KINE Chapter 2

Parallel Muscle Fibers

arranged parallel to length of muscle, greater range of motion

Flat Muscle Fibers

thin and broad, fibrous, sheetlike, spread their force over a broad area

Fusiform Muscle Fibers

spindle shaped, central belly, tapers to tendons, allows them to focus their force on small bony targets

Strap Muscle Fibers

uniform in diameter, arranged in a long parallel manner, small bony targets

Radiate Muscle Fibers

triangular, fan shaped, or convergent, flat and fusiform muscles that originate on a broad surface or apenurosis and converge on a tendon

Sphincter Muscle Fibers

circular muscles that are at an opening/closing joining of two areas (stomach, anus) that function to open and contract

Pennate Muscle Fibers

shorter fibers that are arranged obliquely to their tendons in a structure similar to a feather, increases cross sectional area of the muscle, increases force

Unipennate Muscle Fibers

run obliquely from a tendon on one side only (produce strong forces)

Bipennate Muscle Fibers

obliquely from a central tendon on both sides (produces strong forces)

Multipennate Muslce Fibers

several tendons with fibers running diagonally between them

Irritability/ Excitability

muscle response of being sensitive or responsive to chemical, electrical, or mechanical stimuli

Contractility

ability for a muscle to contract and develop tension against resistance when stimulated

Extensibility

muscle to be passively stretched beyond its normal resting length

Elasticity

muscle can return to it's original resting length following stretching

Intrinsic

muscles belonging soley to a specific part of the body at study

Extrinsic

muscles that originate outside of the body part at study in which they act

Action

concentric contraction of a muscle that crosses a joint

Innervation

segment of the nervous system responsible for stimulating a muscle

Amplitude

range of a muscle fiber length between the maximal and minimal lengthening

Gaster (belly or body)

central, fleshy portion of the muscle, contractile portion generally increases in diameter as the muscle contracts

Tendon

tough yet flexible bands of fibrous tissue connective tissue often cordlike in apperance, connects muscle to bone and other structures

Aponeurosis

tendinous expansion of dense fibrous connective tissue that is sheet or ribbon like in appearance and resembles a flattened tendon

Fascia

sheet or band of fibrous connective tissue tat envelopes, separates, or binds together parts of the body such as muscles, organs, and other soft tissues structures of the body

Origin

the proximal attachment of a muscle to the part that attaches closest to the midline or center of body

Insertion

the end point of where a muscle attaches on the distal part of a structure so farthest from the midline or center of the body

Isometric Contraction (static)

active tension may be developed in the muscle to maintain the joint angle in a relatively static or stable position

Isotonic Contraction (Dynamic)

muscles developing tension to either cause or control joint contractions, varying degrees of active angles to change or controlling the joint angle change that is caused by external forces

Concentric Contraction

muscle developing active tension as it shortens and occur when the muscle develops enough force to overcome the applied resistence

Eccentric Contraction

muscle lengthening under active tension and occur wen the muscle gradually lessens in tension to control the descent of the resistance

Movement Differention

with no movement there may or may not be muscle control or tension

Isokenetics

specific technique that may use any or all of the different types of contractions

Agonist

joint motion through a specific plane of motion

Primary Movers

muscles that are most involved

Antagonist

have the opposite concentric action from agonists

Stabalizers

surround joint or body part and contract to fixate or stabalize the area to enable another limb or body segment to exert force and move (fixators)

Synergist

muscles that assist in action of an agonist but are not necessarily the prime movers, guiders, assist in refined movements

Helping Synergists

have actions in common yet are anatgonists to each other

True Synergists

contract to prevent an undesired joint action of the agonist and have no direct effect on the agonist action

Neutralizers

counteract to neutralize the action of other muscles to prevent undesirable movements such as inappropriate muscle substitutions

Force Couples

two or more forces are pulling in different directions on an object causing the object to rotate on its axis