Nigel has a history of back injuries:-
1. Broke his back in an 'F3' accident in
1979, apparently ending his career. However, he'd already been spotted by Colin Chapman of 'Lotus', who gave him an 'F1' race seat in mid 1980.
2. Crushed some vertebrae in his spine in a practice accident in the 1987 Japanese Grand Prix. The bottom of his spine had endured a 60g impact.
3. Injured his back in practice crash for the 1993 Phoenix 'IndyCar' race, which punctured the outside concrete retaining wall of the track.
Desperate to return ASAP, he had needles drain litres of fluid from his back in between practice sessions for the following race. He won the race and later the championship.