Smallest Real Difference Values Research Articles

The stability of slow-wave sleep and EEG oscillations across two consecutive nights of laboratory polysomnography in cognitively normal older adults.

Laboratory polysomnography provides gold-standard measures of sleep physiology, but multi-night investigations are resource intensive. We assessed the night-to-night stability via reproducibility metrics for sleep macrostructure and electroencephalography oscillations in a group of cognitively normal adults attending two consecutive polysomnographies. Electroencephalographies were analysed using an automatic algorithm for detection of slow-wave activity, spindle and K-complex densities. Average differences between nights for sleep macrostructure, electroencephalography oscillations and sleep apnea severity were assessed, and test-retest reliability was determined using two-way intraclass correlations. Agreement was calculated using the smallest real differences between nights for all measures. Night 2 polysomnographies showed significantly greater time in bed, total sleep time (6.3 hr versus 6.8 hr, p < 0.001) and percentage of rapid eye movement sleep (17.5 versus 19.7, p < 0.001). Intraclass correlations were low for total sleep time, percentage of rapid eye movement sleep and sleep efficiency, moderate for percentage of slow-wave sleep and percentage of non-rapid eye movement 2 sleep, good for slow-wave activity and K-complex densities, and excellent for spindles and apnea-hypopnea index with hypopneas defined according to 4% oxygen desaturation criteria only. The smallest real difference values were proportionally high for most sleep macrostructure measures, indicating moderate agreement, and proportionally lower for most electroencephalography microstructure variables. Slow waves, K-complexes, spindles and apnea severity indices are highly reproducible across two consecutive nights of polysomnography. In contrast, sleep macrostructure measures all demonstrated poor reproducibility as indicated by low intraclass correlation values and moderate agreement. Although there were average differences in percentage of rapid eye movement sleep and total sleep time, these were numerically small and perhaps functionally or clinically less significant. One night of in-laboratory polysomnography is enough to provide stable, reproducible estimates of an individual's sleep concerning measures of slow-wave activity, spindles, K-complex densities and apnea severity.

Test–retest reliability of upper limb robotic exoskeleton assessments in children and youths with brain lesions

In children with congenital or acquired brain lesions, impaired upper limb function can affect independence. Assessing upper limb function is important for planning and evaluating neurorehabilitative interventions. Robotic devices increase measurement-objectivity and enable measuring parameters reflecting more complex motor functions. We investigated the relative and absolute test–retest reliability of assessments to measure upper limb functions in children and adolescents with brain lesions with the exoskeleton ChARMin. Thirty children (9 females, mean age ± SD = 12.5 ± 3.3 years) with congenital brain injuries (n = 15), acquired (n = 14), both (n = 1) and impaired upper limb function participated. They performed the following ChARMin assessments and repeated them within three to seven days: active and passive Range of Motion (ROM), Strength, Resistance to Passive Movement, Quality of Movement, Circle, and Workspace. We calculated the systematic difference, Intraclass Correlation Coefficient (ICC) and Smallest Real Difference (SRD) for each parameter. Six parameters of three assessments showed systematic errors. ICCs ranged from little to very high and SRD values varied considerably. Test–retest reliability and measurement errors ranged widely between the assessments. Systematic differences indicated that random day-to-day variability in performance would be responsible for reduced reliability of those parameters. While it remains debatable whether robot-derived outcomes should replace certain routine assessments (e.g., ROM, strength), we recommend applying certain technology-based assessments also in clinical practice.Trial registration: This study was registered prospectively at ClinicalTrials.gov (identifier: NCT02443857) on May 14, 2015.

Intra-rater reliability and repeatability of pulse oximetry values obtained before, between sets, and after resistive exercise

BACKGROUND: Pulse oximetry measures heart rate (HR) and percent oxygen saturation (SpO2). For aerobic exercise, whereby cellular oxygen demand and delivery are elevated and maintained for extended periods, HR and SpO2 values are consistent when measured by pulse oximetry. Yet due to its intermittent nature, HR and SpO2 values from resistive exercise may exhibit lower data reliability and repeatability. OBJECTIVE: Assess intra-rater reliability and repeatability of pulse oximetry HR and SpO2 values from two identical resistive exercise protocols. METHODS: Subjects (n= 32) performed two calf press workouts on a flywheel-based ergometer as HR and SpO2 were measured before, between sets, and after exercise. Workouts entailed a 4-set 15-repetition protocol separated by 120-second rests. Intra-rater reliability was assessed with intraclass correlation coefficients (ICC). Repeatability was measured by the smallest real difference in absolute and relative terms. RESULTS: ICC and standard error of estimate results for HR ranged from 0.60–0.79 and 9.1–13.0 respectively. SpO2 ICC and standard error of estimate results ranged from 0.16–0.71 and 1.44–4.33 respectively. Between sets, smallest real difference values tended to be less for HR. CONCLUSIONS: Results demonstrate acceptable intra-rater reliability and repeatability for HR, but not SpO2 which we attribute to the exercise mode and protocol examined.

Intra- and inter-rater reliability of lower leg waterplethysmography, bioelectrical impedance and muscle twitch force for the use in standing work evaluation

Objectives. Prolonged standing is associated with multiple risk factors for musculoskeletal and venous disorders. In Germany over 50% of the working population spend most of their working time in a standing position. Basic understanding of prolonged standing physiology is lacking. We therefore plan to investigate the influence of 5 h standing (including breaks) on lower limb oedema measured by waterplethysmography (WP) and bioelectrical impedance (BI) and fatigue in the triceps surae muscle using muscle twitch force (MTF). In order to interpret our results, test-retest and inter-rater reliability of these measurement methods was evaluated first. Approach. 20 subjects (9 female) were included to test each method three times (M1, M2, M3) in 30 min periods with two raters (R1, R2) on separate days. Intraclass correlation coefficient (ICC; 2,1), standard error of measurement (SEM) and smallest real difference (SRD) were calculated for both raters. Main results. The SEM and SRD calculated for WP were 27 and 75 ml, respectively, for R1 and 23 and 64 ml, respectively, for R2 with an ICC of 0.98 (p < 0.0001). Statistically significant mean differences between M1 and M2 (R1 = 23 ml, p = 0.004; R2 = 19 ml, p = 0.027) but not significant mean differences between M2 and M3 (R1 = −6 ml, p = 0.45; R2 = 4 ml, p = 0.27) were calculated for both raters. BI data revealed SEM and SRD values of 3.8 and 10.5 Ω, respectively, for R1 and 3.4 and 9.4 Ω, respectively, for R2 with an ICC of 0.24 (p = 0.001). The differences between M1 and M2 (R1 = 3.9 Ω, p = 0.0001; R2 = 2.4 Ω, p = 0.049) and between M2 and M3 (R1 = 2.3 Ω, p = 0.012; R2 = 2.0 Ω, p = 0.008) were found to be statistically significant for both raters. SEM and SRD for MTF were 0.19 and 0.53 N, respectively, for R1 and 0.23 and 0.64 N, respectively, for R2 with an ICC of 0.71 (p < 0.0001). Mean differences between M1 and M2 were statistically significant for rater 1 but not for rater 2 (R1 = 0.13 N, p = 0.022; R2 = 0.12 N, p = 0.082) and the same was found for the difference between M2 and M3 for both raters (R1 = 0.04 N, p = 0.37; R2 = 0.08 N, p = 0.12). Significance. All three measurement methods showed good reliability and should be suitable for detecting effects of standing work on oedema development and fatigue as seen in previous results of long term standing experiments. Inter-rater reliability is found to be satisfactory as well, demonstrated by the small differences in SEM values of R1 and R2. Statistically significant differences shown for all three measurement methods could be due to lacking standardisation of leg placement and thus an actual lower leg volume change between measurements, indicating possibilities for further improvement of SEM values.

Absolute and Relative Reliability of the Timed 'Up & Go' Test and '30second Chair-Stand' Test in Hospitalised Patients with Stroke.

ObjectiveThe timed ‘Up & Go’ test and ‘30second Chair-Stand’ test are simple clinical outcome measures widely used to assess functional performance. The reliability of both tests in hospitalised stroke patients is unknown. The purpose was to investigate the relative and absolute reliability of both tests in patients admitted to an acute stroke unit.MethodsSixty-two patients (men, n = 41) attended two test sessions separated by a one hours rest. Intraclass correlation coefficients (ICC2,1) were calculated to assess relative reliability. Absolute reliability was expressed as Standard Error of Measurement (with 95% certainty—SEM95) and Smallest Real Difference (SRD) and as percentage of their respective means if heteroscedasticity was observed in Bland Altman plots (SEM95% and SRD%).ResultsICC values for interrater reliability were 0.97 and 0.99 for the timed ‘Up & Go’ test and 0.88 and 0.94 for ‘30second Chair-Stand’ test, respectively. ICC values for intrarater reliability were 0.95 and 0.96 for the timed ‘Up & Go’ test and 0.87 and 0.91 for ‘30second Chair-Stand’ test, respectively. Heteroscedasticity was observed in the timed ‘Up & Go’ test. Interrater SEM95% ranged from 9.8% to 14.2% with corresponding SRD% of 13.9–20.1%. Intrarater SEM95% ranged from 15.8% to 18.7% with corresponding SRD% of 22.3–26.5%. For ‘30second Chair-Stand’ test interrater SEM95 ranged between 1.5 and 1.9 repetitions with corresponding SRD of 2 and 3 and intrarater SEM95 ranged between 1.8 and 2.0 repetitions with corresponding SRD values of 3.ConclusionExcellent reliability was observed for the timed ‘Up & Go’ test and the ‘30second Chair-Stand’ test in hospitalised stroke patients. The thresholds to detect a real change in performance were 18.7% for the timed ‘Up & Go’ test and 2.0 repetitions for the ‘30second Chair-Stand’ in groups of patients and 26.5% and 3 repetitions in individual patients, respectively.

Personalized physiotherapy in frail older adults with mobility problems is (cost)-effective in improving physical activity and frailty: a RCT

exercise tests on treadmill, corridor walking or on stationary cycles. Only few studies have assessed the reproducibility and reliability of the Talk Test. To the best of our knowledge no studies have assessed the measurement error of the Talk Test. Purpose:Our purposewas to assess relative reliability and measurement error of the Graded Cycling Test with the Talk Test for patients with ischemic heart disease. Also we compared the reliability of the patient-rated test, with reliability of the ratings of two physiotherapists. Methods: 64 patientswith ischemic heart disease (women n= 30) were introduced to the test one week prior to testing, and then performed the Graded Cycling Test with the Talk Test twice in one day. Initially patients cycled two minutes at 15watt (W) intensity, followed by 15W increase every minute. Every minute the patient recited a text passage of 30 words, and answered the question “Are you still able to speak comfortably?” with “Yes” (TT+) “Not sure” (TT±) or “No” (TT−). The test ended, when the patient answered “No”. Two physiotherapists rated independently and blinded to patients’ rating, when ventilation affected the patient’s ability to speak. Relative reliability: Inter Class Correlation (ICC2.1) and measurement error: Standard Error of Measurement with 95% CI (SEM 95) and Smallest Real Difference (SRD) were calculated. Results: ICC values of .90, .91 and .90 were observed for TT+, TT± and TT−, respectively. Physiotherapists ICCs ranged between .81 and .88. SEM95 ranged between 17.2 and 18.3W with corresponding SRD values between 24.4 and 25.9W for the patient ratings. The physiotherapists-ratings ranged between 15.8 and 21.4W (SEM95) and 22.3 and 30.3W (SRD). Conclusion(s): The main findings were

The graded cycling test combined with the talk test is reliable for patients with ischemic heart disease

PURPOSE: To assess relative reliability and measurement error of the Graded Cycling Test (GCT) with the Talk Test (TT) for patients with cardiac disease. METHODS: Patients (N = 64; women, n = 30) with ischemic heart disease performed the GCT with the TT twice in 1 day. Every minute the patient recited a text passage of 30 words. The question Are you still able to speak comfortably? was then answered: Yes (TT+), Not sure (TT+/-), or No (TT-). Two physiotherapists (PTs) rated when the speaking ability was affected by ventilation. Relative reliability: intraclass correlation coefficient (ICC)2.1 and absolute reliability: standard error of measurement with 95% CI (SEM95) and smallest real difference (SRD) were calculated. RESULTS: Intraclass correlation coefficient values of 0.90, 0.91, and 0.90 were observed for TT+, TT+/-, and TT-, respectively. Physiotherapist ICCs ranged between 0.81 and 0.88. SEM95 ranged between 17.2 and 18.3 watts (W), with corresponding SRD values between 24.4 and 25.9 W for the patient ratings. The PT ratings ranged between 15.8 and 21.4 W (SEM95) and between 22.3 and 30.3 W (SRD). CONCLUSIONS: The TT, combined with the GCT, was well tolerated by patients with cardiac disease in clinical settings with small measurement error and an excellent relative reliability. These results apply to both patient-rated and PT-rated TT.

Within-Session Reliability and Smallest Real Difference of Muscle Strength Following Nerve Transfers in Patients With Brachial Plexus Injuries

To quantify the smallest real difference (SRD) of muscle strength in patients with brachial plexus injuries (BPI) after nerve transfer. This study enrolled 16 patients with BPI who had C5-C6 and C5-C7 root injuries and who received nerve transfer of the spinal accessory nerve to the suprascapular nerve and fascicles of the ulnar nerve to the branch of the musculocutaneous nerve that innervates the biceps muscle. The quantitative peak strength of the shoulder abductor, external rotator, and elbow flexor in both arms were measured by the hand-held dynamometer. The SRD of each muscle was determined from the values of the intraclass correlation coefficient and standard error of measurement. In the involved arm, peak strength ranged from 18% of the noninvolved (shoulder external rotator) to 40% of the noninvolved (shoulder abductor). The intraclass coefficient for within-session reliability revealed good to excellent reliability for muscles, ranging from 0.86 to 0.99 and 0.87 to 0.91 in the involved and noninvolved arms, respectively. The SRD values were low for the shoulder external rotator (2.6 kg) and high for the elbow flexor (3.3 kg). The hand-held dynamometer is a device with good to excellent reliability for measuring the objective strength of patients with BPI in a single session. The SRD values established in the current study are more applicable for patients achieving a Medical Research Council grading of 3 or higher and can be used to detect real changes occurring after intervention, which can thereby differentiate real changes from changes that could be attributed to random variation in the measurements. Diagnosis II.

Measurement properties of the lower extremity motor coordination test in individuals with stroke

To evaluate the construct validity, inter- and intra-rater reliabilities, best scoring method and testing methods (direct vs video observations), and to determine the smallest real difference (SRD) and standard error of the measurement (SEM) of the lower Extremity Motor Coordination Test (LEMOCOT). Methodological study. Thirty-six stroke subjects. Outcomes include measures of motor recovery, muscular tone, strength, motor coordination, foot tactile sensation, and gait speed. The LEMOCOT scores were able to discriminate between stroke individuals from those predicted for healthy subjects, between the paretic and non-paretic limbs for both the sub-acute and chronic groups and differentiated between individuals with different functional levels and degrees of motor recovery. For the intra- and inter-rater reliabilities, very high and significant coefficients were found for both the paretic and non-paretic lower limbs for both groups (intra-class correlation coefficients (ICC) > 0.97, p < 0.0001). Significant differences were found regarding all scoring methods (18.91 < F < 27.49, p < 0.0001), but they were not clinically important and all showed adequate test-retest reliability and acceptable SRD and SEM (< 15%) values. There was also agreement between the scores from the direct and video observations. The LEMOCOT demonstrated adequate measurement properties in stroke subjects and, therefore, could be an appropriate measure for research and clinical purposes.

The graded cycling test combined with the talk test is reliable for patients with ischemic heart disease.

To assess relative reliability and measurement error of the Graded Cycling Test (GCT) with the Talk Test (TT) for patients with cardiac disease. Patients (N = 64; women, n = 30) with ischemic heart disease performed the GCT with the TT twice in 1 day. Every minute the patient recited a text passage of 30 words. The question "Are you still able to speak comfortably?" was then answered: "Yes" (TT+), "Not sure" (TT±), or "No" (TT-). Two physiotherapists (PTs) rated when the speaking ability was affected by ventilation. Relative reliability: intraclass correlation coefficient (ICC)2.1 and absolute reliability: standard error of measurement with 95% CI (SEM95) and smallest real difference (SRD) were calculated. Intraclass correlation coefficient values of 0.90, 0.91, and 0.90 were observed for TT+, TT±, and TT-, respectively. Physiotherapist ICCs ranged between 0.81 and 0.88. SEM95 ranged between 17.2 and 18.3 watts (W), with corresponding SRD values between 24.4 and 25.9 W for the patient ratings. The PT ratings ranged between 15.8 and 21.4 W (SEM95) and between 22.3 and 30.3 W (SRD). The TT, combined with the GCT, was well tolerated by patients with cardiac disease in clinical settings with small measurement error and an excellent relative reliability. These results apply to both patient-rated and PT-rated TT.

3-D geometric imaging of the trunk in normal adolescents and age-matched patients impaired with idiopathic scoliosis: selected effects of conservative intervention according to Schroth

Method Twenty three adolescents, (12 healthy and 11 with AIS) participated in the study. All AIS patients had at least one curve of 20o, and were skilled in postural corrections based on Schroth principles. Trunk symmetry was assessed using the Coda Cx1 3DMP system. Markers were applied on the head, acromioclavicular joints, suprasternal notch, scapular inferior angles, pelvis, knee, hip, lateral malleoli and the heads of the 5th metatarsus. All patients were measured twice in the same day, (with a 4-hour break between sessions), in natural sitting, standing, and walking. AIS patients were measured again in those three positions, during postural correction according to Schroth. From the test-retest paradigm the stringent cut-off for a true clinical change the smallest real difference (SRD) was derived. Results There was a significant and high correlation between the Cobb angle and scapular transverse misalignment. AIS patients showed significant correction of scapular rotation, in standing, and the location of the center of scapulae relative to the center of the pelvis. At least 36% of the patients corrected the previous, and more than 45% that of the latter, beyond the SRD. With respect to shifting of the shoulder girdle relative to the pelvis in standing and walking, 55% of the patients have exceeded the SRD value.

Smallest Real Difference of 2 Instrumental Activities of Daily Living Measures in Patients With Chronic Stroke

Lu W-S, Chen CC, Huang S-L, Hsieh C-L. Smallest real difference of 2 instrumental activities of daily living measures in patients with chronic stroke. ObjectiveTo estimate the smallest real difference (SRD) values of 2 instrumental activities of daily living measures (the Nottingham Extended Activities of Daily Living [NEADL] and the Frenchay Activities Index [FAI]) in patients with chronic stroke. DesignTest-retest reliability study. SettingPhysical rehabilitation units of 5 hospitals. ParticipantsChronic stroke patients (N=52; 37 men, 15 women) who were discharged from the hospital for more than 6 months. InterventionsNot applicable. Main Outcome MeasuresBoth measures were administered twice about 2 weeks apart to participants. The SRD was calculated on the basis of standard error of measurement: SRD = 1.96 × √2 × Standard error of measurement. SRD% (the value of SRD divided by total score of a measure) was used to compare measurement errors across both measures. Reproducibility between successive measurements of the measures was investigated with intraclass correlation coefficients (ICCs). ResultsThe SRD (SRD%) values of the NEADL and the FAI were 12.0 (21.1%) and 6.7 (14.9%), respectively. Test-retest reproducibility of both measures was high (ICC: NEADL=.89, FAI=.89). ConclusionsBecause of substantial SRD values of the NEADL and the FAI, prospective users should be cautious in using both measures to detect real change for a single subject.

Reproducibility of a measurement for latissimus dorsi muscle length

ABSTRACTLatissimus dorsi is a muscle theorized to undergo length changes due to shoulder region pathology or treatment such as stretching. A latissimus dorsi length measurement would be valuable to determine if length changes have occurred within an individual over time. With no such measurement known, we examined a proposed technique believed to isolate latissimus dorsi. The aim of this study was to determine how accurately a rater could reproduce this measurement in the same individual over a 6-week interval. Thirty subjects without shoulder symptoms were measured at 6-week intervals by either an experienced or novice clinician. A repeated-measures analysis of variance estimated the measurement error used for calculating intrarater correlation coefficients (ICC3,1). The standard error of measurement (SEM), confidence intervals (CI), and the smallest real difference (SRD) were also determined. The ICCs for all raters combined and for the separate groups indicated poor reliability. The SEM and SRD values were similar between groups, but they suggest poor measurement reproducibility in the same subject over a 6-week interval. This technique is not recommended for measuring latissimus dorsi length clinically to assess within-subject change over time.

Inter-rater reliability and smallest real difference of the Chinese Psychoeducational Profile-third edition for children with Autism Spectrum Disorder

The purpose of this study was to examine the inter-rater reliability of the Chinese version of the Psychoeducational Profile-third edition (CPEP-3) in children with Autism Spectrum Disorder. We also calculated the smallest real difference (SRD) for users to determine whether the change score rated by different raters for an individual child is valid. The CPEP-3 was administered to 42 children aged from 2 years 4 months to 7 years 7 months by two independent therapists twice, with an 11- to 21-day interval. The high internal consistency for performance subtests (Cronbach's alpha = 0.92–0.98) and composites (Cronbach's alpha = 0.92–0.95) in the CPEP-3 indicates the homogeneity of all the items in each subtest and composite. The inter-rater reliability of the CPEP-3, examined by intra-class correlation coefficient, ranged from 0.57 to 0.94 for the performance subtests, and 0.63 to 0.89 for the composites. The SRDs of the CPEP-3 ranged from 5.8 to 12.8 for the performance subtests, and 7.3 to 18.0 for the composites. The SRDs of the CPEP-3 were 14.4–51.8% of the possible highest scores of each subtest and composite. The substantial SRDs indicate that clinicians should consider such SRD values in determining whether a child's change score of the CPEP-3 indicates real change when the CPEP-3 is administered by different raters. Further studies to examine the construct validity, responsiveness, and minimally important difference of the CPEP-3 are needed to improve the utility of the CPEP-3.

Reliability of transcranial magnetic stimulation-related measurements of tibialis anterior muscle in healthy subjects

The main purpose of this study was to determine the reliability of transcranial magnetic stimulation (TMS)-related measurements linked to the corticospinal control of the tibialis anterior (TA) muscle in healthy subjects. Inter-investigator and intra-investigator (within-session with a 1.5-h interval; between-session with a 4-week interval) reliability of the motor threshold, recruitment curve with its slope and MEP area at the plateau, MEP latency, maximum MEP (MEPmax) area, and duration of the maximum and minimum silent period (SPmax and SPmin) were assessed in 50 (29 men and 21 women) healthy subjects (mean age 44.8 years, range 22-74 years) using intraclass correlation coefficients (ICC), standard error of measurement (SEM) and smallest real difference (SRD). The high ICC values and lower SEM and SRD values indicate a good intra- and inter-investigator reliability for motor threshold (ICC range 0.94-0.98), MEP latency (ICC range 0.79-0.93), SPmax (ICC range 0.89-0.95) and SPmin (ICC range 0.79-0.81) in healthy subjects. These results suggest that the TMS-related measurements investigated are reliable in healthy subjects. These data could be useful in further studies on cortical excitability changes, such as those induced by therapeutic interventions (e.g. rehabilitative treatment).

Reproducibility of ultrasonic measurements of pelvic floor structures in women suffering from urinary incontinence

The aim of this study was to examine the reproducibility of ultrasound (US) findings relating to pelvic floor muscle in women with urinary incontinence (UI). Eighteen women with UI were examined twice by the same examiners over an interval of 1 month. The US findings comprised of (1) distance between bladder neck and symphysis pubis (BN/SP) at rest, during contraction, and while performing the Valsalva maneuver and (2) distance between anorectal angle and symphysis pubis (AR-SP) during the same conditions. Statistical analysis included test-retest correlations (ICC(3,K)), and the assessment of measurement error and smallest real difference (SRD) for change. BN-SP and AR-SP exhibited high ICCs. The lowest SRD values related to the AR-SP variables (10-19%). US-based measures of the bladder neck and the anorectal angle, distance, and displacement seem to offer reasonable clinical reproducibility.

Clinical measurement of posterior shoulder flexibility

The objectives of this study were to determine both the intra-rater reliability and the smallest real difference necessary to detect meaningful clinical changes over an 8–12 week period for three clinical measures of posterior shoulder flexibility. Posterior shoulder tightness has been associated with abnormal humeral head translations that narrow the subacromial space and contribute to impingement. Posterior shoulder stretching to normalize joint kinematics is often used when treating individuals with subacromial impingement. Currently there is no measurement of posterior shoulder flexibility that has been demonstrated to be reliable or responsive in patients over a treatment interval. Construction workers with overhead work exposure were recruited to an impingement group ( n=37), and an asymptomatic group ( n=22). Three flexibility measurements were taken on each subject at baseline and 8–12 weeks later by the same physical therapist. Intra-rater reliability was determined using intra-class correlation coefficients (ICCs) and standard errors of measurement (SEM). The smallest real difference value (SRD) determined the smallest detectable intervention-related measurement change over time. ICCs for the three measurements ranged from poor (0.40) to good (0.79). The SEM and SRD values reflected high test–retest variability in all three measurements. None of the three measures were proven to be highly stable indicators of posterior shoulder flexibility over this time period, nor were they able to detect small changes over this interval due to the high trial to trial variance in a non-intervention sample. Caution should be used when interpreting these clinical measurements over prolonged time periods.