Are there drills/exercises to build flexibility in the arms? I find myself tapping to kimuras/americanas that don't even seem that tight. My arms are very inflexible in that position: imagine laying on your back with your elbows bent at 90 degrees. If I pull my hands back towards my head/shoulders (like an americana from mount) I can't touch my knuckles to the mat. Would it be a good idea to let training partners put me in "soft" americanas to stretch the muscles or get the arms used to being in that position? I am wondering if that would stretch a muscle and make it more flexible, or if that would cause joint damage.
Are there any other ideas to build flexibility in this area?
Are there any other ideas to build flexibility in this area?