Body Positioning and Muscle Basics Flashcards
Sagittal Plane
Divides body into left and right halves. Movement: Situp. Or, wiping arm straight forward or backward.
Transverse (Horizontal) Plane
Divides body horizontally (top and bottom halves). Movement: The Twist. Or, wiping the counter.
Frontal (Coronal) Plane
Divides body into front and back halves. Movement: Jumping Jack. Or, wiping arm out to sides.
Sagittal (Anterior-Posterior) Axis
A pin that runs from front to back. Movement: Cartwheel.
Transverse (Frontal) Axis
A pin that runs from right to left. Movement: Somersault.
Longitudinal (Vertical) Axis
A pin that runs from head to toe. Movement: Twirling.
Medial vs. Lateral
Medial = toward body center. Lateral = away from body center.
*NOTE: For the hand, the middle finger is the center. Other fingers are lateral to middle finger.
ABDuction vs. ADDuction
ABduction = moving away from body. ADduction = moving toward body.
Flexion vs. Extension
Flexion = Closing the angle. Extension = Opening the angle.
Cranial vs. Caudal
*Used in relating two structures.
Cranial = Toward the head. Caudal = Toward the feet.
(Sternum is Cranial to Pelvis; Femur is Caudal to Pelvis)
Isometric vs. Concentric vs. Eccentric
Types of muscle contractions.
Isometric = Muscle length stays the same. (Stabilizing) Concentric = Muscle length shortens. (Lifting) Eccentric = Muscle lengthens. (Releasing)
- A concentric contraction is balanced by an eccentric contraction.
Agonist Muscle
This muscle is primarily responsible for the motion (ie: quads in knee extension).
Synergist Muscle
Assists the agonist (motion) muscle in desired action. (ie: brachioradialis in elbow flexion—to biceps)
Antagonist Muscle
Muscle that opposes the agonist (motion) muscle. On opposite side of joint, and contracts eccentrically while agonist concentrically. (ie: triceps are antagonist to biceps in elbow flexion)
Stabilizer Muscle
This muscle assists the agonist (motion) muscle by steadily contracting to balance body. (ie: quads help stabilize knee in extension while on tip-toes)
Neutralizer Muscle
Allows for a muscle to perform more than one action. (ie: Biceps has multi functions. Pronator teres contracts to counter biceps for extension to avoid unwanted supination)
% of Body Weight that is Muscle
40-45%
Muscle Components (from smallest to largest)
1) Sarcomeres (contractile unit of muscle made from myosin and actin)
2) Filaments (chains of sarcomeres)
3) Myofibrils (groups of filaments)
4) Muscle Fibers (groups of myofibrils)
Tendons vs. Ligaments
TENDONS attach muscle to bone (to create movement). (Note: also provide stability in GH joint-rotator cuff.)
LIGAMENTS attach bone to bone (to create stability).
Categories of Bony Landmarks
1) PROJECTIONS: appear where tendons, ligaments and fascia are attached. Usually on long bones; used in gonimetry, etc. (ex: iliac crest, lateral epicondyle of humerus, malleolus)
2) DEPRESSIONS (or openings): Holes/depressions providing protection to vital structures (ex: obturator foramen, greater sciatic notch)
Ipsilateral
On the same side of the body; right arm is ipsilateral to right leg.
Orthopedic Model vs. Kinetic Model vs. Biomechanical Model
ORTHOPEDIC: Reductionistic era (30s-50s); takes into mind anatomy, physiology, pathology, kinesiology in addressing impairments/disabilities. OT activities selected based on desired movements.
KINETIC: Medical era (50s-70s); injuries treated to a) improve motion of joints/strength of muscles, b) develop coord, motor skills, work tolerance, and c) prevent unwholesome psychological reactions.
BIOMECHANICAL: Occupation era (70s to present); Restorative approach: isolate/remediate specific impairments in structure/function to improve occ performance.
Locus of control
Refers to who or what has impact over outcomes. Internal LOC = person believes he has control over what happens to himself. External LOC = what happens is result of outside influences/not under his control.
- Can affect clients’ motivation. Can also change!
Social Environment vs. Physical Environment
Environment is considered a factor influencing movement. Environment is divided into two categories:
SOCIAL: Relationships, expectations, fads, sports. May include other people/animals. Expectations of people client interacts with.
PHYSICAL: Built/man-made and natural phenomena. Buildings, roads, structures or pollution, war. Also natural: terrain, sensory, climate, plants/animals, forces like gravity.
Negotiability
Ability of person to interact with environment independently (TP dispensers, doors, etc.). Implies built environment designed to be usable by everyone. Related: UNIVERSAL DESIGN: simplifying life for everyone by making environments useable by as many as possible.
Decubiti
Pressure ulcers caused by shear force.
Center of Gravity (COG)
Point around which the body’s mass is evenly distributed.
Force Couple
Two or more forces with similar magnitude but opposite direction applied to same object to create rotation. Ex: two hands on steering wheel.
Distraction
(Or, traction); pulling apart of two surfaces (such as a joint). Occurs naturally or by external forces.
Active vs. Passive Insufficiency
Insufficiency = when a muscle cannot perform its purpose/potential.
Active Insufficiency = muscle cannot shorten/contract enough to create full ROM. Occurs when client actively contracting muscle.
Passive = muscle cannot stretch/lengthen to full ROM. Occurs in response to a stretch (ie: fully flex wrist and try to flex fingers)
Tenodesis
Tendon binding, or fixation of a tendon. When wrist is extended, fingers flex naturally. Can be used by quadriplegics to create a “tenodesis grasp”—extend wrist to force a grasp with the fingers.
Muscle Imbalance
When one muscle is stronger than its opposing muscle; when an antagonist is stronger than its agonist.
A woman is holding an orange with a bent elbow in front of her, about it put it into her shopping basket. What are:
A: The motion of her elbow as she puts it down;
B: The agonist muscle;
C: The antagonist muscle;
D: Plane the arm is in;
E: Axis the arm is in?
A: Extension B: Biceps C: Triceps D: Sagittal Plane E: Frontal Axis
