"I am satisfied that the substance of Mr Contoyannis’ evidence is that the extra 100 millimetres increased the risk of injury to Mr Sampson..."

 

Extracts from Judge Tsalamandris' comments in relation to evidence provided by expert witness forensic engineer Mr Bill Contoyannis.

Paragraph 107: Mr Contoyannis was of the opinion that the temporary stairway which Mr Sampson was descending at the time of his injury did not comply with the 2010 Standard, in that the riser of the bottom step was 100 millimetres greater than the maximum allowed height of 225 millimetres.

Paragraph 110: In explaining his opinion in respect of the biomechanical forces at play at the time of Mr Sampson’s injury, Mr Contoyannis explained that when descending a stair, a person’s foot is “plantarflexed”, which means the toes are pointing to the ground and the ankle is unloaded. Mr Contoyannis explained that just prior to the work incident, as Mr Sampson descended the stairs and the contact point with the ground was approached, Mr Sampson would have activated his ankle and the loading surfaces of his ankle joint prepared for taking weight. Further, he explained the muscles around the knee are used as the main decelerator of the body when this action occurs. Mr Contoyannis stated that disruption in this process can result in a misstep, including hyperextending of the knee or buckling of the knee. Mr Contoyannis stated that if a change of direction occurs, this misstep, combined with the loading of the body, can result in serious injuries to either the knee, ankle or both.

Paragraph 113: Mr Contoyannis was called to give evidence and was cross-examined in respect of his opinion. He explained the contribution of the larger step height and its role in Mr Sampson suffering his injury. Mr Contoyannis stated that with a larger rise in a step, the biomechanics of how a person steps down changes. He said that when descending in the usual manner, the ankle locks and the knee bends to take all the weight. However, with a larger rise, Mr Contoyannis explained that the foot reaches lower and extends more, and the knee bends less. In addition, the ankle may not be in the right position to lock properly.

Paragraph 115: Mr Contoyannis was cross-examined in respect of the four factors which he said “could” have contributed to Mr Sampson’s injury. Mr Contoyannis accepted that each of the four factors could have caused Mr Sampson’s injury, but also noted the factors were “interconnected”. Mr Contoyannis stated that the larger step height influences the lower limb biomechanics.

Paragraph 126: Mr Contoyannis explained the biomechanics associated with an increased rise in step height. I note that the rise in the defendants’ step was 10 centimetres greater than the recommended standard. As the only witness to give evidence on the biomechanical forces associated with an increased step height, I accept Mr Contoyannis’ evidence that this creates an increased risk of injury to a person descending stairs.

Paragraph 129: Having accepted Mr Contoyannis’ evidence, which was consistent with the safety requirements of the 2010 Standard, and noting the admission by the defendants after the incident that the stair should be rectified, I am satisfied that the defendants were negligent for having the bottom step of this scaffold at a height of 325 millimetres. I am satisfied that the risk of injury from this excessive step height to a person descending the stairs was reasonably foreseeable and was not farfetched or fanciful.

Paragraph 139: I note that Mr Contoyannis stated that those factors were inter-related. I accept Mr Contoyannis’ explanation as to how the increased step rise increases the loading of weight through the knee and ankle. I am satisfied that the substance of Mr Contoyannis’ evidence is that the extra 100 millimetres increased the risk of injury to Mr Sampson as he descended the steps carrying two buckets of rubble.

Paragraph 140: Having considered the whole of the evidence and taking a common sense approach to causation, I am satisfied that the excessive step height was a cause of the aggravation of Mr Sampson’s left knee injury and rupture of his ACL.

Full court report can be accessed via the Australasian Legal Institute - Sampson v Thiess Pty Ltd & Anor [2020] VCC 1568 (15 October 2020).