Lance Stroll has admitted that he also broke a toe in his recent mountain bike crash.
The Canadian sat out pre-season testing but was back in the newly-competitive Aston Martin for the Bahrain season opener.
Stroll, 24, had his wrists bandaged following surgery for a fracture and recovery from a sprain - and he was also photographed being physically assisted out of his cockpit after practice by team mechanics.
"I couldn't move my hands, I couldn't walk," he told Sky Deutschland when asked about his bike crash.
"I also broke the big toe of my right foot. 12 days ago I was under the knife, 10 days ago I was allowed to leave hospital.
"If I had been given only a 1 percent chance, I would have grabbed it," added Stroll, whose mother Claire-Anne Callens, a Belgian fashion designer, is in Bahrain.
There had been rumours hand pain might rule out him out of the running for Sunday's race, but Stroll actually managed to qualify eighth - immediately behind both works Mercedes.
"It's going to be a long race, but I'm looking forward to it," he said.