What type of joint & how many degrees of freedom???
- Sternoclavicular joint
- acromioclavicular joint
- glenohumeral joint
- sternoclavicular joint: saddle/basilar joint 3 degrees
- Acromioclavicular joint : plane/gliding joint 3 degrees
- glenohumeral joint: ball and socket 3 degrees (4)
SCJ Movement, plane, axis
Protraction: horizontal plane about vertical axis
Elevation/Depression: frontal plane about AP axis
Rotation: Sagittarius plane about longitudinal axis (medial lateral axis)
Explain convex concave for longitudinal and transverse part of clavicle and manubrium
Clavicle:
- longitudinal - convex
- horizontal - concave
Manubrium:
- longitudinal - concave
- horizontal convex
Arthrokinematics of Clavicle:
Protraction
- clavicle concave
- roll & slide anteriorly
Arthrokinematics of Clavicle:
Retraction
- clavicle concave
- roll & slide posterior
Arthrokinematics of Clavicle:
Elevation
- clavicle convex
- roll superior
- slide inferior
Arthrokinematics of Clavicle:
Depression
- clavicle convex
- roll inferior
- slide superior
What clavicular ligaments restrict ELEVATION
- costoclavicular ligament becomes taut
- interclavicular ligament becomes slack
What clavicular ligaments restrict DEPRESSION
- interclavicular ligament becomes taut
- Costoclavicular ligament becomes slack - check this CCL
What clavicular ligaments restrict RETRACTION
- anterior capsular ligament becomes taut
- posterior capsular ligament becomes slack
What clavicular ligaments restrict PROTRACTION
- posterior capsular ligament becomes taut
- anterior capsular ligament becomes slack
Acromioclavicular Joint Ligaments
- Coracoclavicular: suspends scapula and rest of extremity from the clavicle
- made up of TRAPEZOID & CONOID
- Sup & Inf Acromioclavicular lig: reinforces the capsule that surrounds the AC joint
ACJ motions, planes, and axis
- upward and downward in frontal plane about sagittal plane
- rotational adjustment motions in horizontal and sagittal planes
- upward rotation: shoulder abduction
- downward rotation: returns scap: addiction or extension
Plane of the Scapula
- resting posture of the scapular
- 10 degrees anterior tilt
- 5-10 degrees upward rotation
- 30-40 degrees of internal rotation
What occurs at the SCJ & ACJ during scapular ELEVATION
Clavicle SC Elevation + AC Downward Rotation (bottom of scapula down)
What occurs at the SCJ & ACJ during scapular DEPRESSION
Clavicle SC depression + AC Upward Rotation
What joint links the axial skeleton to the appendicular skeleton?
Sternoclavicular Joint
What is meant by the term Scaption?
- elevation of the arm within the plane of the scapula (within the scapular plane)
What occurs at the SCJ & ACJ during scapular PROTRACTION
- clavicle SC protraction + AC IR (forward reach)
What occurs at the SCJ & ACJ during scapular RETRACTION
- Clavicle SC elevation + AC ER
What occurs at the SCJ & ACJ during scapular UPWARD ROTATION
- clavicle SC elevation + AC upward rotation
What occurs at the SCJ & ACJ during scapular DOWNWARD ROTATION
- clavicle SC depression + AC downward rotation
Osteokinematics motions of the arm
- Protraction
- upward rotation
- downward rotation
- anterior tilting
- posterior tilting
- protraction: reaching forward
- upward rotation: arm elevation
- downward rotation: lowering arm
- anterior tilting: inf angle of the scapula moves backwards
- posterior tilting: inf angle of scapula moves forward
