliability in terms of the mean distance for medio-lateral was poor to good for older adults (range: 0.38–0.55), and excellent for younger participants. Conclusion: The novel and low-cost force plate reliably measured balance and age affects the reliability of different COP variables, so the results of this study were pertinent to the selection of COP measures.

Neurovascular coupling on trial: How the number of trials completed impacts the accuracy and precision of temporally derived neurovascular coupling estimates

Standard practices for quantifying neurovascular coupling (NVC) with transcranial Doppler ultrasound (TCD) require participants to complete one-to-ten repetitive trials. However, limited empirical evidence exists regarding how the number of trials completed influences the validity and reliability of temporally derived NVC metrics. Secondary analyses was performed on 60 young healthy participants (30 females/30 males) who completed eight cyclical eyes-closed (20-seconds), eyes-open (40-seconds) NVC trials, using the “Where’s Waldo?” visual paradigm. TCD data was obtained in posterior and middle cerebral arteries (PCA and MCA, respectively). The within-day (n = 11) and between-day (n = 17) reliability were assessed at seven- and three-time points, respectively. Repeat testing from the reliability aims were also used for the concurrent validity analysis (n = 160). PCA metrics (i.e., baseline, peak, percent increase, and area-under-the-curve) demonstrated five trials produced excellent intraclass correlation coefficient (ICC) 95% confidence intervals for validity and within-day reliability (>0.900), whereas between-day reliability was good-to-excellent (>0.750). Likewise, 95% confidence intervals for coefficient of variation (CoV) measures ranged from acceptable (<20%) to excellent (<5%) with five-or-more trials. Employing fewer than five trials produced poor/unacceptable ICC and CoV metrics. Future NVC, TCD-based research should therefore have participants complete a minimum of five trials when quantifying the NVC response with TCD via a “Where’s Waldo?” paradigm.

Glittre activities of daily living test is reliable and valid in hemodialysis patients

Purpose To examine the validity, and the relative and absolute within-day reliability of the TGlittre in chronic kidney disease patients undergoing hemodialysis (HD). Materials and methods Thirty HD patients (52 ± 12 years) undertook the TGlittre twice on a single day, in a cross-sectional design. For validation purposes, participants TGlittre performance and accelerometry-based physical activity were correlated. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and minimal detectable change (MDC) were determined to assess within-day reliability. Results There was a moderate correlation between TGlittre performance and moderate to vigorous physical activity (r= −0.587; p= 0.001). The relative reliability of the test showed an ICC of 0.96. For the absolute reliability, the SEM was 13.05 s (0.22 min), and the MDC was 36.17 s (0.60 min). Conclusions TGlittre performance is associated with moderate to vigorous physical activity in HD patients, highlighting that those with higher levels of physical activity are likely to perform better on the TGlittre. Additionally, TGlittre shows a good to excellent intra-rater reliability and a low SEM. An MDC value was established. Implications for rehabilitation Patients on hemodialysis have a low physical capacity and often struggle to simply complete their physical activities of daily living. The TGlittre is a tool for assessing functional capacity through completion of multiple physical activities of daily living and can be easily applied in a clinical setting. TGlittre is a valid test that elicit reliable physiological, hemodynamic, and physical performance responses in HD patients.

Reliability of musculoskeletal ultrasound imaging to measure calcific deposits in patients with calcified rotator cuff tendinopathy

IntroductionThis reliability study was designed to assess intra-rater and inter-rater reliability of musculoskeletal ultrasound as a diagnostic modality to measure calcific deposits in subjects with rotator cuff tendinopathy.MethodsOverall, 15 participants (10 males, 5 females) with calcified shoulder, aged 32–55 years, were examined in the same sitting posture. Two experienced radiologists imaged calcific deposits, measured twice daily by both raters with an interval of 2 hours for within-day reliability and re-measured after 1 week for between-day reliability. Data were analysed by using intra-class and inter-class correlation coefficient.ResultsThe mean size of calcific deposits in supraspinatus tendons was 14.61 ± 1.78, 14.87 ± 1.77, and 14.88 ± 1.88 mm for the first rater and 14.89 ± 1.78, 14.98 ± 1.792, and 15.13 ± 1.84 mm for the second rater. The results reflected excellent reliability, with the intra-class correlation coefficient for within-day comparison calculated as 0.989 (0.975–0.996) for the first rater and 0.984 (0.963–0.994) for the second rater (&lt;i&gt;p&lt;/i&gt; = 0.000). The inter-class correlation coefficient for between-rater comparison equalled 0.991 for the first measurements by the first and second raters, 0.984 for the second measurements, and 0.986 for the third measurements.ConclusionsA high degree of within-day and between-day reliability was observed between the successive measurements. This shows that musculoskeletal ultrasound is a highly reliable diagnostic tool for measuring the size of calcific deposits in patients with tendinopathy.

Normalisation of a biarticular muscle EMG signal using a submaximal voluntary contraction: Choice of the standardised isometric task for the rectus femoris, a pilot study

BackgroundElectromyography (EMG) signal amplitude is often altered by factors related to the participants and the measurement system. To overcome this issue, a normalisation of the EMG signal amplitude can be performed. Recently, it has been demonstrated that a submaximal voluntary contraction (subMVC) normalisation approach, inspired by grade 3 of manual muscle testing, could produce reliable results. However, rectus femoris (RF) normalisation resulted in low reliability. While the normalisation task chosen for this biarticular muscle was to maintain a knee extension against gravity (ISO-K), a hip flexion isometric task (ISO-H) could also be applied. Research questionThis pilot study aimed to assess the impact of the normalisation task on the RF EMG signal quality and related intra‐rater within-day reliability during ISO-K and ISO-H, and intra‐rater between-day reliability of the EMG signal amplitude during gait. MethodsTwenty-four asymptomatic participants were asked to perform ISO-K and ISO-H tasks with both legs and then to walk at self-spontaneous speed, in two identical sessions one week apart. A wireless EMG system was used to record the EMG signal of bilateral RF during each task. ResultsSignal-to-noise ratio during ISO-K and ISO-H was ≥ 15 dB in respectively 51% and 98% of all task repetitions. Intra‐rater within-day reliability was acceptable using ISO-K (ICC = 0.71 (0.57; 0.83)) with high %SEM of 35%, and excellent using ISO-H (ICC = 0.94 (0.90; 0.96)) with high %SEM of 34%. Intra‐rater between‐day reliability during gait was acceptable using ISO-K (ICC = 0.74 (0.61; 0.81)) with a high %SEM of 49%, and excellent using ISO-H (ICC = 0.87 (0.76; 0.93)) with a high %SEM of 38%. SignificanceThe reliability (ICC) of RF EMG signal normalisation was higher using ISO-H than using ISO-K. However, even if signal-to-noise ratio was notably improved using ISO-H, %SEM remains high whatever the normalisation task used. Some additional improvements might thus still be needed to obtain a normalisation protocol allowing more reproducible measurements.

A valid and reliable test of technical skill for vision impaired football

ABSTRACT Objectives The International Paralympic Committee requires international federations to develop and implement sport-specific classification guidelines based on scientific evidence. Performance tests are key to developing new evidence-based criteria in football for athletes with vision impairment (VI). Therefore, the aim of this study was to develop a valid and reliable test of technical performance for VI football. Methods To assure content and face validity, the Vision Impaired Football Skills (VIFS) test was based on recommendations from experienced players and coaches. To test construct validity, we compared 24 sighted football players split into two groups based on highest-level of performance but matched on experience. To test reliability participants completed the VIFS three times on two separate days. Results Results supported construct validity through detecting differences in performance times between the two groups (p = .004, g = 1.28 95% CI = 0.41 - 2.15). Bias between visits (.54s ± 2.93s; 95% LoA = -5.21– 6.29) and intraclass correlations (.81, 95% CI = .56 - .92) showed between-day agreement and reliability. Within-day reliability was good after a familiarisation trial. Conclusions Results support the suitability for the VIFS test for classification research. Future work should establish feasibility for players with a VI.

WITHIN-DAY AND BETWEEN-DAY RELIABILITY OF A FBG-BASED SMART SOCK SYSTEM FOR MEASURING ACTIVE TOE FLEXION DISPLACEMENT OF THE HALLUX

This study examined the test-retest reliability of hallux flexion displacement measured using a smart sock system with embedded fiber Bragg grating (FBG) sensors. Thirty female participants consisting of 15 hallux valgus (HV) patients and 15 control participants were recruited. Maximum active hallux flexion displacement was measured twice on each participant in the first visit; the same procedures were repeated 7 days later. Intraclass correlation coefficients (ICC2,1) and standard error of measurement (SEM) were applied to test within-day and between-day reliability. Paired-samples T-test was performed to compare the displacements between trials. Results showed almost perfect within-day reliability for both HV and control groups ([Formula: see text] and 0.977, respectively) with small SEM (both 0.5[Formula: see text]cm). However, fair to moderate between-day reliability was found (0.323 and 0.438, respectively). Significant differences were found between repeated measurements taken on the same day (mean [Formula: see text][Formula: see text]cm, [Formula: see text]) and on different days (mean [Formula: see text][Formula: see text]cm, [Formula: see text]), though the effect size was small. The poorer between-day reliability is likely due to the inconsistency in fitting the sock onto the foot. Future optimization of the prototype design is called for to improve the fitting consistency of wearable sensors onto patients.

Reliability of transcranial magnetic stimulation measurements of maximum activation of the knee extensors in young adult males.

METHODS: RESULTS: CONCLUSION.