If you've only worked there for one month, normally the boss can dismiss you for no reason given, (provided he gives you notice).
However yours is a different situation - you have been injured at work. Much depends on the circumstances as to what extent you were injured due to your own actions - however employeers have a duty of care, and this didn't happen in your case.
If you feel that the accident was largely due to the employer failing in its duty of car, you are in a stronger position than, say, if you broke your arm playing football on Saturday with your mates.
Are you being paid sickness benefit?