Those strength shoes remind me... At St. Joseph-Notre Dame HS in Alameda California, there is a pair of truly ancient jump-trainers that had been invented by Frank LaPorte, hoops coach at St. Joe's during the 80's and 90's... I know about this because I saw Jason Kidd play there for all four of his incredibly dominant years.
Wish I could find a pic... They were soles you attached to your shoes like the old skate-key roller skates. The were spring loaded, heels down, toes raised. Looked like they were made of steel with rubber soles on the bottom... Also looked dangerous to use. Coach LaPorte was born in 1933, so maybe these things were invented sometime in the late 50's?? I think LaPorte started coaching in 1956, so that's probably a good ballpark date. These contraptions looked like they'd been sitting idle in the trophy case forever.
I guess you could say they were the steampunk version of the shoes above. Now THAT is OLD-school!!