Pistorius's emotional responses explained

Prof Wayne Derman says disabled people respond differently to fear compared to able people.

Oscar Pistorius gets dropped of in front of the High Court in Pretoria ahead of Day 37 of his murder trial on 3 July 2014. Picture: Reinart Toerien/EWN

PRETORIA - A sports medical practitioner says Oscar Pistorius had no choice but to approach a situation he perceived to be dangerous on Valentine's Day last year, because of his disability.

The 'blade runner' is accused of murdering his girlfriend Reeva Steenkamp on 14 February 2013.

While he claims he shot her by accident, the state alleges he intended to kill her.

Oscar Pistorius gets dropped of in front of the High Court in Pretoria ahead of Day 37 of his murder trial on 3 July 2014. Picture: Reinart Toerien/EWN

Professor Wayne Derman is the third defence witness to take the stand this week after a lengthy break during which Pistorius underwent medical observation.

Watch: Pistorius reports to Weskoppies

Derman is testifying about the physical and emotional responses of people with disabilities when faced with fear.

He says disabled people respond differently to fear compared to able people.

Defence advocate Barry Roux has referred back to Pistorius's testimony when he said he wasn't thinking and approached the perceived danger in his bathroom.

Derman says the ' fight or flight' response is a reflex and in this case, despite the existence of Pistorius' disability, he chose the 'fight' option.

He says this is a normal reaction because he couldn't 'flee' because he has no lower limbs.

Pistorius' legal team has referred to his psychological report, which states that there are two sides to the athlete's personality - one of which is extremely vulnerable.

Defence advocate Kenny Oldwage has referred to the psychological report handed into court this week.

The judge ruled that the media can only report on the findings of that report because it contains intimate details about Pistorius.

Oldwage referred to the two Oscars; one which is disabled and vulnerable, the other and successful and confident athlete.

Derman says Pistorius is perceived as being very able because of his athletic career but in reality he's also vulnerable.

He says the hard truth is that Pistorius doesn't have lower limbs and this disability is a daily challenge which affects all aspects of his life.

"You've got a paradox of an individual who is supremely abled and then you've got an individual who is significantly disabled."

Watch: Pistorius trial: Life of a sports icon

During court proceedings on Wednesday the psychological evaluation of Oscar Pistorius found he has no history of abnormal aggression or explosive violence.

This was among the mental health findings read on the record at the High Court in Pretoria.

Watch: 'Oscar Pistorius has no mental defect'

Criminal psychologist Jonathan Scholtz told the court abnormal aggression and violence was never incorporated into Pistorius's personality.

He said the athlete does not display the personality characteristics of narcissism or psychopathy, which are mostly associated with men in abusive relationships.

People interviewed by the psychologist describe him as gentle, respectful and conflict-avoidant.

Scholtz said evidence indicates that Pistorius has genuine feelings for Steenkamp and the couple were in a normal, loving relationship.

He said while their relationship was still young, there were no signs of abuse or cohesion.

Watch: Pistorius trial: Defence presents crux of case

For live updates from the trial on EWN's live blog for more background, visit EWN's Oscar Pistorius portal.