Kinesiology Terminology and Osteokinematics

Active movement at a joint is caused by muscular contraction.

Passive movement at a joint is caused by muscular contraction.

Osteokinematics describes the motion of bones relative to the three cardinal planes of the body: Sagittal, Frontal, and Horizontal.

Degrees of Freedom in a joint refer to the number of permitted directions of linear motion allowed.

Greater degree of freedom in a joint system implies greater stability.

Accessory motion within a joint structure is considered angular movement.

Excessive translation of a bone relative to the joint may indicate normal joint health.

A significant reduction in translation in a joint may indicate pathologic stiffness.

The size of the motor unit does not influence the order in which it is recruited by the nervous system.

The process of modulating the force produced by muscle fibers based on the discharge rate of action potentials is known as rate coding.

If a muscle fiber relaxes completely before the subsequent action potential, the second twitch generates a force higher than the first twitch.

Muscle twitches summate and generate a greater peak force if the next action potential arrives after the preceding twitch has relaxed.

Muscle fibers innervated by small motor units classified as S have fast twitch responses.

SO fibers are characterized by their slow and oxidative histochemical profile.

Soleus muscle fibers are prone to fatigue quickly.

The Henneman Size Principle allows for sudden and uncontrolled increments in force development.

First Class Levers have the Axis of Rotation between two opposing levers.

In a Second Class Lever, the muscle possesses less leverage than the External Force.

Third Class Levers are the most efficient type of musculoskeletal lever.

Mechanical Advantage for 1st Class Levers is always less than 1.

In a Second Class Lever, the Axis of Rotation is at one end of a bone.

The musculoskeletal system functions as the force producers are bones.

Mechanical Advantage is calculated as the ratio of Internal Moment Arm to External Moment Arm.

Third Class Levers are the least common type of musculoskeletal lever.

3rd Class Levers always have an MA greater than 1.

The human body contains over 200 skeletal muscles.

Muscles mainly serve a stability function by controlling the movement of a bony lever around a joint axis.

When a joint is in a close-packed position, the stability role of the muscles is increased.

Skeletal muscles are responsible for heat production during cold stress.

Muscle forces have only rotatory components and no translatory components.

Third-class levers are considered efficient due to their mechanical advantage of greater than 1.

The main function of muscles includes providing postural support.

Muscles with large physiologic cross sections can produce more tension than muscles with small cross sections.

Passive insufficiency occurs when an inactive muscle is of insufficient length to permit a full range of motion at all joints simultaneously.

Increasing the number of motor units firing can increase tension in a muscle.

Muscle fibers innervated by small motor units classified as F have fast twitch responses.

Passive insufficiency can actually pull the bony lever in the direction of the passive muscle pull.

Active movement at a joint is caused by muscular relaxation.

Third-class levers are considered efficient due to their mechanical advantage being greater than 1.

The Henneman Size Principle allows for sudden and uncontrolled increments in force development.

Passive movement at a joint is caused by muscular contraction.