A biomechanical model of the lumbar region of the human trunk is shown. The forces acting in the four muscle groups consist of FR for the rectus, FO for the oblique, FL for the lumbar latissimus dorsi, and FE for the erector spinae. These loadings are symmetric with respect to the y - z plane. Replace this system of parallel forces by an equivalent force and couple moment acting at the spine, point O. Express the results in Cartesian vector form.
Given:
FR = 35 N a = 75 mm
FO = 45 N b = 45 mm
FL = 23 N c = 15 mm
FE = 32 N d = 50 mm
e = 40 mm f = 30 mm

Transcribed Image Text:

FR FL