- ∆SG: Increment of stress in the system produced by the intrinsic eye muscles.
- ∆SP: Increment of stress due to the grip in the back muscles (pinched muscles).
- Distribution of stresses according to equilibrium, constitutive equations, and compatibility of the system.
![](https://miraintegralvision.com/wp-content/uploads/2023/01/Squematic-diagram-stress-with-pinch-muscle.png)