Much to my frustration, my arm/elbow rolls inward towards the end of each movement when doing tricep extension exercises. Is this to be expected, or is there something I can do to prevent this?
To elaborate: On a seated machine, the resting position has the arms curled & inside of the elbow pointing towards the ceiling, parallel to each other. As I extend/straighten my arm against the weight, during the last ~1/3 of the movement, my upper arm & elbow rotate such that the inside of the elbows start to point towards one another. Total rotation probably doesn't exceed 30°, but i can feel how the loading in my tricep shifts as the arm rotates.