First Supplemental Indenture dated as of November 20, 2003




 Exhibit 4.6 
  
 CONCENTRA OPERATING CORPORATION 
  
 and 
  
 THE BANK OF NEW YORK 
  
 as Trustee 
  

  
 FIRST SUPPLEMENTAL INDENTURE 
  
 Dated as of November 20, 2003 
  
 to 
  
 Indenture 
  
 Dated as of August 13, 2003 
  

  
 9 1/2% Senior Subordinated Notes Due 2010 








 FIRST SUPPLEMENTAL INDENTURE dated as of November 20, 2003 (this “Supplemental
Indenture”), between Concentra Operating Corporation, a Nevada corporation (the “Company”), and The Bank of New York, as trustee (the “Trustee”). 
  
 WHEREAS, the Company and certain guarantors named therein have heretofore executed and delivered to the Trustee an indenture
dated as of August 13, 2003, as it may be amended or supplemented (the “Company Indenture”), pursuant to which the Company issued $150,000,000 in principal amount of 9 1/2% Senior Subordinated Notes Due 2010 (the “Notes”); 
  
 WHEREAS, Section 901 of the Company Indenture authorizes the Company, when authorized by a Board Resolution, and the Trustee at any time and from time to
time to enter into one or more indentures supplemental thereto, in form satisfactory to the Trustee, to provide for, among other things, the issuance of Additional Securities in accordance with Section 301, Section 1008 and other limitations set
forth in the Company Indenture; 
  
 WHEREAS, the Company desires
to issue an additional $30,000,000 in aggregate principal amount of the Company’s 9 1/2% Senior Subordinated
Notes due 2010 (the “New Notes”), which will constitute a single series of debt securities with the Initial Securities; and 
  
 WHEREAS, the execution and delivery of this Supplemental Indenture has been authorized by resolutions of the Board of Directors of the Company.

  
 NOW, THEREFORE, in consideration of the above premises, each
party hereby agrees, for the benefit of the others and for the equal and ratable benefit of the Holders, as follows: 
  
 ARTICLE I 
  
 THE SECURITIES 
  
 Section 1.1 Additional
Securities. 
  
 The Company shall issue under the Company
Indenture $30,000,000 in aggregate principal amount of the New Notes. Such New Notes shall have identical terms as the Initial Securities issued on the Issue Date, including with respect to the guarantees in accordance with Article XIV of the
Company Indenture, other than with respect to the date of issuance and issue price. The Company is relying on the first paragraph of Section 1008 of the Company Indenture to issue the New Notes. The purchase price to the initial purchasers of the
New Notes shall be 103.305% of the principal amount of the New Notes. Such price does not cause the New Notes to have “original issue discount” within the meaning of Section 1273 of the Internal Revenue Code of 1986, as amended. The issue
date of the New Notes shall be November 20, 2003. The CUSIP numbers of the New Notes are 20589QAG4, U20442AC0 and 20589QAJ8. The New Notes shall be in the form of Initial Securities. 








 ARTICLE II 
  

MISCELLANEOUS PROVISIONS 
  
 Section 2.1 Defined Terms. For all purposes of this Supplemental Indenture, except as otherwise defined or unless the context otherwise
requires, terms used in capitalized form in this Supplemental Indenture and defined in the Company Indenture have the meanings specified in the Company Indenture. 
  
 Section 2.2 Indenture. Except as amended hereby, the Company Indenture and the Securities are in all respects
ratified and confirmed and all the terms thereof shall remain in full force and effect. 
  
 Section 2.3 Governing Law. THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW
YORK. 
  
 Section 2.4 Successors. All
covenants and agreements of the Company in this Supplemental Indenture and the Securities shall bind its successors and assigns, whether so expressed or not. All agreements of the Trustee in this Supplemental Indenture shall bind its successors
whether expressed or not. 
  
 Section 2.5
Duplicate Originals. All parties may sign any number of copies of this Supplemental Indenture. Each signed copy shall be an original, but all of them together shall represent the same instrument. 
  
 Section 2.6 Severability. In case any provision in this
Supplemental Indenture shall be invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions shall not in any way be affected or impaired thereby.  
  
 Section 2.7 Trustee Disclaimer. The Trustee accepts the
amendment of the Company Indenture effected by this Supplemental Indenture and agrees to execute the trust created by the Company Indenture as hereby amended, but on the terms and conditions set forth in the Company Indenture, including the terms
and provisions defining and limiting the liabilities and responsibilities of the Trustee, which terms and provisions shall in like manner define and limit its liabilities and responsibilities in the performance of the trust created by the Company
Indenture as hereby amended, and without limiting the generality of the foregoing, the Trustee shall not be responsible in any manner whatsoever for or with respect to any of the recitals or statements contained herein, all of which recitals or
statements are made solely by the Company, or for or with respect to (i) the validity or sufficiency of this Supplemental Indenture or any of the terms or provisions hereof, (ii) the proper authorization hereof by the Company or any Holder by
corporate action or otherwise, (iii) the due execution hereof by the Company or any Holder or (iv) the consequences (direct or indirect and whether deliberate or inadvertent) of any amendment herein provided for, and the Trustee makes no
representation with respect to any such matters. 
  
 Section 2.8 Effectiveness. This Supplemental Indenture shall become effective, once executed by all necessary parties, upon receipt by the Trustee of a certificate of the appropriate officers of the Company and an Opinion of
Counsel, each of which shall be dated no earlier than the date hereof. 








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 IN WITNESS WHEREOF, the parties hereto have caused this Supplemental Indenture to be duly executed as of
the day and year written above. 
  

	 Attest:
	 	 	 	 CONCENTRA OPERATING
 CORPORATION

	 	 	 	 	 as Obligor

				
	 /s/ Richard A. Parr II

	 	 	 	 By:
	 	 /s/ Thomas E. Kiraly


	 Richard A. Parr II, Secretary
	 	 	 	 	 	     Thomas E. Kiraly
     Executive Vice President, Chief
     Financial Officer and Treasurer

				
	 	 	 	 	 	 	THE BANK OF NEW YORK,
	 	 	 	 	 	 	 as Trustee

					
	 	 	 	 	 	 	 By:
	 	 /s/ Margaret M. Ciesmelewski


	 	 	 	 	 	 	 	 	     Margaret M. Ciesmelewski
     Vice President


  
 [Signature Page
Supplemental Indenture]