The employee appeals the finding of 23 percent permanent partial disability to the body as a whole to the low back and left leg.  He alleges that the compensation judge must liberally construe the choice of permanent partial disability ratings for an injury occurring before the 1984 changes to Workers’ Compensation Act.  The employee further alleges that the compensation judge erred in failing to apply the simultaneous injury factor to an injury with multiple disabilities.  We affirm.

On August 30, 1978, the employee, Ronald Mogard injured his low back while working for Land O’Lakes.  The employer and its insurer, Traveler’s Insurance Group, admitted primary liability.   The employee did not return to work at Land O’Lakes, but instead returned to work for several other employers over the course of 35 years.

Shortly after the injury, on October 19, 1978, the employee sought treatment with Dr. Steven Lebow who described the injury as an onset of right low back pain radiating down the right leg.  Associated with the pain was sketchy numbness and pain on the sole of his foot and some diffuse weakness of the leg.  While the employee denied a previous history of back problems, Dr. Lebow noted that the medical records established a prior history of low back pain in 1971.  At the time, the employee complained of similar symptoms, but involving the left leg.  Dr. Lebow diagnosed the 1978 injury as low back pain.  The employee consulted with orthopedist Dr. Robert Wengler on June 18, 1982.  Dr. Wengler concluded that the back and right leg pain were characteristic of a nerve root entrapment phenomenon, probably secondary to a damaged disc.  Dr. Wengler determined that the employee’s disability at that time was in the range of a 20 percent permanent partial impairment (PPD) of function of the spine.

In March 1984, the employee underwent surgery at the L5-S1 level for right-sided disc defect and a large posterior bulging disc impinging on the right S1 nerve root.  Dr. Lebow subsequently assigned a PPD rating of 22.5 percent of the spine.

The employee had good relief of pain through April 1991 when, without any known injury, he developed an increase in pain in his back and aching in his left leg.  Dr. Richard Salib noted that this was the leg opposite to his preoperative symptoms for the disc herniation.  An MRI scan of August 6, 1991, confirmed a disc herniation to the left L5-S1 that displaced the left S1 root.  The employee treated intermittently with injections and physical therapy over the next five years.  He developed an increase in symptoms in 1995 after which an MRI scan showed a disc herniation at the L4-5 level.  Dr. Salib recommended surgery.

Dr. Paul Cederberg conducted an examination on behalf of the employer and insurer and wrote a report on December 21, 1996.  He diagnosed the employee’s condition as a herniated L5-S1 disc post right hemilaminectomy and left foraminal disc herniation L4-5 lumbar spine with left L4 radiculopathy.  Dr. Cederberg concluded that the employee sustained a new Gillette-type injury from prolonged sitting while doing computer work, which resulted in an injury to his left L4 nerve root and new rupture of the L4-5 disc. He opined that the employee was a candidate for surgery, but not fusion surgery.  The employee underwent a subsequent low back surgery at the L4-5 level on February 10, 1997.

On July 22, 1998, pursuant to an Award on Stipulation, the employee closed out PPD to the extent of 25 percent of the spine.

There is a paucity of medical evidence from 1997 to 2010.  The employee testified that his pain had been relieved.  He had changed his lifestyle and moved to a warmer climate.

The employee testified that in 2010, something changed.  He got out of the car and felt a twinge in the low back and left side which was the same as in 1984.  He saw Dr. S. Emmett Lucas III in South Carolina, complaining of a new onset of pain radiating down the legs, primarily the left leg.  Dr. Lucas diagnosed him with severe degenerative L4-5 disc with spondylolisthesis and a degenerated L5-S1 with retrolisthesis.  After conservative care, Dr. Lucas recommended an AP fusion.  The employee underwent AP fusion surgery for the L4 to S1 levels on April 12, 2011.

Post-surgery, the employee developed left foot and ankle discomfort.  The right leg pain was gone.  Consultation with Dr. Michael Tollison, a foot specialist, determined that there was no specific foot injury.  Dr. Lucas noted that the employee’s left foot discomfort was due to the nerve being stretched during the low back fusion surgery.  Dr. Lucas noted that the employee used a foot brace, but not all the time.  While the employee testified that his foot flopped, there is no mention in any of Dr. Lucas’s records that the employee suffered from “foot drop.”

On January 27, 2012, Dr. Lucas assigned a 23 percent PPD rating based on the sixth edition of the AMA Guidelines to Permanent Impairment, and not under the Minnesota disability schedules.  He based the rating on a diagnosis of degenerative spondylolisthesis at multiple levels and spinal stenosis at multiple levels with residual left leg symptoms of pain, numbness and tingling.  The rating included radiculopathy.

Dr. Cederberg conducted a medical records review and did not examine the employee.  He issued a narrative report on February 18, 2014, noting Dr. Lucas’s findings and confirmed that the employee had only mild radiculopathy since he had numbness in the lateral shin and no motor weakness.  Dr. Cederberg agreed that Dr. Lucas’s rating of 23 percent was appropriate.

The employer and insurer paid PPD based on Dr. Lucas’s and Dr. Cederberg’s rating of 23 percent.  The 23 percent whole body rating was converted to a pre-1984 PPD rating for a total of 32.39 percent of the spine pursuant to Minn. R. 5223.0250.  The employer and insurer discounted the rating by the 25 percent previously paid pursuant to the 1998 stipulation for settlement.  The employer and insurer paid the remaining 7.39 percent for a total PPD benefit of 32.39 percent of the spine.

Dr. Wengler also conducted a record review and did not examine the employee.  Dr. Wengler concluded that due to the motor weakness involving the 4th and 5th lumbar nerve roots, the employee had weakness of the foot and ankle which represented an additional 15 percent permanent partial impairment of function of the left lower extremity.   Dr. Wengler also found that “the employee’s two-level fusion would entitle him to a 30 percent whole body impairment, which would equate to a 42 percent permanent partial impairment of function of the spine.”  In addition, the employee claimed a 15 percent PPD under Minn. Stat. § 176.101, subd. 3 (46) (1978) which provides, “[i]n cases of permanent partial disability caused by simultaneous injury to two or more members, the applicable schedules in this subdivision shall be increased by 15 percent.”

The employee filed an amended claim petition on January 10, 2014, claiming 42 percent for the low back, 15 percent for the left leg, and 15 percent under the simultaneous injury factor.

The matter was heard before Judge Adam Wolkoff on October 3, 2014.  The parties stipulated that the employer and insurer already paid 32.39 percent permanent partial disability of the spine.  The employer and insurer previously paid 25 percent pursuant to the prior Award on Stipulation for the rating in 1998 and an additional 7.39 percent to the employee following Dr. Lucas’s rating.  The compensation judge found that the employee was entitled to 32.39 percent PPD of the spine as a consequence of the August 30, 1978, work injury.  He denied the employee’s claim for 15 percent PPD for the left leg.  The compensation judge declined to apply the simultaneous injury factor to award an additional 15 percent.   Because the employer and insurer already paid PPD to the extent of 32.39 percent, the compensation judge ordered no additional payment.

The employee makes three arguments on appeal.  First, the employee argues that as the injury occurred in 1978, interpretation of the workers’ compensation statute called for the liberal construction in favor of the employee pursuant to Zak v. Gypsy, 279 N.W.2d 60, 63, 31 W.C.D. 549, 554 (Minn. 1979).  Second, the employee argues that the permanent partial disability rating awarded did not take into consideration the employee’s left lower extremity and foot drop.  Third, the employee argues that he was entitled to the simultaneous injury factor and should receive an additional 15 percent rating under Minn. Stat. § 176.101, subd. 3 (46) (1978).

The employer and insurer argue that the issue of permanent partial disability is a factual determination and the compensation judge is ultimately responsible for determining the degree of disability after considering the evidence as a whole, and therefore that the findings of fact should be affirmed.

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 (2014).  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 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).

“[A] decision which rests upon the application of a statute or rule to essentially undisputed facts generally involves a question of law which [the Workers’ Compensation Court of Appeals] may consider de novo.”  Krovchuk v. Koch Oil Refinery, 48 W.C.D. 607, 608 (W.C.C.A. 1993), summarily aff’d (Minn. June 3, 1993).

The employee was injured in 1978.  The employee argues that the compensation judge did not apply the liberal construction doctrine in determining permanent partial disability for a pre-1984 case.  The law in effect at the time of the employee’s injury in 1978 required application of the liberal construction doctrine.  Developed in common law, the doctrine outlined the remedial nature of the workers’ compensation act.  It sought to accomplish a humane purpose and gave broad and liberal interpretation to the act’s provisions.  See Koktavy v. City of New Prague, 246 Minn. 550, 553, 75 N.W.2d 774, 777, 19 W.C.D. 297, 301 (1956).  Regardless of its purpose, the interpretation of this doctrine did not guarantee unrestricted benefits to the employee.  In Sobczyk v. City of Duluth, 245 Minn. 569, 73 N.W.2d 795, 19 W.C.D. 263 (1955), the Minnesota Supreme Court reversed a finding of timely notice, thereby denying workers’ compensation benefits to a firefighter who experienced symptoms of heart disease during a rescue operation.  In applying the liberal construction doctrine, the court ruled, “[t]he workmen’s compensation provisions of our statutes were enacted as social legislation seeking the accomplishment of humane purposes consistent with the social purpose of the act.  Its provisions should be construed broadly and liberally in order to effectuate that purpose.  However, that does not require us to interpret its various sections so as to defeat the rights and interests of the employer granted . . . under the act.”  Id. at 574, 73 N.W.2d at 799, 19 W.C.D. at 268-69.

For pre-1984 injuries, “the statute does not prescribe a rule or method of determining the extent of disability.”  Hosking v. Metropolitan House Movers Corp., 272 Minn. 390, 398, 138 N.W.2d 404, 409, 23 W.C.D. 673, 685 (1965) (quoting Gurtin v. Overland-Knight Co., 179 Minn. 38, 39, 228 N.W. 169, 169, 6 W.C.D. 94, 95 (1929)).  That determination is “left to the judgment of the trier of fact.”  Id.; see also Erickson by Erickson v. Gopher Masonry, Inc., 329 N.W.2d 40, 43, 35 W.C.D. 523, 528 (Minn. 1983).  The employee expressly acknowledged that the determination of permanency rests with the compensation judge.  The compensation judge agreed that the court has wide latitude in determining the permanency rating for pre-1984 injuries.   In the exercise of that discretion, the compensation judge adopted the opinions of two medical experts who opined that the appropriate rating was 23 percent.  We also agree.  The compensation judge was not required to adopt the rating that was more favorable to the employee.

The employee also argues that substantial evidence does not support the compensation judge’s rating of the employee’s permanent partial disability.  We note that the employee’s symptoms following the injury in 1978 were right-sided with a surgery to relieve a right-sided disc herniation.  In 1991, when the employee was no longer working for the employer, the employee developed a different and significant left-sided lower extremity symptom that was not present before.  The employee underwent surgery in 1997 to address the herniation at an adjacent level and a different side from the original injury.  The medical records establish that the employee’s pain resolved in 1997.  In contrast, the employee testified that he had never been pain free.  As the trier of fact, the compensation judge was in the best position to determine the credibility of the employee’s testimony and weigh it against the record as a whole.  The facts provide substantial support for the compensation judge’s determination.

Pursuant to Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985), it is the compensation judge’s responsibility, as trier of fact, to resolve conflicts in expert testimony.  Dr. Wengler determined that the employee was entitled to a 42 percent rating for the underlying low back and an additional 15 percent for the left lower extremity.  Dr. Lucas, the employee’s treating doctor and surgeon, assigned a 23 percent rating.  Dr. Cederberg, retained by the employer and insurer, agreed with Dr. Lucas’s rating.  We uphold the trier of fact’s choice between experts because the opinions are supported by the record as a whole and affirm.  See id. at 343, 37 W.C.D. at 373.

The employee argues that in addition to the permanent partial ratings for the low back, he is entitled to 15 percent for a separate left leg disability under the simultaneous injury rule.  Minnesota Statutes § 176.101, subd. 3 (46) (1978) provides: “[i]n cases of permanent partial disability caused by simultaneous injury to two or more members, the applicable schedules in this subdivision shall be increased by 15 percent.”  The employee argued that the compensation judge erred in failing to award an additional 15 percent.  Citing Drone v. Control Data Corp., slip op. (W.C.C.A. Apr. 11, 1990), the employee argues that the simultaneous injury factor must be awarded where the same injury caused both disabilities to the low back and to the left leg and foot.

The employer and insurer argue that there was no separate and distinct injury to the left lower extremity on August 30, 1978, and that the injury was limited to the lumbar spine.  They claim that any left leg involvement stemmed solely from the surgeries to the lumbar spine  The employer and insurer also argued that Dr. Lucas and Dr. Cederberg both included the left leg condition in their rating of 23 percent.

The compensation judge declined to apply the simultaneous injury factor.  He noted that the statute intended to address simultaneous injury to multiple body parts resulting from a single event.  He determined that there was no simultaneous injury to the spine and lower extremities, a fact conceded by Dr. Wengler.  Rather, the employee’s lower extremity symptoms were a component of his low back diagnosis, and disability from these symptoms is captured in the rating made by Dr. Lucas and Dr. Cederberg.

The meaning of simultaneous injury was addressed in Drone, and in the Minnesota Supreme Court case of Tracy v. Streater/Litton Industries, 283 N.W.2d 909, 32 W.C.D. 142 (Minn. 1979).  In Drone, this court granted an additional 15 percent for the simultaneous injury factor because the employee suffered an injury initially thought to be to the left arm, but later diagnosed as a neck injury as well.  In finding entitlement to that award, we noted that “the determinative issue is whether the same injury caused both of the disabilities.”  Drone, slip op. at 4 (quoting Schnurrer v. Hoerner-Waldorf, 36 W.C.D. 500, 503 (W.C.C.A 1983) (reversed on other grounds) 345 N.W.2d 230, 36 W.C.D. 504 (Minn. 1984)).

Likewise, in Tracy, an employee injured his spine, but over the course of several months developed ongoing deterioration.  He suffered loss of sensation and use of his legs and arm and ultimately became paraplegic.   The court ruled that where progressive disabilities occurred within a short time after a single injury, and the record did not disclose any intervening cause that might have occurred, there was no reason to deny the additional 15 percent merely because the results were delayed and could not be physiologically traced to the injury with medical precision.  “The statute requires neither absolute simultaneity nor absolute proof.”  Tracy, 283 N.W.2d at 917, 32 W.C.D. at 153.  Accordingly, the court held that simultaneous injuries occurred and the additional 15 percent was proper.

Unlike Drone and Tracy, the employee’s left leg symptoms did not materialize until years and possibly decades later.  The compensation judge declined to apply the simultaneous injury factor.  He noted that the statute intended to address simultaneous injury to multiple body parts resulting from a single event.  He determined that there was no simultaneous injury to the spine and lower extremities, a fact conceded by Dr. Wengler.  Rather, the employee’s lower extremity symptoms were a component of his low back diagnosis, and disability from these symptoms was captured in the rating made by Dr. Lucas and Dr. Cederberg.  Under these circumstances, the compensation judge could reasonably find that the simultaneous injury factor did not apply.  We affirm the compensation judge’s findings and order in its entirety.