Case 1: Unionized Miner

• 44 year old miner has had ongoing altered gait due to ankle problems since 1980 that he believed resulted in his ongoing back problems

Diagnosis

• 1996-computed tomography (CT) scan showed a spinal stenosis with a disc protrusion at L4–5

 History of Presenting Problem

• 1980 - client had slipped and fell while moving a 120 lbs. oxygen bottle and when he slipped the oxygen bottle fell on his ankle.  X-rays showed a fracture across the tip of the medial malleolus. 

• 1981 - the client continued to have many problems with the fracture not healing, pain in his ankle, numbness in his left thigh, leg cramps, wasting of his left calf muscles and the development of a pronounced limp.  X-rays from 1981 showed an un-united fracture at the tip of the medial malleolus, and the remaining bone being shorter. He frequently sought medical attention from his physicians. 

• He continued to experience ongoing problems physically with his ankle such as the ankle giving out and numerous episodes of twisting injuries to his left ankle.

• 1987 - Orthopaedic surgeon reviewed his case - found that his lower extremities were normal except for the left ankle. There was now a ¾” difference in the calf measurements. Stress x-rays taken at this time showed the lateral malleolus had a chip, which did not show up on plain films.

• 1989 - the client attended the Canadian Back Institute (CBI) for recurrent low back pain.   A computed tomography (CT) scan showed a spinal stenosis with a disc protrusion at L4–5. The client was diagnosed with a lateral stenosis and a disc protrusion associated with it.

• 1996 - WSIB wrote to the client and advised that dysfunction of gait does not cause secondary disease of the lumbar spine. A Workplace Safety and Insurance Appeals Tribunal (WSIAT) hearing from March 1992 ruled there is no causal relationship between limping and degenerative disc disease of the lumbar spine. The client was denied entitlement for the lumbar spine.

• The client was referred to OHCOW Sudbury to determine if there was a link between his altered gait and low back condition

 Ergonomist’s Opinion  

• After conducting an extensive literature review and consulting with experts in the field of gait, Ergonomist concluded:

“There appears to be a great deal of literature and biological plausibility to support the client’s claim that his development of L4-L5 degeneration is related to his previous ankle injury that has never healed correctly. When the base of the body’s support is altered, the body adapts by altering its posture in order to establish its center of mass (balance) about its base of support.  Such adaptation is not always best for the load bearing structures that comprise our bodies.  As a result can lead to the development of other disorders while attempting to control for the original problem.  Altered gait leads to a tilt of the pelvis, which causes curvatures in the normally straight spine.  In the case of the client, these microtraumas might also be increased when his ankle gives out causing even greater trauma to the spine.”

 Resolution

• Based on the OHCOW Ergonomic report, the client was awarded a permanent impairment from the WSIAT hearing.

(This case summary was written by Trevor Schell  BSc, MSc, CCPE, Ergonomist, OHCOW Sudbury)