Ultrasound Strain Imaging to Assess the Biceps Brachii Muscle in Chronic Poststroke Spasticity

We sincerely appreciate Dr Sabour for pointing out that intraclass correlation analysis should have been used to test intra-observer agreement in our article.We have, therefore, reassessed intra-observer agreement in our data using intraclass correlation (Table 1).Intraclass correlation coefficient was determined with the statistical package SPSS Version 24.0 (SPSS, Armonk, NY, USA).The intraclass correlation coefficient between 2 measurements performed by a single observer was 0.92 (P < .001).Based on these results, we suggest that ultrasound strain imaging is feasible for quantifying biceps brachii muscle mechanical properties with good repeatability.We hope this response has improved the original article.