IMO - don't ever lean if you can help it - get the distance right.
Regarding "too hard" - that's a tricky one...... whilst you don't "necessarily" want to "club" your training partner into submision Funakoshi tells us to treat each block as and attack with the intent to destroy our attacker.....
...so I guess then that we need to be able to deliver the blocks in a training environment with proper form and "enough" power/deflection to creat the opening to counterattack without damaging the attacking limb.
BTW - I don't consider bruiising as excessive force.... and in fact when I'm successfully blocked I tend to try harder with the attack next time irrespective of the force of the block.....
So technique then - sotu-ude-uke - outside to inside block. Assuming Kihon Basic Blocking here - Blocking hand High (secondary) and primary blocking/striking hand fully thrust to the front (helps deter the attacjker somewhat if done forcefully as well as adding to the block)- body/hips should be in shomen/square-on position.
Starting with the hips pull the forward hand back and simultaneously rotate and drop the the raised arm to block the attacking limb.
Having the blocking arm high and dropping it down (think like cutting with a katana) to meet the attacking limb is important - as opposed to just having the fist shoulder high throughout and simplys rotating in a circular arc - the downward action combined with the circular action shoudl help make the block more effec tive with less power as it will disrupt the attacking limb in two axes - most limbs when striking are stronger in one axis than the other so attacking it in both "vectors" is advantageous.
Now - where to strike/contact the attacking limb ? - the obvious answer is "as far along the limb from the attackers body as practicale" - and this works for me.
In practice this means just bufore or on the wrist joint for a punch attack - any further and you risk missing completely if you time it wrong and any earlier and you lose leverage.
Last point - try to keep the "blocking hand/wrist" "in counter tension" (i.e. if blocking with left hand the raised hand/wrist shoudl start off rotated/twisted/tensioned counter clockwise) throughout the blocvking motion - ideally until you contact the attacking limb - then twist/snap into fully rotated position (clockwise in the left hand blocking example).
Phew ! (Flameproof Suit Engaged
)
So now you know "how" to perform the block - you now need the experience to judge how much force to put into te block for each opponent depending on how strongly they attack - practice practice practice.
I suspect from what you've said that a big part of your problem is "distance/Mai-ai" - get the distabnce correct - don't lean - don't herk the block and try and use strength - rely on your technique to make your blocks better.
Jim
