(

a) For purposes of a member who retires for disability from a system established under this

chapter on the basis of being permanently incapacitated from the performance of their usual and customary duties because of an injury, as described in paragraph (1) of subdivision (c), it shall be presumed that the disability arose out of, or in the course of, the member’s employment. (

b) The presumption described in subdivision (

a) may be rebutted by evidence to the contrary, but unless controverted, the board shall be bound to find in accordance with the presumption. (

c) For the purpose of this section: (1) “Injury” means lower back impairments that develop or manifest itself during a period while a member is in the service of a department, office, or unit, consistent with paragraph (2). (2) “Member” means a member of a public retirement system, established under this chapter, whose job classification is listed in

Section 3213.2 of the Labor Code. (

d) This

section shall apply to a member who has been employed for at least five years on a full-time basis in the classification specified in paragraph (2) of subdivision (

c) and has been required to wear a duty belt as a condition of employment. (

e) This presumption shall additionally apply to a member following termination of service for a period of calendar months for each full year of the requisite service, but shall not exceed months regardless of the member’s length of service, commencing with the last date the member actually worked in the classification specified in paragraph (2) of subdivision (c).