Anatomical Kinesiology: Skeletal Muscles and Contractions

Vocabulary flashcards defining muscle roles, properties, structural fiber arrangements, and types of contractions from the Kinesiology lecture notes.

Concentric contraction

A type of contraction where the muscle shortens while contracting, such as during the upward phase of a bicep curl.

Eccentric contraction

A type of contraction where the muscle lengthens while contracting, such as lowering a dumbbell down.

Agonist muscle

The prime mover muscle primarily responsible for causing the main movement, such as the biceps during a bicep curl.

Antagonist muscle

A muscle that works against the main movement, relaxing to allow the movement to occur, such as the triceps during a bicep curl.

Synergist muscle

A muscle that assists the agonist by guiding movement and preventing extraneous motions, such as the brachialis during a bicep curl.

Stabilizer muscle

A muscle that holds a body part or joint steady while another muscle creates movement, such as the shoulder muscles during a bicep curl.

Neutralizer muscle

A muscle that contracts to stop unwanted movement, such as preventing forearm rotation so a movement stays controlled during a bicep curl.

Force couples

An action occurring when two or more forces pull in different directions to create and control movement, such as different shoulder muscles working together when shooting a basketball.

Irritability / Excitability

The ability of a muscle cell to respond to a stimulus, leading to activation and contraction.

Contractibility

The ability of a muscle to contract and develop an internal force against resistance when stimulated.

Extensibility

The ability for a muscle to be passively stretched beyond its normal resting length.

Elasticity

The ability of a muscle to return to its original length following stretching.

Parallel muscles

A category of muscle fiber arrangement that generally allows for a greater range of motion.

Flat muscles

A type of parallel muscle that allows force to extend over a broad area, such as the abs.

Fusiform muscles

A type of parallel muscle that focuses power onto a small bony target, such as the biceps.

Strap muscles

A type of parallel muscle with strap-like fiber arrangements, such as the sartorius.

Radiate muscles

A type of parallel muscle where fibers spread out from a narrow attachment point to a wider attachment area, such as the pectoralis.

Sphincter muscles

A type of parallel muscle that surrounds openings and closes them upon contraction, such as the orbicularis oris in the mouth area.

Pennate muscles

A category of muscle fiber arrangement with shorter fibers running obliquely, where unipennate and bipennate arrangements produce the strongest contractions.

Unipennate muscles

A type of pennate muscle where fibers run obliquely on one side of the tendon only.

Bipennate muscles

A type of pennate muscle where fibers run obliquely on both sides from a central tendon.

Multipinnate muscles

A type of pennate muscle with several tendons containing fibers that run diagonally between them.

Origin

The attachment point of a muscle located on the least movable bone, such as the scapula for the biceps brachii.

Insertion

The attachment point of a muscle located on the most movable bone, such as the radius for the biceps brachii.

Isometric contraction

A contraction where the muscle contracts but does not change length, producing no movement at the joint, such as pushing on an unmovable wall.

Isotonic contraction

A contraction where the muscle contracts and changes length, resulting in joint movement, such as lifting a dumbbell.