I don’t know, but full depth back squats or front squats make me slower and stiff. But squatting heavy 1/3 of the way down made me faster. For sprints and running that is. I know sometimes people scuff at not squatting parallel or atg but if it doesn’t work for some then it doesn’t work.
The sheer forces on the knees of Machine Hack Squats are off the charts (especially when performed staying on the forefoot/toes). Cant believe a therapist is recommending them. And they are completely devoid of the intermuscular balance/coordination elements of Front/Zercher Squats that provides their real-world strength, athleticism and proprioceptive benefits.
Hack squats are not dangerous unless done irresponsibly (high load relative to strength levels. The stress they place on the knees makes the connective tissues stronger and more resilient to larger ranges of motion. Free weight squats will not make you an elite athlete. They are both just tools to give you bigger and stronger quads, glutes and adductors, and mitigate injury risk.
