The employer and insurer appeal from the compensation judge’s finding that the employee sustained a Gillette-type injury^[1] on his last day of work prior to layoff, from the judge’s award of benefits for permanent partial disability, and from the judge’s evidentiary ruling concerning a letter written by the employee’s attorney to the employee’s independent medical examiner.  We vacate the award of permanent partial disability benefits but affirm on all other issues.

The employee was employed in the logging business for more than 20 years, at some point performing nearly all of the various outdoor jobs common in the industry.  In 1990, he started working for Muller Logging, Inc. [the employer], operating a vehicle called a skidder.  As the employee described it, a skidder is a piece of heavy equipment, fitted with large, tractor-sized tires, that has a blade on the front of it and a grapple on the back.  The operator drives the skidder and uses the blade to clear logging trails and the grapple to pick up and drag timber.  Because the seat on the skidder is fixed, the skidder operator must turn his head to look back when operating the grapple and dragging logs.^[2]  The employee operated two skidders during the course of his employment with the employer.  On one model, the operator’s seat faced straight forward; on a newer model that the employee used the last several years of his employment, the seat was turned slightly to the right, meaning that the employee would not have to turn quite so far to look behind him.  Although the tires on the skidder were very large and the vehicle was articulated in the center, the ride was often rough.

The employee testified that, in February of 2003, while working a “blow down” area,^[3] he began experiencing stiffness and soreness in what he thought of as his back - - the “bump” at the base of his neck - - as well as pain shooting down his arms.  Because he had previously experienced similar symptoms while working in rough conditions, he was not overly concerned.  In about March 2003, he was laid off for a couple of months, and, by the time he returned to work in May, the symptoms had resolved.  The employee then performed his usual job, working without time off or treatment for the next six or seven months, until he was laid off for economic reasons.  However, he testified that his neck and arm symptoms returned and increased during this period and that he told his supervisor, Steven Muller, just before his November 2003 layoff, that “the skidder had [his] back wore out.”  Mr. Muller acknowledged the substance of the conversation but recalled it as having occurred in February of 2003, during work in the blow down area.

The employee first sought treatment for back and neck symptoms on January 7, 2004.  The examining physician, Dr. Bonnie Bailey, reported that the employee had indicated that the symptoms had begun eight months ago, and she noted that the employee thought things would improve after his layoff, “but still no improvement.”  Range of cervical motion was normal, but Dr. Bailey suspected degenerative disc disease and prescribed medication, noting that the employee was uninsured and therefore wanted to defer imaging.  Dr. Bailey also indicated that “this very well may be a work-related problem,” and she encouraged the employee to investigate retraining in another profession.

Cervical x-rays performed on February 11, 2004, revealed degenerative changes with osteophytes, and, in a treatment record from that same date, Dr. Bailey wrote as follows:

The employee obtained health insurance coverage at some point and underwent a cervical MRI scan on April 12, 2004.  The radiologist reported a reversal of the normal cervical lordosis, which he characterized as a “nonspecific finding often associated with neck pain,” and degenerative changes at multiple levels.  There was, however, no evidence of neural compression.

When he returned to see Dr. Bailey on April 23, 2004, the employee asked again whether his condition could be work-related, and he reported experiencing constant aching pain, as well as brief sharp shoulder pain with certain movements, radiating down his upper extremities.  Dr. Bailey noted that the employee seemed able to move his neck fairly freely but had some tenderness at C7 with some increased muscle tension.  Diagnosing chronic neck pain with bilateral radicular symptoms, Dr. Bailey referred the employee to Dr. William Dicks for further evaluation and chronic pain management.

The employee was first seen by Dr. Dicks on May 13, 2004.  According to Dr. Dicks’ notes from this evaluation, the employee reported that his symptoms had become persistent in about February of 2003 and that his work had involved “constantly turning his head, craning to watch the skidder and also bouncing on the seat as the machine made its way through the rough forest floor.” Dr. Dick found the employee’s range of motion of his neck, shoulders, and back to be “entirely normal,” with only minor tenderness, and stated that everything affecting the employee was “reversible.”  The employee was prescribed medication and physical therapy, with instructions to follow up in two weeks.

The employee began physical therapy on May 23, 2004.  On that date, his cervical range of motion was “within normal limits” except for left cervical rotation at 70 degrees compared to 90 degrees to the right.

The employee saw Dr. Dicks again on June 7, 2004.  In the record from that exam, Dr. Dicks discussed the employee’s insurance problems, noting that the employee would be totally uninsured by June 15, 2004.  On the issue of causation, Dr. Dicks indicated that the employee’s cervical condition could be work-related, “but it might be hard to label it as such in a trial situation because it developed over such a long period of time and there does not seem to be any specific single injury that led to the problem.”  However, Dr. Dicks also wrote, “It does appear to be chronic positioning that led to this chronic problem.”  On examination, Dr. Dicks found “very minor” “tight bands in the cervical spine area and through the trapezius and levators.”

On June 15, 2004, the employee underwent a cervical CT scan.  The radiologist reported finding cervical spondylosis at C4-5, C5-6, and to a greater extent at C6-7, along with cervical kyphosis and scoliosis.  Around the same time, the employee was discharged from physical therapy, having reported little or no improvement in his symptoms.  The employee testified that he has had no treatment for his cervical spine condition since June of 2004, in large part because he cannot afford to maintain health insurance coverage.

On July 16, 2004, the employee’s attorney had him evaluated by independent examiner Dr. S. R. Mangiamele.  Dr. Mangiamele diagnosed cervical myofascial pain, cervical degenerative joint and degenerative disc disease, and cervical pain syndrome, which in his opinion were substantially related to the employee’s work activities.  On the issue of causation, Dr. Mangiamele wrote as follows:

In October of 2005, Dr. Gary Wyard evaluated the employee on behalf of the employer and insurer.  While noting slightly limited range of cervical motion on exam, the doctor described the employee’s cooperation as “suspect.”  Dr. Wyard concluded that the employee had degenerative disc disease, “long-standing and secondary to natural consequences as well as smoking”; that the employee had reached maximum medical improvement [MMI] from the effects of any alleged injury culminating on or about November 12 or November 13, 2003; that the employee had no objective findings to substantiate his subjective complaints; that the employee had no permanent partial disability attributable to any work-related injury; and that the employee was not in need of any further medical treatment or any restrictions as a result of either his neck or his low back condition.

The matter came on for hearing before a compensation judge on May 11, 2006, for resolution of the employee’s claim for various benefits resulting from a Gillette-type injury allegedly culminating in disability on about November 12 or 13, 2003, his last day of employment by the employer prior to layoff.  The employer and insurer denied primary liability and notice of injury.  One of the employee’s exhibits at hearing consisted of a letter from the employee’s counsel to Dr. Mangiamele, which focused primarily on the employee’s work activities.  Counsel for the employer and insurer objected, but the compensation judge accepted the letter into evidence.  Other evidence submitted at hearing included the testimony of the employee and of Steven Muller, the employee’s treatment records, and the reports of Drs. Mangiamele and Wyard.

In a decision issued on June 8, 2006, the compensation judge concluded that the employee had sustained a Gillette injury on November 12, 2003, as claimed,^[4] and he awarded various benefits, including benefits for a 10% whole body impairment.  The employer and insurer appeal.

On appeal, the Workers’ Compensation Court of Appeals must determine whether “the findings of fact and order [are] clearly erroneous and unsupported by substantial evidence in view of the entire record as submitted.”  Minn. Stat. § 176.421, subd. 1 (2006).  Substantial evidence supports the findings if, in the context of the entire record, “they are supported by evidence that a reasonable mind might accept as adequate.”  Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984).  Where evidence conflicts or more than one inference may reasonably be drawn from the evidence, the findings are to be affirmed.  Id. at 60, 37 W.C.D. at 240.  Similarly, findings of fact should not be disturbed, even though the reviewing court might disagree with them, “unless they are clearly erroneous in the sense that they are manifestly contrary to the weight of the evidence or not reasonably supported by the evidence as a whole.”  Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).

As previously indicated, the compensation judge admitted a letter from the employee’s attorney to Dr. Mangiamele into evidence, over the employer and insurer’s objection.  On appeal, the employer and insurer argue that the judge erred by accepting this exhibit, in that it was “cumulative,” not probative, and that it was “at best” hearsay testimony by the employee’s attorney, who was not under oath.  Because, the employer and insurer argue, the letter was “highly prejudicial,” its acceptance into evidence mandates reversal of the compensation judge’s decision.  The employer and insurer’s argument on this issue has no merit whatsoever.

It is true that counsel’s letter does not constitute evidence establishing just what the employee did for a living.  Clearly, however, the letter is evidence of what Dr. Mangiamele was told about the employee’s work activities.  In ruling on the issue at hearing, the compensation judge explained,

Evidentiary rulings are generally within the sound discretion of the compensation judge, see, e.g., Ziehl v. Vreeman Constr. Co., slip op. (W.C.C.A. Oct. 15, 1991), and we find no abuse of discretion here.  On the contrary, the judge’s ruling was entirely proper.  No further discussion of this issue is warranted.

“[I]njuries from repeated trauma or aggravations of a pre-existing condition [i.e., Gillette injuries] result in a compensable personal injury when their cumulative effect is sufficiently serious to disable the employee from further work.”  Carlson v. Flour City Brush Co., 305 N.W.2d 347, 350, 33 W.C.D. 594, 598 (Minn. 1981).  However, the date of injury may be different from the last day worked and should “be determined on all the evidence bearing on the issue,” including other “ascertainable events” evidencing disability.  Schnurrer v. Hoerner-Waldorf, 345 N.W.2d 230, 233, 36 W.C.D. 504, 509 (Minn. 1984).

In the present case, the compensation judge concluded that the employee had sustained a Gillette injury effective on about November 12, 2003, the last date he worked for the employer prior to what turned out to be a permanent economic layoff.  On appeal, the employer and insurer contend that the judge’s decision is clearly erroneous and unsupported by the record, because the employee was not “disabled,” for purposes of Gillette injury liability, prior to his economic layoff, and because the employee did not have “a disability significant enough” to warrant a Gillette injury finding.  We are not persuaded.

Substantial evidence clearly supports the judge’s determination that the employee sustained a cervical injury as a substantial result of his work activities for the employer over the years.  Dr. Dicks, a treating physician, indicated that “chronic positioning” led to the employee’s chronic pain, and Dr. Mangiamele explained in some detail how the employee’s work running the skidder caused microtrauma and degeneration to the employee’s cervical discs and facets.

With respect to Dr. Mangiamele, the employer and insurer argue primarily that “[h]is assessments are baseless and groundless” and “without foundation, as he has simply created disability where none otherwise exists.”  However, a compensation judge’s choice between conflicting expert opinions is generally upheld unless the facts assumed by the expert are unsupported by the record.  See Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn.1985).  The employer and insurer have given this court no legal or factual basis to conclude that the judge erred in accepting Dr. Mangiamele’s opinion as to causation.  As for the employer and insurer’s argument that the employee is not sufficiently disabled to support a Gillette injury finding, we would note that the records of Dr. Bailey and of Dr. Mangiamele reasonably support the conclusion that the employee should not return to operating a skidder due to the effects of his work-related cervical condition.^[5]

Finally, we address the suggestion, running throughout the employer and insurer’s brief, that the employee cannot be deemed to have sustained a Gillette injury because there was no disablement from work or other “ascertainable event” until after his economic layoff from the employer on November 12, 2003.  Admittedly, the employee was subject to no formal restrictions and sought no medical treatment prior to his layoff.  However, the layoff date was obviously the last day during which the employee’s work activities could have contributed to his disability.  Certainly January 7, 2004, cannot be used as the date of injury, as the employee was unemployed on that date, and we find no basis for choosing any other date.  Given that the record reasonably establishes that work-related microtrauma contributed to the employee’s cervical condition, the fact that the employee did not seek medical treatment for two months beyond his layoff cannot be used to justify relieving the employer and insurer of liability for that condition.  We therefore affirm the judge’s decision on this issue.

Apparently relying on the opinion of Dr. Mangiamele, the compensation judge concluded that the employee was entitled to benefits for a 10% whole body impairment, pursuant to Minn. R. 5223.0370, subp. 3.C.(2), which reads as follows:

“Ordinarily, permanent partial disability is ascertained after maximum medical improvement.”  Turek v. Northfield Freezings, 652 N.W.2d 265, 269, 62 W.C.D. 622, 626 (Minn. 2002); see also Gibbons v. Weyerhaeuser, 482 N.W.2d 480, 46 W.C.D. 392 (Minn. 1992).  In the present case, MMI was not litigated or determined, and the employee’s counsel suggested at hearing that treatment options have not been investigated due to the employee’s lack of health insurance.^[6] We also note that, while scans clearly support the conclusion that the employee has degenerative changes at multiple levels, the evidence of persistent objective clinical findings is weak, and Dr. Mangiamele, the only physician to rate permanency, did not record any objective clinical findings on examination and did not explain why he chose the rating category at issue.  Under all of these circumstances, especially considering the employee’s relatively short period of treatment and the specific condition and rating category in question, we conclude that a finding as to permanent partial disability is premature.  We therefore vacate that finding, preserving that claim for future litigation, if required.