Background/Objectives: Neuromuscular fatigue (NMF) can impair manual dexterity and strength in healthcare professionals. Due to their high physical and cognitive workloads, physiotherapists (PTs) are particularly susceptible to NMF. This study investigated whether NMF, expressed as changes in manual dexterity and grip strength, occurs over a workday and across a workweek in PTs, and explored its relationship with stress and sleep quality. Methods: A total of 43 full-time PTs (25 female, mean age 37.72 ± 11.94 years) were recruited. Manual dexterity was assessed using the Functional Dexterity Test (FDT), while maximal grip strength (MGS) was measured by a hand dynamometer. Reliability was evaluated on a subgroup using Intraclass Correlation Coefficients (ICC3,1) and Standard Error of Measurement (SEM). Evaluations were conducted at the beginning and at the end of the work shift, on Monday and Friday. Subjective fatigue, perceived stress, and sleep quality were also recorded. Results: The FDT showed excellent intra-rater reliability (ICC > 0.93; SEM < 0.94 s). FDT performance was significantly slower on Friday evening compared to all other time points (p < 0.01), exceeding the minimal detectable change thresholds. No significant changes were observed in MGS across the week. Perceived stress was strongly correlated with fatigue levels on Monday (ρ = 0.731) and Friday (ρ = 0.612) evenings. Sleep quality and professional experience did not correlate with performance changes. Conclusions: PTs experience a significant decline in manual dexterity by the end of the workweek, suggesting an accumulation of NMF. While MGS remains stable, fine motor control is more sensitive to fatigue. Psychosocial stress appears to be a major driver of perceived fatigue in this population.

Clinical assessment of the scapula is challenging because of the complex biomechanics of the scapulothoracic joint. To analyze the concurrent validity, reliability, and precision of goniometry in measuring scapular protraction and retraction. Observational, descriptive design. Academic. Sample of 50 healthy adults. Two experienced raters (occupational therapists and certified hand therapists) measured the resting, protracted, and retracted positions of the scapulae using the superior angle, frontal plane, and acromion as anatomical landmarks. The Dartfish motion analysis system was then used by a blinded researcher for digital measurement of the same scapular positions. Descriptive (means and standard deviations) statistics and reliability analysis (intraclass correlation coefficient [ICC], standard error of measurement [SEM]) were used to analyze interrater reliability. Additional statistics, including Pearson's r and Bland-Altman plots, were used to assess concurrent validity. Measures obtained by both raters demonstrated excellent interrater reliability (ICCs = .89-.99; SEM = .63-1.9: For minimum detectable changes, range = 1.7°-5.3°, and for percentage of the minimum detectable change, range = 7-20%). The mean variance between goniometric measurements and Dartfish values was less than 1°, with very strong correlation (r = .84-.92). The reliability and validity meet or exceed similar psychometric properties of goniometric techniques for other joints of the human body. Goniometric measurement of scapular protraction and retraction is a reliable and valid technique that can be efficiently implemented by rehabilitation practitioners. Plain-Language Summary: Protraction and retraction of the scapula are important, foundational movements of upper extremity function but have proven uniquely challenging to measure. The present findings support the use of goniometry as a valid, reliable, and efficient method for the assessment of scapular protraction and retraction by occupational therapists and other rehabilitation practitioners.

Psychometric testing of a French Canadian version of the MacHAND performance assessment short (MPA-SF) for the adult burn survivor population.

From real to virtual: Kinematic adjustments in gait biomechanics of healthy older adults.

Purpose: Our study aimed to assess the validity, reliability, and minimal detectable change (MDC) of the 6-Minute Pegboard and Ring Test (6PBRT) in patients with heart failure (pwHF). Material and Methods: This cross-sectional study included 37 pwHF. Upper extremity functional capacity was evaluated using the 6PBRT. The 6PBRT was executed twice to investigate test-retest reliability. The upper extremity muscle strength was measured using a dynamometer. Functional capacity, activities of daily living, and quality of life were assessed with the Milliken Activities of Daily Living Scale (MAS), six-minute walk test (6MWT) and Minnesota Living with Heart Failure Questionnaire (MLHFQ), respectively. Results: Test re-test reliability was excellent for 6PBRT with an ICC=0.957 (95% CI 0.863 to 0.982). The MDC of the 6PBRT was 23.75 rings. The 6PBRT was strongly correlated with functional class (rho=-0.778, p

Objective: 3-Meter Backward Walk Test (3MBWT) is a physical performance-based test that assesses balance, proprioception, and fall risk. The present study aimed to reveal the reliability of the test-retest and the concurrent validity of 3MBWT in persons with knee osteoarthritis, which has not been studied yet. Patients and Methods: A total of 37 female patients were involved in the present study. 3MBWT was administered twice (one-week interval between sessions) in two different sessions, and the average score was recorded. The Timed Up and Go Test (TUG), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Modified Falls Efficacy Scale (MFES) were applied in the initial assessment to investigate correlations with 3MBWT. Results: The 3MBWT presented high intra-reliability (ICC=0.872). While, a strong correlation was observed between the 3MBWT and TUG (r=0.791), a moderate correlation was revealed between MFES and 3MBWT (r=-0.671). Significant correlations with the 3MBWT and KOOS subscales (ranging from – 0.726 to – 0.364) were also observed. The standard error of measurement (SEM) and the minimal detectable change (MDC95) were calculated as 2.36 and 6.55 seconds, respectively. Conclusion: 3MBWT is both a valid and reliable measurement tool in persons with knee osteoarthritis. It could be used to monitor the progression of the disease and the functional status of persons with knee osteoarthritis.

Background and Objectives: Sternocleidomastoid (SCM) dysfunction is commonly implicated in several musculoskeletal conditions. Accordingly, shear-wave elastography has been used to characterize SCM stiffness in asymptomatic and clinical cohorts. However, the only reproducibility study available reported limited reliability, so clinical interpretations should be made with caution. Therefore, this study revisits key methodological aspects of that protocol to assess intra-examiner reliability and includes two examiners with different levels of expertise to evaluate inter-examiner reliability. Materials and Methods: A longitudinal observational study was conducted, recruiting twenty-five asymptomatic participants. Two examiners with different experience levels participated in this study after following structured training. For each side, images were obtained in immediate succession in the sequence experienced–novice–experienced–novice (with side order randomized), using an ROI spanning full muscle thickness, stabilizing approximately 10 s before freezing to record Young’s modulus and shear-wave speed. Results: Inter-examiner agreement was good–excellent: single-measurement ICCs were 0.77–0.86, improving to 0.79–0.87 when averaging two trials, which also reduced the standard error of measurement (SEM) and minimal detectable changes (MDCs). Between-examiner mean differences were small and nonsignificant (p ≥ 0.068). Intra-examiner reliability was excellent (ICC ≈ 0.93–0.94) with small absolute errors. Precision was high (SEM ~5–6 kPa; 0.22 m/s), and MDCs were ~15–16 kPa and ~0.60 m/s, with no trial-to-trial bias (all p ≥ 0.311). Conclusions: The revised protocol showed excellent intra-examiner repeatability and good–excellent inter-examiner reliability with minimal bias. Averaging two acquisitions improved precision, while a single operator optimized longitudinal stability.

Quadriceps maximal voluntary contraction (QMVC) reliably measures quadriceps muscle force and predicts mortality in chronic obstructive pulmonary disease (COPD). However, the minimal important difference (MID) of QMVC is not well-established. To estimate the MID of QMVC parameters in people with COPD following pulmonary rehabilitation (PR). QMVC was measured before and after 8 weeks of outpatient PR in people with COPD. Absolute and % change in QMVC, and change in normalised QMVC were calculated using paired t-tests. Anchor and distribution-based methods (0.5×SD change, SEM, minimal detectable change at 95% confidence, effect size and 1.96 SEM) were used to estimate the MID. Of 903 participants, 383 were excluded due to PR non-completion or missing QMVC data with 520 included in the analysis (37% female; mean (SD) age 70.2 (8.4) years; forced expiratory volume in 1 s 51.4 (21.4)% predicted). QMVC parameters increased with PR; mean (95% CI) or mean (SD) change: QMVC 2.0 kg (1.5 kg to 2.5 kg), 10.6% (27.7%) and normalised QMVC 5.0% predicted (3.9% to 6.2%). Anchor-based MID estimates were precluded due to weak/no correlation with external anchors. Using distribution-based methods, the MID for QMVC change, QMVC % change and normalised QMVC change were estimated as mean (range) 3.55 kg (1.84 kg to 5.11 kg), 18.34% (9.60% to 26.60%) and 7.78% (3.78% to 12.48%) for all participants. However, MID estimates for absolute and % change in QMVC differed markedly between men and women. Normalised QMVC estimates demonstrated smaller sex-based discrepancies. We provide MID estimates for QMVC parameters. Sex-specific or normalised MID estimates for QMVC should be used to facilitate the interpretation of change.

Erratum: Minimal Detectable Change in Dual-Task Cost for Older Adults With and Without Cognitive Impairment.

The 8-item Overactive Bladder Questionnaire (OAB-V8) is a readily available instrument for assessing overactive bladder (OAB) symptoms in clinical and research settings. Despite its established validity in Turkish, its psychometric property remains unevaluated. This study aimed to determine the responsiveness, minimal detectable change (MDC), and minimal clinically important difference (MCID) of the Turkish version of the OAB-V8. This retrospective study consisted of 160 women (age 47.49 ± 12.07years) with OAB who completed a standardized, guideline-adherent 8-week pelvic floor muscle training. The OAB-V8 was administered pre- and post-training. The responsiveness of the OAB-V8 was assessed using the Wilcoxon signed-rank test, standardized response means (SRMs), and effect sizes (ESs). The MDC was calculated at the 95% confidence level. Receiver operating characteristic (ROC) analysis was used to determine the MCID, maximizing both sensitivity and specificity. The responsiveness of the Turkish version of the OAB-V8 was excellent (ES = 1.57, SRM = 1.56, p < 0.001). The MDC and MCID values were 12.97 and 12.50, respectively. The ROC analysis demonstrated excellent discriminative ability, with an area under the curve of 0.99 (sensitivity 98.0%, specificity 90.0%). The main findings of this study confirm that the OAB-V8 demonstrated excellent responsiveness and discriminative ability, making it an effective tool for assessing symptoms in women with OAB. Clinicians can confidently use the Turkish version of the OAB-V8 scale to not only monitor treatment efficacy but also to determine whether the observed changes are both statistically significant and clinically relevant for the patient.

This study aimed to evaluate the current literature on its use and derivation of clinically meaningful changes (CMC) in patient-reported outcome measures (PROMs) for evaluation of post-treatment outcomes after anterior cruciate ligament (ACL) reconstruction. A systematic search following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines was conducted using PubMed, Scopus and Web of Science databases from 2008 to 2024. Inclusion criteria included full-text articles in the English language regarding ACL reconstruction that used and described the derivation of CMC metrics in PROMs with a minimum 1-year follow-up. Studies were excluded if they were non-human research, narrative or systematic reviews, case studies, editorials, commentaries, or if CMCs were derived from previous studies. CMC terms included: Minimal Clinically Important Difference (MCID), Patient Acceptable Symptom State (PASS), Minimal Detectable Change (MDC), Substantial Clinical Benefit (SCB), Minimal Important Difference (MID) and Minimal Important Change (MIC). Twenty-two studies met the inclusion criteria with 4852 total patients with a mean age of 24.2 years. The MCID was calculated in 14 studies (63.6%). MCID was calculated using distribution-based methods in 11 studies (50.0%), anchor-based methods in one study (4.5%) and both methods in one study (4.5%). MDC was derived in three studies (13.6%), using distribution-based methods. PASS was derived in six studies (7.3%), SCB was derived in two studies (9.1%), MID was derived in one study (4.5%), and MIC was derived in one study (4.5%), all using anchor-based methods. There is inconsistency in the ACL literature regarding the use and derivation of CMC metrics for the assessment of PROMs. With increased use of PROMs in literature to develop Clinical Practice Guidelines and guide Medicare/Medicaid decisions, standardization of PROM interpretation is necessary. Clear definitions and consistency in the derivation of CMC metrics will help increase standardization in patient outcome assessments. Level IV.

BackgroundTraumatic brain injury (TBI) often causes visual symptoms that hinder rehabilitation. The Brain Injury Vision Symptom Survey (BIVSS) is an established 28-item questionnaire for TBI-related visual symptoms, but it is only available in English. We aimed to create and validate an Arabic version to provide a culturally adapted tool for Arabic-speaking patients.MethodsThe BIVSS was translated into Arabic using Beaton’s cross-cultural adaptation model (forward–backward translation, expert committee review, cognitive debriefing). Twenty-nine TBI patients completed the Arabic BIVSS twice, one month apart. Internal consistency was measured with Cronbach’s alpha. Test–retest reliability was assessed with an intraclass correlation coefficient [ICC(3,1)]. Agreement between test and retest was examined via Bland–Altman analysis (mean bias and 95% limits of agreement [LOA]). We also calculated the standard error of measurement (SEM) and the 95% minimal detectable change (MDC₉₅). Shapiro–Wilk tests were used to assess normality.ResultsThe Arabic BIVSS showed excellent internal consistency (Cronbach’s α = 0.897) and test–retest reliability (ICC(3,1) = 0.952, 95% CI [0.750, 0.984]). Bland–Altman analysis indicated a slight mean bias of −3.59 (test minus retest), with 95% LOA from −11.71 to 4.54. No proportional bias was observed. The SEM was 2.93, and MDC₉₅ was 8.12 points. Score distributions were approximately normal (Shapiro–Wilk p = 0.024 at baseline, 0.083 at retest).ConclusionThe Arabic BIVSS is a reliable and valid instrument for assessing TBI-related visual symptoms. This cross-culturally adapted version can facilitate clinical screening and research in Arabic-speaking populations. However, given the small sample size and lack of a control group, further research is required to establish population-specific cut-off values and assess construct validity and responsiveness.

Introduction: Accurate ocular axial length (AL) measurement is critical for intraocular lens power calculation and refractive outcomes. While optical biometry is the clinical standard, dense media opacities limit its utility. This study evaluated B-mode ultrasound (B-USG) and MRI reproducibility and reliability for ocular AL measurement and assess inter-method agreement as alternative AL measurement methods. Methods: This prospective study included 102 adults (mean age 31.5±6.5 years) with normal ocular anatomy and emmetropic refraction. AL measurement used B-USG (9–12 MHz) and 1.5 Tesla MRI. Two blinded observers performed independent measurements; one repeated measurement after one day. Reliability was assessed using Intraclass Correlation Coefficient (ICC), Standard Error of Measurement (SEM), and Minimum Detectable Change (MDC). Agreement was evaluated with Bland–Altman analysis and Pearson correlation. Results: Mean AL was 23.618±0.726 mm for B-USG and 24.033±0.727 mm for MRI. Both methods showed excellent intra-observer (ICC=0.92 for ultrasound; ICC=0.95 for MRI) and inter-observer reliability (ICC=0.90 for ultrasound; ICC=0.93 for MRI). Strong linear correlation was observed (r=0.95, p&lt;0.001). Bland-Altman analysis revealed significant systematic bias, with MRI measuring systematically longer values (+0.42 mm, 95% CI: 0.38–0.46), with wide limits of agreement (−0.15 to +0.99 mm), indicating non-interchangeable methods. Conclusions: B-USG and MRI are highly reliable and reproducible for AL measurement. However, consistent systematic bias and wide agreement limits restrict interchangeable use for high absolute accuracy applications. These modalities are valuable optical biometry alternatives, provided single method consistency.

Background:Relative humeral retrotorsion (rHRT) is an osseous adaptation in overhead athletes garnered from repetitive overhead throwing. Accurate measurement of anatomic humeral retrotorsion (aHRT) is important as it aids in the determination of rHRT, which influences glenohumeral range of motion profiles. While computed tomography scans are the gold standard for assessing aHRT, their limited clinical utility has driven interest in accessible alternatives, such as diagnostic ultrasound.Purpose/Hypothesis:The purpose of this study was to validate a handheld ultrasound device (HH-US) as a clinically accessible tool to measure aHRT in baseball and softball athletes. It was hypothesized that a HH-US device will be reliable and valid when quantifying aHRT compared with an established benchmark, diagnostic musculoskeletal ultrasound (MSK-US).Study Design:Cohort study (Diagnosis); Level of evidence, 3.Methods:Data were collected from collegiate baseball and softball athletes at 2 local universities. Participants were uninjured at the time of testing and over 17 years old. Anatomic HRT was measured bilaterally using both MSK-US (GE Venue Go) and handheld ultrasound (GE Vscan Air) using previously established methods. The intraclass correlation coefficient, standard error of measure, and minimal detectable change, as well as Bland-Altman plots, were used to assess reliability and agreement between devices, respectively.Results:A total of 93 athletes were included in this study. HH-US had excellent intrarater reliability (ICC2,1 = 0.98; 95% CI, 0.94-0.97; SEM90 = 1.77°; and MDC90 = 4.12°). There was acceptable agreement between the HH-US and MSK-US. The mean difference between devices was −0.63° and 0.48° for the throwing and nonthrowing arms, respectively. Analysis of Bland-Altman plots demonstrated no significant bias across the range of measurements. HH-US measurements were completed in <2 minutes.Conclusion:Our study showed that HH-US provides a reliable and valid measurement of aHRT in comparison to MSK-US and may be an accessible option for clinicians evaluating overhead athletes. Given its strong agreement with established methods, HH-US offers an efficient and cost-effective alternative to MSK-US when measuring aHRT in baseball and softball athletes.

The heterogeneity of threshold values for the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and Patient Acceptable Symptom State (PASS) as reported in the rotator cuff repair literature undermines the utility of these concepts. This systematic review identifies studies with published threshold values and proposes a methodologic framework for determining which values should be used for rotator cuff repair moving forward. To provide recommendations for the MCID, SCB, and PASS thresholds of commonly utilized patient-reported outcome measures for rotator cuff repair, as well as recommendations for how these thresholds should be calculated moving forward. Systematic review; Level of evidence, 3. All studies reporting MCID, SCB, and PASS threshold values after rotator cuff repair published between January 1, 2000, and May 31, 2022, were extracted via systematic review. The following data were collected: follow-up duration and patient attrition; reported threshold values; and data relevant to threshold calculation, including method, anchor questions and responses, area under the curve, and confidence intervals. The authors prioritized values calculated with an anchor question over those calculated without one, values from receiver operator characteristic analysis over those from mean change and logistic regression, and anchor questions with multiple response options over those with binary response options. In total, 41 studies were included in the systematic review: 37 (90%), 11 (27%), and 16 (39%) reported MCID, SCB, and PASS thresholds, respectively. In addition, 12 studies calculated threshold values using anchor-based methods, and 6 calculated threshold values through distribution-based methods. The authors made recommendations for each threshold reported by at least 4 studies: for MCID, American Shoulder and Elbow Surgeons (ASES) = 21, visual analog scale for pain = 1.5, single assessment numeric evaluation (SANE) = 12, University of California at Los Angeles shoulder score = 6, and Constant-Murley score = 5.5; for SCB, ASES = 26 and SANE = 20; and for PASS, ASES = 78, visual analog scale for pain = 1.7, SANE = 71, and Constant-Murley score = 23.3. With standardized MCID, SCB, and PASS threshold values for rotator cuff repair surgery, these concepts hold enormous potential to power future comparative studies, guide reimbursement policy, and aid patient decision-making. Future research on novel MCID, SCB, and PASS threshold values should collect preoperative and 12-month postoperative patient-reported outcome measure data. Anchor questions should pertain to overall satisfaction with surgery and have multiple specific answer choices. These data should be correlated by receiver operator characteristic analysis, and any threshold values should then be compared with the standard error of the mean or minimal detectable change to ensure statistical significance.

Reliability and validity of the Turkish version of the stroke upper limb capacity scale (SULCS) in post-stroke patients.

Background/Objectives: Adolescents may experience psychosocial consequences from minor dentofacial variations. The relationship between objectively rated smile esthetics and self-reported psychosocial impact remains under-studied in Saudi adolescents. This study aimed to investigate the relationship between the objectively measured smile esthetics with the subjectively reported psychosocial impact of perceived smile esthetics. Methods: Cross-sectional, multistage cluster-stratified sample technique was used to study adolescents aged 15–20 years (n = 344) from Al-Ahsa schools. Standardized extra-/intraoral photography supported Dental Esthetic Screening Index (DESI) scoring and psychosocial impact using Arabic Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) were applied. Reliability was assessed through two-way mixed intraclass correlation coefficient (ICC), Bland–Altman analysis, standard error of measurement (SEM), and minimal detectable change at the 95% confidence level (MDC95). Associations were examined using correlations and regression models. Results: The distribution of DESI categories was excellent (6.4%), good (29.7%), satisfactory (42.2%), insufficient (18.9%), and poor (2.9%). The distribution of PIDAQ impact levels was minimal (37.8%), slight (41.6%), moderate (18.0%), and significant (2.6%) (age p = 0.052; sex p = 0.417). DESI and total PIDAQ were weakly correlated (Spearman ρ = 0.248, 95% CI 0.143–0.347; p < 0.001). In a multivariable linear regression model with continuous PIDAQ total score as the outcome (R2 = 0.525; adjusted R2 = 0.516; p < 0.001), self-perceived smile dissatisfaction (B = 7.789; β = 0.478; p < 0.001) and tooth-color dissatisfaction (B = 4.099; β = 0.306; p < 0.001) showed the strongest associations with higher PIDAQ scores, while DESI total score showed a smaller association (B = 0.310; β = 0.120; p = 0.002). Age and sex were not significant predictors after adjustment. Conclusions: Objective smile esthetics were modestly associated with psychosocial impact, whereas adolescents’ self-perceived smile and tooth-color dissatisfaction were strongly associated with worse psychosocial outcomes. Although the smile esthetics may be clinically acceptable, adolescents can still experience reduced oral health-related quality of life due to the psychosocial impact of perceived dental esthetics. These findings support incorporating brief subjective questions on smile and tooth-color perception alongside objective assessment during routine adolescent dental care.

Test-retest reliability of dual-task cost in neurocognitive single-leg hop and countermovement jump tests.

Nacafucasaco, ETA, Da Silva, DDG, Bergamasco, JGA, Bittencourt, D, Chaves, TS, Scarpelli, MC, and Libardi, CA. Influence of image acquisition and biologic variability on measurement reproducibility of vastus lateralis muscle architecture using ultrasound. J Strength Cond Res 40(1): e108-e116, 2026-The objective of this study was to compare 2 reproducibility protocols for muscle architecture measurements of the vastus lateralis using ultrasonography (US): (a) a single image acquisition followed by 2 quantifications with a 72-hour interval (1X protocol) and (b) 2 separate image acquisitions followed by 2 quantifications, each 72 hours apart (2X protocol). A total of 54 subjects had both legs assessed by US, resulting in 104 experimental units. Muscle architecture parameters (cross-sectional area [CSA], muscle thickness [MT], fascicle length [FL], and pennation angle [PA]) were quantified, and typical error (TE), coefficient of variation (CV), minimum detectable change (MDC), and Bland-Altman plots were used for reproducibility analysis. Typical error and CV values were consistently lower for the 1X protocol (CSA: TE = 0.51 cm2, CV = 2.31%, MDC = 1.41 cm2; MT: TE = 0.05 cm, CV = 2.61%, MDC = 0.14 cm; FL: TE = 0.21 cm, CV = 3.00%, MDC = 0.57 cm; PA: TE = 0.55°, CV = 3.68%, MDC = 1.52°) than for the 2X protocol (CSA: TE = 0.92 cm2, CV = 4.15%; MDC = 2.55 cm2; MT: TE = 0.12 cm, CV = 6.22%, MDC = 0.33 cm; FL: TE = 0.48 cm, CV = 6.88%, MDC = 1.33 cm; PA: TE = 1.15°, CV = 7.82%, MDC = 3.18°). Paired t-tests and Wilcoxon tests indicated significant differences between protocols for FL (p < 0.001) and PA (p < 0.026), but not for CSA and MT. Levene's test showed greater variance in all parameters for the 2X protocol (p < 0.001). These findings highlight the influence of reproducibility protocol on measurement variability and emphasize the need to account for evaluator-related and biologic sources of error in US-based muscle assessments.

PurposeReliable gait analysis is essential for clinical assessment and research. Wearable technologies such as the WalkinSense system (WSS), a wireless instrumented insole system equipped with an inertial measurement unit, enable the measurement of spatiotemporal and kinematic gait parameters in real‐world settings. The accuracy of the WSS has been previously validated. This study aims to evaluate the test–retest reliability of the WSS in healthy adults walking and running under various speed and slope conditions.MethodsForty‐nine healthy adults completed two sessions one week apart, walking and running at 3, 4.5 (−3°, −6°, +3°, +6°), 6 and 9 km/h on a treadmill. Spatiotemporal variables, including stance time, swing time, stride time, stride length, single and double support time, as well as kinematic variables such as foot ground angle at initial contact and toe‐off, were recorded using the WSS. Relative reliability was assessed using intraclass correlation coefficients (ICC2,1), while absolute reliability was evaluated using the standard error of measurement (SEM), minimal detectable change (MDC) and their percentage values (SEM%, MDC%). Bland‐Altman plots were used to detect systematic bias and visualise agreement.ResultsResults demonstrated good to excellent reliability for most spatiotemporal parameters across all conditions, with ICC values ranging from 0.76–0.95, while the foot ground angles exhibited lower reliability (ICC: 0.71–0.86). SEM% and MDC% were generally below 10% for spatiotemporal measures (SEM%: 1.63–6.63; MDC%: 3.44–18.36), reflecting both low measurement error and high sensitivity to detect real changes beyond random variation. Bland‐Altman analyses revealed no relevant heteroscedasticity.ConclusionThese findings support the WSS as a reliable tool for assessing spatiotemporal variables in healthy adults across diverse walking and running conditions, underscoring its potential for use in both clinical and research environments. However, clinical studies are needed to fully establish its utility in patient assessment.Level of EvidenceLevel II, diagnostic studies.