An employee was walking along the catwalk while filling a mushroom growing room and monitoring the operation of the net puller. The employee observed a sideboard of the mushroom growing bed moving at the front of the room and proceeded to investigate. While approaching the area, the employee slipped on compost and instinctively reached out to stabilize himself by grabbing onto the bed frame supporting the net puller. The employee's right hand and arm became entangled in moving ropes in the net puller, resulting in arm and wrist fractures and a hand laceration.