Lecture: Muscle Mechanics

1. Prime movers: provide the major force for producing a specfic movement

2. Antognists: oppose or reverse a particular movement (muscles cannot push, only pull)

3. Synergists (help prime movers): add force to a movement and reduce undersirable or unnecessary movement

4. Fixators: synergists that immobilize a bone or muscle's origin

1. Location: bone or body region associated with the muscle

2. Shape: ex- deltoid means triangle

3. Relative size: ex- maximus, minimis, longus, brevis

4. Direction of fibers or fascicles: ex- rectus, transversus, and onlique

5. Number or origins: ex- bicepts means 2 origins, triceps have 3

6. Location of Attachments: ex- sternocleidmastoid

7. Action: ex- flexor or extensor

Circular (Sphincters): organized in concentric rings, such as the orbicularis oris

Convergent: converge toward a single tendon insertion, like the pectoralis major

Parallel: paralell to the long axis of a straplike muscle, like the sartorius

Fusiform: spindle shaped muscles with parallel fibers, like the biceps brachii

• Pennate: looks like a feather, short fascicles attache obliquely to a central tendon running the length of the muscle, such as the rectus femoris

Lever: rigid bar (bone) that moves on a fixed point or fulcrum (joint)

Effort: force (supplied by the muscle contraction) apploed tp a lever to move a resistance (load)

Load: resistance (bone, tissue, and any added weight) moved by the effort

Fulcrum between load and effort

• Like a pair of scissors

Load between fulcrum and effort

Like a wheelbarrel

effort applied bewtween fulcrum and load

Like tweezers