Re: Aikido against strong people...
Tohei had to modify his Aikido to deal with 300lb Samoans, a number of other shihans have said similar things. Pretty sure more force was not the answer, rather more finesse. Kuzushi mitigates strong attacks, kuzushi prevents the strong from gathering and projecting their power, kuzushi makes gravity and their mass your allies. If you are locking to create pain compliance, rather than control, then you are dependent on uke’s pain tolerance and the robustness of their joints. If you are controlling their balance and structure, it takes very little to make them fall down and go boom. A little atemi never hurts if uke has locked down and grounded. Using the ground is a core skill, drilling to move a well grounded uke has value, standing like an immovable lump of granite when nage is trying to learn something is both dickish and of questionable martial value or intent. If you are unable to evolve a response to Johnny vice gripper, consider that you may be putting too much emphasis, effort, and force at the point of contact and not moving your body to compel your course of action.