Re: Posture in Iwama Aikido
A student of Saito Sensei's, Tony Sargeant, used to refer to the "Iwama pelvic tilt", though he wasn't sure whether this derived directly from the example of O-Sensei or from Saito's physical condition.
I find it striking that the characteristic stance in the Iwama tradition is very different from the kamae adopted in the Yoshinkan, which is much more square and tends to a pronounced bend in the front knee. I recall reading an article where Gozo Shioda gently ridiculed the posture of students at Iwama, as he felt that Saito Sensei (for whom I believe he held a deep respect) was restricted in his body movement by his long-term injuries, but his able-bodied students tried to copy him exactly.
I have seen some "Iwama-style" people standing in what seems to me an exaggerated caricature of Saito Sensei's posture, with the front leg almost straight and the weight towards the rear, and often with the backside sticking out.
Mind you, I have seen this amplification of distinctive attributions in the Ki Society too: third-generation students often look much more different in their posture and movements from what would be considered "normal" in the Aikikai than Tohei Sensei ever did.