The employer and insurer appeal from the compensation judge’s findings that the employee sustained Gillette^[1] injuries to his cervical and lumbar spine culminating on January 1, 2005, which substantially contribute to his current condition, claimed temporary total disability and need for medical treatment, and that the employee provided sufficient notice of those Gillette injuries.  The employer and insurer also appeal from the compensation judge’s finding that the employee’s December 29, 1982, personal injury substantially contributes to his current lumbar spine condition, and from the award of temporary total disability benefits and medical expenses.  We affirm.

Mr. David A. Anderson, the employee, has worked for the utility company, Northern States Power, now known as Xcel Energy, since 1973.  He initially worked with a ground crew, preparing holes for power poles, and later worked as a tree trimmer.  He then completed a four-year apprenticeship as a cable splicer.  After working as a journeyman cable splicer, the employee became a foreman of a two or three member splicer crew in 1984, and, since 2002, he has worked as a cable crew foreman responsible for a six member crew.

The employee described the types of duties required of a splicer and of the cable crew, including pulling heavy-duty wires through duct lines, digging trenches for placement of cable, placing cable in line for splicing, soldering, and lifting parts.  He estimated that 80% of his splicing job was performed in manholes and 20% in an overhead truck bucket; his work in manholes required a great deal of bending, as the ceiling height of manholes and trenches range between four and seven feet.  On occasion, especially while soldering, the employee’s work required him to stand in a static position, without breaks for stretching, while completing his soldering project.

The employee described his cable crew foreman position as a “working foreman” position, as he performed essentially the same type of work he had performed as an apprentice and journeyman cable splicer.  He explained that as a foreman, his cable duties did not change but the level of his responsibility changed, as he worked with his crew and was responsible for the other crew members and for their safety.  For example, as a foreman, he  needed to climb down into each manhole and every tunnel to review his crew’s work and to ensure that the crew members were both pulling wire in a safe way and placing their bodies in correct positions.

During the course of his employment with NSP and Xcel Energy (referred to jointly in this decision as Xcel Energy), the employee has sustained multiple injuries, including injuries to his lumbar and cervical spine, elbows, right shoulder and hands.^[2]  The injuries addressed at hearing, and addressed on appeal, are limited to the following:

On December 29, 1982, the employee sustained an admitted injury to his lumbar spine when he slipped and fell on ice at a work site.  The employee’s low back pain persisted following this injury, and he ultimately underwent laminectomy surgery in 1985, at the L5-S1 vertebral level.  The employee eventually returned to work, and was later restricted from work on a periodic basis, due to his low back symptoms.  Although his surgery initially alleviated his pain, the employee’s symptoms recurred within a few months and have progressively worsened to the point where he has experienced numerous flare-ups and has undergone repeated facet injections.  Other conservative treatments for his low back symptoms included physical therapy, pool therapy, laser treatment, and use of prescription pain medications.  In addition, due to increasing difficulties sleeping due to his back pain, and resulting daytime drowsiness resulting from his insomnia and the side effects of pain medication, the employee has undergone sleep studies and has been prescribed medication to alleviate his sleep dysfunction.
 
In October 1985, the employee consulted an orthopedist, Dr. Matthew Eich, and has continued to treat with Dr. Eich, Dr. Mark Sprangers and their colleagues at the Interstate Medical Center (later merged with Fairview Red Wing Health Services).  Records from Fairview Red Wing document the employee’s ongoing low back symptoms, his chronic low back complaints, his physicians’ referrals for outside consultations, and the various types of treatment provided in an attempt to alleviate his ongoing symptoms.  In 1989, at Dr. Eich’s referral, the employee consulted Dr. Alexander Lifson, at the Low Back Institute, to obtain a second opinion on surgery recommendations.  Dr. Lifson noted the employee’s chronic lumbar degenerative disc disease, which he anticipated would continue in the future.  He concluded that the employee was not a candidate for additional surgery at that time, and instead recommended weight reduction and stabilization exercise programs (in which the employee later participated), changes in his pain medication, and continued aggressive conservative management.

On March 8, 1995, the employee sustained an injury to his neck and shoulder, after bending over to push up cement shelves in a manhole, which required awkward positioning of his neck.  That injury was temporary in nature; by May 10, 2005, the employee was released by Dr. Sprangers to return to work without restrictions.  On November 24, 1997, the employee experienced neck and right shoulder pain after digging a trench during the winter with a frost bar.  That injury was also temporary in nature, and, by December 10, 1997, Dr. Sprangers released the employee to return to work without restrictions.

The record documents repeated symptom flare-ups experienced by the employee, and his ongoing consultations with his physicians to obtain treatment recommendations.  By late 2004, he consulted Dr. Eich specifically for his persistent low back pain.  On October 29, 2004, the employee reported difficulty sleeping at night due to back pain and was diagnosed with continued fatigue possibly secondary to back pain and lack of sleep as well as to underlying depression.

On January 4, 2005, the employee again consulted Dr. Matthew Eich, reporting significant back and leg pain, neck and shoulder symptoms, and knee pain.  According to Dr. Eich’s chart note of that date, the employee reported that

On March 2, 2005, at the referral of Dr. Eich, the employee consulted Dr. David Polly, an orthopedist and chief of spine service at the Fairview University Medical Center, for further treatment of his neck symptoms and his sleep deprivation.  Dr. Polly diagnosed diffuse cervical spondylosis with symptomatic C6-7 foraminal stenosis on the left; he also diagnosed lumbar spondylosis and noted the employee’s history of surgeries on his elbows and thumbs.  He related the employee’s degenerative changes in his neck and his clinical syndrome of pain to his workplace duties.  Dr. Polly referred the employee for physiotherapy, a diagnostic foraminal injection at the left C6-7 level, and an MRI scan of the cervical spine, and also referred him to the Fairview Sleep Clinic for further investigation and treatment of his sleep deprivation.

On April 1, 2005, the employee was examined by Dr. John Dowdle, orthopedic surgeon, at the request of the employer.  At that point, the employee advised Dr. Dowdle he had been unable to resume his work activities due to his continuing low back pain.  Based upon his record review and examination of the employee, Dr. Dowdle diagnosed

Dr. Dowdle concluded that the employee was capable of working relative to his low back, within work restrictions including a 30-35 pound maximum lifting limit and avoidance of prolonged single-position activities.  Dr. Dowdle suggested an occasional use of a low back support while performing current physical activities to help protect him and to avoid an exacerbation of his back pain.  Dr. Dowdle acknowledged that the employee had a history of surgical treatment for his back in 1985 that was attributable to a work injury, along with a work injury in January 1994, but concluded that the employee’s physical work restrictions, limitations, and continued back pain were unrelated to his work injuries.  Dr. Dowdle, instead, concluded that the employee’s restrictions and condition were related to his underlying degenerative disc condition in his lumbar spine.  Dr. Dowdle recommended continued use of anti-inflammatory medications, modification of his activity, and occasional use of a low back support.  He also commented that, while not indicated at that point, a further surgical fusion might be necessary, due to the employee’s three-level degenerative disc disease.  Dr. Dowdle also recommended a cervical MRI scan, due to the employee’s continued neck pain and objective examination findings in his neck.  He opined, however, that the employee’s cervical spine pain, shoulder pain and knee pain were unrelated to the employee’s work activities.

At a follow-up appointment on May 9, 2005, Dr. Eich concluded that the employee remained disabled from work activities, due to his multiple orthopedic conditions, and prescribed Vicodin for pain treatment and Ambien as a sleep aid.  Dr. Eich also recommended that the employee continue to follow-up with Dr. Polly.  By mid-July 2005, Dr. Eich recommended that the employee work every other day due to his continued chronic low back pain, neck and shoulder pain, and difficulty sleeping due to his continued pain.

On July 13, 2005, the employee filed a claim petition, seeking entitlement to wage loss benefits, medical expenses, permanent partial disability benefits and rehabilitation services, due to multiple work injuries incurred between 1975 and 1998.  The employer and its insurers denied the employee’s claims, and the matter was scheduled for hearing.

Dr. Dowdle reexamined the employee on October 17, 2005.  At that point, the employee reported continued low back pain, a restricted ability to sit, and an inability to sleep more than two to four hours per night.  Dr. Dowdle reiterated the same opinions rendered following his initial examination of the employee.  In addition, he assigned various permanent partial disability ratings, including a 3% whole body impairment rating relative to the right knee, related to the employee’s work activities.  He assigned a rating of 17% permanent partial disability to the body as a whole to his right wrist, unrelated to work.  Dr. Dowdle also assigned an 11% whole body impairment rating to the employee’s low back, which he attributed to the employee’s work injury and specifically to a 1985 disc herniation in the lumbar spine.  He also noted degenerative changes in the employee’s neck, and assigned a 10% whole body impairment rating based on that condition, concluding, however, that the employee’s neck symptoms were related to age-related degenerative changes and were unrelated to any work injury.

In December 2005, the employee consulted Dr. Richard Salib at Dr. Eich’s referral, reporting chronic back pain radiating into his legs as well as difficulty sleeping due to his back pain.  At that point, the employee’s work was limited to every other day due to his symptoms.  Dr. Salib recommended a bilateral diagnostic L5 nerve root block to see if his back pain could be relieved by the block and to help assess whether decompression or fusion surgery would be appropriate.  Based on the short-term benefit provided by the nerve block, Dr. Salib recommended a bilateral laminotomy and medial facetectomy and foraminotomy, and the L4-5 level.  It is not clear from the record whether that surgery was performed.

In a report dated April 24, 2006, Dr. Eich referred to the employee’s approximately 30 years of medical management for various work injuries, and the causal relationship between his work and his low back and neck symptoms.  He concluded that the employee had sustained a “Gillette type injury to his neck and back” that culminated in his disability from work between January and June 2005.  Dr. Eich opined that “the work activities required of Mr. Anderson and his unique capabilities and experience, expose him to situations where he aggravated both [h]is neck and his back to a very substantial degree.”  He concluded that the employee’s complex work required  various physical activities in awkward positions and cramped spaces, and that the employee

On July 17, 2006, the employee filed a copy of that report and provided it to the employer along with an amendment to his claim petition to include Gillette injuries to his lumbar spine and cervical spine, with culmination dates of January 2005 and April 2006.  The employee testified that he had continued to experience increased neck pain from overhead work, and worsening low back pain from physical work activities, at the time of his claimed Gillette injuries in January 2005.

Following an evidentiary hearing held on August 24, 2006, the compensation judge found that the employee’s work injury of December 29, 1982, was a substantial contributing factor to the subsequent degenerative changes in the employee’s lumbar spine.  She concluded that the employee’s March 1995 and November 1997 injuries were temporary in nature.  She also found, however, that the employee sustained Gillette injuries to his cervical spine and lumbar spine that culminated in disability on January 1, 2005, and that the employee had provided sufficient statutory notice of those injuries.  Based upon the opinions of Dr. Eich and Dr. Polly, the judge concluded that the employee’s December 29, 1982, and January 1, 2005, injuries represented substantial contributing factors to the employee’s temporary total disability between January 1, 2005, and June 14, 2005, and to the employee’s 10% permanent partial disability of the whole body, relative to his cervical spine.

The judge also concluded that the 1982 and 2005 injuries substantially contributed to the medical expenses the employee incurred at Red Wing Corner Drug, Fairview Red Wing Health Services, and University of Minnesota Physicians, including medications for sleep dysfunction.

The employer and insurer appeal.

The compensation judge found that the employee sustained Gillette injuries to his cervical and lumbar spine as of January 1, 2005, that those injuries represented substantial contributing causes to the employee’s current condition, and that the employee provided sufficient statutory notice of his Gillette injuries.  The employer, as self-insured and also through its insurer, appeals, arguing that the employee did not provide timely notice of his January 1, 2005, injuries.

To prove a claim under the Workers’ Compensation Act, an employee must show that the employer had timely notice or knowledge of the employee’s injury within the statutory period.  Issacson v. Minnetonka, Inc., 411 N.W.2d 865, 40 W.C.D. 270 (Minn. 1987).  Minn. Stat. § 176.141 outlines the time requirements for providing notice to an employer of a work-related injury.  Where notice is provided to the employer more than 30 days but less than 180 days from the occurrence of the injury, compensation is still payable if the employee “shows that failure to give prior notice was due to the employee’s . . . mistake, inadvertence, ignorance of fact or law, or inability, or to the fraud, misrepresentation, or deceit of the employer or agent . . . unless the employer shows prejudice . . . .”  Minn. Stat. § 176.141.^[3]  The purpose of the notice requirement is to permit the employer to make such investigation as is necessary to determine its liability for a compensation claim and to allow the employer to provide necessary medical care.  Rinne v. W.C. Griffis Co., 234 Minn. 146, 47 N.W.2d 872, 16 W.C.D. 348 (1951); see also Kling v. St. Barnabas Hosp., 291 Minn. 257, 261, 190 N.W.2d 674, 677, 26 W.C.D. 53, 56 (1971), citing Pojanowski v. Hart, 288 Minn. 77, 178 N.W.2d 913, 25 W.C.D. 206 (1970).  In cases involving a Gillette injury, the period during which notice must be given does not begin to run until the employee, as a reasonable person, should have recognized the probable compensability of the injury.  See Swenson v. Cal-Mech, 50 W.C.D. 1, 11 (W.C.C.A. 1993) (employee not aware of compensable nature of injury until medical report received).

In his report of April 24, 2006, the employee’s treating orthopedic surgeon, Dr. Eich, outlined his opinion that the employee had sustained Gillette injuries to his cervical and lumbar spines as of January 2005.  Dr. Eich stated, in part, that

The employee’s attorney provided a copy of that report to counsel for the employer on July 17, 2006.  The judge found that the employee’s notice of those Gillette injuries was timely provided to the employer.  She concluded that the initial opinion describing Gillette injuries culminating in disability in January of 2005 was rendered by Dr. Eich on April 24, 2006, and that, since that opinion was provided to the employer within 180 days of receipt of that report, provision of notice on July 17, 2006, represented sufficient statutory notice.

“The notice requirement is designed to enable the employer to furnish immediate medical attention in the hope of minimizing the seriousness of the injury as well as to protect the employer by permitting him to investigate the claim soon after the injury.”  Sobczyk v. City of Duluth, 245 Minn. 569, 73 N.W.2d 795, 19 W.C.D. 263 (1955).  In this case, the employee has worked for the employer since 1973.  He had sustained at least three spinal injuries before 2005, which included a lumbar spine injury in December 1982, a cervical spine injury in March 1995, and a cervical spine injury in November 1997.  The employer accepted liability for these injuries and paid the related medical expenses.  The employee testified that his back injuries continued to bother him, that his symptoms worsened, and that the employer was aware of his medical condition.  The employer continued to pay medical expenses for the employee’s treatment for his back, and even scheduled an independent medical examination with Dr. Dowdle on April 1, 2005.  The compensation judge could reasonably conclude that the employee would not know that additional notice was required for his spinal condition until receiving Dr. Eich’s report referring to Gillette injuries.  The employee’s notice of Gillette injuries, culminating in January 2005, was provided within 180 days of Dr. Eich’s opinion indicating that the employee had sustained Gillette injuries.  The employer has not been prejudiced by any delay.  The compensation judge did not err by finding that the employee had given adequate notice under Minn. Stat. § 176.141.  Accordingly, we affirm.

The compensation judge found that the employee’s Gillette injuries to his cervical and lumbar spine, which culminated in disability on January 1, 2005, represented substantial contributing causes to his current condition.  Relying on the medical opinions of Dr. Eich and Dr. Polly, and on the employee’s testimony concerning the nature of his work, the judge concluded that the employee’s repetitive heavy work activities over a period of years, and the continued awkward positioning of his neck and lumbar spine while working, resulted in an aggravation of his underlying degenerative condition of his cervical and lumbar spine.

The employer and insurers appeal, arguing that the employee did not prove he sustained Gillette injuries to his cervical and lumbar spine on January 1, 2005.  They base their contentions on the lack of an accurate foundation in the opinions of Drs. Eich and Polly, arguing that those doctors incorrectly described the nature of the employee’s work that allegedly culminated in a disability on January 1, 2005.  They assert that the employee’s work for the three years preceding this injury date was supervisory, and not “hands-on work,” but was more “look and talk” work as a crew foreman, and, therefore, Drs. Eich and Polly’s opinions fail to supply sufficient legal causation due to a lack of an accurate foundation to implicate the employee’s activities as culminating in a Gillette injury.  (Er.’s Brief, p. 10-11.)

As a reviewing court, we must determine whether the record supports the compensation judge’s determination, and, as part of that consideration, whether the expert medical opinions on which the judge relied are adequately founded.  Upon review, we determine that adequately founded medical opinions provided sufficient support for the compensation judge’s finding concerning the employee’s Gillette injuries.

A Gillette injury is a result of repeated trauma or aggravation of a preexisting condition which results in a compensable injury 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 (1960); Carlson v. Flour City Brush Co., 305 N.W.2d 347, 350, 33 W.C.D. 594, 598 (Minn. 1981).  The question of a Gillette injury primarily depends on medical evidence.  Marose v. Maislin Transport, 413 N.W.2d 507, 512, 40 W.C.D. 175 (Minn. 1987).  The employee "must prove a causal connection between [his] ordinary work and ensuing disability . . . .  Whether given by testimony or written report, an opinion by a medical expert as to the causal link between the claimant's disability and the job must be based on adequate foundation."  Steffen v. Target Stores, 517 N.W.2d 579, 582, 50 W.C.D. 464, 467 (Minn. 1994).

As to whether Drs. Eich and Polly’s medical opinions were adequately founded, and therefore whether the judge could reasonably rely on those opinions, we conclude that foundation existed for their opinions.  The employee’s testimony of his work activities mirrored the histories he had earlier provided to his various medical providers, and outlined the repetitive and heavy nature of those activities.  Dr. Eich had examined the employee periodically since 1985, performed surgery in 1985, referred the employee for various diagnostic testing, provided multiple facet injections, and had available for his review reports from other consulting physicians.  Dr. Polly first examined the employee in March 2005, at the referral of Dr. Eich, and continued to treat the employee in conjunction with Dr. Eich through at least February 2006.  This background, along with both physicians’ examinations of the employee over time and their intake of the employee’s history and symptoms at numerous appointments, constitutes ample foundation for their opinions.

In this case, the compensation judge relied on the medical opinions of both Drs. Eich and Polly.  Dr. Eich, the employee’s treating physician for a substantial period of time, noted the significant progression of the degenerative condition of the lumbar spine as aggravated by the employee’s heavy physical work and awkward positions.  Dr. Eich reasoned that the “work activities required of Mr. Anderson and his unique capabilities and experience, exposed him to situations where he aggravated both [h]is neck and his back to a very substantial degree.”  Dr. Polly also concluded that the employee’s workplace duties significantly contributed to the degenerative changes in his neck and his neck pain.  Both physicians referred to the nature of the employee’s work activities throughout his tenure with the employer when explaining the basis for their opinions.  Even though the employee had worked in a supervisory fashion in the three or four years preceding the hearing, that supervisory work still required physical work in awkward positions–the type of work that Drs. Eich and Polly cited as contributing to the employee’s lumbar and cervical spine symptoms, and work that was similar in nature to that which the employee had performed throughout his tenure with Xcel Energy.  The reports of both Drs. Eich and Polly support the judge’s conclusions concerning the causal relationship between his ongoing work activities and his Gillette injuries culminating on January 1, 2005.

At Finding No. 5, the judge explained that,

The record contains voluminous medical records documenting treatment since the late 1970s.  Those medical records, as well as the employee’s testimony and the opinions of various medical experts, were available for the compensation judge’s review.  It is the compensation judge's responsibility, as trier of fact, to resolve conflicts in expert testimony, and, in this case, the compensation judge found the opinions of Drs. Eich and Polly to be more persuasive than that of Dr. Dowdle.  See Nord v. City of Cook, 360 N.W.2d 337, 342, 37 W.C.D. 364, 372 (Minn. 1985).  We conclude that the record, including adequately founded expert medical opinion, medical records and the employee’s testimony, provides support for the compensation judge’s findings that the employee sustained Gillette injuries to his cervical and lumbar spine, culminating on January 1, 2005, and that those injuries represented substantial contributing factors to the employee’s temporary total disability in 2005, his need for medical treatment for his low back and neck symptoms since 2005, and the 10% permanent partial disability he has sustained relative to his cervical spine.  We therefore affirm those findings.

The compensation judge found that the employee’s work injury of December 29, 1982, represents a substantial contributing factor to the subsequent degenerative changes in his lumbar spine.  The employer and insurers appeal from that finding, and from the finding that the 1982 injury is causally related to the employee’s temporary total disability in 2005 and his later medical treatment to the lumbar spine.  The employer and insurer argue that there is no expert medical opinion indicating that there is a causal relationship between the employee’s disability in 2005 and claimed medical treatment and his 1982 work injury.  They argue that the judge’s conclusions concerning the 1982 injury are clearly erroneous, in that the employee introduced “no medical opinion evidence even mentioning the L5-S1 personal injury of December 29, 1982 in conjunction with the claims of benefits for a period of disability and the need for medical care more than 22 years later in 2005."  The employer and insurer also argue that the medical opinion introduced by the employee and adopted by the judge attributes the recent and current disability to an intervening degenerative Gillette injury to the back culminating on January 1, 2005, and not to the December 29, 1982, injury.  This court’s standard of review on appeal requires us to determine whether the record supports the judge’s findings or whether her findings concerning the 1982 injury constitute clear error.

The employee’s medical records are replete with references to the employee’s long-term work history and long-term low back condition.  In his report of April 24, 2006, Dr. Eich referred to the employee’s severe back injury during the 1970s with a resulting L5-S1 discectomy, which over time resulted in a progressive deterioration of the adjacent L3-4, L4-5 and L5-S1 discs.  Dr. Eich concluded that the employee’s current condition was related to both that progressive lumbar disc degeneration and further progression caused by ongoing work activities.  Dr. Eich’s chart notes throughout his treatment of the employee contain references to a low back injury in the late 1970s, in 1978 or 1979, and the 1980s, each time mentioned in conjunction with a reference to the employee’s 1985 surgery.  The employee sustained an admitted injury on December 29, 1982, following which he underwent surgery in 1985.  Although Dr. Eich’s report does not refer to a specific injury on December 29, 1982, the compensation judge explained in her memorandum that Dr. Eich, in his report of April 24, 2006, “appears to be referencing the lumbar injury of December 29, 1982,” an inference which, based on the context and the record as a whole, was reasonable.

Questions of medical causation fall within the province of the compensation judge.  Felton v. Anton Chevrolet, 513 N.W.2d 457, 50 W.C.D. 181 (Minn. 1994).  In addition to medical opinions, a judge may base his or her conclusions on other reliable evidence in the record.  See Reimer v. Minnit Tool/M.I.T. Tool Corp., 520 N.W.2d 397, 51 W.C.D. 153 (Minn. 1994).  In this case, the compensation judge’s factual conclusion concerning the nature of the employee’s 1982 injury, and its role as a contributing factor to the employee’s current condition, was not clearly erroneous as a matter of law, nor was it factually unreasonable, given the medical evidence of record.  It is the role of this court to 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.  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).  In this case, substantial evidence, including the employee’s testimony and his medical records, supports the compensation judge’s findings that the employee’s 1982 work injury was causally related to his disability in 2005 and his need for claimed medical treatment related to his low back.  Accordingly, we affirm.