The employee appeals from the compensation judge’s finding that his August 20, 2012, work injury was a temporary aggravation of a pre-existing condition and resolved no later than April 17, 2014, and from the judge’s consequent allowance of discontinuance of temporary total disability benefits and denial of proposed surgical treatment.  We affirm.

The employee has worked as a landscaper since graduating from high school in 1997.  Over the years, the employee has had a number of work and non-work injuries and complaints.  In August 2001, he injured his low back in a non-work motor vehicle accident when the pickup truck he was driving rolled over.  He was seen in the emergency department at Park Nicollet Methodist Hospital where he was diagnosed with musculoskeletal low back pain and prescribed Flexeril and Percocet.  The employee returned to the emergency department on November 7, 2001, noting a new onset of back pain after lifting at work.  He reported that he was still following up with another doctor for his previous back complaints.  He was given Darvocet.

On November 12, 2001, the employee again returned to the emergency department for the low back pain he had been experiencing since his motor vehicle accident.  He was seen by Dr. Lund who noted that this was the employee’s fourth emergency department visit for this problem in the past two months.  The employee stated that the Darvocet he had been prescribed a week before had not relieved his pain.  He requested Percocet, which his treating physician, Dr. Sethna, had been prescribing.  Dr. Sethna authorized Dr. Lund to refill the employee’s prescription for Percocet, but advised Dr. Lund that he was not to give any more prescriptions of narcotics from the emergency room, and that he would manage the employee’s prescriptions.

The employee had an MRI of the lumbosacral spine on November 13, 2001.  The scan was read as showing no evidence for disc herniation or spinal stenosis.

The employee returned to the emergency department at Park Nicollet on January 16, 2002, where he was seen by Dr. Atwater.  He stated that he had been in a motor vehicle accident about three months before, and had recently slipped without falling and had since had severe back pain.  Dr. Atwater noted that the employee had a recent MRI which showed disc pathology at two levels.  He diagnosed an exacerbation of chronic back pain.  The employee refused Toradol which he stated “never works.”  The employee was given a shot of Demerol and a prescription for Percocet, Flexeril and Vioxx.

The employee returned to the emergency department on February 7, 2002, where he was seen by Dr. Lynn Simon, who noted that he had been seen there before six times during the past six months.  The employee told Dr. Simon that he had chronic back pain and had re-injured his back two days before while walking. Dr. Simon suspected the employee might be drug seeking.  The employee left after learning that he would not get narcotic medications and Dr. Simon noted he was placing him on the drug-seeking list.

On October 9, 2003, the employee returned to the emergency room stating his low back pain had been exacerbated from playing hockey. The physician at that time indicated his behavior was noted to be suspicious for drug seeking, and that this visit was similar to prior visits in that it involved what was essentially a soft tissue, non-provable new trauma.  He further noted that while the employee had initially stated that he could not dress himself due to pain, he dressed quickly and left when told it was time to leave.

There are few medical records in evidence for most of the next several years, and the record available shows a long gap in medical treatment related to the low back.  The employee testified that he did not recall seeking medical treatment for his low back between 2003 and September 2012.  In 2007, the employee was seen at the St. Francis Regional Medical Center for evaluation of an injury which took place when a bobcat he was operating struck a curb and he struck his head on the roof of the cab.  It was noted at that time that the employee gave a history of intermittent low back pain.  In January 2008, the employee returned to the St. Francis emergency room and reported neck and low back pain after a recent hockey injury.  He was given Vicodin and Robaxin.  The employee also sustained injuries to his right knee in 2008 and 2009, and underwent knee surgery in 2008.

The employee began working for the employer, Edelweiss Design, Inc., on January 28, 2011.  On July 3, 2012, the employee was seen at Twin Cities Orthopedics because his knee went out at work.  He was placed on light duty restrictions and missed some work.  The employee testified that his supervisor assigned him to jobs that would not be as strenuous on his knee and where he might work to the extent he felt he was able.  He continued to work in this limited capacity at and beyond the alleged August 20, 2012, low back injury.

On or about August 20, 2012, the employee was working as foreman supervising three other laborers at a jobsite in taking up sod, doing planting, mulching, and preparing a yard for re-sodding. The employee worked with the other employees to move sod and debris by hand and using a wheelbarrow.  The work involved a lot of shoveling.  The employee testified that he told his supervisor that his back was painful and that he could hardly function and did not want to be at work.  However, he continued to work at this jobsite and on several subsequent jobs and did not seek medical care at that time.

The employee testified that he continued to have low back pain, and that on September 17, 2012, his supervisor advised him to seek medical care.  He was seen the same day at the Ridgeview Medical Center, where he reported injuring his low back on August 20, 2012, after which his pain had continued to worsen.  Chart notes from that date indicate that the employee reported no prior history of any similar problem.   His pain was localized in his low back and his pain did not radiate into his legs.  Tenderness was present in the bilateral paraspinous muscles from L2 to L4.  No back or leg pain was reported on straight leg raising.  Motor and sensory examination was intact and his reflexes were positive and symmetrical.   He was diagnosed with a lumbar strain/spasm.  Flexeril and Norco were prescribed.  The employee was restricted to 15 pounds lifting, with no bending or twisting.

The employee was seen on September 20, 2012, at Valley Family Practice by Lisa Larson, a certified physician’s assistant.  The employee had not yet returned to work.  He was seen to be in no acute distress, although he was pacing the examination room as he found sitting uncomfortable.  He exhibited tenderness over the central lumbar spine and bilateral SI joint region.  Straight leg raising was still negative.  He was diagnosed with a lumbar strain and SI dysfunction.  Diclofenac, Percocet, and Flexeril were prescribed, and the employee was referred for physical therapy.  His work restrictions were continued.

The employee was next seen on September 25, 2012, at the emergency department at Maple Grove Hospital for severe lumbar back pain from a work injury on August 20, 2012.  The employee denied a specific injury, trauma, or fall.  The employee described a sharp pain across his back, at times radiating slightly into his buttocks.  He denied any history of prior back problems.  He received an injection for pain and was told to follow up with his primary care physician.

On September 28, 2012, the employee was seen in the emergency department at Allina Medical Clinic Crossroads in Chaska seeking treatment for his back pain.  He was given Dilaudid.  The emergency room staff told the employee he would no longer be provided with oral pain pills.  Shortly after this he came in to the clinic as a new patient.  It was noted that the employee’s speech seemed slurred.  Chart notes state that when the employee was not given pain medications he seemed frustrated and said several times that pain relief was the purpose for his visit.

The employee had an initial physical therapy evaluation at St. Francis Regional Medical Center on October 1, 2012.  On October 17 and 25, 2012, he attended physical therapy sessions there.  On both occasions he rated his pain at 7/10.  On October 25, he reported that he had been playing on the floor with his son the night before and his back “cracked and he had shooting pain run through it.”

A chart note by physician’s assistant Larson on October 29, 2012, stated that the employee was not reporting much improvement.  He was prescribed Percocet and Diazepam and instructed to continue with physical therapy.

On November 6, 2012, the employee told his physical therapist that he had recently lifted his son and felt an immediate pain in his back.  On November 8, 2012, the employee again informed his physical therapist that as he was picking up his child, he felt increased pain.  He complained that he was not improving.

On December 10, 2012, the employee’s neurologic examination findings were again normal and there was tenderness over the right SI and right paraspinous musculature.  An MRI was recommended.  It was suggested that if the MRI results were normal, a more aggressive physical therapy program might be considered. The employee’s prescriptions for Oxycodone, diazepam, and amitriptyline were refilled and he was given Celebrex samples and a prescription for Flexeril.

The employee underwent an MRI of the lumbar spine on January 7, 2013.  The scan showed a small central and left-sided disc herniation at the L4-5 level displacing and compressing the left L5 nerve root.  A handwritten note on the report stated that the findings at L4-5 did not correspond clearly with the employee’s subjective pain complaints and were likely seen “just by chance.”

On February 11, 2013, Ms. Larson referred the employee to Physician’s Diagnostics & Rehabilitation (PDR).  The record noted that the employee’s attorney asked for an explanation of the note on the MRI report stating that the findings did not correlate with the employee’s pain symptoms.  The chart note explained that this notation referred to the fact that the employee’s reported pain was in a band across the low back, without radiation into the extremities or any complaints of numbness, tingling or weakness.

The employee was evaluated by Dr. Friedman at PDR on February 19, 2013.  His complaint was of low back pain which had started on August 19, 2012, while working loading dirt and sod into a trailer with a shovel, after which the pain had progressively worsened over the next few days.  The employee reported that he had not had back pain before this incident and had performed landscaping work for about 17 years without any problems.

As of April 23, 2013, the employee had completed only four of the 24 physical therapy sessions anticipated in his therapy program.  Dr. Friedman noted that the employee’s attendance was problematic.

The employee had an epidural steroid injection on May 2, 2013, without pain relief.  He sought treatment at the Ridgeview Medical Center emergency room on May 4, 2013.  The employee stated that while he had previously been on long acting morphine, he had stopped taking it a long time ago.  Dr. Dewey noted that the employee had received morphine sulfate tablets as recently as the week before, rather than “a long time ago.”  Dr. Dewey noted that the employee’s primary care physician should solely control his pain management. The employee was, however, given Dilaudid and Valium.

On May 6, 2013, the employee saw Ms. Larson, and reported a worsening of his pain after the injection.  Ms. Larson substituted MS-Contin for his Fentanyl patch.

On June 25, 2013, the employee was evaluated by Dr. Friedman, who again noted that the employee’s physical therapy attendance had been problematic, as he had only completed nine sessions.  The doctor opined the employee’s symptoms were mostly due to muscle weakness, deconditioning, and psychological factors, in that the employee had already decided that he was disabled.  The employee eventually quit his physical therapy.

The employee sought emergency treatment at the Ridgeview Medical Center on August 14, 2013.  He reported that his pain was more severe than usual and had been increasing over the past week.  Dr. Anderson noted that the employee appeared comfortable and walked with no apparent difficulty or distress.  The employee requested more pain medication, but the doctor provided him only with steroids.  It was noted that the employee appeared to be upset with this.

On August 17, 2013, the employee returned to the Ridgeview Medical Center emergency room complaining of moderate-to-severe sharp pain and tingling radiating down both legs.  Dr. Johnson explained to the employee that she would be willing to treat his pain in the emergency department but that he would not be given any further medications to take at home.  The employee was treated with Dilaudid.

The employee was seen again at the Ridgeview Medical Center emergency room on September 1, 2013.  He complained of sharp bilateral lower-back pain radiating down his legs for two days.  Dr. Johnson advised the employee that the emergency department would not treat chronic conditions or prescribe pain medications.  The employee complained of pain at a level of nine on a scale of ten but was seen to be able to walk to the bathroom without obvious pain.  It was noted that the employee had been prescribed 174 Oxycodone during the past month.

On September 12, 2013, Dr. Mullaney saw the employee at the Twin Cities Spine Center.  Sensation was intact in the lower extremities and muscle tone and gait were normal.  There was tenderness across the beltline and along the paraspinous muscles bilaterally.  Flexion and extension were limited.  Dr. Mullaney reviewed the employee’s MRI and noted facet joint changes at L3-4, L4-5, and L5-S1, with bone spurs and synovitis in the joints; otherwise everything appeared normal neurologically.  The disc spaces appeared well maintained, except at L4-5 where there was a slight bulge or degeneration without specific neurological impingement or stenosis.  Dr. Mullaney thought that the employee’s back and leg pain was consistent with facet joint arthropathy, although without neurological impingement.  He referred the employee to Dr. Long for further evaluation of facet-joint injections and pain medications for pain management.

Dr. Long saw the employee on October 2, 2013.  He recommended that the employee discontinue several medications prescribed by his family doctor.  Dr. Long also recommended a lumbar epidural steroid injection at L5-S1.  The injection was performed on November 6, 2013 but the employee reported no pain relief.

The employee returned to the Ridgeview Medical Center Emergency Department on November 11, 2013, where he was provided with Dilaudid and Valium.  The employee’s lower extremity strength was inconsistent on examination.  The doctor told the employee that he would not continue to administer narcotics for the employee’s chronic complaints of pain.

The employee was seen by Dr. Charles Kim at CDI on November 19, 2013.  The musculoskeletal examination showed no deformities.  There was superficial tenderness around the lumbosacral junction and left buttock.  Forward flexion was limited by reported pain.   No atrophy was seen in the lower limbs.  The employee was able to sit and stand without difficulty and could walk on his toes and heels.  Strength was giveaway bilaterally, which was deemed to be inconsistent with his ability to walk on heels and toes.  Dr. Kim noted that the employee followed him out of the examining room to his dictation area because he wanted to review the way his prescription was written, to be sure it would be filled by the pharmacy.  A repeat MRI was recommended.

At a follow up appointment on December 4, 2013, Dr. Long noted a normal and appropriate gait.  The employee asked to switch his oxycodone prescription to hydromorphone, which he had been given in the ER and found more effective.  Dr. Long prescribed hydromorphone every 6 hours as needed.  The possibility of a spinal cord stimulator trial was discussed.

On December 16, 2013, the employee was seen at the Ridgeview Medical Center emergency room reporting constant pain in the left and midline lower back, and radicular pain down the left leg since the night before.  He characterized his pain at a level of 10/10.  He stated that this back pain was different than his usual back pain, and that he had not had similar pain previously.  He was given a prescription for Percocet and Valium.  An MRI was performed and showed a stable annular bulge at L4-5 with a superimposed left paracentral and subarticular disc protrusion, as well as mild narrowing of the spinal canal impinging the left L5 nerve root.

The employee returned to Dr. Long on December 18, 2013, with low back pain radiating down both legs into his feet and toes.  Dr. Long noted no significant change in his review of the newest MRI.  He told the employee that he did not recommend surgery, and instead recommended a work-hardening program.  Dr. Long also set a goal of weaning the employee off of many of his pain medications.

On December 30, 2013, the employee returned to the emergency room at Ridgeview Medical Center for an increase in pain which he attributed to lifting Christmas presents.  Straight leg raising produced leg and back pain.  Moderate tenderness was present in the left paraspinous muscles.  Strength was normal and symmetrical.  The employee’s gait was normal and reflexes were 2+ bilaterally.  The employee requested medication for immediate pain relief.  He was given Dilantin and a prescription for Medrol Dosepak.

The employee returned to the emergency room again on December 31, 2013.  On examination, his leg and back pain on positive straight leg raising was thought to be exaggerated and out of proportion to the amount of tenderness in the left lumbar paraspinous muscles.  The employee was told that his pain physiology had been altered due to chronic use of narcotic medications and advised to get off these medications entirely.

On January 8, 2014, the employee returned to Dr. Long and reported increasing pain radiating down both legs into his feet and toes.  His musculoskeletal and neurologic examination was recorded as essentially normal. The Dilaudid was discontinued and he was put back on Oxycodone.  He was advised to begin a work hardening program.  The employee requested a second opinion about his surgical options.

The employee was again examined by Dr. Long on February 26, 2014, for low back pain radiating down both legs into feet and toes.  He informed the doctor that he was out of medication.  Dr. Long noted that the employee had not attended the prescribed work hardening program.  He referred the employee to Dr. Richard Salib at the Institute for Low Back & Neck Care.

Dr. Salib saw the employee on March 3, 2014.  The employee reported that 70 percent of his pain was in his low back, more left than right.  The pain radiating into his lower extremities was worst along the left posterolateral aspect down to the left foot.  His radicular pain was associated with numbness, tingling and diminished sensation.  On examination, the employee’s gait was essentially normal and he could rise onto this toes and heels.  The employee first showed give-way weakness in every muscle group, but on retest his strength was intact bilaterally throughout the lower extremity muscle groups.  There was a reduced lumbar range of motion.  Seated straight leg raising was negative on the right while on the left it provoked hamstring and left calf irritation at 30 degrees.  Dr. Salib reviewed the MRI scans and opined that latest MRI showed drastic changes from the previous scan, with an increased left-sided disc herniation at L4-5.  He recommended that the employee undergo an anterior total disc replacement at L4-5, or, as a less desirable alternative, either a laminotomy or an anterior fusion of the L4-L5 level with decompression.

The employee was examined on behalf of the employer and insurer on April 17, 2014, by Dr. Hart Garner.  Dr. Garner could identify no objective findings on examination to substantiate the employee’s subjective complaints.  He opined that the December 26, 2013, MRI findings were not substantially different from the previous MRI findings except for minor changes that he did not consider to be clinically significant.  His diagnosis was of lumbar disc degeneration with axial back pain.  He opined that the employee’s subjective complaints were potentially attributable to his preexisting low back condition and consistent with a natural progression of degenerative disc disease.  Based on the timing and contents of the contemporary medical records, he concluded that any injury sustained on August 20, 2012, would have been mild, soft tissue in nature, and not a substantial contributing factor for most of the employee’s ongoing treatment, medications, disability, and diagnostic testing.  He also noted that the findings on the most recent lumbar spine MRI did not appear to relate to any work activities or injury on or around August 20, 2012.  In his opinion, the employee had already reached maximum medical improvement (MMI) from the claimed August 20, 2012, work injury, without permanent partial disability or any need for work restrictions.

Given the employee’s history, Dr. Garner did not think additional treatment would help resolve the employee’s subjective complaints.  He opined that the employee required no additional medical treatment for the alleged August 20, 2012, injury from an objective or functional standpoint.  He did not believe that further injections, a lumbar fusion, or disc replacement surgery would be beneficial.  He suggested that the employee consider the use of a lumbar brace for his degenerative disc disease, although in his view this would be unrelated to the claimed work injury.

In a claim petition filed on March 27, 2014, the employee claimed entitlement to surgical treatment as recommended by Dr. Salib.  The self-insured employer disputed the employee’s claim for surgery.  On July 21, 2014, the employer filed a notice of intent to discontinue temporary total disability compensation from June 6, 2014, based on the MMI opinion of Dr. Garner.  These issues were consolidated, resulting in a hearing on August 19, 2014.  Following the hearing, the compensation judge found that the employee sustained a personal injury to the low back on August 20, 2012, in the nature of a mild lumbar strain that temporarily exacerbated a pre-existing lumbar spine degenerative disc disease, and that this injury had resolved no later than the date of Dr. Garner’s examination on April 17, 2014.  The compensation judge accordingly granted discontinuance of temporary total disability compensation and denied the employee’s claim for surgical treatment.  The employee appeals.

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

“[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.”^[5]

The compensation judge found that the employee had sustained a personal injury to the low back on August 20, 2012, in the nature of a mild lumbar strain which temporarily exacerbated pre-existing degenerative disc disease in the employee’s lumbar spine.^[6]  The judge found that the work injury resolved no later than April 17, 2014.^[7]  The judge further found that the August 20, 2012, personal injury was not a substantial contributing factor to the employee’s subsequent low back condition, or to any restrictions or need for medical treatment.^[8]  Accordingly, the judge concluded that the employer and insurer had established reasonable grounds to discontinue temporary total disability benefits, effective June 6, 2014.^[9]  Finally, the judge held that the surgery recommended by Dr. Salib, specifically, total disc replacement at L4-5 with possible posterior discectomy, was not causally related or reasonable and necessary to cure and relieve the effects of the August 20, 2012, personal injury.^[10]

The employee’s brief states that the issues presented on appeal are whether substantial evidence supports (1) the discontinuance of temporary total disability, and (2) denial of the surgery proposed by Dr. Salib.  However, these two determinations are derivative of the judge’s finding that the employee sustained a temporary injury which had fully resolved.  The employee’s arguments on appeal go to the evidence underlying that finding.  Accordingly, we consider the primary issue on appeal to be whether or not substantial evidence supports the finding of a resolved temporary injury.

The employee points to several facts which he asserts are contrary to a finding that the 2012 work injury was merely a temporary aggravation of a pre-existing condition.  Among these facts, the employee points out that he was able to return to work without restrictions after his prior low back injury, and that the record fails to show any medical care or treatment for the employee’s pre-existing low back condition between October 9, 2003, and the 2012 work injury.  He also relies on the fact that the 2001 MRI scan, subsequent to his non-work motor vehicle accident, was normal, while the first MRI after his 2012 work injury showed an L4-5 herniation with nerve root displacement, and a subsequent MRI in 2013 showed an annular bulge at L4-5, again with nerve root impingement.

We note, however, that the focus of our review on appeal is not whether evidence was present which might have supported a result contrary to that reached by the compensation judge, but whether the findings the judge made were supported by substantial evidence, viewing the record as a whole.  Among the evidence supporting the compensation judge’s findings, we note that the employee had ongoing treatment for prior non-work low back conditions, including an injury from a motor vehicle accident and multiple hockey injuries, through at least October 2003, with reports of intermittent symptoms as late as 2008.  The employee also had a poor record of participating in or completing physical therapy or work hardening.  He was able to continue working for some time following the 2012 date of injury without medical treatment or restrictions, and when he did obtain medical treatment, his symptoms and exam findings were consistent with the diagnosis he was given of a low back sprain or strain.  The compensation judge’s findings were further supported by the expert medical opinion of Dr. Garner,^[11] as well as by the fact that two of the employee’s treating physicians expressly did not recommend surgery.

The employee contends that the compensation judge should have adopted the opinions of Dr. Long^[12] over those of Dr. Garner; however, the choice of medical experts is a matter committed to the compensation judge.  This court will generally affirm factual determinations that are based on the compensation judge’s choice between expert opinions, “so long as the accepted opinion has adequate foundation.”^[13]  The employee has offered no argument suggesting that Dr. Garner’s opinion lacked foundation or was otherwise defective.

The employee, however, argues that although the compensation judge had authority to choose between medical opinions, the compensation judge was required to consider all the evidence before selecting between the expert opinions.  He contends that because the compensation judge does not discuss the opinions of Dr. Long or Dr. Salib,^[14] this court should assume that the judge did not consider those portions of the record.  Thus, he argues, this court must reverse.  We have consistently held that a compensation judge is not required to discuss every piece of evidence introduced at the hearing.^[15]  Here, the compensation judge’s findings together with the record as a whole provide an adequate basis for this court to review the disputed issue.^[16]

While we agree with the employee that the MRI findings could be viewed as suggestive of a causal relationship between the 2012 injury and an L4-5 disc bulge or herniation, those findings are capable of other interpretations, particularly in light of the 12-year interval between the initial MRI scan and the 2012 work injury.  In essence, the compensation judge did not clearly err in giving less weight to the MRI findings than to the opinion of Dr. Garner and the initially minimal symptoms after the 2012 work injury.  As a general rule, the weight of the evidence is a matter committed to the trier of fact.^[17]

The employee next argues that “it is clear from the Findings of [the compensation judge] that he was persuaded by the Employer-Insurer that the Employee has a narcotic drug problem and was exaggerating his symptoms in order to receive medication.”^[18]  The employee contends that the record would not support such a finding, in that treating physicians Dr. Long and Dr. Salib opined that the employee had not shown signs of drug seeking during his treatment with them, and argues, by implication, that the compensation judge’s findings were unduly influenced by an allegedly erroneous view of the employee’s motivations in seeking treatment.

We note, first, that there is evidence in the record which might suggest that the employee had engaged in drug-seeking behavior.  In any case, nothing in the findings or memorandum indicates that the compensation judge in fact relied on the evidence related to this question, and it would be speculative for this court to assume that he was unduly influenced by this evidence from fully considering the other evidence in the case.

In conclusion, the compensation judge’s findings are supported by substantial evidence, and we affirm.