A retired electrical engineer who spent upwards of 85% of his time typing failed to prove his thumb injury, which he originally alleged was caused by repetitive use of the space bar, was work-related, a Missouri appeals court ruled Tuesday in affirming the denial of a $22,000 workers compensation claim.

Jonathan Mirfasihi began working for Honeywell Federal Manufacturing & Technologies LLC in 1984 as an electrical engineer and for the last 15 years of his employment was a program manager, tasked with writing proposals. In 2017 Mr. Mirfasihi began to experience pain in his left hand and reported it to his employer, which directed him to seek medical care.

Mr. Mirfasihi reported that he “awakens with no pain, then pain occurs as his workday progresses” and that the pain was associated "with using the keyboard space bar with his left thumb,” according to documents in Jonathan Mirfasihi v. Honeywell Federal Manufacturing & Technologies LLC, filed in the Court of Appeals of Missouri, Western District, in Kansas City.

Following his retirement later that year Mr. Mirfasihi filed a claim for compensation with the Missouri Division of Workers’ Compensation, asserting that he had suffered a “left hand and left thumb repetitive motion injury or disease” while employed by Honeywell as a program manager.

After conducting a hearing and admitting into evidence medical records, an administrative law judge found Mr. Mirfasihi suffered a compensable injury and awarded him more than $22,000 in benefits.

On appeal, the Missouri Labor and Industrial Relations Commission reversed, finding Mr. Mirfasihi “failed to demonstrate that his work duties were the prevailing factor causing his thumb injury,” according to documents.

The commission noted that at the hearing before the administrative law judge, Mr. Mirfasihi for the first time explained other aspects of his work that might have contributed to his thumb injury, including using his left hand to carry his briefcase and traveling through three sets of heavy doors.