Biomechanics of the Shoulder
BIOMECHANICS OF THE SHOULDER
Hand and Upper Extremity Certification
SHOULDER BIOMECHANICS * MOTION (Kinematics) * STABILITY (Constraint) * STRENGTH (Force Transmission)
OBJECTIVES * -Introduction * -Review of bone and joints * -Scapulo-humeral rhythm * -Review of muscles and force couples * -Biomechanical applications
What does the shoulder do?
Shoulder Movement
SHOULDER VS. ARM ELEVATION * Note difference in terminology
Normal Shoulder AROM
Activity and AROM (McGee)
Bones of the Shoulder
Clavicle * Crank shaped strut * Convex towards sternum/concave towards humerus * Attaches shoulder to axial skeleton, force transmission to scapula, contributes to ROM * Palpation
Scapula * Between T2 and T7 * Landmarks * Primary function: muscle attachment * Palpation: Acromion, Coracoid Process
Acromion Variations (Bigliani)
Glenoid Fossa
Plane of the Scapula * Superior aspect 30◦- 45◦ a * anterior to frontal plane * Arm elevation in plane vs out of plane of scapula * Try this motion!
Humerus * Structures * Tubercules (externally rotate humerus for grt. tubercule to clear acromion process and acromioclavicular ligament) * Try this!
Inclination and torsion * Humeral head inclination=135◦ * Retroversion * Angle of torsion=30◦
JOINTS OF THE SHOULDER * Acromioclavicular * Sternoclavicular * Glenohumeral * Scapulothoracic
Acromioclavicular Joint * 3 degrees of freedom * Elevation/depression * Abduction/adduction * Rotation of clavicle * Ligaments: * Coracoclavicular * Acromioclavicular (surround capsule)
Trapezoid Ligament * Medial stability during medial blow to shoulder facilitated by TRAPEZOID ligament
Conoid Ligament * Arm elevation: initially clavicle and scapula in upward rotation together. * Scapula continues to elevate
Hand and Upper Extremity Certification
SHOULDER BIOMECHANICS * MOTION (Kinematics) * STABILITY (Constraint) * STRENGTH (Force Transmission)
OBJECTIVES * -Introduction * -Review of bone and joints * -Scapulo-humeral rhythm * -Review of muscles and force couples * -Biomechanical applications
What does the shoulder do?
Shoulder Movement
SHOULDER VS. ARM ELEVATION * Note difference in terminology
Normal Shoulder AROM
Activity and AROM (McGee)
Bones of the Shoulder
Clavicle * Crank shaped strut * Convex towards sternum/concave towards humerus * Attaches shoulder to axial skeleton, force transmission to scapula, contributes to ROM * Palpation
Scapula * Between T2 and T7 * Landmarks * Primary function: muscle attachment * Palpation: Acromion, Coracoid Process
Acromion Variations (Bigliani)
Glenoid Fossa
Plane of the Scapula * Superior aspect 30◦- 45◦ a * anterior to frontal plane * Arm elevation in plane vs out of plane of scapula * Try this motion!
Humerus * Structures * Tubercules (externally rotate humerus for grt. tubercule to clear acromion process and acromioclavicular ligament) * Try this!
Inclination and torsion * Humeral head inclination=135◦ * Retroversion * Angle of torsion=30◦
JOINTS OF THE SHOULDER * Acromioclavicular * Sternoclavicular * Glenohumeral * Scapulothoracic
Acromioclavicular Joint * 3 degrees of freedom * Elevation/depression * Abduction/adduction * Rotation of clavicle * Ligaments: * Coracoclavicular * Acromioclavicular (surround capsule)
Trapezoid Ligament * Medial stability during medial blow to shoulder facilitated by TRAPEZOID ligament
Conoid Ligament * Arm elevation: initially clavicle and scapula in upward rotation together. * Scapula continues to elevate