Body Positioning and Muscle Basics

Question 1

Sagittal Plane

Answer 1

Divides body into left and right halves. Movement: Situp. Or, wiping arm straight forward or backward.

Question 2

Transverse (Horizontal) Plane

Answer 2

Divides body horizontally (top and bottom halves). Movement: The Twist. Or, wiping the counter.

Question 3

Frontal (Coronal) Plane

Answer 3

Divides body into front and back halves. Movement: Jumping Jack. Or, wiping arm out to sides.

Question 4

Sagittal (Anterior-Posterior) Axis

Answer 4

A pin that runs from front to back. Movement: Cartwheel.

Question 5

Transverse (Frontal) Axis

Answer 5

A pin that runs from right to left. Movement: Somersault.

Question 6

Longitudinal (Vertical) Axis

Answer 6

A pin that runs from head to toe. Movement: Twirling.

Question 7

Medial vs. Lateral

Answer 7

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.

Question 8

ABDuction vs. ADDuction

Answer 8

ABduction = moving away from body.
ADduction = moving toward body.

Question 9

Flexion vs. Extension

Answer 9

Flexion = Closing the angle.
Extension = Opening the angle.

Question 10

Cranial vs. Caudal

Answer 10

*Used in relating two structures.

Cranial = Toward the head.
Caudal = Toward the feet.

(Sternum is Cranial to Pelvis; Femur is Caudal to Pelvis)

Question 11

Isometric vs. Concentric vs. Eccentric

Answer 11

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.

Question 12

Agonist Muscle

Answer 12

This muscle is primarily responsible for the motion (ie: quads in knee extension).

Question 13

Synergist Muscle

Answer 13

Assists the agonist (motion) muscle in desired action. (ie: brachioradialis in elbow flexion—to biceps)

Question 14

Antagonist Muscle

Answer 14

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)

Question 15

Stabilizer Muscle

Answer 15

This muscle assists the agonist (motion) muscle by steadily contracting to balance body. (ie: quads help stabilize knee in extension while on tip-toes)

Question 16

Neutralizer Muscle

Answer 16

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)

Question 17

% of Body Weight that is Muscle

Answer 17

40-45%

Question 18

Muscle Components (from smallest to largest)

Answer 18

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)

Question 19

Tendons vs. Ligaments

Answer 19

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).

Question 20

Categories of Bony Landmarks

Answer 20

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)

Question 21

Ipsilateral

Answer 21

On the same side of the body; right arm is ipsilateral to right leg.

Question 22

Orthopedic Model vs. Kinetic Model vs. Biomechanical Model

Answer 22

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.

Question 23

Locus of control

Answer 23

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!

Question 24

Social Environment vs. Physical Environment

Answer 24

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.

Question 25

Negotiability

Answer 25

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.

Question 26

Decubiti

Answer 26

Pressure ulcers caused by shear force.

Question 27

Center of Gravity (COG)

Answer 27

Point around which the body’s mass is evenly distributed.

Question 28

Force Couple

Answer 28

Two or more forces with similar magnitude but opposite direction applied to same object to create rotation. Ex: two hands on steering wheel.

Question 29

Distraction

Answer 29

(Or, traction); pulling apart of two surfaces (such as a joint). Occurs naturally or by external forces.

Question 30

Active vs. Passive Insufficiency

Answer 30

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)

Question 31

Tenodesis

Answer 31

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.

Question 32

Muscle Imbalance

Answer 32

When one muscle is stronger than its opposing muscle; when an antagonist is stronger than its agonist.

Question 33

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?

Answer 33

A: Extension
B: Biceps
C: Triceps
D: Sagittal Plane
E: Frontal Axis