Muscle Architecture Flashcards
Different types of muscles?
Cardio, Smooth, Skeletal
Components of Skeletal Muscle?
Muscle–>Fascicle–>Muscle fibre–>Myofibrils
The origin of a muscle is usually?
Proximal (toward midline) and more stable.
The insertion is usually?
Distal (away from midline) and closer to whats moving
What are the three types of lever systems?
First, second, third
Most muscles are typically which lever?
Third
What are the different fascicle arrangements?
Circular, parallel (fusiform), convergent, pennate
What are the different pennate orientations?
unipennate, bipennate, multipennate
What makes up a circular pattern?
Responsible for opening and closing of muscles. Circular formation
What makes up a parallel (fusiform) arrangement?
fibres run parallel to each other and run origin–>insertion. The types are thin, fusiform, flat.
What makes up the convergent pattern?
Big origin but lead to one insertion
Unipennate muscle pattern?
One direction, weaker.
Bipennate muscle patter?
2 directions, more fibres and therefore more force.
Multipennate?
2 or more directions of muscle fibers, more force.
What is an agonist (prime mover)?
Produces a specific movement when it contracts. Main component in contraction.
What is an antagonist?
Action opposes the agonist.
What is a synergist?
Aids the agonist or prime mover.
Types of contractions?
Isometric, concentric, eccentric
What is an isometric contraction?
There is muscle contraction but there is no change in position, angle remains the same. No shortening.
What is a concentric contraction?
Muscles are contracting and shortening. Angle becomes smaller. Flexion of bicep curl
What is an eccentric contraction?
Muscle fibres are contracting but fibres are lengthening, angle growing. Make the origin and insertion farther apart. Extension of bicep curl.
What causes shoulder pain?
Decreased subacromial space, impingement with exercise, rotator cuff tendinopathy (from instability or overuse), swelling of rotator cuff tendon, leads back to decreased subacromial space.
What is scapulohumeral rhythm?
2:1 ratio between the ab/adduction of the shoulder and scapula. For every 1 degree of scapular rotation there is 2 degrees for humeral rotation in order to reach full 180 degrees.
What are the scapular stabilizers?
Pectoralis minor, trapezius, serratus anterior
What muscles balance upward and downward rotators?
levator scapulae, rhomboids, pec minor
Long thoracic nerve (Scapular control)
Innervates the serratus anterior, damage by traction on neck or shoulder by blunt trauma. Causes paralysis of the serratus anterior.
What is subscapular nerve entrapment?
The nerve passes through the subscapular notch and supplies the supraspinatus and infraspinatus muscles.
What causes subscapular nerve entrapment?
Tight muscles around a nerve causes swelling and inhibits function. Most common with throwing motions.
