Before you decide that your client has “tight” external rotators of the hip from your visual, static assessment, you better check them for femoral retroversion. Retroversion is the result of a reduced femoral neck angle relative to the line through the femoral condyles.
The reduced angle will result in a greater degree of hip external rotation and a reduction in hip internal rotation.
To identify this you’ll use Craig’s Test which you’ll find with a quick Google search.
Bill