Your biceps muscle is attached with tendons to the top of your humerus and to the end of your radius, near your elbow. what would happen if the biceps were attached to the top and bottom of your humerus instead? you would not be able to pull your forearm up toward your shoulder. your humerus would lengthen and shorten each time your biceps contracted. you would be able to pull your forearm toward your shoulder with more force. your triceps muscle would make your arm bend backward when it contracted.