Appendicular Skeleton: Bones and Movement

• The session learning objectives are to understand the major bones of the pectoral/pelvic girdles, describe the bones of the upper and lower limbs and their main anatomical landmarks, identify the bony attachments with the axial skeleton, and describe the factors that contribute to movement and stability of the glenohumeral, hip, knee, and ankle joints.

Five Types of Bones

• There are five types of bones long, short, flat, irregular, and sesamoid.
• Bones provides shape and support, site for attachments, facilitates movement, protects internal organs, storage site for minerals, and development and storage of blood cells

Skeletal System Components

• The skeletal system is composed of 206 bones
• The skull has 22 bones
• The vertebral column has 33 bones
• The thoracic cage has 25
• The shoulder girdle and upper limbs has 64 bones
• The pelvic girdle and lower limbs has 62 bones

Appendicular Skeleton

• The functions of appendicular skeleton are to facilitate movement
• Also provides site for attachments (ligaments, muscles, tendons) via bony projections and landmarks.
• Provides articulations/joints that connect bone together (via ligaments)
• Hyaline cartilage prevents cortical bone erosion (bone can rub on bone)

Pectoral Girdle & Upper Limb

• Girdle arrangement consisting of the bones that connect the limbs to the axial skeleton
• The pectoral girdle includes the clavicle and the scapula and associated joints, its function is to connect arms on L and R side.
• It anchors upper limb to the sternum
• Provides passageway for blood vessels, lymphatic vessels, and nerves from the head/neck to limbs
• The upper limbs include the arm (humerus), forearm (radius and ulna), hand (carpal bones, metacarpals, and phalanges)
• Supports the attachment & functions of the UL to the human body
• Allows body to perform many functions and movements (i.e. care of self and others).

Clavicle Characteristics

• Clavicle also known as the "little key" is horizontal, S-shaped shaft
• Clavicle functions include increases UL efficiency, muscle attachment, transmits forces to axial skeleton, and strut
• Orientation of the clavicle includes
• Medial end: manubrium articulation and large
• Lateral end: acromion articulation and flat
• Superior surface smooth
• Inferior surface: roughened, for ligamentous attachment sites
• Varies in thickness, Curves, muscle attachments, and can be used for sex identification
• The Clavicle facts include
• 1st bone to ossify (5-6wks intrauterine)
• One of the last to finish ossification
• Long bone with NO medullary cavity

Scapula Functions and Orientation

• The scapula functions are structural, attach the UL to the thorax, and arm stabilisation.
• Orientation includes lying over ribs 2 to 7
• Also classified as a irregular/flat bone
• Glenoid fossa has 1/3 diameter of humeral head (shallow)

Differences in Bone Markings

• Trochanter is very large bump for muscle attachment that means runner
• Tuberosity is oblong, raised bump for muscle attachment with tuber meaning bump or lump
• Tubercle is a small tuberosity

Humerus Characteristics

• Orientation of the humerus Head = medial and proximal and olecranon fossa = posterior and distal
• The Distal Humerus is composed of olecranon fossa (posterior), capitulum (small, lateral), trochlea (lateral) shaped like a pulley, medial epicondyle (flexors of wrist), and lateral epicondyle (extensors of wrist)

Glenohumeral Joint

• The glenohumeral joint is synovial, the multi-axial ball and socket joint located in head of the humerus and glenoid fossa of the scapula
• Head of humerus surface area ≈ 3X glenoid concavity and held together by
  • Glenoid labrum deepens
  • Glenohumeral, Coracohumeral and Transverse Ligaments: STATIC STABILIZERS
• Muscles provide concavity compression : DYNAMIC STABILIZERS

Pectoral Girdle Ligaments

• Ligaments of the pectoral girdle include acromioclavicular (resist AP displacement of AC joint)
• Also includes the coracoacromial (restricts upward displacement of the acromial head)
• The coracoclavicular (resists rotation and vertical translation of AC joint) and the coracohumeral ligaments (tightens during external rotation)

Forearm Bones: Ulna and Radius

• The radius and ulna work together at the elbow to produce pronation and supination
• The ulna articulates with the humerus to form the elbow joint.
• Ulna features: Medial forearm bone Runs parallel to radius.
• Long slender bone that only contributes to the elbow joint
• Olecranon, coronoid, and trochlear notch
• Radius features: Lateral forearm bone Curved bone.
• Contributes to the elbow, proximal ulnar-radial and wrist joints.
• styloid process

Upper Limb Articulations

• At the elbow the olecranon process rolls into the olecranon fossa of the humerus
• The radial head functions to rotate against the proximal ulna = pivot joint

Elbow Joint & Ligaments

• Type of joint: Synovial, hinge
• Main ligaments: Radial collateral, Ulnar collateral & Annular ligament

Carpal Bones

• Carpal bones has 8 short bones
• Located in the wrist (carpus)- proximal aspect of the "hand"
• Carpal rows (proximal & distal), 4 bones each. Form gliding joints
• Scaphoid & lunate articulate with radius; no bones articulate with the ulna
• High flexible and High ROM

Carpals

• The proximal row consists of scaphoid, lunate, triquetrum, and pisiform
• The distal row consists of trapezium, trapezoid, capitate, and hamate.

Carpal Bones Mnemonic

• So Long To Pinky, Here Comes The Thumb” Mnemonic for carpal bones names

Metacarpals

• The 5 long bones that form palm of hand numbered from lateral to medial (thumb), consist of a base, shaft & head (knuckles)
• Base articulates with distal row of carpals and head articulates with proximal phalanges

Phalanges

• All digits except the thumb have three phalanges: proximal, middle, and distal.
• Digit I (thumb) lacks the middle phalanx.
• Metacarpals assigned Roman numerals I to V starting from the great toe.

Pelvic Girdle Functions

• The pelvic girdle function distributes load from the spine to sacrum, splitting across the SA joints, passed on to the femurs
• Transfer of weight can occur with the assistance of bony structures and ligaments

Pelvic Girdle Components and Functions

• The pelvic girdle components are coxal bones (Os Coxae or Innominate)
• Also Sacrum, Coccyx, Function/ contains supports intestines, urinary and reproductive organs.
• Attaches lower limb to axial skeleton, restricted mobility, and stabilize locomotion.
• Transfers of body weight and is a point of attachment
• Ilium (largest and most superior bone) Ischium (postero-inferior region)
• Pubis (antero-inferior)

Male v Female Pelvic Bone Characteristics

• Male :THICK & HEAVY in structure NARROW & DEEP in lesser pelvis HEART-SHAPED pelvic inlet SMALL Pelvic outlet
• < 70° Subpubic Angle
• Female: THIN & LIGHT structure WIDE & SHALLOW lesser pelvis OVAL-SHAPED pelvic inlet LARGE pelvic outlet

80° Subpubic Angle

Landmarks of the Pelvic Bone

• Landmarks - iliac crest, sacroiliac joint, anterior superior iliac spine, anterior inferior iliac spine.
• Also contains a pubic tubercle, obturator foramen, subpubic angle and pubic symphysis

Ligaments of the Pelvis

• Include sacroiliac, two Ilio lumbar bands, sacrospinous and sacrotuberous
• The sacroiliac ligaments are posterior, anterior and Interosseous, as well as help holding the pelvic complex together to aid, allowing for upper extremity, lower body weight transitions
• The sacrospinous ligament, extends from the sacrum to the ischial spine to aid the lesser sciatic foramen and sacrospinous prevents sacrum from collapsing anteriorly under weight of body

Femur (Thigh bone)

• Femur articulates with the acetabulum for the femoro-acetabular joint

• Is approximately 4 x femoral length in height

• Curvature indicates Race and a medial Head and anterior patellar Surface

• Head - rounded, articulates with acetabulum
  Greater & lesser trochanters – muscle attachment Gluteal tuberosity - muscle attachment site Linea aspera - vertical ridge on posterior shaft

  • Lateral & medial condyles - articulate with tibia Patellar surface - articulates Patella EXTRA-CAPSULAR Iliofemoral Ligament: Y-shaped (anterior) resists hyperextension

• Pubofemoral Ligament: resits abduction

• Ischiofemoral Ligament:Posterior - resists hyperflexion

• FUNCTION: Provides stability to acetabulofemoral joint Intracapsular

Transverse acetabular ligament and Ligamentum Teres - (femoral head

 - Without muscles & ligaments, stability is achieved by Acetabular labrium Zona orbicularis

Patella Characteristics

• Patella is a trangular sesamoid bone
• Enclosed in the quadriceps tendon that attaches the anterior thigh muscles to the tibia
• Functions to protect the knee joint, to increase the effective extension capacity of the quadriceps femoris (knee extension) and the contact area of the patellar ligament and the femur

Leg Bones: Tibia

• The leg bones/Tibia, (shin bone) is a Medial bone of the leg, receives the weight of the body
• Leg contains Medial & lateral condyles that articulate with the condyles of the femur to form the tibiofemoral joint.
• It has Tibial tuberosity where attachment site for anterior thigh muscles and a Medial malleolus/bulge of ankle that articulates with the talus distally, The Lateral bone of the leg acts to stabilize the ankle and does not bear weight is what?

Fibula Characteristics

• Provides sites for muscle attachment
• Head: articulates with proximal aspect of tibia Interosseous membrane connects bone to Tibia and the bone forms Lateral malleolus articulates with Talus bone of foot & forms lateral bulge of ankle

Knee Joint & Ligaments

• Synovial, hinge that contains the Anterial Cructiate Posterior Cruciate medial and Lateral Collateral Meniscus What type of jt helps resists displacement and is a c shape?

Bones of Ankle and Foot

The 4 Major structures consists what bones/ structures?

• Distal fibula and Tibia, Tarsals and metatarsals as well phalanges What type of bones allows balance and flexibility?Composed of 33 joints that allow for shock absorption, flexibility, & provide balance during locomotion

Tarsal Bones

Tarsal bones has 7 posterior hind foot weight bones and organized in digital and proximal groups. Which is primarily carried by talus and calcaneus and creates achilles?

Arches of foot

Arch's anchored in metatarsel what are some key stucts in each arch?
Which Keystone is Cuboid for the Lateral longitudinal? Talor head for medial long.?