Not really... brace yourself for a bit of anecdata folks.
I was left hooked (by an ambulance of all vehicles). As I gracefully flew over his bonnet I automatically 'tucked and rolled' - a reflex action honed by years of judo (or so I like to think
) . I landed on my shoulder on the other side of the vehicle, dislocating my AC joint and smashing my clavicle. However, as I rolled, the foam extrusions on the rear of the helmet (which extended several inches beyond the natural curve of my head) came into contact with the road.
As they weren't the shiny plastic of the helmet, which is designed to slide on contact, they snagged on the tarmac. My neck was hyperextended, fracturing my C7 vertebra, crushing the brachial plexus on the left side and tearing the brachial plexus on the right.
The clavicular and AC joint injuries took 5 rounds of surgery over two years to sort out. The fracture in my neck complicated matters, as you need to rotate on C7 in order to intubate duing general anesthaesia, which meant I ended up having surgery unintubated - increasing the risk substantially. Unfortunately, I couldn't have nerve blocks for the surgery as the damage to the nerves was so bad that they didn't work.
Whilst the bony injuries have now healed, the damage to the nerves is permanent. I've been left with nerve impairment in both arms and I'm in constant pain low level pain, which gets worse if there is any pressure on my neck. I also have problems with motor control in my right arm.
The consultant orthopaedic surgeon and the consultant neurologist who treated my injuries, and the specialist consultant orthopaedic surgeon and consultant neurologist who examined me for the the legal case, all agree that the helmet I was wearing made my injuries worse - in fact it made me suffer injuries that in all probability I would have avoided if I hadn't been wearing a helmet. They were so confident in their opinion that they included in the reports to the court.
OK - my case is only one case... but I wasn't the only case that the medics treating me had seen. Let's just say they were equivocal about the benefits of helmets.