Frame of reference

Phases of qualitative analysis

Preparation - observation - evaluation/diagnosis - intervention

Three requirements of preparation

1. Tools to properly observe and evaluate

2. Knowledge of skill

3. Systematic strategy for observation, evaluation and intervention

Two tools to properly observe movement tasks

1. Understand how: frame of reference, anatomy and vectors

2. Mechanical principles to describe movement

Knowledge of skills and specific considerations

1. Goal of movement - critical features
2. Knowledge of performers
3. Observational bias
4. Knowledge of effective instruction

How to observe a movement (4 steps)

1. Frame of reference

2. Free body diagram

3. Vectors (forcesO

4. QAA (functional anatomy)

Frame of reference

Way to describe an objects position in space and whole body orientation and with respect to external landmarks

Two types of frame of reference we use

1. Global

2. Local (egocentric)

Sagittal plane

Cuts body into left and right plane

* observe from the side

Frontal plane

Front and back

* view from either front or back

Transverse plane

Top and bottom

* ex. Volleyball serve

Egocentric planes of observation: where to observe

• principle plane of movement

• Line of sight perpendicular to plane

• Left or right side

• Multiple view points

Axis

Straight line where two planes intersect

* line about which an object may rotate

Z-axis

Frontal and sagittal plane intersection

* vertical axis - up and down

Y-axis

Frontal and transverse plane

* left or right

X-axis

Sagittal and transverse

* travelling forward or backwards

Parallel axis

Axis throughout body that can indicate alignment

* parallel in standard anatomical position
* Determine posture abnormalities in frontal plane

Parallel axis in transverse

See shoulder and hip misalignment

Parallel axis in sagittal

See tilt of pelvis

Parallel axis during movement

Tells you about how the body is bending

* where the bending occurs and how much
* Can be used for injury reduction

Joint axis

Visualize a line throughout joint

* can indicate pronation/supination

What can you detect using frame of reference?

• performers location in space (global/local)

• View through planes

• Alignment and balance of body segments