ESS 303

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ESS 303 Biomechanics

• Upper Extremity Shoulder Girdle

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Shoulder Girdle

• Made of clavicle and scapula
• 3 joints sternoclavicular, acromioclavicular,
  and coracoclavicular
• Articulations
• Manibrium/clavicle
• Scapula to torso too complex and difficult to
  analyze for this class

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The Scapula (Right)
Anterior View Posterior View
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The Clavicle (Right)
Superior View
Inferior View
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Shoulder Girdle
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Shock Absorption

• S shaped clavicle
• Fibrocartilage disk (Meniscus between
  manebrium/costal cartilage and clavicle)
• Double diarthrotic joint
• Side-impact

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Movements Major Muscles

• Elevation upper trapezius, levator scapulae,
  rhomboid major rhomboid minor
• Depression pectoralis minor lower trapezius
• Protraction (abduction) pectoralis minor,
  serratus anterior
• Retraction (adduction) middle trapezius, levator
  scapulae, rhomboid major rhomboid minor
• Upward rotation upper trapezius, lower
  trapezius, serratus anterior
• Downward rotation levator scapulae, pectoralis
  minor, rhomboid major rhomboid minor