A great alternative to the barbells and dumbells are to be found in almost any gym. Cables.
An example of using these is to substitute for bench presses, which are very hard on the shoulders.
Use a reasonable weight that you can do 10 reps with. Set the cables at chest height or a little above, and pull in to the center of your chest while crossing your hands when they meet.
This is a fine pectoral builder.
You can do overhead presses, curls, rowing, shoulder raises, and more with cables.
Try this to get out of any rut you might be in with your workout.
Change is good.