For much of its history, the cello was played without an endpin. Musicians had to grip the heavy instrument between their calves to keep it steady while playing. This restricted the player's movement and made certain technical passages difficult. The modern endpin—the metal rod that supports the cello on the floor—became standardized in the mid-19th century, largely credited to the influence of French cellist Adrien-François Servais. The endpin allowed the cello to be held at a more consistent angle and freed the legs, which in turn allowed cellists to reach higher positions on the fingerboard more easily. Today, some cellists use a 'Strad' or 'Tortelier' endpin, which is curved to allow the cello to sit more horizontally, bringing the weight of the instrument closer to the player's body for better ergonomic balance.