23.32 Scapulo-thoracic movment

• The scapula swings on the thorax during abduction or elevation in the scapular plane

• This is caused by rotation around several centers of rotation

  • From 0-60\(^{\circ}\) of elevation, the center of rotation is close to the glenoid and occurs mainly due to movement at the acromio-clavicular joint

  • From 60-120\(^{\circ}\) the center of rotation is closer to the base of the spine of the scapula. This involves significant sterno-clavicular joint motion

• The center of rotation of the scapula is displaced upwards and laterally towards the base of the coracoid process

• The acromio-clavicular joint is involved in the tilting movement of the scapula between 120-180 \(^{\circ}\) of elevation

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