Download Musculoskeletal Anatomy of the Upper Limb

Musculoskeletal Anatomy of the Upper Limb
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Regions of upper limb:
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Shoulder
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Arm – brachium
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Forearm – antebrachium
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Wrist – carpus
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Hand – manus
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Digits
Spaces between structures very important for positioning of neurovascular
bundles
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Relate surface anatomy and bony landmarks to musculoskeletal
structures and so neurovascular anatomy
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In upper limb, axilla, cubital fossa and carpal tunnel – axilla contains
nerves to upper limb (derived from brachial plexus), arterial supply to
limb, veins and lymph vessels and nodes
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Bones:
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Shoulder – clavicle, scapula
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Arm – humerus
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Forearm – radius, ulna
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Wrist – eight carpals
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Metacarpus (no common term for manus referring to metacarpals) –
five metacarpals
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Digits – 14 phalanges (three each digit except two in first digit)
JOINTS
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Joint occurs where pair of bones contact, usually named after bones involved
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Limb joints need to be mobile so are synovial – cartilage on
articulating surfaces, synovial fluid to absorb load and reduce friction,
synovial membrane and fibrous capsule
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Most joints also contain articular discs/menisci, fat pads, bursae and
collateral/accessory ligaments for strength
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Basic joint system in upper limb matches basic system in lower limb
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Axial skeleton to girdle – sternoclavicular joint
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Between girdle bones – acromioclavicular joint (not particularly mobile)
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Girdle to propodial (proximal joint) – glenohumeral joint
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Propodial to epipodial (mid-limb joint) – humeroradial joint
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Between epipodials – proximal and distal radioulnar joints
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Epipodial to autopod (distal joint) – radiocarpal joint (no joint with
ulna)
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Between carpals/tarsals – intercarpal joints
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Carpal/tarsal to metacarpal/metatarsal – carpometacarpal joint
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Between metacarpals/metatarsals – intermetacarpal joint
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Metacarpal/metatarsal to phalanges – metacarpophalangeal joints
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Between phalanges – interphalangeal joints
Two types of movement in space:
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Rotation – movement about axis, for synovial joint generally one or
two axes of rotation
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Translation – sliding along surface, not usually good for synovial joint
(causes dislocation)
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Categorise joints based on number of axes of rotation or small translation
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Ball and socket – three axes of rotation e.g. glenohumeral joint
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Hinge – one axis of rotation, movement at right angles to long axis of
articulating bones e.g. humeroradial joint
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Pivot – one axis of rotation, movement parallel to long axis of
articulating bones e.g. proximal radioulnar joint
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Ellipsoid – two axes of rotation, sub-equal range of motion e.g.
radiocarpal joint, metacarpophalangeal joints
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Saddle – two axes of rotation, approximately equal range e.g.
carpometacarpal joint of thumb
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Planar – small translations e.g. intercarpal joints
SHOULDER
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Bones:
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Girdle – clavicle, scapula
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Propodial – humerus
Joints:
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Axis-girdle – sternoclavicular joint
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Girdle-girdle – acromioclavicular joint
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Girdle-propodial – glenohumeral joint
Muscles
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Axis-girdle – 7 (four posterior and three anterior) and two neck
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Girdle-propodial (attached to trunk) – 8 (four prime movers and four
rotator cuff)
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Girdle-propodial (attached to limb) – five (three ventral and two
dorsal)
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Bone surface features occur where soft tissue attaches – type of feature
doesn’t reveal type of soft tissue
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Border – edge
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Angle – corner
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Process – knob, protuberance
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Tubercle – small process
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Spine – sharp process
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Fossa – pit, concavity
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Tuberosity – rounded process
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Condyle – convex part of joint surface
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Cotyle/socket – concave part of joint surface
Clavicle – S-shaped bone with articular surfaces at each end
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Superior surface is smooth, inferior surface has roughened areas for
ligament attachments
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Medial (sternal) end is triangular, lateral (acromial) end is flatter
Scapula – flat, triangular bone with two prominent processes and spine
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Coracoid process protrudes to clavicle
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Acromion is joined to spine of scapula that extends to medial border
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Three borders and three angles – one angle forms glenoid fossa/cavity
(articular surface)
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Three fossae – subscapular, supraspinous and infraspinous
Names of many major features on scapula relate to location e.g.
supraspinous fossa
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