Correct body alignment is the optimum position of the human skeletal structure in which the body is perfectly balanced. 

Focus on Nasal inhalation (In through the nose) and unforced exhale. Deep diaphragmatic (Belly) breathing. 

The ability to control movement through a range of motion

The ability to maintain control of joint movement or position by coordinating actions of surrounding tissues and the neuromuscular system

The ability to carry out work against a resistance. Strength is the maximal force you can apply against a load.