When fabricating a mobilization orthotic with an outrigger it is best to have a _____ line of pull from the long axis of the bone.

When fabricating a mobilization orthotic with an outrigger it is best to have a _____ line of pull from the long axis of the bone.

• A. 0 degree
• B. 45 degree
• C. 135 degree
• D. 90 degree

Answer: (D)

The key idea is that the effectiveness of a mobilization orthosis with an outrigger comes from generating a bending moment at the joint rather than simply pulling along the bone. Placing the line of pull perpendicular to the bone’s long axis creates this bending moment with a given force, giving you efficient, targeted mobilization while minimizing unintended axial load or shear. If the pull runs parallel to the bone, you mostly get distraction or compression along the bone, which is not how mobilization with an outrigger is intended to work. An oblique angle blends bending with other forces and can produce less controlled or less effective joint motion. So aligning the line of pull at a right angle to the bone optimizes the mobilization effect.

The key idea is that the effectiveness of a mobilization orthosis with an outrigger comes from generating a bending moment at the joint rather than simply pulling along the bone. Placing the line of pull perpendicular to the bone’s long axis creates this bending moment with a given force, giving you efficient, targeted mobilization while minimizing unintended axial load or shear. If the pull runs parallel to the bone, you mostly get distraction or compression along the bone, which is not how mobilization with an outrigger is intended to work. An oblique angle blends bending with other forces and can produce less controlled or less effective joint motion. So aligning the line of pull at a right angle to the bone optimizes the mobilization effect.