Here is a beginners resource which sets out to explain some basic structure, joints, muscles and terminology, which otherwise may leave the new starter confused. The Muscles The human body had 600 muscles, which are used to facilitate movement, posture, production of heat and energy and core stabilisation. There are three types of muscle tissue. Cardiac Smooth Skeletal Cardiac muscle forms the heart walls, while smooth muscle is found in the walls of internal organs such as the stomach and blood vessels. Both of these muscle types are activated involuntarily by the autonomic nervous and hormonal systems. Skeletal muscle forms the bulk of the muscles we commonly know. Muscles attach to the bones via tendons. The attachement points are known as the origin and insertion, and to work a muscle it need to be contracted between those points. Here you can see the bicep originates toward the shoulder and inserts down toward the elbow. The origin is usually the least moveable point, acting as the anchor, while the insertion is usually the most moveable part and can be drawn toward the origin. In order to develop a balanced (and safe) exercise programme it is important to understand the origin and insertion points of the muscles, what movement they cause and what joint(s) they cross. The Skeleton Our skeleton consists of bones, ligaments (which join bone to bone) and joints. The primary role of the skeleton is to support the muscles, protect the soft tissue and internal organs, storage of surplus minerals and the formation of red blood cells in the bone marrow of long bones. The word skeleton originates from a Greek word meaning dried up. Children are born with 350 bones, which fuse as they grow, forming single bones. Adults have 206 bones. The nervous system interacts with the muscles to facilitate the contraction and relaxation of muscles, while the articular system of joints allows the levers of the body to move. Anatomical Planes The body is divided into three imaginary planes. Median - Sagittal Plane Transverse - Horizontal Plane Coronal - Frontal Plane Why is knowing this necessary? Understanding how a joint moves is important in analyzing how an exercise works. Here are some examples, in addition to an explanation of movement terms: - Movement - Flexion Plane - Sagittal Description - Decreasing the angle between the two structures Example - Standing barbell curl (This becomes an extension when doing the downward phase of this movement) Movement - Elevation Plane - Coronal Description - Movement of the scapula Example - Shoulder shrugs Movement - Abduction Plane - Transverse Description - Movement of scapula away from the spine Example - Seated low cable pully row Movement - Circumduction Plane - All planes Description - Complete circular movements (shoulder or hip) Example - Swinging the arms in circles Movements usually occur in pairs (as shown in the example of the barbell curl). Typical pairs are: - Flexion and extension Abduction and adduction Internal and external rotation Protraction and retraction Glossary of terms Abduction - Movement of a limb away from the centre line. Adduction - Movement of a limb toward the midline of the body. Agonist - A muscle that causes motion. Antagonist - A muscle that moves the joint opposite to the movement produced by the agonist. Compound exercise - Involving two or more joint movements. Concentric - A muscle contraction resulting in it shortening. Eccentric - The contraction of a muscle during its lengthening. Extension - Straightening, extending or opening a joint, giving an increased angle between the two bones. Flexion - Bending a joint, giving a decrease in the angle. Isolated - An exercise that involves on joint movement. Isometric - Contracting a muscle without significant movement. Pronation - Internal rotation of of the foot or forearm. ROM - Range of motion. Supination - External rotation of the foot or forearm (results in the hand or foot facing upwards). Resource: Anatomy for strength and fitness training by Mark Vella.