I was just looking through the British and american news channels (trying to see our revolution from their perspective) when I suddenly heard Hammond's name. Best wishes to him.
Lower back pain... doesn't sound good. If his spine is damaged, it could be anything from a minor pain to complete immobility.
If we are to send a letter to him (with a couple sentences from everyone), I think we should include a national flag next to each poster, which would probably help in making Hammond and others realise how widespread TG fans are.