Kaley Cuoco missed filming two episodes of season four because of a broken leg.
You may have missed Penny in season four after not seeing her in two consecutive episodes. This is because the actress, who’s actually an avid equestrian, fell off her horse during her riding lesson and had to miss the filming for two episodes in order for her to recover. She later went on The Ellen Show and detailed the accident, sharing that the horse actually stepped on her leg and heard her bones crack. She only realized it was broken when she saw that her foot was facing her. Ack!