The employee appeals from the compensation judge’s finding that the employee’s August 20, 2002, injury did not represent a substantial contributing factor in the cause of, aggravation of, or acceleration of his current condition, and from the compensation judge’s related denial of his claim for benefits.  We affirm.

This case is before the court on appeal from issuance of a Findings and Order on Remand.  Background facts of this case are set out in the court’s previous decision, McCue v. Balzer Manufacturing, slip op. (W.C.C.A. June 23, 2005).  In summary, Mr. Michael W. McCue, the employee, sustained an admitted injury on August 20, 2002, while working as a welder for Balzer Manufacturing.^[1]  The employee was diagnosed with a recurrent right inguinal hernia.  Although the employee also claimed that he injured his low back as a result of the same incident, the employer and insurer denied primary liability for a low back injury.

The employee’s medical records outline earlier treatment the employee received for his low back, and contain information on earlier work-related injuries he sustained.  In 1992, the employee injured his low back while working in Montana for Parts Plus.  He received physical therapy; he testified that he remained off work for approximately six-eight months following that injury, although other references in his medical records indicate that he was off work for approximately one year.  Dr. James R. Burton, orthopaedic surgeon, with whom the employee treated in 1992 after his injury at Parts Plus, examined the employee on April 27, 1993.  According to a letter prepared by Dr. Burton on that date, the employee dated his onset of low back symptoms to his February 1992 work injury at Parts Plus.  Dr. Burton noted that the employee’s X-rays were within normal limits, that he had reached maximum medical improvement, and that he had sustained no permanent partial disability based on the lack of any strong positive orthopedic or neurological findings.

The employee also sustained an admitted work-related low back strain on March 27, 1997, when he moved a table while working as a welder for Modern Tool, Inc.  He received medical treatment in April 1997 and, by April 9, 1997, Dr. T.G. Domino, at the Aspen Clinic, determined that the employee had reached maximum medical improvement from that injury, that he had sustained no permanent partial disability as a result of the injury, and that he could return to work with no restrictions.

At a December 1998 appointment, the employee reported low back pain since a lifting incident three weeks earlier; an MRI scan taken in December 1998 showed multi-level degenerative disc disease and bulging discs at two levels without significant stenosis.  On October 26, 1999, the employee sustained another low back injury while working as a machinist and welder at Dick’s Welding.  He received medical and chiropractic treatment following that incident, and testified that he missed one to two days of work thereafter.  Dr. Steven Hartberg determined that the employee had reached maximum medical improvement from his 1999 injury as of November 16, 1999, and that he had sustained no permanent partial disability as a result of that injury.

In November 1999, the employee switched jobs to Balzer Manufacturing.  There is no reference in the record to any additional medical or chiropractic treatment the employee received between November 1999 and August 2002, and he testified that he was able to perform heavy duty work during that time period.  On August 20, 2002, while standing on a platform at Balzer Manufacturing, the employee lifted a steel reinforcing plate that weighed approximately 50-60 pounds.  He fell backwards onto the ground, landing on his tail bone area with the steel plate landing on top of his mid section.  The employee sought medical treatment at the Mountain Lake Medical Clinic.  He reported to Dr. Leo Avenido that he was experiencing increased heartburn, and increasing pain at his right lower quadrant.  According to the doctor’s chart notes, the employee reported a history of right inguinal hernia repair, and that because he felt he may have pulled a muscle in that area and had been experiencing chronic pain, he was concerned about a recurrent hernia; the chart notes on that date do not refer to an incident at work.  Dr. Avenido examined the employee, diagnosed worsening GERD,^[2] and a possible recurring right inguinal hernia, and recommended a surgical consultation for a potential hernia.

Dr. Ernest Lampe, surgeon at the Mankato Clinic, examined the employee on August 28, 2002, and recorded a history from the employee that he was involved in a motorcycle accident about 20 years ago, at which time he had a back injury as well as a right groin injury that was repaired.  The employee reported to Dr. Lampe that he had noted intermittent discomfort since that time but was able to pursue activities without limitation, and that one month ago, while lifting a heavy piece of steel at his usual employment, he felt a “tearing” and persistent pain and tenderness in the right groin.^[3]  Dr. Lampe’s chart note states the employee had chronic back discomfort and reflux disease.  He recommended surgery for a right inguinal hernia.  Dr. Lampe stated that the “findings of right inguinal hernia are entirely related to his current employment and not in anyway related to the history of an injury 20 years ago.”

In a preoperative physical examination conducted on September 23, 2002, at Immanuel-St. Joseph’s hospital, under “review of systems” there is a reference to “back pain.”  On September 25, 2002, Dr. Lampe surgically repaired the employee’s hernia.  Dr. Lampe restricted the employee from work for approximately three weeks; he returned to work on a light-duty basis on October 17, 2002, with work restrictions assigned for a three-week duration.  On November 6, 2002, the employee consulted Dr. Lampe, reporting an acute onset of right flank and groin pain after he lifted a 100-pound item and twisted to place it on a shelf.  Dr. Lampe diagnosed a right back strain with possible muscular disruption and hematoma, and stated that the “findings on physical examination suggest a significant muscular injury.”

On November 26, 2002, the employee reported to Dr. Avenido that he had spasms of his back muscles up to his hip area, and that although he was taking Vicodin, he was not able to function well.  At an exam on December 2, 2002, the employee reported back and right hip pain which seemed to start about 4 weeks earlier after he lifted a heavy item at work.  Dr. Avenido’s chart note includes a reference by the employee to an earlier low back problem secondary to a motor vehicle accident and that his pain seemed to be similar to that earlier pain.  Dr. Avenido’s chart note of December 24, 2002, refers to severe low back pain; his chart note of January 10, 2003, states that the employee reported that his back pain was “almost totally gone now.”  Dr. Avenido recommended a back strengthening program through the physical therapy department.  The employee continued to consult Dr. Avenido and Dr. Lampe in 2003, reporting continued low back symptoms and continued right abdomen pain.

Mankato Clinic records also refer to a work injury the employee sustained on March 28, 2003, following which he noted groin and abdominal pain.  Dr. Lampe noted that there was a possible injury to the employee’s hernia repair.  In October 2003, the employee consulted Dr. Lampe, again reporting that his back pain continued.  At Dr. Avenido’s referral, the employee also consulted Dr. Amir Mehbod in March 2004.  Dr. Mehbod recommended low back surgery in the nature of one- level fusion at the L3-4 level, to decompress and stabilize the employee’s back and to treat his spondylolisthesis.

Based on their denial of primary liability, the employer and insurer did not authorize that proposed surgery.  The employee then filed a claim petition, seeking payment for medical expenses and wage loss benefits which he attributed to his low back injury in 2002.  While that claim was pending, the employer and insurer scheduled the employee for an independent medical examination with Dr. Robert Barnett.  In his report of July 12, 2004, Dr. Barnett concluded that the employee’s work-related injury of August 20, 2002, did not represent a substantial cause of the employee’s medical treatment and current low back condition.  He concluded, instead, that the employee’s condition resulted from the progressive degeneration dating back to a 1991 motorcycle accident.  Dr. Barnett also referred to other back injuries and episodic exacerbations of symptoms since 1992.  Although Dr. Barnett concluded that the fusion surgery proposed by Dr. Mehbod would be reasonable and necessary, he concluded that the employee’s need for that surgery was unrelated to his August 2002 work injury.

The employee’s claim petition was addressed at a hearing on September 23, 2004.  In his Findings and Order, the compensation judge found that the employee had not shown that his injury in August 2002 substantially contributed to his current condition and, therefore, denied the employee’s claims.  The compensation judge concluded that the employee did not complain of low back pain immediately following that 2002 injury, that the medical records reflect a long-standing preexisting low back condition which caused the employee’s chronic low back pain, that the employee’s first significant low back complaints were made almost two months after the injury, and that the low back problems “could simply be a natural progression of [the employee’s] preexisting condition.”  The compensation judge concluded that the evidence did not show the August 2002 injury was a substantial contributing cause of his current condition.

The employee appealed, and on appeal this court vacated a portion of the compensation judge’s findings on causation and remanded the case to the judge for reconsideration.  This court determined that, in view of the conflicting evidence concerning causation of the employee’s low back condition, and in view of the conflicting references in the employee’s medical records concerning the dates of past medical treatment and injuries, the court was uncertain whether the compensation judge relied on Dr. Barnett’s comment that the employee’s low back condition and symptoms originated with his 1991 motorcycle accident.  Dr. Barnett’s comments contradicted the employee’s testimony that the motorcycle accident occurred in approximately 1986 and not in 1991 and that he had not injured his back in that accident.  The record did not contain evidence as to the specific date of that accident.  In view of the impact that the conflicting medical records may have had on the compensation judge’s findings on causation, we vacated those findings that related to the compensation judge’s determination that there was no causal relationship between the employee’s 2002 work injury and his current condition and disability, and remanded the matter to the compensation judge for reconsideration of the employee’s claims.

In his Findings and Order on Remand, the compensation judge incorporated his earlier Findings and Order, as modified by the June 23, 2005, decision of the Workers’ Compensation Court of Appeals.  He reached the same conclusion on remand, that is, that the employee’s August 20, 2002, work injury did not represent a substantial contributing factor in either the cause of, aggravation of, or acceleration of the employee’s current condition.  The compensation judge concluded that the employee’s current symptoms and need for treatment were the natural progression of his preexisting low back condition.  The judge cited to the employee’s extensive history of periodic low back symptoms dating back to at least 1991.  He cited to the employee’s report in 1997 that he had not been pain free since 1992, and cited to an MRI scan in 1998 that showed multi-level degenerative changes with bulging and significant stenosis.  The compensation judge also referred to the employee’s report in 1999 that he had experienced a “pop” in his low back.  He noted that the employee’s first significant low back complaints started two months post-injury, and that his symptoms abated in January 2003, and were not a significant problem until October 2003.  The judge found this pattern to be consistent with the employee’s medical history predating his August 2002 injury.  Despite the employee’s contention that his low back symptoms had resolved over time, and despite the apparent lack of medical treatment he received between 1999 and 2002, the judge was not persuaded that the employee’s condition had resolved.  The compensation judge again concluded that the employee’s current symptoms and need for treatment were the result of the natural progression of his preexisting low back condition, and therefore denied the employee’s claims.  The employee again appeals from the compensation judge’s Findings and Order on Remand.

The compensation judge found that the employee’s work injury of August 20, 2002, did not represent a substantial contributing factor in his current condition, but that, instead, his current symptoms and need for medical treatment are causally related to his low back condition that pre-existed his August 2002 injury.  The employee appeals from that finding and from the denial of his claims for benefits.  The employee argues that in spite of his medical history, including his history of low back injuries and related medical treatment, he was able to work for the employer full-time as a welder, in a job that required him to stand at a welding table 40 hours each week, to routinely lift pieces of steel weighing 50-60 pounds and to perform other job duties related to the manufacture of heavy farm equipment.  The employee contends that his symptoms prior to August 20, 2002, did not compare in any way to the more severe symptoms he has endured following his August 2002 injury and argues that the record does not contain credible evidence supporting the judge’s decision.

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).  After his review of the medical records in evidence, as well as testimony presented by the employee, the compensation judge found that the evidence in this case failed to show that the employee’s current low back complaints were causally related to his August 20, 2002, work injury.  The judge noted the employee’s extensive pre-existing condition dating back to at least 1991.

The record contains medical opinions from various treating physicians, and also from Dr. Robert Barnett, the independent medical examiner.  In the compensation judge’s original findings and order, issued on November 29, 2004, the compensation judge referred to the employee’s history of low back complaints and the treatment he had received prior to his August 2002 injury.  The compensation judge also relied in part on Dr. Barnett’s opinion, and that reliance was the subject of this court’s decision and its remand to the compensation judge for reconsideration.  In his earlier decision, the judge adopted Dr. Barnett’s opinion that the employee’s 2002 work injury did not represent a substantial contributing cause of his low back condition or symptoms.  In his decision on remand, the compensation judge refers more generally to the medical record as a whole, and comments on the various references to the employee’s report of symptoms and medical treatment dating back to at least 1991.

For example, the compensation judge referred to the employee’s report in 1997 that he had not been pain free since 1992.  Following his injury on March 27, 1997, the employee consulted Dr. T. D. Domino at Aspen Clinic.  In a chart note dated April 2, 1997, Dr. Domino noted that the employee reported that he had a previous work injury his low back in 1992, was off work for one year and had never been without pain since, and also that his injury of March 27, 1997, had worsened his back pain.  The compensation judge also listed the employee’s report in 1999 that he had experienced a “pop” in his low back; that statement may have been based on a chart note from Dr. Steven Hartberg, dated October 26, 1999, stating that the employee was pulling on an iron worker device when he slipped on the floor at work, and that he felt a snap and a pop sensation in the low back and had a sudden onset of very sharp low back pain radiating into his right buttock and down his right leg.

Whether the employee’s injury of August 2002 aggravated his pre-existing condition is a question of fact.  Bender v. Dongo Tool Co., 509 N.W.2d 366, 367, 49 W.C.D. 511, 513 (Minn. 1993), citing to 1 Larson, The Law of Workmen’s Compensation §§ 12.15 3-475-76 (1993).  In addition to medical opinions, a judge may base his 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).  We have again reviewed the record and noted the evidence of medical treatment the employee received prior to his August 2002 injury.  We note that there are various discrepancies in the history outlined in various medical records concerning the pre-2002 injury dates and dates of treatment.  The record, however, contains sufficient information on which the compensation judge could base a conclusion that the employee’s current condition is related to his medical condition that pre-existed his 2002 work injury.

The employee argues that his symptoms are much worse than those he experienced before his 2002 work injury.  He argues that before that injury, he had never been assigned a permanent disability rating, he had received no recommendation for surgery, he was able to work without physical restrictions and was able to participate fully in normal activities of daily living, all factors that have changed since his 2002 injury.  In addition, the employee contends that Dr. Barnett’s emphasis on a purported 1991 motorcycle accident is misplaced.  The employee’s medical records refer to his earlier motorcycle or motor vehicle accident, and Dr. Barnett referred to that accident as being the initial cause of the employee’s low back symptoms.  Regardless of when the employee’s motorcycle occurred–since various general dates are listed in the medical records–there is no dispute that the employee injured his back at least as early as 1992, when he injured himself while working for Parts Plus, and he has treated periodically since then for low back symptoms. 

Although there is evidence in this case that the employee’s low back condition did not return to his pre-injury condition, including the employee’s testimony, the issue on appeal is not whether substantial evidence would support an alternative finding, but whether substantial evidence supports the judge’s findings.  See Land v. Washington County Sheriff’s Dep’t, slip op. (W.C.C.A. Dec. 23, 2003); see also Ludford v. Honeywell, Inc., slip op. (W.C.C.A. Mar. 17, 2004); Moe v. Dr. Matthew A. Gahn, slip op. (W.C.C.A. Dec. 31, 2003).  In addition, where more than one inference may reasonably be drawn from the evidence, the compensation judge's findings shall be upheld.  Nord v. City of Cook, 360 N.W.2d 337, 342, 37 W.C.D. 364, 371 (Minn. 1985).   And, although the record contains conflicting medical opinions on the effects of the employee’s pre-existing medical condition as compared to the effects and duration of his 2002 work injury, a conflict in the opinions of medical experts is generally to be resolved by the compensation judge.  See Reuther v. State of Minn., Mankato State Univ., 455 N.W.2d 475, 478, 42 W.C.D. 1118, 1123-24 (Minn. 1990) (cites omitted).

As the Minnesota Supreme Court stated in Hengemuhle, the Workers’ Compensation Court of Appeals, when reviewing a claim on appeal, is “not to treat the findings of the factfinder lightly, while at the same time the reviewing court remains cognizant of its own responsibility to exercise good judgment in reviewing what the evidence will reasonably sustain.”  Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 60, 37 W.C.D. 235, 240 (Minn. 1984).  Based upon our review of the record as a whole, and mindful of our role in reviewing this matter on appeal, we conclude that there is substantial evidence in the record, including medical opinion and extensive medical records, supporting the compensation judge’s findings that the employee’s August 2002 work injury did not cause, aggravate or accelerate his current condition.  As the compensation judge’s determination is supported by substantial evidence and is not clearly erroneous, we must, under this court’s appellate standard of review, affirm that decision.  We accordingly affirm the Findings and Order on Remand and the denial of the employee’s claims for benefits.