Upper extremity soft tissue stiffness measured with shear wave elastography: A between-day reliability study

Area of Science:

• Biomechanics
• Musculoskeletal Ultrasound
• Medical Imaging

Background:

• Soft tissue stiffness (STS) imbalances in the pectoralis muscles and common wrist extensors (CWEs) can negatively impact upper extremity function.
• Shear wave elastography (SWE) provides precise, repeatable, and objective measurements of STS.

Purpose of the Study:

• To determine the between-day intrarater reliability of SWE for measuring pectoralis and CWE tendon stiffness.

Main Methods:

• 2D SWE ultrasound imaging was used to measure STS (shear wave modulus in kilopascals) in the pectoralis major, pectoralis minor, and CWE tendons bilaterally.
• Measurements were taken on two separate days by the same examiner.
• Intraclass correlation coefficients (ICC (3, 3)), standard error of the measure, and minimal detectable changes were calculated to assess reliability.

Main Results:

• Acceptable between-day intrarater reliability was found for all measured muscles.
• ICC values for pectoralis major ranged from 0.63 to 0.70.
• ICC values for pectoralis minor and CWE tendons were consistently 0.75.

Conclusions:

• SWE exhibits acceptable reliability for assessing pectoralis and CWE tendon stiffness.
• Future research should control for variables that may influence STS measurements.