1. The Appendicular Skeleton
Chapter 8
The Appendicular Skeleton

2. Appendicular Skeleton
126 bones
Allows us to move and manipulate objects
Bones that compose upper and lower extremities
Includes bones of the pectoral and pelvic girdles

3. Appendicular Skeleton
Pectoral (shoulder) Girdles:
Attach upper (arms) extremities to the axial skeleton at the manubrium
Positions shoulders
Provides a base for arm movement
Comprised of the clavicle and scapula
Clavicle - “Collarbone” articulates with scapula and manubrium of the sternum of the axial skeleton.
Medial STERNAL end articulates
with the manubrium of sternum
Lateral ACROMIAL end articulates with the scapula at acromion
Conoid tubercle – attachment site for conoid ligament to scapula
Costal tuberosity – attachment site for costoclavicular ligament which attaches clavicle to sternum

4. Appendicular Skeleton
Scapula: “Shoulderblade” - Triangular shaped
Held in place with muscles; that articulate with the arm bone (humerus) and clavicle; supports upper limbs and arm movement
Skeletal muscles support and position has no bony or ligament contact with thoracic cage.
Supports Spine: posterior bony ridge
Acromion: sole attachment point of scapula and the upper limb to the rest of the skeleton; extension of the spine
Coracoid process: provides attachment for tendons of the biceps brachii and other arm muscles
Glenoid cavity: lateral cavity that articulates with head of humerus---forms glenohumeral joint (shoulder joint)
Appendicular Skeleton
Suprascapular notch – conspicuous notch on superior border provides passage for the suprascapular nerve
Subscapular fossa- anterior surface

5. Appendicular Skeleton
Scapula:

6. Upper Limb Brachium -Arm Humerus Antebrachium -Forearm Radius Ulna
Carpus-Wrist
Carpals
Manus -Hand
Metacarpals
Phalanges
Olecranon
fossa
Olecranon
process
Head of
radius
ulna
Neck of
radius
radius
ulna
ulna
carpals
metacarpals
phalanges

7. Upper Extremity HUMERUS- Articulates with the
scapula proximally and with the
bones of the forearm (ulna and
radius) distally.
Head: articulates with glenoid cavity of scapula
Anatomical neck: just distal to head
Greater and lesser tubercle: lateral and anterior projections just distal to anatomical neck
Intertubercular sulcus: groove between greater and lesser tubercles
Surgical neck: area distal to tubercles; humerus narrows
Body: shaft of the bone
Radial groove: depression that
marks the path of the radial
nerve that extends the elbow
Radial groove

8. HUMERUS
Deltoid tuberosity: lateral projection; attachment site for tendon of deltoid muscle
Medial and lateral epicondyles: projections on the distal humerus; attachment points for muscles of the forearm
Ulnar nerve crossing medial epicondyle produces numbness / odd sensation when struck: “funny bone”
CONDYLES:
Capitulum: rounded structure on distal humerus (lateral); articulates with radius
Trochlea: medial to the capitulum; shaped like an hourglass on its side; articulates with the ulna
Coronoid fossa: depression above the trochlea; receives the coronoid process of the ulna when forearm flexed
Olecranon fossa: posterior fossa receives olecranon process of ulna
Radial fossa: fossa above the capitulum receives the head of the radius when the arm is flexed

9. Humerus

10. Humerus- Review Greater tubercle Lesser tubercle Anatomical neck
Head
Greater tubercle
Lesser tubercle
Anatomical neck
Surgical neck
Body (Shaft)
Deltoid tuberosity
Coronoid fossa
Olecranon fossa
Radial fossa
Med/Lat Epicondyles
Capitulum
Trochlea

11. Upper Extremity Antebrachium Forearm
Composed of the radius and the ulna
Articulate with humerus to form elbow joint
Interosseous membrane
Connects lateral margin of ulnar shaft to radius
Radius
Ulna

12. Upper Extremity Radius
Radial head: disc shaped; articulates with the capitulum of humerus / rolls into the radial fossa
Radial tuberosity: bony projection medially located; attachment site for biceps brachii muscle
Styloid process: process on lateral aspect of radius; attachment site for brachioradialis muscle; can be palpated near thumb; stabilizes wrist joint (radius and carpal bones)
Ulnar notch: notch that articulates with the head of the ulna

13. Upper Extremity Ulna –medial forearm
Trochlear notch: articulates with trochlea of humerus; between coronoid process and olecranon process
Coronoid process: anteriorly located; fits in coronoid fossa of humerus when elbow flexed (bent)
Olecranon process: posteriorly located bony process of the elbow. Fits in olecranon fossa of humerus when elbow extended (straightened)
Radial notch: articulates with the head of the radius
Styloid process: affords attachment to the ulnar ligament of the wrist-joint.

14. Carpal Bones 8 bones form wrist 2 rows of 4 bones > proximal row
allow movements of flexion, extension, abduction and adduction
2 rows of 4 bones
> proximal row
scaphoid, lunate, triquetrum, and pisiform (“pie' si form”)
> distal row:
trapezium, trapezoid, capitate, and hamate
“Sally Left The Party
To Take Charlie Home”

15. Wrist Joint
Wrist joint is formed from the distal end of radius with the carpal bones scaphoid and lunate.
NOTE: the ulna does not directly articulate at the wrist but is functionally part of the wrist joint

16. Upper Extremity Metacarpals Phalanges -“fingers”
5 long bones of the hand
Numbered I–V from lateral (thumb) to medial
Phalanges -“fingers”
14 bones for each hand (each bone called a phalanx)
4 fingers: 3 bones each
Proximal, middle, distal
Each thumb has 2 bones
proximal and distal phalanx
Thumb also known as the pollex

17. The Pelvic Girdle
Complete ring composed of two hip bones (coxal bones); connected via pubic symphysis
Strong to bear body weight, stress of movement
Bones more massive for weight bearing
Articulations of the pelvic girdle
Coxal bones
Sides of the pelvis formed as cartilage, ossifies as 3 main bones that remain separate through childhood
Ilium (articulates with sacrum)
Pubis
Ischium
Ilium
Pubis
Ischium

18. Coxal bones
ILIUM: Posterolateral
very rough for better contact of buttock and thigh muscles
ILIAC crest- rest hands on hips feel this structure
ILIAC SPINE - for hip and thigh muscle attachment.
McBurney's point is the name given to the point one-third of the distance from the anterior superior iliac spine to the umbilicus (navel); roughly corresponds to the most common location of the base of the appendix
Greater sciatic notch- allows nerve to enter thigh region
Iliac fossa
Iliac fossa- concave depression that supports abdominal organs/ area for muscle attachment

19. ISCHIUM:
Lesser sciatic notch –allows access for blood vessels and nerve
Obturator foramen
Attaches hip muscles
Ischial spine- landmark for saddle block procedure
Ischial tuberosity
Bears weight of the body when sitting
Massive ligament (sacrotuberous ligament) joins sacrum to tuberosity Helps to stabilize sacroiliac joint

20. Hip bone

21. Coxal bones PUBIS: Obturator foramen
Almost entirely closed by thin fibrous membrane which almost completely closes the obturator foramen. Both obturator muscle are connected with the membrane.
Pubic symphysis padded with fibrocartilage
ACETABULUM
Also called the hip socket
The meeting point of the ilium, ischium, and pubis
Articulates with head of the femur
Vinegar cup
Vinegar is acetic acid

23. Pelvic Girdle Pubic symphysis Pubic arch-
Pelvic inlet – opening that infant’s head must pass during birth
Sacroiliac joint
Articulation of posterior auricular surface of ilium with the sacrum
Stabilized by ligaments of iliac tuberosity
Weight of the body is transferred from the spine onto this joint

24. Childbirth
As labor begins, infants head enters the inlet with the forehead facing one ilium and the occipital region facing the other.
The coccyx and ischial spines protrude into the outlet opening A sharply angled coccyx or large sharp spine can present problems in childbirth.
As the baby passes through inlet it rotates so the forehead faces posteriorly and the occipital anteriorly. Born face down then turns.
Animation:

26. Male vs. Female Pelvis Male: (right side) Narrow
Female: (left side)
Wider—allows for childbirth
Pelvic arch >100 degrees
Less curvature
Smoother / lighter
Less prominent surface markers/projections blunted
Coccyx more moveable
Wider circular pelvic inlet
Sacrum wider
Male: (right side)
Narrow
Pelvic arch < than 90 degrees
Larger, heavier
Large surface markers
Pelvic inlet narrower
Sacrum narrower

27. The Lower Limbs Functions of the Lower Limbs
Weight bearing- transfers the weight of the body to the ground
Motion
Note: leg = lower leg thigh = upper leg
30 Bones of the Lower Limbs
Femur (thigh)
Patella (kneecap)
Tibia and fibula (leg)
Tarsals (ankle) (7)
Metatarsals (foot) (5)
Phalanges (toes) (14)

28. Lower Extremity Femur: Largest, longest bone
Can sustain severe stress during jumping- 2 tons per square inch
Length approx. 1/4th person’s height
Proximal head articulates with acetabulum of coxal bone; via the ligament at the fovea capitis pit
Neck- narrow area distal to head weakest area of the bone (common fracture site)
Distal end articulates with TIBIA (leg bone) and PATELLA (knee cap) NOT the fibula!
Gluteal tuberosity- vertical ridge
Greater and lesser trochanters- posterior projections that serve as attachment sites for tendons of thigh and buttocks
Linea aspera- attachment for thigh/hip muscles. Divides into a pair of ridges that continue with M/L epicondyles –part of knee joint

29. Lower Extremity- Femur
Medial and lateral CONDYLES- articulate with tibial condyles (held in place with menisci)- part of the knee joint
Lateral epicondyle smaller than the medial epicondyle, attachment to the fibular collateral ligament of the knee-joint.
Medial epicondyle bony protrusion on the medial side of the bone's distal end; bears an elevation for the attachment of the "tendinous insertion", of the adductor magnus.
Intercondylar fossa- found between condyles (posterior surface)
Patellar surface- found on anterior surface

31. Femur Review neck greater trochanter lesser trochanter
head
neck
greater trochanter
lesser trochanter
gluteal tuberosity
linea aspera
med/lateral condyles
intercondylar fossa

32. Lower Extremity PATELLA: “kneecap”
Sesamoid bone- cartilage at birth but ossifies once walking begins at 2yrs to puberty
Primary functions are to protects the knee joint and extend the knee
Patellar ligament / tendon connects apex of patella to tibia
Upper 3/4 of the patella articulates with the femur. Secures anterior thigh muscles to the tibia
It is attached to the tendon of the quadriceps femoris muscle
Improves leverage of thigh muscles across knee joint by increasing the angle at which it acts.
Patella action superior/inferior. Running on hard or slanted surfaces can result in “runner’s knee” –improper tracking of patella across patellar surface

33. Lower Limb Femur Patella Tibia Fibula Tarsals Metatarsals Phalanges

34. Tibia Medial leg bone- “shin bone”
Supports weight of body-receives weight from femur and transfers to the foot
Articulates with femur and fibula (proximally)
Articulates with fibula and talus -ankle (distally) – Lateral malleolus
Articulates with medial malleolus bony knob on inside of ankle at distal end; medial projection at the ankle
Joined to fibula by interosseous membrane; allows little to no movement; less flexible stronger and more stable
Medial and lateral condyles fairly flat articular surfaces articulates with femur condyles
Intercondylar eminence – ridge separating condyles
Tibial tuberosity – attachment of quadricep muscles; attaches patellar ligament
Anterior crest – sharp, angular; not covered by muscle

35. Lower Extremity Fibula Long, slender; lateral to tibia
Does NOT articulate with femur
Does not bear any body weight- no transfer of weight to ankle or foot
Attaches muscles for the feet and toes
Does not contribute to knee joint
Lateral malleolus- distal end—lateral “ankle”; bony protrusion laterally. Articulates with talus of the ankle and stabilizes the ankle joint
Lower Extremity

36. The Ankle (Tarsus) & Foot
7 bones
Body weight is carried by the two largest bones
Calcaneus forms heel attaches the calcaneal (Achilles tendon)
When standing most body weight transfers to the tibia then to talus to calcaneus then to the ground
Tendon enables the lifting of the heel to stand on tiptoes
Talus most superior tarsal bone - forms ankle joint with the lateral and medial malleoli
Carries weight from tibia across trochlea- pulley-shaped articular process
Navicular articulates with
talus and cuneiforms
Cuboid
Cuneiforms - medial, lateral, and
intermediate
The Ankle (Tarsus) & Foot M I
cuneiform L
navicular
cuboid
Talus
Trochlea of the talus
calaneus

37. Lower Extremity Metatarsus: Five Phalanges:
Numbered I–V, medial to lateral
Articulate with toes
Phalanges:
14 bones of the toes
Three phalanges (distal, medial, proximal)
Hallux- (big toe); 2 phalanges =proximal and distal

38. Foot Arches Bones of foot arranged into two arches
Ligaments and tendons hold them in place
Distribute body weight—function as a spring
Support body weight and provides balance while walking
Provide leverage when walking and running (puts considerable stress on the feet)
3 arches in total
Medial and Lateral horizontal arch
Transverse arch

39. Foot Arches The 3 springy arches absorb stress Longitudinal arch
Talar or medial from heel to hallux; curves well above the ground- causes a break in footprint leaving no mpression; elasticity provides shock absorption from sudden changes in weight bearing. Action of the posterior tibialis muscle
Calcaneal or lateral longitudinal arch from heel to little toe; less curvature
Transverse arch across middle of foot
Distribute ½ of standing and walking weight to the heel; the other ½ to the heads of the metatarsals
Held together by short, strong ligaments
FLAT FEET –arches never form or fall- Less tolerance for long standing or walking (prevented enlistment in Army military service)

40. Foot Disorders/Treatment
Club foot –Foot twisted medially; Treatment: orthopedic manipulations
Flat feet – Longitudinal arch decreased; Treatment includes muscular exercise training while feet are still growing. Once development has arrested no change will occur with exercise.
Claw feet / Pes cavus longitudinal arch increased; treatment includes custom shoes and/or surgery– stretching and strengthen exercises, massage
Bunion- deformity of the big toe; surgery; orthotics