There are obvious differences in how we load muscles and joints between the hack squat and the leg press. Both of these are very effective pieces of kit, but what’s not obvious is how the loading parameters would be best be complemented by internal cueing and internal stability.
When using machines, a novice lifter might forget about stabilizing their joints internally, and as a consequence just let the passive, external stability of the machine in which their using provide them with stability. When a lifter just relies on the stability of the machine they are using to stabilize, they leave a huge opportunity to generate force unrealize, and they take a ton of tension off the table.
When your body feels stable it allows your nervous system to exert as much force as possible, when it feels unstable, it governs your force output. Simply put, more stability, more force. Less stability, less force. So when you’re using a machine, cueing internal stability as well as relying on external stability will allow for the greatest amount of force output, and as a consequence, the greatest amount of tension through the muscles.
When we think about training machines for multi-joint compound exercises, we need to think about their free weight counterpart that most closely emulates the mechanics of this machine.
The leg press replicates more of a back squat pattern of knees hips and back, so it should be internally stabilized as such, by using more lat engagement to create a stable low back and the greatest amount of output. Whereas the hack squat replicates a front squat movement, which will require more core “engagement” and a more neutral pelvis in order to stay stable and challenge the quads.
Making sure we create an internally stable environment that best complements the machines we are using will help us get the greatest amount out of each set, each rep.
Stay Strong,
Jordan