His derny driver was killed , and Merckx injured his head and , more significantly , displaced some vertebrae in his back .
In September 1969 , Merckx suffered a debilitating crash during a motorpaced track race in Blois , France .
Merckx 's derny driver was killed , Merckx Merckx injured his head and , more significantly , displaced some vertebrae in his back .
In September 1969 , Merckx suffered a debilitating crash during a motorpaced track race in Blois , France .