The employee appeals from the compensation judge’s denial of his claims for temporary total disability benefits, permanent partial disability benefits and medical expenses.  We affirm.

Thomas S. Corradi, the employee, began working for Minnesota Conway Fire & Safety, the employer, in August of 1997.  His duties included servicing fire extinguishers and selling equipment to commercial and multi-unit housing properties.  At the center of the dispute on appeal are three claimed work-related injuries the employee sustained in May and September 2000 while working for the employer.

The employee earlier injured his low back in 1995, while employed by Continental Baking Company.  While working as a delivery person, he lifted trays of product and noted severe back pain and spasms.  He remained off work for three to four weeks following this incident and underwent a CT scan in July 1995 which was interpreted as showing a central disc protrusion at both the L5-S1 and L4-5 vertebral levels.  The employee received medical and chiropractic treatment for his low back symptoms, and by late October 1995 was reported to be “back to normal” and was released to work without restrictions.

On May 30, 2000, as he was installing fire extinguishers for a golf course, the employee injured his low back.  While drilling into poured concrete wall, he felt something “pull” in the middle of his back, and noticed pain radiating up to his shoulder blades and down to his lower back.  On the next day, May 31, 2000, the employee’s back pain persisted.  As he lifted an 18-pound fire extinguisher onto his truck bumper, the employee felt severe pain in his low back.  He was unable to finish his work shift that day; after resting for approximately 1½ hours, he was finally able to get into a sitting position so that he could drive home.  The employee returned to work the next day, but within approximately two weeks, he noted problems with his left leg, including a burning sensation into his left foot.  According to the employee’s testimony at the hearing, his symptoms were especially intense for approximately one week after his injury, and persisted to a lesser degree throughout the summer of 2000.

On September 4, 2000, in a nonwork-related incident that occurred while the employee was mowing a residential lawn, he bent over to pick up a scrap of paper and noticed a severe increase in his low back pain.  The employee characterized his pain as being the same type of low back pain he felt on May 31, 2000, when he lifted the fire extinguisher.  Although he attempted to return to work the following day, his severe back pain prevented him from getting out of his truck.  The employee sought chiropractic treatment from Dr. Keith Johnson on September 5, 2000.  He reported a “flare-up of spasms from [a] previous injury” in May 2000.  The employee also consulted Dr. James Anderson at Fairview Healthworks Clinics, on September 6, 2000, reporting the incidents in May and September 2000.  Dr. Anderson prescribed pain medication and muscle relaxant medication, and recommended physical therapy.  The employee continued receiving therapy through his chiropractor, Dr. Johnson; at a September 12, 2000, appointment with Dr. Anderson, the employee reported that his back was still sore but somewhat improved.  Dr. Anderson diagnosed a lumbar strain, and recommended continued physical work restrictions.

The employee remained off work from September 5 through September 11, 2000, at the recommendation of Dr. Johnson.  Evidently at the request of the employer, the employee switched his chiropractic treatment to Brook West Chiropractic, which was within the employer’s healthcare network.  The employee obtained chiropractic treatment from Dr. Alvin Stachowski.

The employee returned to work for MN Conway Fire & Safety on September 11, 2000.  On that date, while loading fire extinguishers into his truck and strapping them in, the employee pulled something in his upper back.  He continued to receive chiropractic treatment at Brook West Chiropractic through mid-October 2000, but Dr. Stachowski eventually referred the employee to Dr. Paul Crowe for an orthopedic consultation because of an acute aggravation the employee experienced on October 10, 2000, caused by prolonged sitting on a hard chair.

On October 24, 2000, Dr. Crowe examined the employee, and concluded that the employee had some sciatic nerve irritation but mostly low back pain.  Dr. Crowe diagnosed a nine-day course of Prednisone “to try to quiet down his back.”  Dr. Crowe referred the employee for an MRI scan of his lumbar spine; that scan, taken on November 16, 2000, showed a central disc protrusion at the L4-5 level with associated annular tear abutting the L-5 nerve roots bilaterally, on the left side greater than the right.  Dr. Crowe diagnosed a left-sided disc herniation at the L4-5 level which he concluded caused pinching of the left L-5 nerve root.  Dr. Crowe advised that the employee likely would need a left L4-5 micodiscectomy at some point, but reported that the employee declined both surgery and an epidural steroid injection at that time.

The employee also consulted Dr. Iammatteo, D.O., on December 28, 2000.  Dr. Iammatteo recommended physical therapy and lumbar traction, and instructed the employee in back exercises.  The employee received physical therapy treatments in December 2000 and January 2001 at the Institute for Athletic Medicine.  At a follow-up visit on January 23, 2001, Dr. Crowe diagnosed a significant disc herniation of the L4-5 level with left L-5 radiculitis, and again discussed the possibility of surgery and cortisone shots with the employee.  Dr. Crowe’s chart note of January 23 reflects that the employee would consider the matter and would advise Dr. Crowe if he needed additional care in the future.

On August 14, 2001, the employee underwent an independent medical examination with Dr. David Boxall, at the request of MN Conway Fire & Safety and its insurer, State Fund Mutual Insurance Company.  Dr. Boxall diagnosed multiple level degenerative disc disease of the lumbar spine with herniated disc at the L4-5 level on the left, as well as a history of a thoracic spine injury in May 2000.  Dr. Boxall concluded that the employee’s L4-5 disc herniation was caused by both his July 1, 1995, work injury at Continental Baking and his September 4, 2000, lawn mowing incident.  Dr. Boxall apportioned 2/3 of the liability for the employee’s herniated disc to his 1995 injury and 1/3 to his nonwork-related injury in September 2000.  Dr. Boxall characterized the employee’s May 30, 2000, work injury as a temporary injury to the employee’s neck and upper back, and concluded that such injury was entirely unrelated to the employee’s later need for treatment, disability from work or permanent partial disability to his thoracic or lumber spine.

On April 9, 2002, the employee underwent an independent medical examination with Dr. Paul Cederberg, at the request of Continental Baking Company and Constitution State Service Company.  Dr. Cederberg also diagnosed a herniated disc at the L4-5 level, and assigned a 9% permanency rating based on that herniation, but concluded that the employee’s September 4, 2000, incident was the sole cause of his disc herniation and permanent partial disability.  Dr. Cederberg recommended work restrictions of no lifting over 75 pounds without assistance.  He also stated that, in his opinion, the employee’s prognosis was excellent, and recommended against any surgery or injections at that time, since he believed that any “potential complication of surgery far outweigh the potential benefits.”

The employee has noted flare-ups of his lumbar spine condition since his May 2000 injuries.  According to the employee, the chiropractic treatment he received following his September 2000 injuries provided symptomatic relief.  The employee returned to Dr. Keith Johnson for additional chiropractic treatment between June and October 2002, but discontinued his standard chiropractic treatments because those treatments no longer relieved his symptoms.

On April 22, 2003, the employee consulted Dr. Crowe again, reporting residual leg symptoms.  Upon examination, Dr. Crowe noted a positive straight leg raise on the left side, restricted range of motion with flexion of the back, and spasm on the left side.  Dr. Crowe again assessed a L4-5 disk herniation on the left, which he considered to be work-related.  Dr. Crowe noted that he would follow-up with the employee on an as-needed basis, and suggested that his treatment plan “at this point is just for him to observe it and live with it as best he can.”

The employee later investigated an alternative type of traction treatment, entitled DRX9000 and described as providing a type of spinal decompression treatment.  In June 2004, he consulted Dr. Frederick Claussen, D.C., about the treatment.  He later obtained DRX9000 treatment from Dr. Tracy Andrews, D.C., with whom he had treated in the past.  Before undergoing that treatment, the employee underwent a lumbar MRI scan, which was performed on February 25, 2005, and was interpreted as being unchanged from his November 2000 scan.  The employee ultimately underwent DRX9000 treatments commencing in March 2005, and testified that he was extremely satisfied with the results.  He testified that following this treatment, his leg pain was significantly reduced and he was able to sit for longer periods of time.

On July 14, 2005, the employee was again seen by Dr. Boxall for a follow-up examination.  In his report issued following that examination, Dr. Boxall advised that none of his opinions had changed from his previous 2001 report, that is, that the employee’s L4-5 disc herniation was caused by the employee’s July 1, 1995, work injury and his September 4, 2000, lawn mowing incident.  In his second report, however, Dr. Boxall assigned a permanency rating of 10% permanent partial disability of the whole body.^[1]

The employee filed a claim petition and amended claim petition, based on his admitted injury of July 1, 1995, and his claimed injuries of May 30 and 31, 2000, and September 11, 2000.^[2]  He sought payment of temporary total disability benefits between September 5 and 11, 2000, and again between March 21 and April 24, 2005, during the time he received DRX9000 treatments.  He also sought payment of permanent partial disability benefits and medical expenses related to his treatment since September 2000.  His claim for permanency benefits was based on ratings assigned by both Dr. Crowe and Dr. Andrews.  In a report dated February 19, 2002, Dr. Crowe assigned a permanency rating of 9% permanent partial disability of the body as a whole.  On October 31, 2000, Dr. Andrews rated the employee as having sustained a 12% permanent partial disability relative to his lumbar spine, and a 2.5% permanency rating relative to his thoracic spine, for a combination of 14.2% permanent partial disability to the body as a whole.^[3]

Both employers and their respective insurer and insurance administrator denied liability for the claimed benefits.  The employee’s claims were addressed at a hearing on February 22, 2006.  Before that hearing, the employee settled separately on a Pierringer^[4] basis with the self-insured employer at the time of his 1995 injury, Continental Baking Company, and its insurance administrator, Constitution State Service Company.  The employee’s claim proceeded against his employer at the time of his 2000 injuries, Minnesota Conway Fire and Safety, and its insurer, State Fund Mutual Insurance Company.

Following submission of written closing arguments, the compensation judge issued his findings and order on May 16, 2006, in which he found that the employee’s work injuries of May 30 and 31, and September 11, 2000, were not substantial contributing factors to the employee’s spinal condition, related disability and medical treatment, and denied the employee’s claims in their entirety.  The compensation judge found that the employee’s work-related injuries of May 30 and 31, 2000, were temporary in nature, and resolved within one to two weeks.  He determined that the employee’s current spine problem was due to his nonwork-related injury of September 4, 2000, which occurred while he was mowing a lawn.  The compensation judge also found that the employee’s work-related injury of September 11, 2000, was temporary in nature and resolved by October 2000.  As a result, the compensation judge denied, in their entirety, the employee’s claims for temporary total disability benefits between September 5-11, 2000 and March 21 through April 24, 2005.  He also denied the employee’s claims for permanent partial disability benefits, and his claims for medical and chiropractic treatment.  The employee appeals from the denial of his claims.

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 (2004).  Substantial evidence supports the findings if, in the context of the entire record, "they are supported by evidence that a reasonable mind might accept as adequate."  Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984).  Where evidence conflicts or more than one inference may reasonably be drawn from the evidence, the findings are to be affirmed.  Id. at 60, 37 W.C.D. at 240.  Similarly, findings of fact should not be disturbed, even though the reviewing court might disagree with them, "unless they are clearly erroneous in the sense that they are manifestly contrary to the weight of the evidence or not reasonably supported by the evidence as a whole.”  Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).

The employee appeals the denial of his claims, arguing that the compensation judge’s findings were not supported by substantial evidence of record.  The compensation judge found that the employee’s work-related injuries of May 30 and 31, 2000, and September 11, 2000, were temporary in nature and had resolved shortly after those injuries.  Based on those findings, the judge determined that the employee’s time loss from work in September 2000 and in March and April 2005, and all claimed medical and chiropractic treatment, were not causally related to the employee’s claimed work injuries.  He also denied the employee’s claim for permanent partial disability benefits, again finding no causal relationship between the employee’s claimed work injuries and any permanent partial disability that had been rated by various treating and consulting physicians and chiropractors.

"[I]n order to recover workers' compensation benefits, the employee must establish that his work-related injury is a substantial contributing factor to his current disability."  Steinhaust v. F.B. Clements, 47 W.C.D. 22, 30 (W.C.C.A. 1992).  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).  The issue for this court on appeal is whether substantial evidence exists to support the decision of the compensation judge.  Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984).

As an explanation of his basis for his findings, the judge specifically noted that between May 30 and September 4, 2000, the employee received no medical treatment for his spine or leg problems nor did he lose any time from work nor have any work restrictions assigned to him during that period of time.  The judge also noted that the history recorded in Dr. Johnson’s chiropractic record of September 5, 2000, that the employee’s pain had subsided within a week of his May 2000 injuries, supported the conclusion that the work-related injuries of May 2000 were temporary in nature.

In addition, the compensation judge relied on the medical opinions of Dr. David Boxall and Dr. Paul Cederberg, in support of his conclusion that the employee’s work-related injuries in 2000 were temporary in nature.  Neither one attributed the employee’s time loss from work, need for medical and chiropractic treatment and permanent partial disability to the employee’s claimed injuries.  Dr. Boxall concluded that the employee’s L4-5 disc herniation was caused by both his July 1, 1995, work injury at Continental Baking and his September 4, 2000, nonwork-related lawn mowing incident.  Dr. Cederberg concluded that the employee’s September 4, 2000, incident was the sole cause of his disc herniation and permanent partial disability.

The employee argues on appeal that the compensation judge’s findings concerning the nature and extent of the employee’s work injury are clearly erroneous.  The employee cites to his testimony concerning leg symptoms that he noted following his May 2000 injuries.  The employee also relies on Dr. Crowe’s opinion that the employee’s work injuries in May 2000 substantially contributed to his disc herniation.

The compensation judge accepted the medical opinions of Drs. Boxall and Cederberg in arriving at his conclusions concerning the nature and extent of the employee’s injuries and his subsequent disability and need for medical treatment.  Both physicians had examined the employee, taken a history from him and had reviewed his medical and chiropractic records, and had adequate foundation for their opinions.  Although Dr. Crowe’s opinion is divergent with that of Drs. Boxall and Cederberg, and even though conflicting inferences may reasonably be drawn from the evidence, it was reasonable for the compensation judge to find the opinions of Drs. Boxall and Cederberg to be persuasive.  See Nord v. City of Cook, 360 N.W.2d 337, 37 W.C.D. 364 (Minn. 1985) (a compensation judge’s choice between conflicting expert opinions is generally upheld unless the facts assumed by the expert are not supported by the record); see also Redgate v. Sroga’s Standard Serv., 421 N.W.2d 729, 734, 40 W.C.D. 948, 957 (Minn. 1988).  Based upon our close review of the record, including testimony at the trial, documentary evidence submitted and the arguments presented by counsel at the hearing, we conclude that the record as a whole contains substantial evidence to support the compensation judge’s findings.  We therefore affirm.