Unlockable knee joint mechanism for powered gait orthosis

Gyoosuk Kim, Shinill Kang, Sungjae Kang, Jeicheong Ryu, Museoung Mun, Kyunghoon Kim

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)


Walking with the knee joint locked increases the amplitude of pelvic tilt and results in an unnatural gait. This paper introduces a powered gait orthosis with a moveable knee joint designed to improve the gait speed of patients with spinal cord injury (SCI). The unlockable knee joint powered gait orthosis (UKJ-PGO) uses a gas spring cylinder and a solenoid locking device to enable flexion of the joint, while the rigidity of the hip-joint device is enhanced using air muscles. A gait analysis was conducted to evaluate the performance of the UKJ-PGO, and the kinematic parameters obtained were compared with those of a standard PGO. In the gait of SCI patients using the UKJ-PGO, the new knee-joint device enabled flexion during the swing phase and showed a decrease in pelvic tilt compared with the standard PGO gait. As greater flexion was possible at the knee joint, the duration of the stance phase substantially decreased to near to the normal value, and the duration of the swing phase increased accordingly. In addition, the gait using the UKJ-PGO was faster than that with the standard PGO.

Original languageEnglish
Pages (from-to)83-89
Number of pages7
JournalInternational Journal of Precision Engineering and Manufacturing
Issue number3
Publication statusPublished - 2009 Jul

Bibliographical note

Funding Information:
This study was supported by grant 02-PJ3-PG6-EV03-004 from the Korea Health 21 R&D Project of the Korean Ministry of Health and Welfare.

All Science Journal Classification (ASJC) codes

  • Mechanical Engineering
  • Industrial and Manufacturing Engineering
  • Electrical and Electronic Engineering


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