EPHE 201 Midterm 1 (Oct 9)

what is heaving and its anatomical term?

movement up and down along the z-axis, aka elevation/depression

what is swaying and its anatomical term?

movement side to side along the y(?) axis, aka left/right deviation

what is surging and its anatomical term?

movement forward and backward along the x-axis

what is rolling?

rotating about the z axis, left and right

what is pitching?

rotating about the y axis, forward and backward

what is yawing?

rotating about the x axis, side to side

what are the four steps to qualitative biomechanics?

• preparation: research, ensuring understanding, creating theoretical frameworks

• observation: observe the performance

• evaluation/diagnosis: compare performance to theoretical framework

• instruction/intervention: feedback (loop back to observation for the individual to apply feedback)

what are the four disciplines that largely contribute to qualitative analysis of human movement?

• motor learning

• exercise physiology

• motor control

• motor development

what are the subcategories of mechanics?

statics and dynamics

kinetics and kinematics are components of….

dynamics (which forms mechanics, along with statics)

what is the difference between kinematics and kinetics?

• kinematics: the study of motion exclusive of the influences of mass and force

• kinetics: the study of the relationship between motion and the forces affecting motion; bodies changing motion as unbalanced forces act on them

what are the benefits of FBDs?

• remove all unnecessary visual information

• focus simply on the structural movement

• rigid segments where forces act

what are the limitations of FBDs?

• loss of perspective / plane of movement

• loss of depth (can’t represent 3D)

• difficult to visualize ROM of a joint

• subjectivity (joint centers)

what are the two main methods of vector addition?

• tip to tail method

• breaking each vector into components

what are the four main types of forces we want to show on a FBD?

• center of gravity

• action force

• reaction force

• movement

compare an egocentric (local) frame of reference vs a global frame of reference

• egocentric (local): from the client / other person’s point of view, describing movements relative to themselves

• global: describing movements relative to the environment

what is the plane that cuts the body in half through the midline?

midsagittal / sagittal plane

what is the plane that divides the body front and back?

the frontal plane

what is the plane that is parallel to the floor?

transverse plane

the axis going up and down is the

z axis

the axis going left and right is the

y axis

the axis going forward and backwards is the

x axis

using parallel axes is important because

they help examine body alignment

when the shoulders are not parallel with the hips, for example, can be an indication of improper body alignment / injury

why is it important to understand anatomical regions of the body for qualitative analysis?

because these regions and their anatomical markers are often used to 3D motion tracking

what are degrees of freedom?

the set of displacements and rotations along which an object can move

define circumduction

complex movements of a joint that can be achieved due to many degrees of freedom

Eg: shoulder, arm swings

how many degrees of freedom does the wrist have

2: flexion/extension (pitch), abduction/adduction (yaw)

how many degrees of freedom does the ankle have

2: flexion/extension (pitch), inversion/eversion (yawing)

how many degrees of freedom in the hip complex?

• flexion/extension (pitching)

• abduction/adduction (yawing)

• internal/external rotation (rolling)

what are the four properties of a force vector?

• line of action

• point of application

• direction

• magnitude

why are there pairs of muscles with opposite joint actions at every joint?

because muscles can only pull, not push

what are the two ways that video of a skill be divided into phases for qualitative analysis?

• temporal: time segments

• key phases: degrees about a joint / steps of a skill

what are the two joints that can hyperextend without injury and why?

• the hip and the shoulder

• their regular ROM is restricted by soft tissue, so when you move fast you can hyperextend without injury

provide the headers for this table from left to right

1. joint

2. frames

3. joint motion

4. muscle contraction

5. active muscle group

6. rapid acceleration or impact

7. extreme ROM

what is the likely muscle contraction when you are resisting gravity?

eccentric (lengthening)

what are the 3 possibilities when a force is applied to an object?

the object can:

• accelerate

• decelerate

• deform

what are the two types of internal forces in the body and what structures create them?

• compressive forces: mostly in the bones

• tensile forces: muscle

what is the advantage of tensile forces created by muscles in a joint?

creates stability

what are the two types of external forces?

contact and non-contact

what are the three types of non-contact external forces?

gravity, magnetic, electrical

it is important to consider coefficients with exponents in an equation, because

they are likely highly influential

air resistance and water resistance are

fluid contact forces

why is dynamic friction always lower than static friction?

because the surfaces of both objects can’t settle into their respective peaks and valleys, so they slide along each other more easily