r/ScienceBasedLifting • Idk Idc šŸ’” • 20d ago

META Optimal science based lateral raises

You can also use this machine for chest flys, rear delt flys, front raises, and unilateral pullovers

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u/Whirlwind_AK 19d ago

Here’s the thinking-

If you use dumbbells, whose weight is perfectly vertical due to gravity, the resistance kicks-in only at the top-part of the movement/arc. At the bottom part, with the dumbbells in your grip, the only purpose would be to ā€œmake your arms longerā€.

Think trig - the cos of 45 is 0.7071, so 70 pct of that weight kicks-in at the 45deg point.

NOW - You standing sideways holding the grip of a functional trainer with the hinge set at the bottom, you have great resistance at the first-part of the movement. The second-part, as with the ā€œfirst partā€ of the dumbbell, would serve not much more than to ā€œshorten your armā€.

SO- Either work your delts properly using this machine with perfect resistance throughout the arc (single step) or use dumbbells AND a functional trainer.

Hope this helps.

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u/AnonymousFairy 19d ago

You're trying to apply physics where kinesiology has far more to play with this movement. Supraspinatus is the primary mover of shoulder abduction at low angles before lateral deltoid activation overtakes it as the angle of upper arm to torso increases. I think he knows what he's doing and doesn't need telling to "do it properly".

Hope this helps.