Pairing of Shoulder Girdle and Shoulder Joint Movements

What is the generally accepted ratio between the motion of the glenohumeral joint and the motion of scapula?

2:1 (for every 2 degrees of glenohumeral motion, there's 1 degree of scapula motion)

Extension (Shoulder Joint)

Depression (Shoulder Girdle) Downward Rotation (Shoulder Girdle)

Adduction (Shoulder Joint)

Downward Rotation (Shoulder Girdle)

Flexion (Shoulder Joint)

Elevation (Shoulder Girdle) Upward Rotation (Shoulder Girdle)

Horizontal Adduction (Shoulder Joint)

Protraction (Shoulder Girdle)

Internal Rotation (Shoulder Joint)

Protraction (Shoulder Girdle)

External Rotation (Shoulder Joint)

Retraction (Shoulder Girdle)

Horizontal Abduction (Shoulder Joint)

Retraction (Shoulder Girdle)

Abduction (shoulder joint)

Upward Rotation (Shoulder Girdle) Elevation (Shoulder Girdle)

Why is determining the exact range of motion for the glenohumeral joint difficult?

because of the accompanying shoulder girdle movement

Are the movements of the shoulder girdle dependent on the shoulder joint and its muscles?

no

Does scapulohumeral rhythm happen in a totally sequential fashion?

no

The shoulder girdle muscles contract to maintain the scapula in a relatively _________ position during many shoulder joint actions.

static

What is scapulohumeral rhythm?

synergistic relationship between the actions of the scapula and the glenohumeral joint

When is total shoulder range of motion accomplished?

when the glenohumeral joint is paired with the shoulder girdle