Ultrasound shear wave elastography in assessment of skeletal muscle stiffness in senior volunteers.

PURPOSE: The aim of the study was to evaluate the reliability of ultrasound shear wave elastography (SWE) to assess biceps brachii muscle (BBM) and quadriceps muscle (QM) stiffness in senior volunteers.

METHODS

Using a linear array ultrasound transducer (7 MHz), we prospectively measured shear wave velocity (SWV) of BBM and QM in passive joints (elbow and knee) flexion (90°) and extension (180°) in 19 senior volunteers by two operators. We developed SWV rate (SWVelbow-extension - SWVelbow-flexion)/SWVelbow-flexion to assess BBM contractibility. Statistical analysis included unpaired t-test to examine the difference in SWV of muscle between left vs right limbs, men vs women, and athletes vs nonathletes; Intraclass correlation coefficient (ICC) and violin plots for analyzing intra- and inter-observer reliability in performing SWE in muscles.

RESULTS

There was no significant difference in SWV between left vs right (flexion or extension), male vs female (flexion or extension), for BBM and QM, and athlete vs nonathlete extension for QM (all p > 0.05). The difference in SWV of BBM in elbow extension and in SWV rate between athlete and nonathlete was significant (p < 0.05). The difference in muscle SWV between joint flexion and extension was also significant (p < 0.05). Reliability in performing SWE of BBM and QM was good (ICC > 0.75).

CONCLUSIONS

Our results suggest that ultrasound SWE is feasible in estimating BBM and QM stiffness in seniors with good reproducibility. SWV rate and SWV of the extended BBM representing muscle contractibility in athlete were higher than in nonathlete.