# Reactions
Reactions are calculated at constrained nodes. The constraint can be due to a restraint or a spring support.
# Total Loads & Reactions
‘Total loads’ and ‘Total reactions’ represent a sum of all loads and reactions observed in a model. Moments are reported about the global origin. It is a useful check to monitor that the total loads reported in a model are approximately in equilibrium with the total reactions. If it is judged that the total loads and reactions differ significantly, this may in general be a result of two types of error:
- A load is applied to a degree of freedom that is not active in the model. For example, from applying a moment to the end of a bar element. In this case the load is reported as being applied, but is ignored by the solver.
- The imbalance is as a result of the numerical solution itself. This may be evidence of ill-conditioning (opens new window). You can run a model stability analysis to check for disproportionately large stiffnesses.
To help differentiate the difference within a model, an entry ‘Ignored loads’ is reported that accounts for the first type of error above.