The employer and insurer appeal from the compensation judge’s determination that the employee sustained a permanent work-related injury to his low back on January 30, 2013, that the employee has not yet reached maximum medical improvement (MMI), that the employee was entitled to temporary total disability from the date of injury through September 24, 2013, and that the employee is a qualified employee for the purpose of receiving rehabilitation assistance.  We affirm.

Marcel Medlock was an employee of Masterson Personnel d/b/a Masterson Staffing Solutions.  Through his employment with Masterson, the employee began work at the Otis Spunkmeyer Company on January 30, 2013.  The employee claimed that on that date, while working on the production line, he sustained an injury to his low back.  He stated he noticed sharp pain in his lower back, but attempted to continue working for about half an hour.  He testified that he advised his supervisor of his injury, and that at the supervisor’s suggestion, he took a 15-minute break to sit down.  Upon returning to the production line, the employee stated his supervisor sent him home.

On February 4, 2013, the employee presented to Fairview Ridges Hospital emergency room reporting low back pain from five days earlier.  He stated he was sent home from work and had been in pain since.  The employee was diagnosed with a recent lumbar injury with acute lumbar pain progressing to paraspinal thoracolumbar pain, with pain radiating down the left buttock over the distribution of the left sciatic nerve.  The employee received work restrictions excusing him from work until February 7, 2013.

The employee returned to the Fairview emergency room on February 13, 2013.  The employee reported worsening pain after a work injury.  The doctor indicated that given the nature of the work injury, the employee needed to follow up with a physician that could see him more than once because he might need an MRI scan or other studies depending on the progression of symptoms.  The employee did not receive any work restrictions at the visit on February 13, 2013.

The employee was seen by Physicians Assistant Michael King at Hennepin County Medical Center (HCMC) on April 10, 2013.  The employee reported an injury two months earlier at work while pulling boxes off a conveyor belt and stacking them on a pallet at Otis Spunkmeyer.  He stated he turned and felt a pop in his back.  The employee reported ongoing low back pain and pain radiating to his left hip.  He stated he had tried to be active, but his back was giving him problems.  On examination, PA King noted tenderness to palpation in the lower back and left side as well as positive straight leg raising test on the left.  PA King recommended conservative treatment and, on April 15, 2013, took the employee off work until April 24, 2013.

The employee returned to see PA King on April 24, 2013.  The employee reported that he “fell in the slush and hurt his back again.”  The employee indicated that he had been using Tramadol and was almost out.  PA King noted “he feels that he has not made much progress with his pain since late January.”  The employee began physical therapy on May 1, 2013.  He was noted to have low back pain with an onset of symptoms three months earlier.  He said he was at work and pulled a muscle in his back.

On May 13, 2013, PA King issued a letter indicating the employee was to remain off work until June 7, 2013.  The employee returned to see PA King on June 10, 2013. The employee said his pain continued, especially after he had physical therapy.  The employee was diagnosed with chronic back pain.  PA King continued the employee off work until July 1, 2013.

The employee was discharged from physical therapy on July 1, 2013.  He was noted to have impaired lumbar range of motion along with low back and left leg pain.  The employee was rating his pain at 7 out of 10.  The employee also saw PA King on July 1, 2013.  The employee felt that his pain had not changed over the past 4-5 months.  PA King recommended a pain clinic due to the employee’s reported lack of improvement.

On July 22, 2013, the employee was seen by Certified Nurse Practitioner Kari Ann Webber at the HCMC pain clinic.  He reported he had not been able to be as active due to pain.  He was reporting 7-8 out of 10 pain in his low back with left greater than right and into his left leg.  He was looking for a less strenuous job at that time.  An MRI scan on August 13, 2013, was interpreted as showing mild degenerative disease, with no spinal canal stenosis and no nerve root impingement.  On September 4, 2013, the employee underwent a lumbar epidural steroid injection performed by Dr. Constantine Starchook at the HCMC pain clinic.

On September 24, 2013, the employee was seen in follow-up by CNP Webber.  He stated he wanted to try to return to work.  CNP Webber concluded that “if you have to work and can tolerate the pain you probably could work without restrictions, it may be painful but is not damaging to your back.”^[1]  The employee subsequently underwent lumbar medial branch blocks performed by Dr. Starchook on November 29, 2013, and on March 5, 2014.

On April 4, 2014, Dr. Starchook issued a report in response to questions regarding the employee’s injury, diagnosis, symptoms, and treatment.  Dr. Starchook described the employee’s leg and back symptoms upon presentation to the HCMC pain clinic, and stated the employee’s back pain developed as a result of lifting at work in January or February 2013.  In his opinion, the employee’s pain presentation and clinical symptoms were correlated with the onset of his injury at work.  The doctor diagnosed chronic low back pain and lumbar facet joint arthropathy, and opined the employee’s treatment was reasonable and necessary given the mechanism of the injury and his clinical presentation.  Dr. Starchook stated that because of the employee’s history of back pain and symptoms, the pain clinic was currently recommending lifting no more than 10 pounds.  The doctor did not believe that the employee was at MMI.  Dr. Starchook also believed the employee most likely had permanent partial disability and that he would continue to experience pain and discomfort in the lumbar area.

At the request of the employer and insurer, Dr. Thomas Nelson conducted a paper review of the employee’s medical records and issued a report dated April 15, 2014.  The doctor concluded the employee did sustain a lumbar strain on January 30, 2013, without any disc herniation or nerve root impingement, but opined the employee’s strain resolved within four to six weeks after the injury.

Following a hearing, a compensation judge issued a Findings and Order on June 16, 2014, in which the judge found that the employee sustained an injury to his low back arising out of and in the course and scope of his employment on January 30, 2013.  The judge further found the employee was temporarily and totally disabled from January 30 through September 24, 2013.  The judge also found the employee had not yet reached maximum medical improvement, and that the employee was a qualified employee for purposes of receiving rehabilitation assistance.  The employer and insurer appeal.

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.”^[2]  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.”^[3]  Where evidence conflicts or more than one inference may reasonably be drawn from the evidence, the findings are to be affirmed.^[4]  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.”^[5]

“[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.”^[6]

In her findings of fact, the compensation judge concluded the employee had not yet reached MMI from his work-related injury.  The compensation judge explained her reasons behind the conclusion in her memorandum and specifically referred to the opinion of Dr. Starchook in support of her conclusion.

The employer and insurer argue the opinions of Dr. Starchook lack adequate foundation because he did no more than administer injections to the employee on three occasions, and there is no indication that the doctor had sufficient background, information, and knowledge about the employee’s condition to issue a report.^[7]  Accordingly, the appellants urge this court to reverse the judge’s finding on MMI and adopt the expert medical opinion of Dr. Nelson.  We are not persuaded.

Adequate foundation is necessary for a medical opinion to be given evidentiary value.^[8]  Whether an expert is qualified to provide expert medical testimony depends on the degree of the witness’s scientific knowledge and the extent of the witness’s “practical experience with the matter which is the subject of the offered testimony.”^[9]  Ultimately, the evidence must support the facts upon which the doctor relies for his opinions.^[10]

The employee received his treatment for the work injury, beginning on and after April 10, 2013, at Hennepin County Medical Center, the facility where Dr. Starchook works.  The employee’s treatment records from HCMC were available to the judge and were clearly reviewed by the judge in making her decision.  The compensation judge also accepted the testimony of the employee that Dr. Starchook was his primary physician at the HCMC pain clinic, that the doctor performed a physical examination at the employee’s first appointment with him, and that Dr. Starchook discussed with the employee during each visit his condition, current symptoms, and how well he was responding to the ongoing treatment.  Dr. Starchook observed the median branch blocks had reduced the employee’s pain and recommended radiofrequency ablation of the lumbar facet joint.  Dr. Nelson did not examine the employee, but conducted a paper review of the employee’s medical records.  He agreed that radiofrequency ablation was reasonable medical treatment for the employee’s back, but opined it was not related to the work incident of January 30, 2013.

The compensation judge was presented with conflicting medical opinions, and the judge’s choice between those opinions was a significant issue in this case.  In making her decision, the compensation judge relied not just on Dr. Starchook’s report, but considered both medical experts’ opinions along with other medical evidence submitted at the hearing, including the employee’s treatment records from Fairview Regions Hospital emergency room and HCMC.^[11]

A decision based on a compensation judge’s choice between competing medical opinions is generally upheld where the opinion relied upon has adequate foundation.^[12]  While a failure to explain the mechanism of injury or the underlying reasons for the opinion may go to the weight to be afforded the opinion by the compensation judge, it does not render the opinion without foundation.^[13]  Upon review of the record, we cannot conclude that Dr. Starchook’s opinions lacked foundation.

The employer and insurer urge this court to adopt Dr. Nelson’s opinion.  The doctor agreed the employee sustained a low back injury on January 30, 2013, but concluded it resolved within four to six weeks after the injury.  The employer and insurer argue the employee’s treatment records support Dr. Nelson’s conclusion, pointing out the employee received treatment at the Fairview Ridges Hospital emergency room on February 4 and February 13, 2013, and then had no treatment for his low back until April 10, 2013, when he was seen by PA King at HCMC.

In February 2013, the Fairview emergency room doctors advised the employee to follow up with a primary care physician.  The employee testified the delay in time between the emergency room visits and seeing PA King occurred because he did not have medical insurance and could not get an earlier appointment to see PA King at HCMC.  On April 10, 2013, the employee told PA King he had injured his back while working for Otis Spunkmeyer two months previously and had been seen at the Fairview emergency department.  He was diagnosed with chronic low back pain, and conservative treatment was recommended.  The employee continued to treat at HCMC for his back pain thereafter.  In his April 4, 2014, report, Dr. Starchook at the HCMC pain clinic opined the employee had chronic low back and left leg pain that “correlated with” the January 2013 injury at work and that the injury was likely permanent.

The issue here is largely one of the compensation judge’s choice between opposing medical expert opinions.  As discussed above, Dr. Starchook’s opinions do not lack foundation, and we conclude the compensation judge did not err in rejecting Dr. Nelson’s opinion regarding the nature of the employee’s injury.  We accordingly affirm.

The employer and insurer further argue the compensation judge’s finding that the employee returned to Fairview Ridges Hospital on February 13, 2013, with increased pain^[14] is not supported by the record.  The February 13, 2013, treatment note from Fairview states the employee reported persistent pain in his lower back with pain into both legs, now radiating into the right leg, whereas initially, on February 4, 2013, the employee reported pain in the left leg only.  Based on the Fairview treatment notes, the compensation judge’s finding is consistent with the evidence of record.

The employer and insurer additionally argue the compensation judge failed to address the employee’s statement, when he returned to HCMC on April 24, 2013, that he had slipped in the slush and hurt his back again.  Following the April 10, 2013, visit at HCMC, the employee was scheduled for a follow-up in two weeks, on April 24, 2013.  The treatment notes for April 24 indicate the employee did not feel he had made much progress with his pain since late January.  He was diagnosed with chronic back pain, and physical therapy ordered on April 10 was to start the next week.  There was no further discussion or reference to the reported slip in the testimony at hearing nor in the medical records.  It is the responsibility of the compensation judge to review and weigh the evidence.  Upon review of the record, we cannot conclude the compensation judge committed an error in concluding the employee sustained an ongoing work injury from and after January 30, 2013.

The appellants contend the compensation judge’s finding that the employee advised the employer of the injury is based on inadmissible hearsay and must be reversed.

The appellants assert that prior to the hearing, at his deposition, the employee testified he reported his injury to a supervisor but could not recall his name.  At the hearing, the employee testified that the supervisor was Juan.^[15]  The employee testified he attempted to keep working for about half an hour.  He then stated that Juan came over and asked him if he was okay, and told him to take a 15-minute break from work.  After returning from the break, the supervisor told him to go home.^[16]  The compensation judge accepted the employee’s testimony, and, in a separate finding, found the employee advised the employer of his injury.^[17]  The employer and insurer maintain that withholding the name of the supervisor prevented them from questioning the supervisor or calling him as a witness, and argue there is no basis for finding that timely notice of the injury was given by the employee to the employer.

Evidentiary rulings are generally within the sound discretion of the compensation judge.^[18]  On review, considerable latitude is given to a compensation judge with respect to the conduct of a workers’ compensation hearing.  To warrant reversal, a compensation judge’s admission of evidence must be prejudicial as well as erroneous.^[19]

The employer and insurer argue the employee had an express duty to supplement discovery information pursuant to Minn. R. Civ. P. 26.05.  Workers’ compensation proceedings are not, however, subject to rules of evidence governing judicial courts.^[20]

In their brief, the employer and insurer state “[t]he Respondent testified at his deposition that a supervisor - - who was not an employee of the Employer . . . was aware of the incident and told him to sit down, and ultimately [sent him] home from work.”^[21]  Despite not knowing the name of the employee’s supervisor on the day of the incident, the appellants were apparently aware prior to the hearing that the employee alleged his supervisor was aware of the claimed injury, assisted him, and sent him home, and could have contacted Otis Spunkmeyer to ascertain who the employee’s supervisor was at or around the time of the alleged incident.

With respect to notice of the injury, the employee testified he contacted the employer the morning after the incident.  When his back did not improve, he sought treatment at the Fairview Ridges Hospital emergency room on February 4, 2013, stating he had pulled something in his lower back five days previously.  He returned to the Fairview emergency room on February 13, 2013, with persistent lower back and leg pain.  He stated that one and a half weeks ago he had a back injury at work while lifting and moving heavy boxes.  The employee testified he went into the employer’s office after visiting the emergency room the second time.  He stated he gave the employer copies of the Fairview doctors’ notes and filled out paperwork at the request of the employer on that date.^[22]

Accepting the employee’s testimony as true, the judge concluded the medical records were consistent with the testimony of the circumstances surrounding the incident.  Assessment of a witness’s credibility is the unique function of the trier of fact.  This court must give due weight to the compensation judge’s opportunity to judge the credibility of the witnesses.^[23]  It does not appear the judge relied solely on uncorroborated hearsay evidence or that the employer and insurer were unduly prejudiced.  Under the circumstances, we find no abuse of discretion in the judge’s consideration and acceptance of the employee’s testimony.

The employer and insurer argue there are significant gaps in the employee’s work restrictions and there are no medical records indicating the treating doctors or other medical providers took the employee off work between February 8, 2013, and April 23, 2013, or after July 1, 2013.  The appellants accordingly contend the compensation judge erred in finding the employee was restricted from work and was entitled to temporary total disability benefits until September 24, 2013.  We disagree.

The employee was given work restrictions by the Fairview Ridges Hospital emergency room physician excusing him from work from February 4 through February 7, 2013.  The employee returned to Fairview on February 13, 2013, seeking additional treatment for worsening symptoms.  The employee testified he had not followed up with a primary care physician because he had to first sort out his insurance and he had been unable to get into HCMC for another month.

The employee was seen by PA King at HCMC on April 10, 2013, with persistent low back and left leg pain.  PA King thereafter provided a memorandum, dated April 15, 2013, taking the employee off work until follow-up on April 24, 2013.  PA King subsequently continued the employee off work through May 9, June 7, and July 1, 2013.

On July 1, 2013, the employee reported to PA King that his pain had not improved over the past 4-5 months.  PA King, accordingly, referred the employee to the pain clinic for further treatment.  The employee was seen at the HCMC pain clinic on July 22, 2013.  CNP Webber noted the employee had not been able to be as active due to his low back and leg pain, but was looking for a less physically strenuous job.  The employee continued to treat at the pain clinic.  He underwent an MRI scan and received a lumbar epidural steroid injection on September 4, 2013.  The employee was seen in follow-up by CNP Kari Webber on September 24, 2013.  The employee stated his pain was not improving and had increased after the injection.  He stated he wanted to try to return to work, but CNP Webber indicated he would probably need to have his restrictions lifted by his primary care doctor.  Later in the chart note CNP Webber stated, “[i]f you have to work and can tolerate the pain you probably could work without restrictions, it may be painful, but is not damaging to your back.”^[24]

The compensation judge found the employee was restricted from work following his injury by his treating physicians and medical personnel at HCMC and remained subject to work restrictions through September 24, 2013.  The judge acknowledged, in her memorandum, that the medical records are unclear as to what extent the employee continued to be restricted from employment as a result of the work injury.  Relying on CNP Webber’s chart note stating the employee “probably could work without restrictions,” the judge concluded the employee was “restricted from employment” through “at least” September 24, 2013, and found the employee was no longer temporarily totally disabled after that date.^[25]

The issue of whether an employee has work restrictions is a question of fact for the compensation judge.^[26]  It is well-established that formal written restrictions are not required.  An employee’s testimony alone may constitute sufficient evidence to support a compensation judge’s determination.^[27]  The employee provided a reasonable explanation for the gap in medical care between February 13 and April 10, 2013.  By memorandum dated April 15, 2013, PA King provided restrictions taking the employee off work through April 24, 2013.  PA King continued to take the employee off work through July 1, 2013.  The employer and insurer concede the short gaps in May and June were likely due to the scheduling of follow-up appointments and do not argue that these gaps negate ongoing restrictions.^[28]  On July 1, 2013, the employee was referred to the HCMC pain clinic by PA King due to his lack of improvement, and there is nothing in the pain clinic treatment records releasing the employee to return to work until CNP Webber’s note of September 24, 2013.  The compensation judge could, based on the employee’s testimony and his treatment records, reasonably conclude that the employee had ongoing symptoms which precluded a return to work until September 24, 2013, and we, accordingly, affirm.

The employer and insurer maintain the compensation judge found the employee did not have any work restrictions after September 24, 2013, and it was, therefore, inconsistent for the compensation judge to find the employee was a qualified employee for purposes of rehabilitation services after that date.  The employer and insurer assert that although the qualified rehabilitation consultant (QRC) in this case stated the employee was a qualified employee eligible for rehabilitation services, he qualified his opinion, stating that the employee’s eligibility for rehabilitation services depended on work restrictions.  We are not persuaded.

In determining whether an employee is eligible for rehabilitation services, the compensation judge must first determine whether the employee is or is not likely to be permanently precluded from the employee’s customary occupation or pre-injury job.^[29]  Implicit in this determination is the issue of whether or not the employee has restrictions.^[30]  In the context of an employee’s entitlement to rehabilitation services, this court has held repeatedly that the question of whether an employee has sufficient restrictions or limitations to justify rehabilitation assistance is a question of fact committed to the compensation judge.  The judge may rely on the employee’s testimony alone about his physical capabilities following the injury, both where there has been an unrestricted authorization to return to work or where no medical provider or physician has issued restrictions on the employee’s ability to work.^[31]

In this case, the employee testified he needs help carrying anything, cannot move many things he needs to move on a regular basis, and cannot walk around for an extended period of time.  He stated his range of motion is limited and that certain activities, including bending certain ways, hurt him.  The employee last received treatment for his back in March 2014, and testified he continues to feel a constant dull, aching, and throbbing pain in his low back and pain radiating down his left leg.  The employee testified that the QRC wanted to see him and work with him after he restarted physical therapy.^[32]  In addition, Dr. Starchook opined in his April 4, 2014, letter report that the employee was not at maximum medical improvement, needed further medical treatment, and, as a result of his chronic back pain and lumbar facet joint arthropathy, should not, at that time, lift more than ten pounds.

The compensation judge found credible the employee’s testimony that he has never fully recovered from the 2013 work injury, and accepted the employee’s testimony regarding the effects of the injury on his daily activities.^[33]  The compensation judge considered all of the evidence in reaching her conclusion that the employee continued to have a residual disability which entitled him to receive rehabilitation assistance, including the testimony of the employee, and the medical records and opinions of his treating physician.

In the end, this issue turns on the employee’s credibility.  This court must give due weight to the opportunity of the compensation judge to judge credibility.  It is not the role of this court to re-evaluate the credibility and probative value of a witness’s testimony.  The legal question is whether the findings of the compensation judge are supported by evidence that a reasonable mind might accept as adequate.  Redgate v. Sroga’s Standard Serv., 421 N.W.2d 729, 734, 40 W.C.D. 948, 957 (Minn. 1988).  We conclude the compensation judge’s decision is supported by substantial evidence, and we affirm.