# A New Flexometric Method to Evaluate Range of Movement: A Validity and Reliability Study
## 2 Materials and Methods
### Data Analysis
#### 2.3.2 Statistical Analyses  
Statistical analyses were performed using the SPSS software package version 15.0 (SPSS Inc., Chicago, IL, USA) for Windows statistical program. Descriptive statistics (mean and standard deviation or SD) were used to summarize ROM measurements for both the FM and WI measurements. Two attempts for every test were recorded in each participant. Inter- and intra-observer reliability were evaluated by the interclass correlation coefficient (ICC), i.e., a two-way random effects model with a single measure (model 2.1). The ICC value can range from 0 to 1; values close to 1 indicate high reliability. Our interpretation  
Figure 2: An illustrative chart of the study design. HA: hip abduction test; SLR: straight leg raise test; SLR-R: R: right leg; SLR-L: left leg. WI: WIMU system; FM: flexometric method.  
of the ICC value was based on guidelines provided by [PERSON] and [PERSON] [35], where 1 = perfect reliability, 0.90 to 0.99 = very high reliability, 0.70 to 0.89 = high reliability, 0.50 to 0.69 = moderate reliability, and a value of 0.90-0.95 was considered satisfactory for individual comparisons [36]; Scientific Advisory Committee of the Medical Outcomes Trust; [9; 37; 38]. In order to perform research on hip ROM and contribute to the existing knowledge, we should consider providing data on measurement properties (e.g., the standard error of measurement, SEM; and minimal detectable change, MDC) [3]. Therefore, the measurement error was evaluated by the SEM for intra- and inter-observer reliability using the formula \(\text{SEM}=\times\text{SD}\sqrt{1\text{Sr}}\), where SD is the standard deviation of observed test scores and r is the Pearson's correlation coefficient (PCC) for those data [9]. SEM provides an estimate of the amount of day-to-day fluctuation that is expected for a given individual's score due to factors such as fatigue, motivation, or compliance [39]. In addition, the MDC for the inter-rater measurements at the 90% confidence level (\(\text{MDC}_{90}\)), also called the reliable change index [40], was employed to analyze the clinically meaningful degree of difference using SEM, and was defined as \(\text{MDC}_{90}=1.65*\text{SEM}*\sqrt{2}\). \(\text{MDC}_{90}\) determines the magnitude of change that would exceed the threshold of measurement error at the 90% confidence level [40]. Pearson's (r) correlation coefficients were calculated additionally to determine concurrent validity between FM and \(\text{WIMU}^{\text{\textregistered}}\) system. The r values yield the degree of correlation between two measures, where 0 = no correlation between two scores and 1 or \(-\)1 = the absolute correlation between two scores. Pearson's correlation coefficients are interpreted as follows: 0.00 to 0.19 = very weak correlation; 0.20 to 0.39 = weak correlation; 0.40 to 0.69 = moderate correlation; 0.70 to 0.89 = strong correlation; and 0.90 to 1 = very strong correlation [41; 42]. [PERSON] and Altman plots were used to provide a visual illustration of the relationship and 95% limits of agreement between the mean angle of measurement and the individual mean difference scores [35] from the validity and inter- and intra-rater reliability analyses.