🦴↪️🦴

#joint flexion #joint bending #articulation #bone movement #hinge joint

🔗↔️↪️

#hinge joint #pivot point #linkage

🦵↔️

#knee bend #leg movement #hinge joint #flexion #extension #range of motion

↪🪞↫

#foldable mechanism #hinge joint #collapsible design #folding action #compact design