BlueEyed Lady, it looks to me that you've established a negative cycle re: diaper changes. Your DS expects a negative experience, tenses, has a negative experience and on it goes.
Would it help to do "dry" runs?
(I crack myself up.
) Practice the hold playfully when you are NOT in need of changing the diaper. Tickle him, use his foot as a telephone (my dc love that!), sing a song about the different parts of his body a la "Aluetta" or Head and Shoulders. Help him move in to a happier space so that when you do need to change his diaper, he can expect a happier experience, and relax instead of tensing for the inevitable fight.
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sister to Blue-EyedLady since forever
wife to Trooper (Wounded Warrior) 3-98
Graphics designing sapphiremama to EBug 2-04, ABoo 2-06, and Goggle 8-09