Anatomic motor point localization for partial quadriceps block in spasticity.

Abstract

To identify the location of the vastus intermedius nerve and its motor point (point M) and to precisely identify its coordinates in relation to anatomic surface landmarks. Descriptive study. Anatomy institute of a university school of medicine. Twenty-nine adult cadaver limbs immobilized in anatomic position. Anatomic dissection to identify point M. Anatomic surface landmarks were point F, the issuing point of femoral nerve under the inguinal ligament; point R, the middle of superior edge of the patella; segment FR, which corresponds to thigh length; point M', point M orthogonal projection on segment FR. Absolute vertical coordinate, distance FM, relative vertical coordinate compared to the thigh length, FM'/FR ratio; absolute horizontal coordinate, distance MM'. The absolute vertical coordinate was 11.7+/-2 cm. The relative vertical coordinate was at .29+/-.04 of thigh length. The horizontal coordinate was at 2+/-.5 cm lateral to the FR line. Point M can be defined with relative precision by two coordinates. Application and clinical interest of nerve blocking using these coordinates in quadriceps spasticity should be studied.