Craig-Scott orthosis: a biochemical and functional evaluation

Area of Science:

• Orthotics and Biomechanics
• Rehabilitation Engineering

Background:

• The Craig-Scott double upright knee ankle orthosis is a common bracing solution.
• Previous biomechanical evaluations of orthoses provide comparative data.

Purpose of the Study:

• To biomechanically and functionally evaluate the Craig-Scott knee ankle orthosis.
• To compare its performance against other common orthoses.

Main Methods:

• Biomechanical analysis of force interaction with the limb.
• Functional evaluation of donning, doffing, transfers, and ambulation.
• Comparison of results with existing data from other orthoses.

Main Results:

• The design concentrates stabilizing force on a small area, potentially exceeding tolerance.
• Low anatomic knee shear was observed.
• Functional performance was comparable to other double upright designs.
• Adequate rigidity was confirmed with a tibial band and bail.
• A tendency for the orthosis to slide forward during transfers was noted without posterior closure.
• Adding a posterior closure eliminated sliding with minimal impact on donning/doffing times.

Conclusions:

• The Craig-Scott orthosis demonstrates adequate rigidity and low knee shear.
• Modifications, such as adding a posterior closure, can improve functional performance and address potential issues like slippage during transfers.