DHL and the Insurance Company of the State of Pennsylvania/Sedgwick Claims Management Services, Inc., appeal from the compensation judge’s finding that the employee sustained a permanent injury to her right knee on September 27, 2006, and that the injury arose out of her employment with Kandersteg, Inc.  We affirm.

On September 27, 2006, Tresa Papesh, the employee, sustained an injury to her right knee while working for Kandersteg, Inc., d/b/a KDG Ventures.^[1]  On that date, the employee worked as a package delivery person, a position she had held since July 2005.  Her typical work shift, which began at 7:00 a.m., included unloading items from a larger truck, sorting the items inside Kandersteg’s facility, and then loading her assigned packages into her delivery van.  She delivered packages ranging from letters to items or packages weighing over 100 pounds.

On September 27, 2006, the employee made three or four delivery stops before the one at which she first noticed right knee symptoms.  She pulled onto the paved, slightly-inclined residential driveway, and walked to the back of her van.  The employee then stood at the back of her van, and reached inside for a box.  She grabbed the box, which she estimated weighed ten pounds, and then straightened up. As she was standing with both feet on the ground, the employee turned to her left, and, in the process of turning, she twisted her right knee.  She testified that she felt a snap “kind of in the front, toward the side” of her right knee, and that it “felt like it tore and it just gave out.”  She also testified that her knee hurt and that her pain worsened throughout the day.

The employee reported her injury to her supervisor at the end of her day’s shift.  She also sought medical treatment at NowCare on that same date.^[2]  X-rays showed degenerative changes with evidence of fabella, but no evidence of a fracture or dislocation.  Victoria Fenstermacher, nurse practitioner, assessed “right knee pain secondary to possible meniscal tear.”  She prescribed a cartilage knee support splint, and advised the employee to return to work within assigned restrictions.  Ms. Fenstermacher also recommended that the employee use ibuprofen for pain, that she rest and elevate her right leg, and that she use ice to treat her knee.

Dr. Paul Havel, orthopedist, examined the employee on October 5, 2006, at the referral of the employee’s nurse practitioner.  At Dr. Havel’s recommendation, the employee underwent an MRI scan of her right knee.  The scan was interpreted as showing a lateral meniscal tear, described as a degenerative tear through the apex of the posterior horn of the lateral meniscus.  In addition, the scan showed moderate chondromalacia of the patella and moderate lateral patellar subluxation and tilting, in addition to mild chondromalacia of the lateral femoral chondyle.  On the basis of the results of the MRI scan, Dr. Havel diagnosed right knee pain, lateral compartment tearing and degeneration.  At an examination on October 12, 2006, the employee reported continued pain, and a cracking and popping sensation in her right knee.  Dr. Havel recommended nonsurgical treatment at that point, and provided the employee with a steroid injection.  In addition, he restricted her to light-duty office work.

Dr. Havel ultimately recommended arthroscopic surgery, which he performed on December 22, 2006, including a partial meniscectomy and debridement of loose cartilage fragments.  His surgical findings in the employee’s knee were consistent with degenerative and chronic changes.  The employee remained off work following surgery until January 15, 2007, when she returned to an office position, initially for six hours per day.  She performed various office duties, including customer service work, order scheduling and tracking, preparing and generating computer reports and records, and communicating with customers via telephone.

Following surgery, the employee underwent physical therapy.  At an examination on February 1, 2007, the employee reported that her right knee pain persisted.  Between February and May 2007, Dr. Havel provided the employee with four Synvisc injections to her right knee; according to the employee those injections provided some limited relief.  Dr. Havel and the employee’s physical therapist recommended heel lifts for the employee’s shoes, to assist with her walking pattern.  The employee’s right knee restricted her from returning to her original delivery job, and so she continued to work for the Kandersteg in an office setting.

Due to the employee’s ongoing difficulties with her right knee, Dr. Havel suggested a femoral osteotomy, but also referred the employee to Dr. Mark Dahl, orthopedist, for a second surgical opinion.  Dr. Dahl examined the employee on June 28, 2007, at which time she complained of “right lateral knee pain.”  She provided a history of her injury occurring while she was unloading a box at work and feeling a “sudden popping painful sensation in her knee.”  Dr. Dahl diagnosed “recent degenerative lateral meniscus tear of the right knee in association with an obese individual with longstanding bilateral genu valgum and advanced degenerative change radiographically.”  Dr. Dahl suggested that the employee quit smoking and that she initiate a significant weight loss program including a possible bariatric surgery; he recommended against a varus producing distal femoral osteotomy because, at best, he could anticipate “60% pain relief.”  He instead recommended “serious efforts at weight loss, health changes and consideration of viscosupplementation under Dr. Havel’s care.”

In early 2008, Dr. Havel performed another series of three Synvisc injections, but the employee later reported that the injections had not been helpful.  Dr. Havel noted that the employee continued to use Vicodin and diagnosed “chronic knee pain secondary to patellar chondyle wear.”

In June 2008, the employee was laid off from her employment with Kandersteg due to a slow down in business.  Kandersteg filed for bankruptcy in 2008.  Following her layoff, the employee was paid unemployment compensation benefits.  She testified that she conducted a job search by reviewing information in newspapers, telephone directory yellow pages, and on Craigslist, although the record contains no documentation of her job search until June 2009.

In early January 2009, the employee consulted Dr. Havel, who noted that the employee continued to use Vicodin for her pain.  In June 2009, based on x-ray results, Dr. Havel recommended an additional arthroscopic surgery to debride and clean her right knee, which he believed could be effective if there were large areas of cartilage damage detected at the time of surgery.  Dr. Havel also anticipated that the employee may eventually require a total knee replacement but recommended avoiding the same due to her age and chronic obesity.  Dr. Havel scheduled a right knee arthroscopy with debridement; the employee did not undergo that surgery evidently due to denial of insurance coverage.

The employee’s medical history includes treatment for low back pain resulting from earlier injuries.  The record includes references in medical records to right knee pain, in part during times when the employee was undergoing medical treatment for her low back condition.  The first reference to right knee pain dates from June 1990, in chiropractic records which documented the employee’s treatment for her low back following a lifting injury.  The employee injured her low back in 1994, and noted further problems with her low back in July 1997; she ultimately underwent surgery to her lumbar spine in June 1998.  While the employee attended physical therapy in January 1999 she reported recent right knee pain.  In September 2001, the employee sought orthopedic treatment for left knee pain; Dr. Kurt Anderson performed arthroscopic surgery to the employee’s left knee in October 2001, including debridement of the patellofemoral joint along with a partial lateral meniscectomy.  During surgery Dr. Anderson detected patellofemoral chondromalacia, a small lateral meniscus tear, and grade II changes to the lateral tibial plateau, findings which were very similar to those detected at the time of the employee’s right knee surgery in 2009.

On July 20, 2008, Dr. Paul Wicklund examined the employee at the request of DHL and its insurer.  Dr. Wicklund concluded that the employee sustained no more than a temporary knee strain on September 26, 2006, which resolved within six weeks, and that her injury was not a substantial contributing factor in her need for surgery in December 2006.  He diagnosed the following:

On November 19, 2009, the employee was evaluated at the request of the DHL and its insurer by vocational expert David Berdahl, who also performed a labor market survey relative to the employee’s work experience, background and work restrictions.  Mr. Berdahl concluded that the employee had the “necessary skills set to be able to look for and secure employment pursuant to her own efforts,” but that she had not conducted a serious or diligent job search since May 2008.  He advised, however, that the employee could benefit from rehabilitation services, including professional placement assistance “of a more hands-on advocacy nature.”  By the time of hearing, on January 13, 2010, the employee had not received any interview or job offer.

In a report dated December 18, 2009, Dr. Havel outlined his opinion that the employee’s work-related injury of September 27, 2006, constituted a substantial contributing factor to her present knee condition, explaining that

On December 21, 2009, Dr. Robert Wengler examined the employee upon referral from her attorney.  He concluded that “[t]he September 2006 injury appears to have resulted in disruption of a degenerated lateral meniscus.  This resulted in a material aggravation of a pre-existing condition by accelerating the degenerative process within the knee.  The September 27, 2006, work injury constitutes a substantial contributing cause to the present condition of the knee.”  Dr. Wengler concluded that the orthopedic treatment rendered by Dr. Havel had been reasonable and appropriate, but advised that he did not think another arthroscopic procedure would “change the picture significantly.”  He deferred that surgical decision, however, to the employee’s treating physician.  Dr. Wengler felt that the employee was a potential candidate for patellar joint arthroplasty but recommended a bariatric procedure prior to that surgery.  Dr. Wengler assigned a rating of 15% whole body impairment.^[4]

The employee filed a claim petition, seeking payment of temporary total disability benefits following her 2006 surgery and following her layoff in June 2008.  She also sought payment of medical expenses; provision of a statutory rehabilitation assistance; and permanent partial disability benefits.  DHL and its insurer denied primary liability for the employee’s claimed injury, asserting that the employee’s claimed injury was not causally related to her work and contesting its alleged general contractor status at the time of the employee’s claimed injury, under Minn. Stat. § 176.215.

On January 11, 2010, DHL and its insurer petitioned for a temporary order under which they agreed to pay any awarded benefits; the temporary order was served and filed January 15, 2010.  The employee’s claims were addressed at a hearing on January 13, 2010.  By agreement between DHL and the Special Compensation Fund, the employee’s claims and the issue of primary liability were bifurcated from the separate issue of DHL’s general contractor status.  Only the employee’s claims were addressed at the hearing and in the findings and order which are the subject of this appeal.

Following the hearing, the parties submitted written arguments and information requested by the compensation judge.  In his findings and order issued on March 23, 2010, the compensation judge determined that the employee sustained a personal injury to her right lower extremity on September 27, 2006, as a result of her work, and that she was entitled to payment of temporary total disability benefits from December 22, 2006, through January 14, 2007, during her recuperation from surgery; ongoing payment of temporary total disability benefits from June 11, 2009; payment of medical expenses; and provision of a rehabilitation consultation.  The compensation judge denied the employee’s claim for temporary total disability benefits between May 2008 and June 2009, due to her lack of a diligent job search during that time frame.  He also concluded that the employee had sustained a 2% whole body impairment as a result of her right knee condition, but that payment for that permanency rating would be premature at this point due to his award for ongoing temporary total disability benefits.  DHL and its insurer appeal from the determination that the employee’s right knee pain arose out of her employment.^[5]

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 (2008).  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 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).

Pursuant to Minn. Stat. § 176.021, subd. 1, employers are liable to pay compensation “in every case of personal injury . . . arising out of and in the course of employment without regard to the question of negligence.”  The phrase “in the course of” refers to the time, place, and circumstances of the incident causing the employee’s injury.  Gibberd v. Control Data Corp., 424 N.W.2d 776, 780, 40 W.C.D. 1040, 1047 (Minn. 1988).  “Arising out of” connotes a causal connection between the employee’s injury and the employment, although not necessarily in the sense of proximate cause.  Id.  The requisite causal connection “exists if the employment, by reason of its nature, obligations, or incidents may reasonably be found to be the source of the injury-producing hazard.”  Nelson v. City of St. Paul, 249 Minn. 53, 55, 81 N.W.2d 272, 275, 19 W.C.D. 120, 123 (1957).

Under the “increased risk” test, applicable in Minnesota, the employee must show that the injury was caused by an increased risk to which the employee was subjected by his or her employment beyond that experienced by the general public.  See Kirchner v. County of Anoka, 339 N.W.2d 908, 36 W.C.D. 335 (Minn. 1983); Bohlin v. St. Louis County/Nopeming Nursing Home, 61 W.C.D. 69 (W.C.C.A. 2000); see also Pratt v. Minnesota Tex Invs., 63 W.C.D. 33 (W.C.C.A. 2005); Goebel v. Dyneon Corp./3M Co., No. WC04-243 (W.C.C.A. Jan. 24, 2005).  The increased risk need not be unique to employment.  Breimhorst v. Beckman, 227 Minn. 409, 35 N.W.2d 719, 15 W.C.D. 395 (1949).  The increased risk test is met if the injuries are the result of a “natural incident of work.”  Foley v. Honeywell, 488 N.W.2d 268, 272 (Minn. 1992).  Whether the employee has met the burden of proving that the injury arises out of employment is a question of fact for the compensation judge.  Schreier v. Bruning Const., 61 W.C.D. 507 (W.C.C.A. 2001); Kaisershot v. Earthworks Excavating, slip op. (W.C.C.A. July 23, 2003).

We have noted that “[n]o one comprehensive definition can be fashioned to fit all cases addressing whether an injury arises out of and in the course of employment” and that “each case stands on its own facts.”  Anderson v. Smead Mfg Co. No. WC08-216 (W.C.C.A. Feb. 19, 2009); see also Gibberd v. Control Data Corp., 424 N.W.2d 776, 780, 40 W.C.D. 1040, 1047 (Minn. 1988); Novack v. Montgomery Ward & Co., 158 Minn. 495, 498, 198 N.W. 290, 292, 2 W.C.D. 156, 159 (1924).  There is no dispute in this case that the employee was in the course of her employment when the work injury occurred.  She was in the process of delivering a package, her usual work activity, during her regular shift.  The issue on appeal is whether the employee’s injury arose out of her employment.

The employee’s medical records support the judge’s determination regarding causation.  Dr. Wengler concluded that the employee’s September 2008 incident at work accelerated the degenerative process within her knee, resulting in a material aggravation of a pre-existing condition, and therefore that the work injury constituted a substantial contributing cause of the employee’s current knee condition.  Dr. Havel also opined that the employee’s work-related injury in September 2008 constituted a substantial contributing factor to her present knee condition and that the employee may need additional surgery for her right knee.  While Dr. Havel and Dr. Wengler did not specifically address whether the employee was exposed to an increased risk at the time of her injury, they were aware that she worked as a delivery person and that she was handling a package and was turning to make the delivery of that package at the time she experienced right knee symptoms.  A compensation judge’s choice between conflicting medical opinions is generally upheld if the facts assumed by the expert are supported by the record.  Nord v. City of Cook, 360 N.W.2d 337, 342-43, 37 W.C.D. 364, 372-73 (Minn. 1985).  Further, a work injury need not be the sole cause of an employee’s condition, only a substantial contributing cause, to support a finding of liability.  See Salmon v. Wheelabrator Frye, 409 N.W.2d 495, 497-98, 40 W.C.D. 117, 122 (Minn. 1987).

DHL and its insurer argue that Rowan v. United States Steel Corp., No. WC08-135 (W.C.C.A. July 7, 2008) is controlling in this case.  In Rowan, the employee also developed knee symptoms while turning at work, but the compensation judge found that the incident was not a substantially contributing cause of the employee’s meniscus tear and that the employee did not sustain a knee injury arising out of and in the course of his employment.  This court affirmed, citing expert medical opinion in evidence and the employee’s pre-existing condition.  DHL and its insurer note similarities between the facts in Rowan and this case, and argue that the finding that the employee’s knee injury arose out of her employment must be reversed.  We disagree that the Rowan case is controlling here.  In the Rowan case, this court affirmed a factual determination by a compensation judge.  Under our standard of review, cases affirming a compensation judge on substantial evidence grounds have limited precedential value.  Regan v. VOA Nat’l Housing, 61 W.C.D. 142, 151 (W.C.C.A. 2000), summarily aff’d (Minn. Apr. 6, 2001).

While the employee may have been more susceptible to a meniscal tear because of the valgus alignment of her knees and obesity, “an employer takes the employee as it finds him [or her] with all of his [or her] inherent weaknesses.”  Schlichting v. Holm Bros., 30 W.C.D. 289, 291 (W.C.C.A. 1978).  The employee reported minor right knee pain in 1990, 1999, and 2001, and had very little medical treatment for her right knee.  She had no right knee symptoms from 2002 until the date of the injury and had no problems with her right knee at work during that time.  In her job as a delivery person, the employee made numerous package deliveries each day.  On the day of the injury, she grabbed the ten pound package out of her van and as she straightened, and as she was standing with both feet on the ground, the employee turned to her left.  In the process of turning, she twisted her right knee and felt a snap in the front lateral portion of her right knee as well as pain and a “give-way” sensation.  The compensation judge could reasonably conclude that the employee established that the “injury was caused by an increased risk to which the claimant, as distinct from the general public, was subjected by [her] employment.”  Bohlin, 61 W.C.D. at 72 (W.C.C.A. 2000), quoting 1 A. Larson and L.K. Larson, Workers’ Compensation Law § 3.00 (1999); see also Kirchner, 339 N.W.2d at 911, 36 W.C.D. at 338 (the “arising out of” standard for compensability requires “a showing of some hazard that increases the employee’s exposure to injury beyond that of the general public”).  Based on our review of the evidence as a whole, we conclude that the record supports the compensation judge's findings.  See Hengemuhle; see also Wermerskirchen v. United Parcel Service, slip op. (W.C.C.A., Oct. 7, 2003) (employee’s medial meniscus tear while working as a delivery person and walking down stairs found compensable).

We are mindful that there is evidence in the record that supports the arguments presented by the DHL and its insurer.  The record also contains evidence to the contrary.  The issue under this court's standard of review is not whether the facts will support findings different from those made by the compensation judge, but, rather, whether substantial evidence supports the findings of the judge.  Land v. Washington County Sheriff’s Dep’t, slip op. (W.C.C.A. Dec. 23, 2003); see also Ask v. Winona Health, No. WC08-156 (W.C.C.A. Oct. 29, 2008); Redgate v. Sroga’s Standard Serv., 421 N.W.2d 729, 734, 40 W.C.D. 948, 957 (Minn. 1988) (“whether [the appellate court] might have viewed the evidence differently is not the point, but whether the findings of the compensation judge are supported by evidence that a reasonable mind might accept as adequate”).  Substantial evidence supports the compensation judge’s finding that the employee’s work injury arose out of her employment, and we affirm.