Basic information about Anatomy and Physiology of Body Movement

Anatomy and Physiology of Body Movement

The knowledge of anatomy and physiology is an essential basis for healthful living.  It is equally essential in understanding the pathological state of the body.  Before one can bring sick individuals back to normal anatomically, and physically, this subject is very important.  Anatomy and Physiology is also one of the basic subjects in medicine and allied courses: like nursing, medical-technology, midwifery, etc.

Anatomy is the study of different structures of the plants and its parts.  The two principal methods of this science are:

a) Gross Anatomy – the dissected body and its parts are seen by the naked eye (i.e. without the aid of the microscope.

b) Minute Anatomy or Histology – the tissues and organs are examined with the aid of the microscope.

Posture is “the relationship of the various parts of the body at rest or in any phase of activity.” Posture is considered to be good when proper placed upon the muscles, ligaments, and joints in maintaining balance.

Body movements are made principally by means of the skeleton, the muscles and the nervous system.  The skeleton is made up of bones, two of the functions of which are to provide an attachment for muscles and ligaments and to act as levers.  The proximal end of a skeletal muscle is attached to the less movable bone; this point of attachment is called the origin of the muscle.  The distal end of the muscle is attached to a freely movable bone; this point is called the insertion of the muscle.

The muscles, which are composed of fibers, contract to produce motion. Skeletal muscles are continuously in slight contraction, or tonus.  General good health, good nutrition, alternate rest and activity help to maintain the extensibility of muscle without stretching and thus affect muscle tone favorably.

The bones of the body also act as levers, and in body mechanics the principle of leverage is frequently used.  A lever is “a rigid bar which revolves about a fixed point, the fulcrum of the lever is a fixed point.  The resistance arm is the area between the resistance or weight and the fulcrum.  The effort arm is the area between the point at which the energy is applied and the fulcrum.  The levers of the body vary in shape and even in rigidity.  The principles of leverage are applied in the procedures described.

The spinal nerves are directly involved in trunk and limb movements.  Each spinal nerve has an anterior and a posterior root.  The anterior root constructs impulses to the muscles from the central nervous system; the posterior root conducts impulses from the sensory receptors to the central nervous system.

Body movement is also affected by gravity, the force which pulls all objects toward the center of the earth.  Most movement, then, involves pulling to at least some extent against the force of gravity.  To describe the movement of the body parts, term such as abduction, adduction, flexion, and extension are used.  Abduction refers to movement away from the central axis of the body.  Adduction refers to movement toward the axis of the body. Flexion is the act of bending; extension can be described as the act of straightening.  Illustrations of abduction, adduction, flexion and extension are given later in the chapter.

Body movements can be described relative to three planes; the sagittal, frontal and transverse.  When the body is in the anatomical position, the sagittal plane divides in into right and left sections, the frontal plane into dorsal and ventral sections and the transverse plane into upper and lower sections.