Design of an automated device to measure sagittal plane stiffness of an articulated ankle-foot orthosis.
The purpose of this study was to design a new automated stiffness measurement device which could perform a simultaneous measurement of both dorsi- and plantarflexion angles and the corresponding resistive torque around the rotational centre of an articulated ankle-foot orthosis (AAFO). This was achieved by controlling angular velocities and range of motion in the sagittal plane. The device consisted of a hydraulic servo fatigue testing machine, a torque meter, a potentiometer, a rotary plate and an upright supporter to enable an AAFO to be attached to the device via a surrogate shank. The accuracy of the device in reproducing the range of motion and angular velocity was within 4% and 1% respectively in the range of motion of 30° (15° plantarflexion to 15° dorsiflexion) at the angular velocity of 10°/s, while that in the measurement of AAFO torque was within 8% at the 0° position. The device should prove useful to assist an orthotist or a manufacturer to quantify the stiffness of an AAFO and inform its clinical use.
Kobayashi
Toshiki
T
Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong, PR China.
Leung
Aaron K L
AK
Akazawa
Yasushi
Y
Naito
Hisashi
H
Tanaka
Masao
M
Hutchins
Stephen W
SW
D000843:Ankle Joint / Q000502:physiology*; D001186:Artificial Limbs; D001696:Biomechanical Phenomena / Q000502:physiology; D005528:Foot / Q000502:physiology*; D006801:Humans; D008422:Materials Testing / Q000379:methods; D010969:Plastics; D011474:Prosthesis Design / Q000379:methods*; D016059:Range of Motion, Articular / Q000502:physiology; D019415:Torque
D010969:Plastics