1. Muscular System Types of Body Movements
600+ skeletal muscles attached to bone or connective tissue at no less than 2 points
Origin – attached to immovable bone
Insertion – attached to movable bone
MUSCLE MOVES TOWARD ORIGIN DURING CONTRACTION

2. Most Common Types of Body Movements
Flexion (decrease angle)
Extension (increase angle)
Abduction (moving limb away)
Adduction (moving limb toward)
Rotation (move bone along longitudinal axis)
Circumduction (combination)

3. Common Types of Movement (cont.)
Pronation (moving palm up to down; forces radius to cross ulna)
Supination (moving palm down to up into anatomical position; radius and ulna parallel)
Inversion (turning sole of foot medially)
Eversion (turning sole of foot laterally)
Dorsiflexion ( ankle movement/ instep up)
Plantar flexion (straighten ankle/instep down)

4. Types of Muscles
Movement is result of team of muscles. Whatever team can do, another team can reverse.
Prime Mover (agonist) = the muscle (of team) that has major responsibility for causing a particular movement
Ex: biceps brachii for elbow flexion
Antagonist = muscles that oppose or reverse movement (located opposite side of joint from agonist)
Ex: triceps brachii antagonizes biceps brachii, but is also prime mover for forearm extension
Synergist = muscles that help prime mover
Add force and reduce undesirable movements
Fixators = specialized synergists (stabilize)
Immobilize bone or muscle’s origin (i.e,scapula)

5. Naming Skeletal Muscle
Muscles are named on the basis of several criteria (Look for the hints!)
Direction of muscle fiber (and fascicles)- in relation to lines like midline and axis of limb)
rectus [straight] – run parallel
oblique –run at a slant
transversus – at right angles
Rectus femoris – straight muscle of thigh
Transversus abdominus

6. Naming Skeletal Muscle (cont.)
Relative size of muscle
maximus [largest] – gluteus maximus
minimus [smallest]- gluteus minimus
longus [long]- fibularis longus
brevis [short] – extensor pollicis brevis
Number of origins
Biceps [2], triceps [3], quadriceps [4]
biceps brachii, triceps brachii, quadriceps femoris

7. Naming Skeletal Muscle (cont.)
Location of muscle’s origin and insertion
Ex: intercostal muscle
“costal” = rib
runs between the ribs
Ex: temporalis muscle
overlies temporal bone
Ex: sternocleidomastoid muscle
“sternum” and “clavicle” [origin]
mastoid process of temporal [insertion]

8. Naming Skeletal Muscle (cont.)
Shape of the muscle
Deltoid = triangular
Trapezius = trapezoid
Action of the muscle
Flexor – flexor digitorum superficialis
Flexes wrist and middle phalanges
Extensor – extensor carpi radialis longus
Action, joint (wrist), lies close to radius of the forearm, size rel. to other wrist extensors
Adductor – adductor longus
Adducts, medially rotates thigh

9. Muscle Mechanics –Fascicle Arrangement
Review muscle force and speed
Patterns of fascicle arrangement
Circular – concentric rings (sphincters)
Orbicularis oculi (eye); orbicularis oris (mouth)
Convergent – fascicles converge to single tendon of insertion(triangular or fan-shaped)
Pectoralis major
Parallel (& fusiform)– straplike or spindle shaped
Sartorius (thigh to knee) – longest muscle in body
Biceps brachii – flexes elbow, supinates forearm

10. Muscle Mechanics –Fascicle Arrangement (cont.)
Pennate – attach obliquely to central tendon
Unipennate (one side of tendon) – extensor digitorum longus (leg)
Bipennate (from opposite sides of tendon) – rectus femoris (thigh) [like a feather]
Multipennate – [like many feathers together]
Deltoid muscle (shoulder)

11. Muscle Mechanics –Fascicle Arrangement (cont.)
Arrangement determines range of movement and power
Parallel = shorten most but not powerful
Power depends on total muscle cells in muscle (more cells=more power)
Bipennate and multipennate = most fibers but shorten little & very powerful

12. Bone-Muscle Relationships – lever systems
Lever systems- partnerships between muscular and skeletal systems
Lever – rigid bar that moves on a fixed point (fulcrum) when force applied
Applied force (effort) moves a resistance (load)
Joints = fulcrums
Bones = levers
Muscle contraction = effort (applied at insertion)
Load = bone + tissues + what is moved with lever

13. Bone-Muscle Relationships – lever systems (cont.)
Lever operates at mechanical advantage when load is close to fulcrum and effort is applied far from fulcrum
Used to move large load over small distance (power lever)
Slower, more stable, strength is priority
Lever operates at mechanical disadvantage when load is far from fulcrum and effort is applied near fulcrum
Force greater than the load moved (speed lever)
Force lost, but speed and range of movement gained

14. Bone-Muscle Relationships – lever systems (cont.)
Lever classes
First-class lever
Effort applied at one end of lever; load at other end; fulcrum between (scissors)
Lift head off chest
some act at mechanical advantage; others disadvantage
Second-class lever
Effort applied at one end; fulcrum at the other end; load between (wheelbarrow) (uncommon)
Standing on toes
Third-class lever
Effort applied between the load and fulcrum (tweezers) (act at great speed & mechanical disadvantage)
Most skeletal muscle