The connection between the heads and the is called -ing.

Hi, you've asked an incomplete question. I inferred you need a brief about the Sliding Filament Theory.

Sliding Filament Theory

Explanation:

Remember, the term filament refers to a long thread-like chain of proteins that aid in muscle contraction.

The Sliding Filament Theory is a theory about how muscles contract and the resulting effects of such movements.

For example, the theory states that when thick filaments of muscle fibers undergo a sliding movement that past the other type of filament; the thin filaments during muscle contraction, they both would still have the same length.