Muscles & Movement: Terminology & Concepts

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What is a Muscle

• Organ - comp of muscle fibres / connective tissue membranes - prod / controls mvmt / maintains posture / gen heat / stabilizes joints

What is a Muscle Head

Part of same muscle - orginate in different parts > share a common attachment w other heads

• (ceps - head)

• Bi - 2

• Tri - 3

• Quad - 4

What is a Tendon

Thick rope-like connection between muscle / other body part (bone / muscle / etc)

• point of trans to muscle-to-bone = musculotendinious junction

• tendons trans force via contracting muscle to bone / body to be moved

What is a Apneorusis

Wide / Flat connection between muscle / other body part (bone / muscle) - like tendoms / aponuroses > transmits force from contracting muscle to bone / body part to be moved

What is a Fascia

cont 3d netword of connective tissue > surrounds / connects / supports > all strctures within the body

• helps oragnize tissues / assist in transmission of mechanical forces / provides pathway for mvmt of intersitital fluid = supports nutreient echancce / waste removal

• SOME SPECIALIZED REGIONS OF FASCIA HAVE DISTINCT NAMES

What is a Myofascial

• Both Muscle (‘myo’) and fascia > muscles do not work in isolation

• Connected by / supported by surrounding fascial tissue > forming an intergrated system that helps maintain structure / transmit mechanical forces

What is a Muscle Contraction

• When a muscle contracts, it shortens = prod foce transmitted by connective tissues (eg; tendon, apenrousis, fascia) > to attached bone / structure = resulting in-movement

What movement?

Concentric

• muscle shortens as it gen tension

• origin / insertion move closer tg

What movement?

Isometric

• muscle does not change length as it gen tension

• no joint mvmt / change in distance between origin / insertion

What movement?

Eccentric

• muscle lengthensas it gen tension

• origins / insertion move apart\

• muscle is declearting / slowing / controlling a mvmt

• may be contracting against a greater opposing force controlling against gravity

What role is this?

Agonist (Prime Mover)

• Principle Muscle Involved in action

• Eg; Biceps Brachii / Brachialis

What role is this?

Antagonist

• (Opposes) action of Agonist

• Eg; Triceps Brachii

What role is this?

Synergist

• Assists the Agonists’ Action

• (Eg; Brachioradialis)

What role is this?

Stabilizer / Fixator (Stabilizes stanioary attachment - Origin)

• eg; Deltoids, Rotator Cuff, (others)

What is this?

Innervation

• nerve that supplies a muscle / delivers signals from brain to intiate contraction

What is occuiring

Muscle Contraction / Force Transmission

What is occuring?

Action

• Movement produced when muscle is contracted = (SHORTENING)

True?

(Origins and insertions are on different bones allowing movement across a joint?)

YES

What type of muscle?

Monoarticular Muscle = (Spans a single joint)

• Plays a key role in precse control at single joint they cross

• Multiarticular muscles presanet > (Monoarticular are located deeper)

What type of muscle?

Multiarticular Muscle

• two or more joints - (biartiular muscle) = spans two joints

• play a key role in coordinanting complex mvmts by transf force / energy across multiple joints / distal surfaces’

• BECAUSE THEY CROSS MULTIPLE JOINTS = strength they can produce and the movement they allow - (ROM) at 1 joint depens on pos of other joints

• FORCE MAY BE REDUCED - (active insuffciency) = muscle is shortened @ another joint it crosses / strenched / lengthed (passive insufficiency)

What is occuring?

Active Insufficiency

• multiarticular muscle cannot shorten enough to prod full force at joint

• already too contracted (actively shorrtened) across other joints it crosses’

What is occuring?

Passive Insuffciency

• When an Multiarticular muscle cannot stretch enough to allow full mvmt of a joint becus it is alr strectched at another joint

What movement?

Open Kinetic Chain (OKC)

• movement where distal / terminal segment moves freely

What movement?

Closed Kinetic Chain (CKC)

• movmements where distal / terminal segment is fixed (foot / hand)

• benefical for training functional movement patterns - (mimic everday actitives) - types of exercises

What is a Strain?

• Stretch / Tear of Muscle / Tendon / Aponeurosis / Both

• Graded on severity on muscle fibre damage

What type of Strain

Grade I (mild)

• only a few muscle fibres damaged / (tendon damage = severe cases)

What type of Strain

Grade II (moderate)

• more muscle fibres torn

• loss of strength / function

What type of Strain

Grade III

• (Severe) complete tear / rupture of muscle

may involve tendon

What pathology?

Tendinitis

• inflmattion of tendon

What pathology?

Tendinopathy

• Umbrella term > charterized by pain, degeneartion, / dysfunction

• Acute / Chornic shows stctural changes within tendon wo inflamamtion (most chornic tendon pathlogies dont involve true inflmattion)

What pathology?

Tendinosis

• chornic temdon degeneration wo inflamattion ,

• seen using imaging / histology

Which is more advantagous OKC or CKC?

• Both have their advantages

• Complete training regmiment utilzes both types of exerices’

What is an innsertion?

Skeletal Muscles attach at, atleast 2-points (ATTACHMENT SITES)

What Insertion?

Origin (O)

• Attachment Site - (the bone) REMAINS: Stainonary during mvmt

What Insertion?

Insertion (I)

• Attachment site (i.e.,) move during mvmt

What structure is this?

Muscle Belly

• Thick / Central part where most muscle fibres are located

• Greatest cross-sectional area

What is cross-sectional in-regards to muscle?

the thickness or size of a muscle, which directly dictates its capacity to produce force and generate strength

What are some functional considerations?

• Standard convention; mvmt occcurs as insertion moves toward origin

• determine a muscles action > visuailze mvmt along lines of muscle fascisicles

• to strech a muscle > move origin and insertion further apart

• during eccentric contractions ; muscle lengthens under tensiom = attachments move apart

What are some key priciples to consider?

• Origins / insetions are on diff bones; allowing mvmt across a joint

• in most lumb muscles / origin is prox / insertion distal

• muscles pull on bone / not push

What are exceptions / notes

• in-reality; insertions can be stabilized while origin moves (biceps brachii during pull up)

• both attach,ent sites > also move simutansosuly depending on tasks

• origin / insertion = conventional labels used for consistency / communication