<unk> : A sarcomere in relaxed (above) and contracted (below) positions The<unk>  explains the mechanism of muscle contraction based on muscle proteins that slide past each other to generate movement. According to the<unk> , the myosin (thick<unk> s) of muscle fibers slide past the actin (thin<unk> s) during muscle contraction, while the two groups of<unk> s remain at relatively constant length. The<unk>  was independently introduced in 1954 by two research teams, one consisting of Andrew Huxley and Rolf Niedergerke from the University of Cambridge, and the other consisting of Hugh Huxley and Jean Hanson from the Massachusetts Institute of Technology. It was originally conceived by Hugh Huxley in 1953. Andrew Huxley and Niedergerke introduced it as a "very attractive" hypothesis. Before the 1950s there were several competing<unk> es on muscle contraction, including electrical attraction, protein folding, and protein modification. The novel<unk>  directly introduced a new concept called cross-bridge<unk>  (classically swinging cross-bridge, now mostly referred to as (cross-bridge cycle) which explains the molecular mechanism of<unk><unk> . Cross-bridge<unk>  states that actin and myosin form a protein complex (classically called actomyosin) by attachment of myosin head on the actin<unk> , thereby forming a sort of cross-bridge between the two<unk> s. The<unk>  is a widely accepted explanation of the mechanism that underlies muscle contraction.
Sliding filament theory
Functional matrix hypothesis
Activation-synthesis hypothesis
Kindling model
Reed–Frost model
Lipid hypothesis
Bidomain model
Wilson–Cowan model