You have sprained your wrist. You will not be able to hold weapons until you treat it, or it heals over time.
In-game description

A sprained wrist may be caused by a fall, uneven terrain or an animal attack. It is possible to sprain both wrists at once, even in the same event. While at least one affliction is possessed by the player, the player cannot use the hunting rifle, distress pistol, Stone or the survival bow.

  • A sprained wrist is treated by consuming either 2 x Painkillers, 1 x Rose hip tea or resting for 2 cumulative hours.
  • It will not pass on its own but will be cured by simply 2 total hours of rest.
  • It may be possible to sprain your wrist while traversing dangerous terrain or when throwing stones (needs confirmation)
Positive Fatigue reducedImproved restWarming upWell Fed
Injury Blood lossBroken ribsBruisingBurnsFrostbiteLacerationSprained ankleSprained wrist
Disease Cabin feverDysenteryFood poisoningHypothermiaInfectionIntestinal parasites