Anatomy and Movement Mechanics

LRAS OCR 2005

Functions of Skeletal System

1. Protect organs and soft tissues

2. Support soft tissues/Gives Shape

3. Facilitate production of RBCs

4. Acts as a reservoir for minerals e.g. phosphorus and calcium

5. Provides attachment for skeletal muscles (produces a lever system for body movement)

Simple Skeletal Anatomy

Axial Skeleton consists of…. Skull Spinal column Ribs and sternum

Appendicular Skeleton consists of… Appendages…arms, legs and pelvic

girdle

Types of Bones

Long bones Legs, arms, fingers and toes Consist of a DIAPHYSIS or shaft Ends of long bones are EPIPHYSES Joint surfaces of bones covered with

ARTICULAR CARTILAGE Outer membrane of bone is PERIOSTEUM

Flat bones Cranium

Types of Bones

Short bones Bones of the ankles (tarsal bone) and wrist

(carpals) Mostly spongy bone with thin outer layer of

compact bone Irregular shaped bones

Vertebrae Muscle attachments

Seasmoid bones Patella – Found within a ligament

Joint Structure and Function

An articulation (joint) is a point of contact between two or more bones.

Trade off between strength and stability. CLASSIFICATIONS:

Immoveable (fibrous) (Synarthrodial); sutures of skull

Cartilaginous (or Amphiarthrodial) Bones separated with fibrocartilage disk

Synovial (or Diarthrodial) Freely moveable; most common Ligaments, muscles provide stability

Anatomy of a Synovial Joint

Joint enclosed in articular capsule (ligamentous)

Synovial membrane lines inner surface of articular capsule

Synovial membrane secretes synovial fluid

Hyaline or articular cartilage lines bone ends (absorbs shock and decreases friction)

Anatomy of a Synovial Joint

Articular discs (menisci) Pads of fibrocartilage Maintain stability & fit, ↓

friction Torn cartilage

Bursae Saclike structures Alleviate friction Lined with synovial

membrane Between skin and bones ;

tendons and bones; ligaments and bones

Bursitis

Factors affecting movement at Synovial Joints

1. Shape of articulating bones2. Strength and tension of ligaments3. Arrangement and tension of muscles4. Apposition of soft parts5. Hormones

Types of Synovial Joints

Uniaxial or HINGE joint Movement in only one plane Knee/elbow

Biaxial or CONDYLOID Movement in two plane or

two axis of motion Wrist

Triaxial or BALL AND SOCKET 3 planes of motion involving a

concave surface Hip joint/ Shoulder joint

Synovial Joints con’t….

Nonaxial or GLIDING Motion is sliding rather than motion around an axis Bones of the wrist

SADDLE joint Movement in two planes Thumb joint

PIVOT Joint Turning movement about

one long central axis Radio-ulnar joint

Planes of Movement

Planes Human movements are described in three dimensions based on a series of planes and axis. There are three planes of motion that pass through the human body.

•The sagital plane•The frontal/coronal plane•The transverse (horizontal) plane

The sagital plane lies vertically and divides the body into right and left parts.

The frontal plane also lies vertically however divides the body into anterior and posterior parts.

The transverse plane lies horizontally and divides the body into superior and inferior parts.

Anatomical PositionNeed reference terms to describe the relationship of body structures to one another.

Superior..a structure that is higher than another e.g. knee is superior to ankle joint

Inferior…a structure that lies below another e.g ankle joint is inferior to knee joint

Anatomical Position

Posterior: The back of the body or structure e.g. the back is posterior to the abdominals

Anterior: The front of the body or structure e.g. The bellybutton is anterior to the gluteal muscles

Anatomical Position

Medial: A structure that is closer to the midline of the body or movement towards the midline e.g. the sternum is medial to the shoulder

Lateral: A structure further away from the midline or movement away from the midline e.g the shoulders are lateral to the chin

Anatomical Position

Distal: The end of a structure on the extremities located further from the trunk e.g.the hand is distal to the elbow.

Proximal: The end of a structure on the extremities located closer to the trunk e.g the elbow is proximal to the hand.

Anatomical Position

Dorsal: The top of the foot

Plantar: The bottom of the foot

Dorsal

Plantar

Movement Mechanics

Nervous Sysytem and Muscular Sysytem coordination to produce movement involves the principle of LEVERS.

4 elements: Rigid levers are long bones of body Joint act as the fulcrum or axis of movement Muscles act as the force is applied to the lever Body segments or external resistance act as the

load.

Types of Contractions

Concentric contraction (shortening) Forcible contraction leading to muscle

shortening Understand role of AGONIST &

ANTAGONIST MUSCLES Eccentric contraction (lengthening)

Muscle acts as a brake to control speed of movement caused by another force

Isometric contraction (static) Muscle exerts a force that counteracts

an opposing force

Types of Movements

Anatomical Position/Foetal position

Flexion/Extension Horizontal Flexion/Extension Abduction/Adduction Rotation Circumduction Pronation/Supination Dorsiflexion/Plantarflexion Lateral Flexion

Task 10 P14-15

Movements

Movements

Movements

Joint Movements

Shoulder Flexion – anterior movement of the arm to a decreasing

angle from neutral Extension – posterior movement Abduction – raising arm to side away from body Adduction – bringing arm towards the side Internal rotation – medial rotation so that anterior surface is

turned to the body External rotation – lateral rotation Horizontal Flexion/Extension Scapular elevation - raising to head/ears Depression - lowering shoulder blades Protraction - forward Retraction – back or shoulder blades together Rotation (Up or Down)- refers to lower angle of scapula Circumduction – Extension, Abduction, Flexion, Adduction

Joint Movements

Elbow Flexion Extension Slight Abduction, Adduction

Radio-Ulnar Pronation Supination

Knee Flexion Extension Slight Abduction, Adduction

Joint Movement

Spine

Flexion (sit-up)ExtensionRotationLateral Flexion (side bend)

Joint Movements

Hip Flexion…thigh up to abdomen Extension Adduction Abduction Lateral or outward rotation Medial or inward rotation Circumduction

Joint Movements

Ankle Dorsiflexion Plantar flexion Inversion Eversion

Wrist Flexion/Extension Adduction or radial deviation Abduction or ulnar deviation Circumduction