Where are the crossbridges involved in muscle contraction are located in?

Crossbridges involved in muscle contraction are located in the sarcomeres of muscle fibers. Specifically, they form between the myosin heads and the actin filaments during the contraction process. When a muscle is stimulated, these crossbridges facilitate the sliding of actin over myosin, leading to muscle shortening and contraction. This interaction is a key component of the sliding filament theory of muscle contraction.