Topic 3 Flashcards
Advantages of quantitative analysis
- measures magnitude
- detects small changes
- objective feedback
- detailed information
Disadvantages of quantitative analysis
- expensive
- needs well trained operators
- mathematical
Advantages of qualitative analysis
- freely available
- quick, easy, simple
- cheap
Disadvantages of qualitative analysis
- requires good background knowledge/experience
- subjective
- difficult to track improvement
Steps in qualitative anlalysis
- focus attention on the sequence of movement events
- identifies & directs attention to the most significant aspects of a particular skill/movement sequence
- identifies elements of the movement for instruction and feedback
- evaluating development of movement and assessing performance over time
Skill - Nature
skill, movement pattern, constraints, style, technique
Skill - type
open, closed, discrete, continuous, serial, constraints
movement pattern
general series of anatomical movements that have common elements of spatial configuration
skill
a general movement pattern is adapted to the constraints of a particular task/sport
e.g. tennis backhand
technique
a particular type of the same skill
e.g. tennis backhand with topspin or backspin
style
individual adaptations to a technique
e.g. knee bend during a backhand
constraints
event limitations = physical boundaries, and rules concerning uniform/equipment/environment
performer limitations = anthropometrics, skill level, muscular strength/power/endurance/flexability
closed skill
performed in a predictable environment
free to execute the skill without making quick decisions due to unexpected changes
easiest skill to learn
open skill
skill is performed in and in response to an unpredictable and changing environment
discrete skill
defined beginning and end, can be divided into seperate phases
continuous skill
no defined beginning and end, repeated cycles of same movement
serial skill
discrete skills performed in a series
phases of a discrete skill
- preparation 2. execution 3. recovery/follow through
steps in analysisng movement
- preparation - what to observe
- observation - the performance
- evaluation - detect faults/weaknesses
- intervention - correct the performance
preparation phase you need:
knowledge of: normal movement, biomechanics, motor control, performer (anthropometry, genetics, age, weight, injury history), environment (where the skill will be performed, what environmental factors influence performance)
sources of info: professional experience (coaches, anecdotal), expert opinion (journal articles, websites).
preparation phase steps
- identify overall performance objective (OPO)/goal of skill
- divide skills into discrete parts
- identify the mechanical purpose (MP) of each discrete part to achieve the OPO
- list the biomechanical factors (BF) of each discrete part to enable the accomplishment of the MP
- list the critical features (CF) - movements to be performed to achieve the BF
vantage point in observation
angle/plane of view, location of sun, distance from activity, height of observation.
The sampling theorom
when recording, the sampling frequency must be at least twice as high as the highest frequency of the movement
other things to remeber for observations
deidentify performer (e.g. trial ID), subject preparation (joint markers, measurements, tight clothing, clutter-free background), scaling reference for displacement/velocity/acceleration
evaluation
judgment of quality, assess good/bad points, critique against normal/elite performance, refer to BF & CF, cause of error?
Intervention
reliability of info, selection of most appropriate intervention, clearly differentiate good/bad performance, info at the appropriate time and is easily absorbable, rapidity of feedback is critical
feedback
don’t overload performer (1 cue at time, easiest corrections first), then reassess movement after feedback
methods of feedback
visual (demo, pics, video), exaggerate the demonstrations, task modification, manual/mechanical guidance, conditioning (flexibility/strength issue?)
