Noninvasive measurement of the stiffness of tissue in the above-knee amputation limb.

In order to characterize the mechanical properties of the soft tissue in above-knee amputations, nine subjects were measured with a Doppler ultrasound system. Measurements were made at four locations: anterior, posterior, lateral, and medial. The characterizations included tissues up to 2.5 cm deep. The average posterior moduli are significantly greater than the anterior and lateral parameters. No significant difference was found among moduli from the medial zone compared to other areas. Superficial tissue had a significantly higher modulus than the tissue beneath. A simple method for transducer placement produced repeatable results. The present technique proved to be useful with patients in good health, and with no severe residual limb complications. The information generated with the ultrasonic device may aid in prosthesis fitting and will be used in a Computer-Aided Design (CAD) system as well as in other clinical applications.