The Safety of C-Leg: Biomechanical TestsBy Blumentritt, Siegmar; Schmalz, Thomas; Jarasch, Rolf; Journal of Prosthetics & Orthotics, Vol. 21, No. 1, pp. 2-15
Publication Date: January 2009
Study reports preliminary results from a novel protocol permitting functional testing of different prosthetic knee joints in critical situations likely to cause an amputee to stumble and fall. Three hydraulic knee joints offering yielding stance control were investigated: (a) Otto Bock 3C1 (Mauch SNS hydraulic system), (b) Otto Bock 3R80 (rotary hydraulic system), and (c) Otto Bock C-Leg (microprocessor-controlled system). In a gait laboratory setting, three study participants with unilateral transfemoral amputations wearing a safety harness were tested under conditions that simulated five common real-world situations: (1) walking on even ground, (2) abruptly stopping, (3) abruptly sidestepping, (4) inadvertently stepping onto an object, and (5) tripping when the knee is extending during swing phase. Kinematics and kinetics of the knee joints were measured using two Kistler force plates and the six-camera VICON system 460. Results from instrumented gait analysis were shown to provide an objective reason for knee stability or instability for each individual trial, including the reason for knee collapse. Participants confirmed that the gait disruption occurring under the tested conditions corresponded closely to critical everyday situations that may lead to fall. Tripping with 3R80 and stepping onto an object with 3C1 resulted in a significant risk of falling. Because of its biomechanical performance under high-risk conditions, C-Leg was deemed to be the most suitable design to prevent falls with the prosthesis.
Assistive Products Discussed: C-LEG (MODEL 3C100)
3R80 PROSTHETIC KNEE
Published by: Lippincott, Williams, & Wilkins (Website:http://www.lww.com)
This publication is included in the library of the National Rehabilitation Information Center (NARIC), accession number J55887