Workflow does not trigger on direct database update. CRM 2011

Hi all,

I have a workflow on change of a field. It works fine when the value is changed from the form. But in my case the field is updated using stored procedures(SP) which directly impacts the database table. If the field is changed through SP or direct changed by editing the table, the workflow does not trigger. Any ideas??

Any help will be greatly appriciated.

Thanks

Sundar