The employee appeals from the compensation judge’s denial of his claim for workers’ compensation benefits and seeks a new trial.  We affirm.

Donald P. Meysembourg, the employee, began working for the University of Minnesota, the employer, as a book binder in August 1985.  In general, a book binder inserts flat sheets of paper into different machines to fold and join the paper together into a book or a pamphlet.  For the first ten years of his employment, the employee worked on a stitcher machine which stitched pages together and two different folder machines which folded paper.  The employee testified he spent most of his time on a small folder machine that required him to lift sheets of paper from a pallet, fan the paper, and curl the corners and place it into a feeder.  The paper weighed from three to fifteen pounds.  To place the paper in the feeder, the employee stated he grabbed the paper with both arms close to his body and then lifted up with his arms stretching out in front of him.  As he did so, the employee stated his elbows came out and his shoulders rose up and then he laid the paper down.  The employee described the process of placing papers into the machine as continuous up to ten to twenty times a minute for a smaller machine.  When the paper came out of the machine, the employee squeezed the paper to remove the air, stacked the paper in a carton, sealed the carton, and placed the carton on a pallet. During this time period, the employee testified he had shoulder pain which affected his ability to raise his arms out to the side or over his shoulder.

From 1995 to 2005, the employee stated he spent the majority of time working on pile feed folders which he operated in the same manner as the folder machines as described above.  The employee also worked on a jogging machine and a cutting machine that involved taking paper from a lift, placing it on a jogger that evened out the paper, and then moving the pile of paper to the cutter that cut the paper to size.  In 1995, the employee recalled having difficulty lifting his arms above his waist due to shoulder pain.  The employee testified he did not seek medical attention for his shoulder pain at this time.

Between 2005 and April 2007, the employee primarily worked on a continuous feed folder machine with some jogging, cutting, and some work on the stitcher machine and the small pile feed folder.  During this period of time, the employee stated his shoulder pain was becoming more constant and he felt weakness in his right arm.

On March 9, 2007, the employee sustained an injury to his right elbow when a wheel axle fell on his elbow while repairing a trailer at the home of a friend.  The employee testified he had some bleeding and swelling as a result of this injury and he sought treatment at the Aspen urgent care clinic on March 12, 2007.

The employee was at work on Friday, April 20, 2007, operating a continuous feed folder and testified he was having a difficult time keeping up with the machine due to his elbow injury.  The employee left work and saw Dr. Robert Florence at the Aspen Medical Group that same day.  The employee gave the doctor a history of his March 2007 right elbow injury and stated this condition had improved until his employer assigned him a heavier job at which time he noticed increased elbow pain with lifting or movement.  Dr. Florence diagnosed epicondylitis due to the March 2007 injury and assigned a twenty pound lifting restriction.

The employee returned to work on Monday, April 23, 2007.  After working on the folding and jogging machines, the employee noticed right shoulder and arm pain with numbness in the arm.  The employee filled out an injury report that day.  On April 26, 2007, the employee saw Dr. Michael McDonald at the Aspen Medical Group complaining of right elbow and shoulder pain with numbness down the right arm.  The doctor diagnosed right arm pain due to repetitive use at work, prescribed physical therapy, and increased restrictions on use of the right arm.  The employee returned to see Dr. McDonald on May 24, 2007.  The doctor administered a Cortisone injection and continued the work restrictions.  A June 2007 MRI scan of the right shoulder ordered by Dr. McDonald reflected an acromioclavicular arthropathy causing supraspinatus impingement with a partial thickness tear of the supraspinatus tendon.  An MRI scan of the cervical spine reflected multilevel degenerative disc disease with central spine stenosis and boney forminal stenosis from C4 through C7.

The employee saw Dr. Michael Freehill, an orthopedic surgeon, on July 3, 2007.  The employee gave the doctor a history of his March 2007 right elbow injury and described the onset of right shoulder pain over many years that had recently worsened.  Dr. Freehill reviewed the June 2007 MRI scan and diagnosed right shoulder high grade partial-thickness tearing of the supraspinatus with supraspinatus and infraspinatus tendonopathy, AC arthrosis, and mild glenohumeral joint degeneration and right elbow epicondylitis, improved with physical therapy.  Dr. Freehill recommended right shoulder surgery which he performed on November 17, 2007.

The employee continued to work up to the date of his surgery.  Following his surgery, the employee returned to work on May 20, 2008, with restrictions.  The employee returned to work without restrictions on July 1, 2008.

By letter dated October 24, 2007, Dr. Freehill stated it was his opinion that the employee’s work activities as a book binder for the employer were a substantial contributing factor to the employee’s right shoulder injury.  The doctor stated the employee’s “repetitive labor activities demanded of him while working as a book binder over the years are a significant contributor to his right shoulder degeneration and subsequent need for surgery intervention.”  (Pet. Ex. 2.)

Dr. Paul Wicklund examined the employee on behalf of the employer on July 31, 2008.  The doctor obtained a history from the employee, reviewed medical records, and performed a physical examination.  By report dated August 10, 2008, Dr. Wicklund diagnosed a partial thickness right rotator cuff tear of the right shoulder, with impingement, treated surgically with a good result, multilevel degenerative disc disease of the cervical spine, and resolved eipcondylitis of the right arm and elbow.  The doctor opined the employee sustained neither a specific nor a Gillette^[1] injury to his right shoulder arising out of his employment with the employer.

In January 2009, the employee’s counsel sent to Dr. Freehill the employee’s deposition transcript, the August 2008 report of Dr. Wicklund, and pictures of the employee’s job duties.  By report dated March 12, 2009, the doctor stated the employee’s job required repetitive lifting of stacks of paper with frequent manipulation which required repetitive extreme reaching away from the body.  Dr. Freehill concluded the employee’s work activities with the employer “did culminate on or about 4/23/07 with a substantial acceleration of his right shoulder rotator cuff symptoms.  It was at that point that his symptoms began to be significantly progressive, requiring surgery.  Upon review of his medical records and the IME report of Dr. Wicklund, he was noted to have intermittent history of right shoulder rotator cuff problems, which he had always related to his work activities as a book binder.”  The doctor rated a 9% whole body disability for the rotator cuff tear and a distal clavicle excision.  (Pet. Ex. B.)

The deposition of Dr. Wicklund was taken on March 17, 2009.  In conjunction with his deposition, the doctor reviewed the employee’s medical records, including the June 2007 MRI scan, a job analysis of the employee’s job, a DVD showing various aspects of the jobs the employee performed for the employer, and pictures of a person working on a jogging machine.  Dr. Wicklund diagnosed a partial thickness right rotator cuff tear with impingement, treated surgically with a good result and resolved epicondylitis of the right elbow.  The doctor testified all of the employee’s pathology was chronic and he stated he saw nothing on the June MRI scan or in the surgical report which suggested there had been a progression or acceleration of this chronic condition.  Dr. Wicklund opined none of the employee’s work activities with the employer aggravated or accelerated any pre-existing condition, and concluded his need for surgery was totally unrelated to his work activities.

The employee filed a claim petition seeking workers’ compensation benefits secondary to an alleged Gillette personal injury culminating on April 23, 2007.  The case was heard before Compensation Judge Carol Eckerson on April 2, 2009.  Prior to issuing a findings and order in the case, Judge Eckerson resigned her position with the Office of Administrative Hearings.  By Order served and filed August 20, 2009, Assistant Chief Administrative Law Judge William R. Johnson ordered that the case be assigned to a different compensation judge to listen to the digital recording of the hearing and issue a findings and order deciding all of the issues presented at the hearing.  Each party was afforded an opportunity to file a petition for reassignment of the case to a different compensation judge.  By notice served August 20, 2009, Judge Danny Kelly was assigned as the compensation judge.  The employee filed a petition for reassignment under Minn. Stat. § 176.312 and by notice served August 25, 2009, the case was reassigned to Judge Janice Culnane.  No findings and order was filed by Judge Culnane.  By notice dated February 4, 2010, the case was reassigned to Judge Adam Wolkoff.  In a Findings and Order served and filed June 24, 2010, Judge Wolkoff found the employee did not sustain a Gillette injury to his right shoulder arising out of his employment on April 23, 2007, and denied the employee’s claims.  The employee appeals.

This case was submitted to Judge Eckerson on April 2, 2009, but the findings and order were not filed until June 24, 2010.  The employee contends this delay violated Minn. Stat. § 176.371 and entitles the employee to a new trial.  We disagree.

Minn. Stat. § 176.371 provides: “All questions of fact and law submitted to a compensation judge at the hearing shall be disposed of and the judge’s decision shall be filed with the commissioner, except where expedited procedures require a shorter time, within 60 days after the submission, unless sickness or casualty prevents a timely filing, or the chief administrative law judge extends the time for good cause.”  The statute goes on to provide that no part of the salary of a compensation judge shall be paid unless all decisions of a compensation judge are issued within the statutory time limit.

In Ettedgui v. Master Craft Cabinets, slip op. (W.C.C.A. Sept. 19, 1995) a compensation judge failed to issue a decision following an expedited hearing within the 30 days required by Minn. Stat. § 176.238, subd. 6.  On appeal, the appellant argued that due to the compensation judge’s failure to issue a decision within the statutory time, the decision was void and should be vacated.  This court disagreed and held that Minn. Stat. § 176.238, subd. 6, does not provide for a remedy, specific to the parties, for a failure to issue a decision within the statutory period.  The court went on to state that nothing in Minn. Stat. § 176.238, subd. 6, suggests that a failure to issue a decision within the requisite period constitutes a jurisdictional defect.

The same reasoning applies to Minn. Stat. § 176.371.  The statute provides only that the salary of a compensation judge may not be paid unless all decisions of that judge are issued within the prescribed time limits.  Clearly, the intent of the statute is to promote the prompt determination of all matters pending before a compensation judge.  The statute provides no remedy to a party if a decision is not issued within the prescribed period.  The compensation judge had jurisdiction to decide the case, and we cannot conclude that the post-hearing delay in issuing the decision negates that jurisdiction.  We find no statutory basis to order a new trial for failure to issue a decision within the statutory time limit.

Judge Wolkoff ultimately issued a findings and order in this case based upon a digital recording of the hearing and a transcript of the hearing.  The employee argues he is entitled to a new trial because Judge Wolkoff did not have the opportunity to view the witnesses to determine their credibility.  Absent the ability of the compensation judge to observe the witnesses to determine their credibility, the appellant contends he was denied due process and a fair trial.  We disagree.

While the credibility of a witness may be judged, in some part, by a judge’s observation of a witness, there is much more to evaluating credibility than observation.  Other factors bearing on a witness’s credibility include, but are not limited to: character, reputation, conviction of a crime, interest in the outcome, relationship with a party, knowledge of the facts, opportunity to observe, inconsistent statements, and the consistency of the witness’s testimony with other facts, witnesses, and documentary evidence.  The specific factors bearing on credibility will vary from case to case.  In this case, each party was afforded the opportunity to call witnesses, introduce documentary evidence, and cross-examine the opposing witnesses.  The compensation judge had the opportunity to review and consider the testimony of all of the witnesses and the documentary evidence in the case.  We are not persuaded that the inability of the judge to observe the testimony impaired the judge’s ability to make a credibility determination.

Furthermore, a crucial issue in this case was whether the employee’s work activities caused a Gillette-type personal injury.  Resolution of this issue depends primarily on the medical evidence.  Steffen v. Target Stores, 517 N.W.2d 597, 50 W.C.D. 464 (Minn. 1994).  The medical evidence on this issue was submitted by report and deposition so the compensation judge did not have the opportunity to personally observe the testimony of either Dr. Freehill or Dr. Wicklund.  We conclude the inability of the compensation judge to personally observe the witnesses’ testimony does not, standing alone, require a new trial.

Following the hearing before Judge Eckerson, the assistant chief administrative law judge ordered the case be assigned to a different compensation judge to listen to the digital recording of the hearing and issue a findings and order.  Judge Kelly was then assigned as a compensation judge following which the employee filed a petition for reassignment under Minn. Stat. § 176.312.  The case was then reassigned to Judge Culnane.  No findings and order was filed by Judge Culnane and the case was then reassigned to Judge Wolkoff.  The employee contends the reassignment of the case from Judge Culnane to Judge Wolkoff was a violation of Minn. Stat. § 176.307, which entitles the employee to a new trial.  We disagree.

Minn. Stat. § 176.307 provides:

The February 4, 2010, Notice of Judge Reassignment reassigning the case to Judge Wolkoff did not state the reason for the reassignment.  However, the case was initially assigned to Judge Culnane on August 25, 2009, and no findings and order had been issued.  Minn. Stat. § 176.307 specifically allows a system of case assignment other than the block system to insure that cases are timely decided.  In this case, the chief administrative law judge properly acted within his discretion and reassigned the case to Judge Wolkoff.

The appellant further argues the reassignment to Judge Wolkoff violated Minn. Stat. § 176.312 which allows for affidavits of prejudice and petitions for reassignment of a compensation judge.  We find no merit to this argument.  Following the reassignment to Judge Kelly on August 20, 2009, the employee filed a petition for reassignment.  Under the statute, a party may file a petition for reassignment only once.  Since the employee exercised that right following the assignment to Judge Kelly, the employee is not entitled to second request for reassignment.

The employee next contends the compensation judge erred in rejecting the causation opinion of Dr. Freehill.  In his memorandum, the compensation judge noted Dr. Freehill’s opinion that the employee sustained a Gillette injury is “based on his assumption that the employee’s job duties required repetitive extreme reaching away from the body.  This assumption is not supported by the preponderance of the evidence.”  (Mem. at 9.)  The compensation judge then concluded Dr. Freehill’s causation opinion failed for lack of adequate foundation.  The employee contends the compensation judge erred as a matter of law in this conclusion.  We are not persuaded.

The competency of a medical expert depends both upon the extent of the scientific knowledge of the witness and the witnesses’ practical experience with the matter which is the subject of the offered testimony.  Reinhardt v. Colton, 337 N.W.2d 88 (Minn. 1983).  Sufficient knowledge of the subject matter can be obtained through personal knowledge, a hypothetical question, or testimony at the hearing.  Scott v. Southview Chevrolet Co., 267 N.W.2d 185, 30 W.C.D. 426 (Minn. 1978).  The facts upon which the expert relies for a medical opinion must be supported by the evidence.  McDonald v. MTS Sys. Corp., 43 W.C.D. 83 (W.C.C.A. 1990), summarily aff’d, (Minn. July 13, 1990).

In his March 12, 2009, medical report, Dr. Freehill stated the employee was “involved in repetitive lifting of stacks of paper with frequent manipulation, which requires repetitive extreme lifting away from the body.  This is confirmed in his deposition as well as his IME.  Therefore, within a reasonable degree of medical certainty, we feel that the employee’s work activities were cumulative, culminating on or about 4/23/07, his most recent date of injury.”  (Pet. Ex. B.)  The compensation judge concluded the employee’s job duties did not require repetitive extreme reaching away from the body.  On this basis, the compensation judge rejected the causation opinion of Dr. Freehill.  The issue on appeal is whether the compensation judge’s decision is supported by substantial evidence.

Mark Masica, the assistant plant superintendent of the employer, was involved with the preparation of a DVD that demonstrates the operation of the jogger machine, the small folder machine, and a pallet jack.  Mr. Masica testified the DVD accurately depicts the employee’s job duties on these machines.  Christopher Remarke was employed as a bindery operator for the employer and testified he was very familiar with the job of a jogger/cutter.  Mr. Remarke was present in the courtroom when the DVD was shown and testified it was a correct and accurate depiction of the job duties of a jogger operator.  On April 23, 2007, Mr. Remarke was the cutter operator and worked with the employee who was operating the jogger machine.  He testified the employee operated the jogger machine in substantially the same fashion as that depicted in the DVD.  He testified that a jogger operator was not required to lift paper above shoulder height and stated none of the operations required repetitive use of the arms above chest height.

Prior to his deposition, Dr. Wicklund reviewed the DVD showing the job duties performed by the employee.  In addition, the doctor testified he was familiar with the printing business and had personally observed the jogging operation performed both by hand and by machine.  Dr. Wicklund concluded the employee’s job duties did not require repetitive extreme reaching away from the body.  Dr. Wicklund testified the June 2007 MRI scan demonstrated the employee had a type II acromion with significant arthritic changes and spurring on the undersurface of the acromioclavicular joint that impinged on the rotator cuff causing a partial thickness tearing.  The doctor stated these conditions were chronic and the employee’s work activities with the employer did not contribute to, cause, or aggravate the employee’s shoulder condition.

An underlying factual basis for Dr. Freehill’s opinions was that the employee’s job required repetitive extreme lifting away from his body contrary to the judge’s finding that the job duties did not require extreme reaching away from the body.  This finding is supported by the DVD of the job duties and the testimony of the witnesses.  Since the facts upon which Dr. Freehill relied for his opinion were not supported by the evidence, the compensation judge could reasonably reject the opinions of Dr. Freehill and accept those of Dr. Wicklund.  Accordingly, the decision of the compensation judge is affirmed.