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