Careless behavior causes most pump-jack accidents. OSHA insists that pump poles must be spaced less than 10 feet apart when wooden planks are used. Seldom are the prescribed guardrails, midrails, endrails and toeboards installed on residential applications. Poles must be braced at the top, bottom and every 10-feet along the height of the pole. And the plank ends must be secured to the pump foot.
Poles are a weak link in pump staging.
OSHA regulations specify that spliced 2x4's must develop the full strength of the unjoined member. Good luck here. The only way to do that is by attaching a long plate to the outside surface of the pole - An unlikely feature on most pump poles. Improper materials and inadequate joint design cause many pole failures. But lateral buckling of joints is easily avoided.