So I understand how upper arm position relative to shoulder can put our biceps / triceps into a shortened or lengthened state and the same for upper leg to hip for hamstrings / quads. How would one alter the muscle length for say a lat or pec?
You can only alter resistance curve on exercises on those muscles. With legs and arms, long head of the bicebs is connected to the shoulder which makes shortening/lenghtening possible. With chest for example there is only one way you can shorten and lenghteng spesific divison of a pec most. You see all the pec divisons connect to shoulder directly but with biceb its only the long head which connects to the shoulder.
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