Joints, Muscles and Movement I ANPS Anatomy & Physiology Joints, Muscles and Movement I

Joints/Articulations points of contact – where bone meets bone compromise between stability vs mobility properties and support of a joint depend on its function shape of joint surfaces or articular surfaces ligaments (connective tissue from bone to bone; can be part of articular capsule) tendons (connective tissue from muscle to bone) Joint: bone meets bone Stable joints: cranium, pelvis  inflexible Flexible joints: shoulder, knee, hip  unstable and prone to injury

Joint Types/Classifications Bony – bone on bone Fibrous – bones linked by fibrous connective tissue (suture, syndesmosis, gomphosis) Cartilagenous – bones linked by cartilage connective tissue (synchondrosis, symphysis) Synovial Joints – ends of bones not connected by connective tissue; contains joint cavity (many types) little/no movement movement

Bony joint – frontal bone Glabella Supraorbital foramen (or notch) Supraciliary arch -two pieces of frontal bone fused where bony joint is present Frontal bones newborn skull

Sutures - Fibrous joint Coronal Anterior Sagittal Suture joint- locked together by fibrous CT, can move a little bit Pterion Posterior Lamboid

1st costal joint - Cartilagenous joint clavicle first rib Sternal costal joint: between sternum & costal rib (first picture) Sternoclavicalar joint: between sternum & clavicle (second picture)

Basic Synovial Joint Architecture Articular cartilage – hyaline cartilage at ends of bones Joint capsule – fibrous capsule reinforcing joint Synovial membrane – capsule lining; produce synovial fluid Joint cavity – space in capsule separating articular cartilage Synovial Joint= MOVABLE Synovial fluid= lubricant, allows joint to move better

Synovial Joint Modifications Articular disc – fibrocartilage disc that supports joint shock or fit (vertebral disc/meniscus in knee) Labrum – fibrocartilage ring that deepens a synovial joint (shoulder/hip joints) Bursa – closed synovial sac reducing friction between surfaces Ligaments – bone/bone connective tissue supporting capsule Tendons – muscle/bone connective tissue; can support capsule - Labrum: inner lip - Burse: between muscle & bone, tendon & bone

glenoid fossa bursa labrum labrum shoulder joint hip joint

Synovial Joint Modifications Articular disc – fibrocartilage disc that supports joint shock or fit (vertebral disc/meniscus in knee) Labrum – fibrocartilage ring that deepens a synovial joint (shoulder/hip joints) Bursa – closed synovial sac reducing friction between surfaces Ligaments – bone/bone connective tissue supporting capsule Tendons – muscle/bone connective tissue; can support capsule

Types of Synovial Joints Gliding / planar joint – sliding movement (sternoclavicular joint) Hinge joint – joints permitting flexion/extension (elbow/knee joints) Pivot joint – joints permitting rotation (atlantoaxial/radioulnar joints) Saddle joint – saddle shaped articular surfaces (metacarpal finger joint) Ball/socket joint – best known (shoulder/hip joints) Know all these Joints Hinge joints: move in one plane (up or down), tempomandibular joint Pivot joint: left & right Saddle joint: 2 planes, conduylar joint (base of thumb) Ball /socket joint: rotation

Motion terms Flexion and Extension. Abduction and Adduction. Usually occurs in the sagittal plane. Flexion typically results in a decrease in joint angle. Extension typically results in an increase in joint angle. Abduction and Adduction. Usually occurs in the coronal plane. Abduction typically results in movement away from the midsagittal plane. Adduction typically results in movement toward the midsagittal plane. Medial- and Lateral-Rotation. Movement along the long axis of a long bone. Medial rotation anterior surface rotates medially towards the midsagittal plane. Lateral rotation anterior surface rotates laterally away from midsagittal plane. Anatomical Position & Body Planes Anatomical Position: Body is upright, arms at sides, palms faced out, toes pointed out Sagittal Plane: right & left halves Coronal Plane: anterior & posterior = ventral & dorsal Transverse Plane: superior (upper) & inferior (lower) Hyper extension: moving (arm) into posterior plane

Motion terms Pronation and Supination. Protraction and Retraction. Pronation - rotation of radioulnar joint such that the palm is down. Supination - rotation of radioulnar joint such that palm is up. Protraction and Retraction. Protraction - forward (anterior) movement of body part. Retraction - backward (posterior) movement of body part. Elevation and Depression. Elevation - superior movement of body part (i.e., scapula). Depression - inferior movement of body part (i.e. scapula). - Pronation: not long axis of long bone (because radius folds over ulna) Protracting: punching someone Retraction: wind up of punch Elevation: shrugging shoulders Depression: dropping shoulders

Motion terms Inversion and Eversion. Dorsiflexion and Plantarflexion. Inversion – inward rotation of foot such that the sole is turned medially. Eversion – outward rotation of foot such that the sole is turned laterally. Dorsiflexion and Plantarflexion. Dorsiflexion – flexion of foot at the ankle joint towards the leg. Plantarflexion – extension at the ankle joint or flexion of foot towards the sole (pointing toes). Opposition. Movement of thumb such that it can touch all other digits. Lateral Bending. Side to side bending (as in vertebral column) in coronal plane. - Refer to feet: Inversion, Eversion, Dorsiflexion, Plantarflexion Dorsiflexion: feet point up Plantar flexion: feet point down Lateral Bending in neck, torso

Glenohumeral Joint (shoulder joint)

* * * * * Glenohumeral Joint (shoulder joint) (3)* capsule reinforced by: 4 ligaments (blue asterisk) and rotator cuff muscle tendons (red asterisks) * * * (3)*

Elbow joint (humeroradial/humeroulnar joints) Radioulnar joint

Hip joint Hip Joint * * *

Knee joint * * * * “unhappy triad” Unhappy triad: combination that gets damaged together Anterior cruciate ligament Medial meniscus Medial collateral ligament Medial collateral ligament * Lateral collateral ligament * “unhappy triad”

Muscles and motion For action, muscles cross 1 or more joints. Muscles can have multiple actions Actions dependent on joints crossed, size (complexity) and distal attachments Principal vs secondary actions On axial skeleton, unilateral actions of muscles can be different from bilateral actions Coordinate actions of multiple muscles can be different from actions of individual muscles (sum is different from its components). Principal actions: major actions (vs. secondary minor)