The employee appeals the compensation judge’s finding that the employee’s October 22, 2008, low back injury was a temporary injury that had resolved as of October 22, 2009, and was no longer a substantial contributing factor to the employee’s claimed ongoing disability, and also appeals his denial of the employee’s request for a second opinion on his surgical request.  We affirm.

On October 22, 2008, Brandon Klemek, the employee, sustained a personal injury to his low back while employed as an apprentice plumber for J-Berd Mechanical Contractors, the employer, then insured for workers’ compensation liability by General Casualty Companies, the insurer.  The employee was injured when he fell while carrying a bathtub/shower unit with a co-worker.  Because he was walking backwards as he carried the bathtub, the employee did not see a board that was nailed into the floor.  He tripped over the board, landing on a pile of two by four boards.  He felt a sharp pain in his entire back, and was able to complete his shift, but the next day he had difficulty walking and reported the injury to the employer.

The employer and insurer admitted primary liability for the employee’s injury and paid temporary total and temporary partial disability benefits for various periods of time following his injury.

The employee was 19 years old at the time of the injury.  He had undergone previous treatment for low back pain before his 2008 injury, including chiropractic care in 2005 and a lumbar MRI on November 11, 2005, which had indicated areas of minimal disc bulging at L5-S1 and L4-5, and no significant herniation, protrusion, or mass affect on the thecal sac.  The employee also experienced low back pain and received short term chiropractic treatment in 1997, 1998, and 1999.  He testified that his work as a plumber’s apprentice involved various physical tasks and that he had no physical difficulties performing his work before his injury.

On October 27, the employee was examined by a physician assistant at Lakewood Health Systems for his low back pain and for an abrasion on his right leg.  The employee reported that in the past he had intermittent back pain, but nothing that had lasted or for which he had received medical care.  The physician assistant diagnosed a low back strain, prescribed medication, and provided the employee with a tetanus shot for his abrasion.  Although he was released to work the next day within restrictions, the employee remained off work through October 2008.

The employee apparently returned to work on November 1, 2008, but on November 3 he left early due to low back pain and returned to Lakewood Health Systems the following day.  An x-ray of his lumbar spine showed mild disc space narrowing at L5-S1.  The employee was treated with additional medication and was referred for physical therapy.

On November 26, 2008, the employee was examined by Dr. Phillip Bachman at Midwest Occupational Medicine, evidently on referral by a representative of the insurer.  Dr. Bachman diagnosed a work-related lumbar strain and contusion and referred the employee for physical therapy.  Dr. Bachman indicated that he could return to work on December 1, 2008, with restrictions of limited bending, no lifting over 20 pounds, no sweeping, avoiding sitting, and a maximum of four hours of work per day.

The employee attempted to return to work on December 3, but was unable to continue due to back pain.  He underwent a lumbar spine MRI scan on December 10, 2008, which indicated that at the L5-S1 level, the intervertebral disc was normal in height demonstrating diffuse disc desiccation with Grade I retrolisthesis of L5 on S1 and a posterior central disc protrusion without central canal stenosis or neural impingement; a diffuse annular bulge at L4-5 with no focal herniation, neural foraminal narrowing or central canal stenosis; and no evidence of a pars defect or stress fracture at any level.  During an examination on December 15, at which time the employee had not returned to work, Dr. Bachman reviewed the findings on the MRI scan and again diagnosed a lumbar strain and contusion.  He continued the employee’s restrictions which limited his work to four hours per day and which restricted the amount of bending, sitting, and sweeping the employee could perform at work.

Dr. Bachman referred the employee to Dr. Thomas Balfanz at Physicians Neck and Back Clinic, who evaluated the employee in early January 2009.  Dr. Balfanz determined that the employee was a candidate for a rehabilitation program, including twice weekly sessions.  By March 2009, after 20 sessions, Dr. Balfanz concluded that the employee had been unable to reach the stated program goals, as he had reported increased rather than reduced back pain and had been unable to tolerate increased weights during the sessions.  Dr. Balfanz discontinued the rehabilitation sessions.  He assigned work restrictions of four hours of work per day, and recommended that the employee exercise with a Roman chair to maintain his strength on a long-term basis.

Dr. Balfanz also referred the employee to Dr. Steven Sabers at the Institute for Low Back and Neck Care.  The employee continued to report low back pain that had worsened since his injury.  Dr. Sabers referred the employee for diagnostic and therapeutic facet joint injections and restricted him from work.  On April 9, 2009, Dr. Sabers noted that because the employee had not benefited from the facet joint injections, it appeared that “his pain [was] discally-mediated” and therefore would not be expected to respond to a decompression and discectomy.  Dr. Sabers instead considered fusion or disc replacement and recommended a discography to further evaluate the need for surgery.

On April 22, 2009, the employee was evaluated by Dr. Richard Hadley at the employer and insurer’s request.  Dr. Hadley opined that the employee’s persistent low back pain was attributable to the employee’s work injury, but that it was unclear whether the work injury aggravated a pre-existing condition.  Dr. Hadley evidently did not have available for his review any medical records that pre-dated the employee’s injury, but stated that it was “certainly possible that some degree of degenerative disc disease predated the injury in question, but it is also clear that these changes were not of sufficient severity to come to medical attention or to require treatment.”  Dr. Hadley recommended that the employee undergo additional diagnostic studies, including a discogram, and that the results of the additional studies would determine what further medical treatment he would recommend.

On May 5, 2009, the employee underwent a three-level discogram followed by a CT scan of the lumbar spine.  The discogram indicated discogenic low pressure positive concordant pain at L5-S1 with posterior annular tear.  The CT scan resulted in positive findings including a Grade III L5-S1 annular tear and a moderately-sized central disc protrusion at the L5-S1 level which resulted in a mild effacement of the ventral subarachnoid space.  Dr. Sabers concluded that the employee had “discogram-proven discogenic pain which has been recalcitrant to extensive nonsurgical treatment modalities,” and referred the employee to Dr. Jeffrey Pinto for a surgical consultation.

Dr. Pinto reviewed the employee’s CT scan and MRI, and concluded that the employee had degenerative disc disease at L5-S1 and relatively normal-looking discs at L4-5 and L3-4.  Dr. Pinto recommended a L5-S1 lidocaine injection for further diagnosis, which the employee underwent on June 9, 2009.  The injection provided pain relief for the employee which, according to Dr. Pinto, confirmed that the L5-S1 level was contributing to the employee’s symptoms.  Dr. Pinto recommended consideration of a disc replacement surgery as opposed to a one-level fusion.

On October 2, 2009, the employee was examined by Dr. John Sherman at the employer and insurer’s request.  Dr. Sherman took a history from the employee.  He also reviewed the employee’s medical records as well as copies of postings on a social-networking website in which the employee had written about his various activities.  Dr. Sherman concluded that the employee had “subjective complaints of pain in excess of any objective findings on physical exam or radiographs,” and that there was no evidence of interval injury when comparing the employee’s pre- and post-injury MRIs.  Dr. Sherman expressed concern about the reliability of the employee’s discogram results and the potential for false-positive results for a discogram study due to the subjective nature of the test.  He also expressed concern about any surgical intervention.  Dr. Sherman feared that the inherent risk of disc replacement surgery was that it might not resolve the employee’s symptoms.  Dr. Sherman also felt that a revision of a total disc arthroplasty in the employee at his young age would be “an extremely difficult and potentially lethal undertaking.”  He also concluded that the employee was capable of working full time without restrictions, that the employee “should be informed that he has no structural abnormalities as far as his back in concerned,” and that he should be weaned from narcotic pain medication.  Finally, Dr. Sherman concluded that the employee had reached maximum medical improvement from his injury without any permanent partial disability.

Dr. Pinto reviewed Dr. Sherman’s report and consulted with the employee, his family, and his QRC.  Dr. Pinto indicated that he “definitely [did] not think a fusion” was in the employee’s best interests, in part due to his young age, and that he had reservations about a disc replacement, stating that “doing a disc replacement at L5-S1 is pushing the limits of that device.”  Dr. Pinto advised that he was in favor of obtaining another medical opinion, and that he would discuss the matter with Dr. Sabers.  He also proposed obtaining a Functional Capacities Evaluation (FCE) to determine the employee’s level of pain control and his physical capabilities.

A dispute arose concerning the employee’s entitlement to a second medical opinion concerning the necessity of surgery as recommended by Dr. Pinto.  The employer and insurer ultimately filed a request for a formal hearing on that issue.  In the meantime, Dr. Pinto referred the employee to Dr. Amir Mehbod for another surgical opinion.  Dr. Mehbod examined the employee on December 21, 2009, at which time the employee reported ongoing pain and that even doing household chores caused pain significant enough to require medication.  Dr. Mehbod indicated that the employee’s options included nonoperative care, such as an FCE, permanent restrictions and training for new employment, or surgery to address his ongoing low back pain.  Dr. Mehbod concluded that any of these options, including disc replacement surgery or fusion surgery, would be reasonable in view of the employee’s exhaustion of conservative medical treatment.

Dr. Pinto saw the employee again on February 10, 2010, the day before the hearing held on this matter, after reviewing Dr. Sherman’s report and the website postings.  Dr. Pinto discussed various options with the employee, including either proceeding with no further treatment, obtaining a FCE to evaluate his physical capabilities, or going forward with surgery.  In his chart note, Dr. Pinto stated, in part, that

Dr. Pinto further commented that he had discussed matters at length with the employee, and advised that “I think he understands it and I hope he is smart enough to know that if he is not having that kind of pain, [it] would be a grave mistake to move forward with surgery.”  Following his examination of the employee on February 10, 2010, Dr. Pinto again restricted the employee from work until after the hearing, and limited him to working in a seated position thereafter.

The employer and insurer petitioned to discontinue the employee’s temporary disability benefits, contending that his 2008 injury was temporary in nature and had resolved.  An evidentiary hearing was held on February 11, 2010, to address both the employer and insurer’s petition to discontinue and their objection to the employee’s request for a second surgical opinion. 

Witnesses at the hearing included the employee, his mother, father and brother, and the employee’s QRC.  Documents submitted into evidence included the employee’s medical records in addition to copies of postings on a social-networking website, dated from June 2008 through September 2009, in which the employee wrote about his various activities.  When asked during the hearing about the activities described in the postings he had entered during the months after his back injury, the employee acknowledged that he had engaged in activities such as cleaning, laundry, painting, sanding floors, changing oil on a car, riding a rollercoaster, teaching his cousin how to swim, walking three to four miles, attending the Renaissance Festival, traveling to Virginia, climbing a net made of rope, and bowling.  The employee also testified, however, that he had to take Vicodin before participating in any activity, and that his participation in those activities had been limited.

In his findings and order, served and filed March 3, 2010, the compensation judge found that the employee’s October 22, 2008, low back injury was a temporary injury that had resolved as of October 22, 2009, and was no longer a substantial contributing factor to the employee’s claimed ongoing disability.  He therefore granted the employer and insurer’s petition to discontinue the employee’s benefits and denied the employee’s request for a second surgical opinion.  The employee appeals.

The compensation judge relied on Dr. Sherman’s opinion that the employee’s October 22, 2008, low back injury was a temporary injury that had resolved as of October 22, 2009, and was no longer a substantial contributing factor to the employee’s claimed ongoing disability.  The compensation judge accepted Dr. Sherman’s opinion, in part based on Dr. Sherman’s review of the employee’s medical history, including treatment predating his 2008 injury, and the employee’s postings on a social-networking website.  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 determining such questions, it is the compensation judge’s responsibility, as trier of fact, to resolve conflicts in expert testimony, and this court generally must affirm findings that are based upon the judge’s choice between the divergent opinions of medical experts, unless the opinion chosen lacks adequate foundation.  Nord v. City of Cook, 360 N.W.2d 337, 342, 37 W.C.D. 364, 372 (Minn. 1985).  Where evidence is conflicting or more than one inference may reasonably be drawn from the evidence, the findings of the compensation judge are to be upheld.  Redgate v. Sroga’s Standard Serv., 421 N.W.2d 729, 734 40 W.C.D. 948, 957 (Minn. 1988).

The employee, however, questions whether Dr. Sherman had adequate foundation for his opinion and therefore contests the compensation judge’s reliance on Dr. Sherman’s opinion over those of Drs. Sabers, Pinto and Mehbod.  To be of evidentiary value, an expert medical opinion must be based on adequate foundation.  Welton v. Fireside Foster Inn, 426 N.W.2d 883, 41 W.C.D. 109 (Minn. 1988); Bode v. River Valley Truck Ctr., No. WC09-132 (W.C.C.A. Sept. 29, 2009).  The competence of a witness to render expert medical testimony depends upon both the degree of the witness’s scientific knowledge and the extent of the witness’s practical experience with the matter at issue.  Reinhardt v. Colton, 337 N.W.2d 88 (Minn. 1983).  In this case, Dr. Sherman examined the employee, took a history, and reviewed his medical records.  As a general rule, this level of knowledge establishes a doctor’s competence to render an expert opinion.  See Grunst v. Immanuel-St. Joseph’s Hosp., 424 N.W.2d 66, 40 W.C.D. 1130 (Minn. 1988); Suess v. St. Jude Med., Inc., No. WC09-155 (W.C.C.A. Nov. 25, 2009).  Dr. Sherman had adequate foundation for his medical opinion.  He reviewed the employee’s 2005 and 2008 MRI scans, and concluded that that the 2005 study showed a minimal central bulge at L5-S1 which was similar to the subsequent study in 2008, and that there was no evidence of any interval injury between the two studies.  Dr. Sherman did not mention the employee’s May 5, 2009, CT scan in his October 2009 report, but he reviewed that CT scan in February 2010, and stated that the 2009 CT scan results did not change his earlier opinion.  The compensation judge did not err by relying on Dr. Sherman’s opinion.

It is evident from the findings and order that the compensation judge did not rely solely on Dr. Sherman’s opinion.  He also referred to other portions of the employee’s medical records.  In addition, in his memorandum he referred to the opinion of Dr. Pinto, who had questioned the need for surgery, and to that of Dr. Mehbod, who felt that the proposed surgery was elective in nature.

The compensation judge also based his conclusions, in part, on the testimony presented by the employee at the hearing.  The employee claims that the compensation judge erred by relying on the employee’s references to activities, posted on a social-networking website, when determining that the employee demonstrated more physical ability than he was reporting to his doctors.  The compensation judge, however, did not rely solely on the posted reports.  The employee was questioned at the hearing regarding his activities as described in the postings and he admitted that he had participated in various physical activities, but that he needed to take Vicodin before participating in the described activities, and that his participation in those activities had been limited.

The compensation judge had the opportunity to review the employee’s testimony along with the other evidence in the record.  Following his review, the judge assessed that testimony in conjunction with the medical records in evidence.  He concluded that the employee had “understated his actual abilities and overstated his pain complaints.”  It is the trier of fact's responsibility to assess the credibility of a witness, and we therefore defer to the judge’s determination concerning the employee’s credibility when testifying about his activities and the extent of his injury.  See Tolzmann v. McCombs-Knutson Assocs., 447 N.W.2d 196, 198, 42 W.C.D. 421, 424 (Minn. 1989) (citing Even v. Kraft, Inc., 445 N.W.2d 831, 835, 42 W.C.D. 220, 225 (Minn. 1989)).

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.  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 have reviewed the evidence as a whole, and conclude that the record supports the compensation judge's findings.

Based on our review of the evidence submitted into the record and the briefs prepared by the parties, we acknowledge that there is evidence in the record that could support the employee’s ongoing claim, including the employee’s testimony.  Under our standard of review, however, where evidence is conflicting or more than one inference may reasonably be drawn from the evidence, the compensation judge’s findings are to be affirmed.  Id. at 60, 37 W.C.D. at 240.  The issue on appeal is not whether the record would have supported the employee’s arguments, but whether the judge’s decision is supported by evidence that a reasonable mind might accept as adequate.  Reel v. Loftness Specialized Farm Equip., slip op. (W.C.C.A. Feb. 3, 2004).  In this case, the compensation judge reviewed the evidence and testimony submitted into the record and concluded that the employee’s October 22, 2008, low back injury was a temporary injury that had resolved as of October 22, 2009, and was no longer a substantial contributing factor to the employee’s claimed ongoing disability.  The compensation judge’s findings are supported by substantial evidence in the record as a whole.  We therefore affirm his findings along with the related orders granting the petition to discontinue and denying the request for an additional surgical opinion.