(dissenting). The law is clear. An applicant for accidental disability retirement under G. L. c. 32, § 7(1), as appearing in St. 1982, c. 630, § 18, must prove permanent and total disability “by reason of a personal injury sustained or a hazard undergone as a result of and while in the performance of, his duties at some definite place and at some definite time.” To succeed, the applicant must prove that the disability arose (1) “either from a specific incident or series of incidents at work,” or (2) from gradual deterioration, caused not by wear and tear but rather “from an identifi-cable condition that is not common and necessary to all or a great many occupations.” Zerofski’s Case, 385 Mass. 590, 594-595 (1982). “Proof of either hypothesis ha[s] to satisfy the strict causation standard imposed by the controlling statute: that the [applicant’s] employment was ‘a natural and proximate cause of the incapacity.’ ” Blanchette v. Contributory Retirement Appeal Bd., 20 Mass. App. Ct. 479, 485 (1985).
The fact that an applicant, such as Adams, may have a preexisting medical condition does not bar recovery or lessen or increase his or her burden. He or she still must establish that the preexisting condition was aggravated by a specific incident or series of incidents at work, or by gradual deterioration, other than wear and tear. Zerofski’s Case, 385 Mass. at 592-593. However, “when work is merely a contributing cause of the injury the ‘natural and proximate result’ test for causation necessary to the recovery of accidental disability retirement benefits under G. L. c. 32, § 7(1), has not been satisfied.” Blanchette v. Contributory Retirement Appeal Bd., supra at 487, quoting from Campbell v. Contributory Retirement Appeal Bd., 17 Mass. App. Ct. 1018 (1984). The fact that we remanded this case to CRAB for further proceedings does not, in any way, lessen Adams’s burden.
I agree with the majority that the line between compensa-ble injury and mere “wear and tear” is a delicate one. Moreover, I agree that “[frequency and intensity of activity compared to other occupations are factors in deciding whether the activity will support a claim for benefits after injury.” *179However, on each occasion where those factors were considered, the decision denied recovery because the injury resulted from mere wear and tear. See Burns’s Case, 266 Mass. 516 (1929) (watchman denied recovery where his heart failure was due to the aggravating effect of miles of nightly walking upon a preexisting heart condition); Pimental’s Case, 235 Mass. 598 (1920) (recovery denied where years of sitting with poor posture to roll cigars caused nerve disorder); Spalla’s Case, 320 Mass. 416, 418 (1946) (evidence that years of hard labor weakened abdominal walls insufficient to permit recovery).
Here, the majority identifies the condition in Adams’s employment that is not common and necessary to all or a great many occupations to be “bending which was deeper, more frequent, and more intense than that which would be expected in the general run of occupations.” The majority do not cite a single decision which holds that “bending” of the magnitude it describes is an identificable condition that would permit this applicant to receive accidental disability.1 Moreover, the opinion fails to mention the considerable number of decisions in which the court concluded that the gradual deterioration was caused by “wear and tear.” See Zerofski’s Case, 385 Mass. at 593-595.
This case is remarkably similar to Blanchette v. Contributory Retirement Appeal Bd., supra, in which this court in affirming CRAB’s denial of an application for accidental retirement benefits, stated, “In upholding the decicion of [CRAB] we have given consideration to: . . . the board’s experience in the area and its function in applying the controlling statute, necessarily on a case-by-case basis, to a difficult area of the law; and . . . [CRAB’s] prerogative in this case ... to decide the probative value of the evidence, and to reject the opinion of an essential medical expert which was, *180at best, equivocal . . . .” 20 Mass. App. Ct. at 487-488. That language is particularly appropriate to this matter.
I respectfully dissent.
In McManus’s Case, 328 Mass. 171 (1951), cited by the majority in a different context, the employee was injured when he bent over to pick up a hose. The injury, therefore, arose from a specific incident and not from gradual deterioration caused by frequent bending.