Hi OpenSim Team,
I have a question regarding the directionality of subtalar moments during walking on a treadmill using OpenSim. My understanding is that the joint angles were calculated based on the motion of the proximal segment relative to the distal segment, resulting in plantarflexion being marked as negative (-) and dorsiflexion as positive (+), as shown in the left figure. Where I am confused is in the interpretation of the directionality of the subtalar moment. Is it correct to interpret inversion as negative (-) and eversion as positive (+) on the right side of the figure?
Best,
Jaeho
Subtalar Moment Directionality
- JAEHO JANG
- Posts: 5
- Joined: Thu Sep 23, 2021 7:55 pm
- Mohammadreza Rezaie
- Posts: 412
- Joined: Fri Nov 24, 2017 12:48 am
Re: Subtalar Moment Directionality
Hi, it depends on how coordinates are defined in the model you are using. In Rajagopal and gait_2392 models, supination angle is positive and pronation is negative, and internal joint moment [muscles] follows this rule, i.e., supinator moment [+] and pronator moment [-].
- JAEHO JANG
- Posts: 5
- Joined: Thu Sep 23, 2021 7:55 pm
Re: Subtalar Moment Directionality
Thanks so much for your help!