Question | Answer |
Extension of forearm | triceps and anconeus |
Pronation of forearm | pronator teres and pronator quadratus |
Supination of forearm | supinator and biceps |
Extensor muscles attached to lateral epicondyle | extensor carpi radialis and ulnaris, digitorum, digiti minime |
Flexor muscles attached to medial epicondyle | flexor carpi radialis, palmaris longus, flexor carpi ulnaris, digitorum superficial |
Shoulder joint abduction | scapula rotates upward |
Shoulder joint adduction | scapula rotates downward |
row movement muscle primarily involved | latissimus dorsi |
protractors | pectoralis minor, serratus |
triceps are mainly... | elbow extensors assisting in lengthening |
Muscles involved in Scapular elevation | rhomboids, trapezius (upper and middle), levator scapulae |
Muscles involved in Scapular depression | trapezius (lower), pectoralis minor |
Muscles involved in Scapular abduction | serratus anterior, pectoralis minor |
Muscles involved in Scapular adduction | rhomboids, pectoralis minor |
Muscles involved in Scapular downward rotation | rhomboids, pectoralis minor |
Muscles involved in Scapular upward rotation | trapezius (middle and lower), serratus anterior |
Elbow flexor that inserts on radius | bicep |
Elbow flexor that inserts on ulna | brachialis |
The properties of striated muscle tissue | extensibility, elasticity, and contractility |
epimysium- | covers muscle (entire muscle) |
perimysium- | covers bundles (fascicles) of muscle fibers (cells) |
endomysium- | covers each muscle fiber (individual cells) |
sarcomere | basic contractile unit |
myofibrils- | groups of sarcomeres |
myofilaments- | myosin and actin |
slow twitch fibers | don't generate a lot of tension, endurance for long duration- almost always used |
fast twitch fibers | strength and power, intense for a short period of time |
parallel/longitudinal fiber arrangement | strap-like, longitudinal: fusiform, quadrate, biceps, and soleus |
pennate fiber arrangement | allows for high tension, fast movement in short ROM- pennate, bipennate, and multi-pennate ex) rectus femoris, semimembranous |
convergent fiber arrangement | broad muscles where all fibers attach @ one point- fan shape ex) pecs |
circular fiber arrangement | circular pattern, eyes, sphnincters |
pennate allow for .... | more muscle cells to be packed in a cross-sectional area allowing more tension |
The movement that the contracting muscle produces is determined by: | 1) type of joint it spans 2) relation of muscle's line of pull to the joint |
tension and angle of attachment: shallow angle mostly along bone= | stabilizing |
larger angle of attachment= | more rotary component of force |
angle changes throughout ROM- | alters rotary component |
Stabilizers | brachioradialis, subclavius, coracobrachialis |
concentric contraction- | shortening (toward middle) |
eccentric contraction- | lengthening (away from middle) |
isometric- | equal length |
The rotator cuff muscles are: | supraspinatus, infraspinatus, and subscapularis |
supraspinatus- | acts w/ deltoid in abduction of arm, flexion, horizontal extension, contributes to stabilization of GH joint O: med 2/3 of supraspinatus fossa I: superior greater tubercle |
infraspinatus- | external rotation horizontal abduction, extension, stabilize GH joint |
subscapularis- | med rotation of humerus, adduction, extension, contributes to stabilization of GH joint O: surface of subscapular fossa I: lesser tubercle of hunerus |