Stretching exercises can help extend your range of motion. How?

To understand, the Harvard Medical School, HEALTHbeat breaks down the structures and inner workings to explain how they can help — or hinder — a joint's flexibility:

  • Joints are the junctions that link bones together. The architecture of each joint — that is, whether its structure is a hinge, pivot, or ball-in-socket — determines how the bones can move.
     
  • Muscles surround joints and provide the energy used to move them. The amount of tension in the muscles surrounding a joint is a key factor in how big of a range of motion that joint can achieve. Muscle tension can be affected both by passive factors, such as tissue scarring or your habitual posture, and by active factors, such as involuntary muscle spasms or purposeful muscle contractions.
  • Tendons are flexible cords of strong tissue that connect muscles to bones and make movement possible. When a joint moves, energy from the muscles is transferred into the tendons, which tug on the bones.
     
  • Ligaments are tough, fibrous bands of tissue that bind bone to bone, or bone to cartilage, at a joint. An example is the anterior cruciate ligament (ACL), one of five ligaments that together control the movements of the knee. Among other things, the ACL keeps the knee joint from rotating too far. 
When you stretch, you’re working muscles and tendons rather than ligaments. Ligaments are not supposed to be elastic. An overly stretchy ligament wouldn’t provide the stability and support needed for a safe range of movement.
— Harvard Health Publications, HEALTHbeat, July 3, 2016

Source: http://www.health.harvard.edu; Harvard Health Publications, July 3, 2016