Biomechanics of Resistance Exercise Flashcards
Anatomy
study of components that make up the musculoskeletal “machine”
Biomechanics
focuses on mechanisms through which these components interact to create movement
Axial Skeleton
skull, vertebral column, ribs and sternum
Appendicular Skeleton
shoulder girdles, bones of arms and wrists, and hands, pelvic girdle, bones of legs, ankles, and feet
Joint
junctions of bones
Fibrous Joints
allows virtually no movement (sutures of skull)
Cartilaginous Joint
allow limited movement (intervertebral disks)
Synovial Joint
allows considerable movement (elbows and knees)
Hyaline Cartilage
smooth covering on ends of articulating bones
Synovial Fluid
fills entire joint capsule
Uniaxial Joint
operate as hinges, rotating about only one axis (elbow)
Biaxial Joint
allow movement about two perpendicular axes (ankle and wrists)
Multiaxial Joints
allow movement about all three perpendicular axes that define space (shoulder and hip)
Vertebral Column
made up of several vertebral bones separated by flexible disks that allow movement to occur
Cervical Vertebrae
7 vertebrae in neck region
Thoracic Vertebrae
12 vertebrae in middle to upper back
Lumbar Vertebrae
5 vertebrae in lower back
Sacral Vertebrae
5 vertebrae which are fused together and make up rear part of pelvis
Coccygeal Vertebrae
3-5 vertebrae which form a kind of vestigial internal tail extending downward from the pelvis
Origin
traditionally, the proximal attachment
Proximal
toward the center of the body
Insertion
traditionally, the distal attachment
Distal
away from the center of the body
Fleshy Attachment
most often found at the proximal end of a muscle; muscle fibers are directly affixed to the bone, usually over a wide area
Tendon
type of fiberous attachment
Agonist
muscle most directly involved in bringing about a movement; prime mover
Antagonist
a muscle that can slow down or stop the movement
Synergist
a muscle that assist indirectly in a movement
Lever
a rigid or semirigidbody that, when subjected to a force whose line of action does not pass through its pivot point, exerts force on any object impeding its tendency to rotate
Fulcrum
pivot point of a lever
Moment Arm
aka force arm, lever arm, torque arm; perpendicular distance from the line of action to the force of the fulcrum. The line of action of a force is an infinitely long line passing through the point of aplication of the force, oriented in the direction in which the force is exerted
Torque
aka moment; the degree to which a force tends to rotate an object about a specified fulcrum. It is defined quantitatively as the magnitude of a force times the length of its moment arm
Muscle Force
force generated by biomechanical activity, or the stretching of noncontractile tissue, that tends to draw the opposite ends of a muscle toward each other
Resistive Force
force generated by a source external to the body (gravity, inertia, friction) that acts contrary to muscle force
Mechanical Advantage
the ratio of the moment arm through which an applied force acts to that through a resistive force acts. For there to be a state of equilibrium between the applied and resistive torques, the product of the muscle force and the moment arm through which it acts must be equal to the product of the resistive force and the moment arm through which it acts. Therefore, a mechanical advantage greater than 1.0 allows the applied (muscle) force to be less than a restrictive force to produce an equal amount of torque. A mechanical advantage of less than 1.0 is a disadvantage in the common sense of the term.
First-Class Lever
a lever for which the muscle force and resistive force act on opposite sides of the fulcrum
