Rule 35 (a)(1) of the Federal Rules of Civil Procedure provides in part: "The court where the action is pending may order a party whose mental or physical condition - including blood group - is in controversy to submit to a physical or mental examination by a suitably licensed or certified examiner." Most states have adopted these Procedural Rules in one form or the other.
This form is a generic example that may be referred to when preparing such a form for your particular state. It is for illustrative purposes only. Local laws should be consulted to determine any specific requirements for such a form in a particular jurisdiction.