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Other/Mixed Q about contraction types

Other strength modalities (e.g., Clubs), mixed strength modalities (e.g., combined kettlebell and barbell), other goals (flexibility)


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I have a two-part question - mostly theoryish, not practical - proceed at risk of boredom if that ain't your jam.
Part 1. I'm looking to refresh my memory about a contraction type I once read about and can no longer find a reference to. There are the big three - concentric, eccentric, and isometric. Also, Isotonic seems to be a movement category that describes the combination of a concentric and eccentric movement - i.e. up and down = isotonic. All of this is presented in the simplistic format of a single joint exercise. Fine, it facilitates understanding. But what about a movement that acts on a muscle from both ends - a multi-joint (compound) movement? So I'm looking for the term for when a muscle shortens at one end and lengthens at the other remaining relatively unchanged in length during the movement of two joints. Like what a chin-up does to a bicep or a squat does to a hamstring.
If I knew the term, talking about part 2 would be a little easier:
Part 2. I have generally accepted that compound exercises are more worthy of my time. However, if a hamstring in a squat lengthens at the hip and shortens at the knee as the body lowers, since its overall length remains less changed during the movement (compared to a SLDL or Goodmorning), does that mean less contraction? Is the action at the hip somehow more important than the action at the knee? Is it a contraction that is both concentric and eccentric at the same time during the lowering and raising of the weight? Or the nature of a double joint movement means more weight is generally used so any muscle involved gets more loading?

Note that I'm not asking whether or not I should be doing bicep curls vs chin-ups or any of these body-building hamstring movements at all. Just wanted your thoughts on how single joint exercises seem to have a more predictable (reliable?, plannable?) action of concentric-up-shorten, eccentric-down-lengthen, whereas a double joint is doing something more complex in that the muscle length changes little/less, yet it is effective.
Co-contractions and muscle stuff

Isotonic > Isometric > Isokinetic

(another way to think of Isokinetic is speed controlled with resistance variable where isotonic is resistance constant and speed variable)

Lombard's Paradox (co-contraction info)
Lombard's Paradox: A unique look at the cooperation of the quadriceps and hamstrings — The Gait Guys
The functional roles of the hamstrings and quadriceps during cycling: Lombard's Paradox revisited - PubMed

Long story you compound movements and let the body figure it out and have a mix of the two main types (isotonic and isometric since isokenetic require special machines).
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