The self-insured employer, Julius B. Nelson & Son, Inc., appeals from the compensation judge’s determination that the employee sustained a personal injury to his cervical spine as a result of his work activities, culminating on or about August 4, 2006, and that this injury represents a substantial contributing factor in the employee’s cervical condition, disability, and need for medical treatment.  We affirm in part and vacate in part.

Mr. Patrick Lowrie [the employee], has worked as a painter in both commercial and residential settings for over 30 years.  On approximately January 23, 2005, while working for Swanson & Youngdahl [S & Y], self-insured employer, the employee sustained an admitted injury when he slipped on a protective covering or drop cloth laid on top of some steps and fell, striking the back of his neck on a concrete step riser.  The employee felt stunned, immediately felt pain in the back of his neck, and developed a severe headache and symptoms in both shoulders.  The employee did not miss any time from work following this injury, but as he continued to perform his usual duties as a painter, he began to notice some weakness in his arms.  He performed light-duty work for a few days, and then resumed his normal work activities.

Following this incident, the employee sought treatment at Now Care, where his physician recommended an MRI scan of his cervical spine.  The employee was unable to undergo that scan due to claustrophobia; he made a second attempt to undergo a scan the next day, but was unable to do so for the same reason.  The employee testified that by approximately two weeks after his injury, his symptoms decreased and mostly resolved after six to seven weeks following his injury, and he received no further medical treatment for his neck symptoms while working for S & Y.

The employee continued to work for S & Y until September 2005, at which time he was laid off.  He occasionally experienced neck and upper extremity symptoms while working, particularly when he performed work at ceiling level and on bar joists.  Between September and mid-November 2005, the employee worked for another employer for approximately six to eight weeks.  Some of his work there included spraying ceiling joists, which he characterized as physically difficult work and requiring overhead work.  Between November 2005 and June 2006, the employee was unemployed.  He testified that he was relatively sedentary during the months he was unemployed, and experienced no neck or upper extremity symptoms during those months, nor did he seek any medical treatment for his neck or upper extremity complaints during that period of time.

On June 1, 2006, the employee began working for Julius B. Nelson & Son, Inc. [Nelson], self-insured employer, and worked for that employer through August 4, 2006, painting various buildings on the grounds of the Minnesota State Fair.  The employee’s work included overhead work, and at times required him to work with his arms extended over his head and to move his head side to side and up and down.  In mid-July 2006, the employee began to experience  symptoms in his upper extremities, including weakness, difficulty grasping and numbness and tingling, which he attributed to his painting work and his “out of shape” condition resulting from being off work for a few months.  He consulted Dr. Bernarda Zenker at the Quello Clinic,  reporting that he felt discomfort in his shoulder extending down to his forearm when he used his right arm while painting and when looking above his head while working.  On July 27, 2006, at Dr. Zenker’s referral, the employee underwent an MRI scan of his cervical spine, which showed congenitally acquired cervical stenosis from the C3-4 through C7-T1 levels.

On August 4, 2006, the employee lost all sensation in his right arm as he reached into his refrigerator to grab a half-gallon container of milk.  He dropped the container; he also found that he could not move his right arm on its own.  The employee sought medical treatment at the hospital emergency room, reporting severe neck and shoulder pain.  On August 7, he consulted Dr. Zenker, whose chart notes state that the employee had come in to review the results of his MRI scan.  The employee reported numbness and tingling in both arms.  Dr. Zenker referred him on an urgent basis to Dr. Michael Smith, of Cervical Spine Specialists.  The employee consulted Dr. Smith the following day, reporting substantial neck pain, shoulder pain and lateral arm and dorsal radial forearm symptoms.  The employee also recounted recurrent symptoms earlier in 2006, including numbness in both left and right upper extremities with slight tingling on the left side, significant strength deficit on the right side, and inability to perform fine tasks.  He reported to Dr. Smith that his work as a painter, including holding his head in certain positions, seemed to exacerbate his pain.

Dr. Smith restricted the employee from work and referred him for a CT scan, which he interpreted as showing severe cervical stenosis and foraminal stenosis bilaterally, worse on the left than right.  Dr. Smith recommended that if the employee’s symptoms worsened and if he did not wish to consider a rehabilitation program, he then should consider a canal-expanding laminoplasty. Alternatively, Dr. Smith suggested an anterior fusion in the cervical spine, in view of the severity of the employee’s degenerative changes.  In his report of August 15, 2006, Dr. Smith concluded that the employee’s “significant repetitive vertical gaze postures . . .ultimately have culminated in his complaints.”

On November 8, 2006, Dr. Smith performed a laminoplasty, with a three-level fusion in the employee’s cervical spine.  By mid-December 2006, the employee still experienced central posterior neck pain, and, at that point, Dr. Smith recommended that the employee commence a rehabilitation program.  He underwent physical therapy for his cervical spine from late December through mid-April 2007.  At Dr. Smith’s referral, the employee also consulted Dr. Frank Wei, physiatrist, who oversaw the employee’s therapy, and provided prescription medication and periodic therapeutic injections.

In early February, the employee’s vehicle was rear-ended; his neck symptoms were temporarily exacerbated as a result of that incident.  He also experienced low back symptoms following that accident and underwent physical therapy to treat his low back.

On February 10, 2007, at Nelson’s request, Dr. Mark Larkins conducted an independent medical examination of the employee.  Based upon the results of his testing,  examination, and review of the employee’s medical records, Dr. Larkins concluded that the employee had sustained a permanent aggravation of his underlying cervical stenosis at the time of his January 2005 injury.  He also initially concluded that the employee sustained a Gillette^[1] injury culminating in August 2006, explaining that the employee’s work as a painter, including prolonged upgazing and frequent maintenance of the neck in static positions, had resulted in a permanent aggravation of his condition.  Upon review of additional records, however, Dr. Larkins revised his opinion and concluded that the employee’s Gillette injury actually culminated in January 2005, and that

Dr. Larkins assigned work restrictions including no lifting more than ten pounds over shoulder level and no more than twenty pounds below shoulder level.  Dr. Larkins concluded that the employee had not yet reached maximum medical improvement (MMI) from his neck and upper extremity condition, as he was only three months post-surgery.  He provided a minimum permanency rating of 15% whole body impairment, pursuant to Minn. R. 5223.0370, subp. 4E(2).

By contrast, Dr. Smith, the employee’s treating physician, concluded that the employee’s cervical spine condition was substantially related to his work activities as a painter, and that he had sustained a Gillette injury to his neck, particularly in light of the “repetitive vertical gaze and hyperextension postures of his neck, coupled with a preexisting propensity to develop stenosis because of his underlying congenital stenosis.”  In his report of January 3, 2007, Dr. Smith concluded that

The employee filed a claim petition, alleging a specific injury of January 23, 2005, and a Gillette injury of August 4, 2006.  The employer at the time of the admitted 2005, injury, S & Y, paid benefits to or on behalf of the employee pursuant to a temporary order served and filed on June 13, 2007.  That employer also filed a petition for contribution and reimbursement against Nelson, the employer at the time of the employee’s claimed 2006 Gillette injury, contending  that the employee’s work injury in 2005 was not a substantial contributing factor in the employee’s neck condition, and that the employee’s 2006 injury substantially contributed to the employee’s current condition, disability and need for medical treatment.  Nelson denied primary liability for the alleged Gillette injury.

A hearing was held on November 16, 2007, to address the apportionment of liability between the employee’s 2005 and 2006 injuries, and also to address the claim for reimbursement of medical expenses asserted by the employee and intervenors.  Separate litigation is pending on the employee’s claim petition and the claim for contribution and/or reimbursement.

In her findings and order served and filed January 16, 2008, the compensation judge concluded that the employee sustained a personal injury to his cervical spine as a result of his work activities, and that his injury culminated on or about August 4, 2006.  The compensation judge relied upon the opinion of the employee’s treating physician, Dr. Smith, in reaching her conclusion that the employee’s job duties for Nelson, along with his underlying congenital stenosis, resulted in his symptoms and, ultimately, a Gillette injury.  In her memorandum, the compensation judge acknowledged that the employee had sustained an injury in January 2005, while working for S & Y, but concluded that the 2005 injury was a temporary aggravation of the employee’s underlying cervical stenosis and was not a substantial contributing factor in the employee’s condition after August 4, 2006.

Nelson appeals.

Nelson, the employer at the time of the employee’s Gillette injury on August 4, 2006, contends that substantial evidence does not support the compensation judge’s finding that the employee sustained a work-related Gillette injury to his cervical spine that culminated on that date, nor does the evidence support the judge’s conclusion that 100% liability for the employee’s condition and disability should be attributed to the employee’s August 4, 2006, injury.

A Gillette injury is an injury resulting from repeated trauma or aggravation of a preexisting medical condition.  Such a condition becomes compensable when the cumulative effect is sufficiently serious to disable an employee from further work.  Gillette v. Harold, Inc., 257 Minn. 313, 321-22, 101 N.W.2d 200, 205-06, 21 W.C.D. 105, 111-13 (1960); Carlson v. Flour City Brush Co., 305 N.W.2d 347, 350, 33 W.C.D. 594, 598 (Minn. 1981).  A finding as to a Gillette injury is primarily dependent on the medical evidence.  See Marose v. Maislin Transp., 413 N.W.2d 507, 40 W.C.D. 175 (Minn. 1987).  The compensation judge relied on Dr. Smith’s opinion in support of his conclusion that the employee’s cervical spine condition was causally related to his work activities, and that he sustained a Gillette injury to his neck, culminating on August 4, 2006.

Nelson seeks a reversal of the compensation judge’s findings on the determination of liability for the employee’s cervical spine condition.  Nelson argues that the employee’s minimal work while in its employ could not be considered a substantial contributing cause of the employee’s neck condition.  Nelson asserts that the following factors show that the compensation judge’s findings are not supported by substantial evidence in the record: (1) the employee’s January 2005 injury was significant, (2) he noted radicular symptoms and sought medical treatment after that injury, (3) the medical records document numerous references to the onset of the employee’s symptoms in January 2005, and (4) the employee himself attributed his condition to his fall in January 2005.

Nelson also argues that certain factual discrepancies exist between the record and the compensation judge’s findings, and that such discrepancies render the findings unsupported by substantial evidence.  For example, in unappealed Finding No. 5, the compensation judge outlined the circumstances surrounding the employee’s January 23, 2005, injury, and stated that the employee’s “symptoms mostly resolved after six to seven weeks following the injury.”  Nelson contends that the employee never reported that his symptoms had completely resolved, and that on occasion, according to his testimony, his neck hurt to some degree depending on the type of painting projects he performed.  Nelson points to the employee’s medical records from early 2006 that reflect his recurring residual discomfort from his January 2005 injury.  Based on our review of the record, however, we note that the employee’s testimony was consistent with the judge’s conclusions, and that his medical records reflect a resolution of his symptoms after his 2005 injury.  In view of the record as a whole, the compensation judge could reasonably conclude that the employee’s symptoms mostly resolved after six to seven weeks following his 2005 injury.

Nelson also contends that a discrepancy exists between the  number of days the employee actually worked each week and the number of days assumed by the compensation judge.  At Finding No. 8, the compensation judge found that the employee worked seven days per week at Nelson from June 1 to August 4, 2006.  According to his testimony, the employee never worked a seven-day work week (T. 106) although he was scheduled to start working seven days per week commencing August 4, 2006.  While it appears that the compensation judge misunderstood the employee’s testimony on this point, that misunderstanding “does not appear to be central to the compensation judge’s determination nor of such magnitude as to require reversal in the light of the substantiality and extent of the other evidence supporting the compensation judge’s findings.”  Dodgen v. Casey’s General Stores, Inc., slip op. (W.C.C.A. Nov. 8, 2002).  We therefore vacate the portion of Finding No. 8 that refers to a seven-day work week.

Nelson also argues that the compensation judge erred when she concluded, also in Finding No. 8, that the majority of painting work the employee performed for Nelson involved overhead work.  Nelson argues that although the bulk of the employee’s testimony about his work duties was spent describing overhead work, that type of work did not constitute the majority of his actual work, as documented by the work records maintained by Nelson.^[2]  According to Nelson’s records, the employee spent a combined total of 21 hours painting ceilings during his tenure with Nelson, out of his total 341.5 hours of work for Nelson in 2006.  Based on that information, Nelson contends that only approximately 6% of the employee’s work for Nelson involved overhead painting.

Our review of the hearing transcript shows that the employee testified about the nature of his painting duties.  His testimony was quite comprehensive, and included his descriptions of the movements required by his painting work.  At unappealed Finding No. 3, the judge stated that “[r]egardless of the type of tools he used, the type of surface he painted, the height of the surface he painted or the position from which he painted, the employee constantly moved his neck from side to side and front to back while performing painting duties.”  That finding is consistent with the employee’s testimony; no appeal was taken from that finding.  In addition, it was the compensation judge’s responsibility to assess the credibility of a witness.  See Noeker v. Nordling Constr., No. WC06-226 (W.C.C.A. Feb. 28, 2007) (cites omitted).  Based on the employee’s testimony, it was not unreasonable for the compensation judge to conclude that the majority of the employee’s work with Nelson “involved overhead work and required the employee to work with his arms extended above head and to move his head side to side and up and down.”

Dr. Smith concluded that the employee sustained a Gillette injury in August 2006, and that it was this Gillette injury that resulted in the employee’s cervical spine condition.  By contrast, Dr. Larkins concluded that the employee’s condition was related to his injury on January 23, 2005, and also to his work activities during the 25 years leading up to the injury in January 2005.  The compensation judge adopted Dr. Smith’s opinion on the issue of causal relationship.  She concluded that Dr. Smith had adequate foundation for his conclusion, and had based his opinion on a history of the employee’s work, the employee’s symptoms and medical treatment, his treatment of the employee and his review of the diagnostic tests performed on the employee.

As to whether Dr. Smith’s medical opinion was adequately founded, and therefore whether the judge could reasonably rely on that opinion, we conclude that foundation existed for Dr. Smith’s opinion.  A review of the record indicates that Dr. Smith had access to the employee’s medical records, including those summarizing the employee’s diagnostic testing and treatment, that he initially examined the employee in August 2006 and obtained his history of symptoms, and that he has periodically treated the employee since then, including performing surgery in October 2006, and that he reviewed supplemental records documenting the employee’s medical treatment, all which provided foundation for his opinions.

In her memorandum, the compensation judge stated that,

The compensation judge was presented with opposing medical opinions as to whether the employee sustained a Gillette injury in 2006, and it is the responsibility of the compensation judge, as the trier of fact, to resolve such conflicts in expert testimony.  See Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985).  The compensation found Dr. Smith’s opinion to be convincing.  It is the role of the compensation judge to consider the competing medical opinions and to determine which opinion is most persuasive.  A compensation judge’s decision based on that choice is generally upheld.  Kelsey v. Lovegreen Indus. Servs., No. WC07-159 (W.C.C.A. Dec. 12, 2007), citing Smith v. Quebecor Printing, Inc., 63 W.C.D. 566 (W.C.C.A. 2003); Maricle v. Farmstead Foods, No. WC06-289 (W.C.C.A. June 14, 2007); and Johnson v. SICO, Inc., No. WC05-226 (W.C.C.A. Jan. 20, 2006).

We acknowledge that the record contains a medical opinion that supports the position and defenses raised by Nelson.  The issue on appeal, however, is whether there is adequate evidence in the record to support the compensation judge’s resolution of this factual issue.  This court must determine whether the findings of fact and the order are clearly erroneous and unsupported by substantial evidence in view of the entire record as submitted.  Minn. Stat. § 176.421, subd. 1.  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).  We conclude that, based on the medical evidence in the record documenting the employee’s symptoms and medical treatment, the compensation judge reasonably relied on Dr. Smith’s causation opinion.  Substantial evidence supports the compensation judge’s findings that the employee sustained a Gillette injury to his cervical spine on or about August 4, 2006, as a result of his work activities with employer Nelson and that the employee’s injury in January 2005 did not represent a substantial contributing cause of the employee’s current condition and disability, and therefore that Nelson is liable for payment of benefits to the employee.  We therefore affirm those findings.