[Rob_Maate]

Lol that's so prone to bugs.

Just create a variable:

pawn Код:

new bool:IsPlayerDowned[MAX_PLAYERS];

Reset it in OnPlayerConnect (so there's no issues between new players joining with old in-use ID's)

pawn Код:

IsPlayerDowned[playerid] = false;

Finally, in your OnPlayerUpdate:

pawn Код:

public OnPlayerUpdate(playerid)
{
      new Float:phealth;
      GetPlayerHealth(playerid,phealth);
      if(phealth <= 50 && IsPlayerDowned[playerid] = false)
      {
          //apply the fall animation 
          TogglePlayerControllable(playerid,0);
          SendClientMessage(playerid,-1,"You have falled to the ground because you are injured");
          IsPlayerDowned[playerid] = true;
      }
      return 1;
}

When you want him to stand up again, just clear animations, set his HP to above 50 and set IsPlayerDowned[playerid] to false.