In science, mechanical energy is the sum of potential energy and kinetic energy. It is the energy associated with the motion and position of an object.The law of conservation of mechanical energy states that in an isolated system that is only subject to conservative forces the mechanical energy is constant.n science, mechanical energy is the sum of potential energy and kinetic energy. It is the energy associated with the motion and position of an object.
As with the standing shin stretch, the cross-over stretch is well-suited for pre- and post-running stretching. You can perform this stretch with or without shoes. Start standing with your feet together. Cross your right leg in front of your left leg and place the tops of your pointed right toes on the ground.
Hold the stretch for 10 to 30 seconds, then repeat. 1  Extend one arm in front of you at shoulder height. 2  Keep your palm down, facing the floor. 3  Release your wrist so that your fingers point downward. 4  With your free hand, gently grasp your fingers and pull them back toward your body.  Hold for 10 to 30 seconds.