diff --git a/docs/toolboxes/modules/cfd/pages/toolbox.adoc b/docs/toolboxes/modules/cfd/pages/toolbox.adoc
index 9c0c80034..0d644d924 100644
--- a/docs/toolboxes/modules/cfd/pages/toolbox.adoc
+++ b/docs/toolboxes/modules/cfd/pages/toolbox.adoc
@@ -567,13 +567,18 @@ The user must define:
 
 
 ==== Forces
-compute lift and drag
+Compute the surfacic forces \$(F_x,F_y)\$ applied by the fluid to the object. Il the flow is aligned with the _x_-axis, those forces are drag and lift.
 
 [source,json]
 ----
-"Forces":["fsi-wall","fluid-cylinder"]
+"Forces":["marker1","marker2"]
 ----
+Where `markerX` are the markers of where we want to compute the forces. The results will be given in a csv file whith those columns :
 
+- time
+- drag_marker1
+- lift_marker1
+- idem with marker2...
 
 
 === Export user functions