TY - GEN
T1 - A Method to Estimate the Oblique Arch Folding Axis for Thumb Assistive Devices
AU - Nanayakkara, Visakha K.
AU - Sornkaran, Nantachai
AU - Wegiriya, Hasitha
AU - Vitzilaios, Nikolaos
AU - Venetsanos, Demetrios
AU - Rojas, Nicolas
AU - Sahinkaya, M. Necip
AU - Nanayakkara, Thrishantha
PY - 2019/7/3
Y1 - 2019/7/3
N2 - People who use the thumb in repetitive manipulation tasks are likely to develop thumb related impairments from excessive loading at the base joints of the thumb. Biologically informed wearable robotic assistive mechanisms can provide viable solutions to prevent occurring such injuries. This paper tests the hypothesis that an external assistive force at the metacarpophalangeal joint will be most effective when applied perpendicular to the palm folding axis in terms of maximizing the contribution at the thumb-tip as well as minimizing the projections on the vulnerable base joints of the thumb. Experiments conducted using human subjects validated the predictions made by a simplified kinematic model of the thumb that includes a foldable palm, showing that: (1) the palm folding angle varies from 71. 5 ∘ to 75. 3 ∘ (from the radial axis in the coronal plane) for the four thumb-finger pairs and (2) the most effective assistive force direction (from the ulnar axis in the coronal plane) at the MCP joint is in the range 0 ∘< ψ< 30 ∘ for the four thumb-finger pairs. These findings provide design guidelines for hand assistive mechanisms to maximize the efficacy of thumb external assistance.
AB - People who use the thumb in repetitive manipulation tasks are likely to develop thumb related impairments from excessive loading at the base joints of the thumb. Biologically informed wearable robotic assistive mechanisms can provide viable solutions to prevent occurring such injuries. This paper tests the hypothesis that an external assistive force at the metacarpophalangeal joint will be most effective when applied perpendicular to the palm folding axis in terms of maximizing the contribution at the thumb-tip as well as minimizing the projections on the vulnerable base joints of the thumb. Experiments conducted using human subjects validated the predictions made by a simplified kinematic model of the thumb that includes a foldable palm, showing that: (1) the palm folding angle varies from 71. 5 ∘ to 75. 3 ∘ (from the radial axis in the coronal plane) for the four thumb-finger pairs and (2) the most effective assistive force direction (from the ulnar axis in the coronal plane) at the MCP joint is in the range 0 ∘< ψ< 30 ∘ for the four thumb-finger pairs. These findings provide design guidelines for hand assistive mechanisms to maximize the efficacy of thumb external assistance.
KW - Foldable palm
KW - Metacarpophalangeal joint
KW - Thumb assistance
KW - Thumb kinematics
UR - http://www.scopus.com/inward/record.url?scp=85068960389&partnerID=8YFLogxK
U2 - 10.1007/978-3-030-23807-0_3
DO - 10.1007/978-3-030-23807-0_3
M3 - Conference proceeding
AN - SCOPUS:85068960389
SN - 9783030238063
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 28
EP - 40
BT - Towards Autonomous Robotic Systems - 20th Annual Conference, TAROS 2019, Proceedings
A2 - Althoefer, Kaspar
A2 - Konstantinova, Jelizaveta
A2 - Zhang, Ketao
PB - Springer-Verlag Italia
T2 - 20th Annual Conference on Towards Autonomous Robotic Systems, TAROS 2019
Y2 - 3 July 2019 through 5 July 2019
ER -