ehs 218 occupational ergonomics anatomy. basic anatomic positions anatomic position

EHS 218 Occupational EHS 218 Occupational

ErgonomicsErgonomics

Anatomy

Basic Anatomic Positions

• Anatomic Position

Basic Anatomic Positions

• Anterior = front

• Posterior = back

Basic Anatomic Positions

• Medial = toward midline of body

• Lateral = away from midline of body

Basic Anatomic Positions

• Proximal = closer to attachment / trunk

• Distal = farther from attachment / trunk

Basic Anatomic Positions

• Palmar = palm side

• Dorsal = back side of hand

Basic Structures and Functions

Bones, Ligaments, Tendons, Nerves, Muscles, and Joints

Bones

• Support weight and protect organs

• Body movements– 1st, 2nd, 3rd class lever

systems

• Blood cell formation • Storage of minerals

Ligaments

• Strong, flexible, stress resistant, somewhat elastic fibrous tissue

• Connect bone to bone• Stabilize joints - resist

movement for which joint is not constructed

• Guide motion

Tendons

• Connect muscle to bone

• Transmit force from muscle to bone

• Continuations of muscle tissue

Nerves

• Transmit and receive signals for movement and sensation

• Central nervous system, peripheral nervous system, autonomic nervous system

Muscles

• Composed of skeletal muscle tissue, nervous tissue, blood, and various connective tissues

• Only tissue that can shorten and produce tension at ends

• Generate force• Create motion• Muscle origins and insertions

– origin is usually proximal or stabilizer– insertion is usually distal or mover

Major Muscle Groups

Upper extremity

Lower extremity

Torso

Muscles of the Upper Extremity• Shoulder and back

– Deltoids– Trapezius– Latissimus dorsi

• Chest– Pectoralis major/minor

• Arm– Biceps– Triceps– Lower arm muscles

Deltoid

Trapezius

Pectoralis

Latissimus Dorsi

Biceps Brachii

Triceps Brachii

Lower Arm - Flexors

Lower Arm - Extensors

Muscles of the Lower Extremity

• Thigh– Quadriceps– Hamstrings– Abductors– Adductors– Gluteals

• Leg– Calf muscles

Quadriceps

Hamstrings and Gluteals

Calf Muscles

Muscles of the Torso

• Anterior torso– Abdominals

• Posterior torso– Erector spinae

Joints

Shoulder, Elbow, Wrist/Hand, Hip, Knee, and Spine

Joints

• When 2 or more bones meet• Functional junctions between

bones• Classified on basis of

structure and movement– Fibrous, cartilaginous,

synovial– Immovable, slightly

moveable, freely moveable

Basic Joint Movements

• Flexion – angle between segments decreases

• Extension – angle between segments increases

Basic Joint Movements

• Abduction – segment moves away from midline of body

• Adduction – segment moves toward midline of body

Basic Joint Movements

• Dorsiflexion – point foot up

• Plantar flexion – point foot down

Basic Joint Movements

• Inward rotation – rotation toward midline of body

• Outward rotation – rotation away from midline of body

Basic Joint Movements

• Supination – palm facing upward

• Pronation – palm facing downward

Basic Joint Movements

• Circumduction - complete rotation about segment midline

Upper Extremity - Shoulder

• Bones - clavicle, acromion, scapula, humerous• Muscles - rotator cuff (subscapularis, teres minor,

infraspinatus, supraspinatus), deltoids, latissmus dorsi, triceps, biceps, pectoralis

• Nerves - brachial plexus located deep within the shoulder

• Type of joint - ball-and-socket (synovial)

Movements ofthe Shoulder

• Flexion and extension• Horizontal flexion and

extension• Abduction and

adduction• Circumduction• Internal and external

rotation

Upper Extremity - Elbow

• Bones - humerous, radius, ulna• Muscles

– Flexors = biceps– Extensors = triceps

• Nerves - brachial plexus: musculotaneous, radial, ulnar, and median nerves pass through

• Joint type - hinge between humerous and ulna; sliding joint between humerous and radius (synovial)

Movements of the Elbow

Flexion and Extension, Pronation and Supination (at hand)

Upper Extremity – Hand/Wrist

• Bones - radius, ulna, 8 carpal bones, metacarpals, phalanges

• Muscles– all originate from distal end of humerous radius/ulna– flexors on anterior side– extensors on posterior side

• Nerves - brachial plexus: median nerve (lateral side of palm, palmar/dorsal aspects of thumb, index finger, middle finger, 1/2 ring finger); ulnar nerve (little finger and 1/2 ring finger)

Upper Extremity – Hand/Wrist

• Joint type - gliding joint (synovial)• Flexor retinaculum - creates the carpal

tunnel between the carpal bones and the retinaculum, through which the flexor tendons and median nerve pass

Movements of the Hand

Movements of the Thumb

Lower Extremity - Hip

• Bones - Femur and acetabulum of coxal bone• Muscles - anterior: flexors, adductors, abductors;

posterior: extensors (gluteals)• Nerves - Lumbosacral plexus• Movement - flexion/extension,

abduction/adduction, inward/outward rotation, circumduction

• Joint type - ball and socket (synovial)

Movements of the Hip

• Flexion and extension• Abduction and

adduction• Inward and outward

rotation• Circumduction

Lower Extremity - Knee

• Bones - femur, tibia, patella• Muscles

– Flexors = hamstrings (bicep femoris, semitendinosis, semimembrinosis), satrorious, gracilis, popliteus, gastrocnemius

– Extensors = quadriceps femoris

• Nerves - Lumbosacral plexus• Join type – synovial (most complex)

Movements of the Knee

• Flexion and extension

• Internal and external rotation (in flexion only)

Movements of the Foot

• Dorsiflexion and plantar flexion

• Eversion and inversion

Neck and Back

• Bones - vertebrae, C1-C7, T1-T12, L1-L5, sacrum and coccyx

• Muscles - erector spinae, abdominals• Function of spine - supports head and

trunk, protects spinal cord, permits movement

• Movement – between adjacent segments is limited; but the whole vertebral column has great flexibility

Neck and Back

• Intervertebral disks– Bands of fibrocartilage with

gelatinous core– No blood supply– Nutrition via pressure changes,

thus movement is required

• Curves of spine – “S” shape– thoracic and pelvic concave

anteriorly– cervical and lumbar convex

anteriorly

Movements of the Neck

• Flexion and extension• Lateral flexion (right

and left)• Rotation (right and

left)

Movements of the Back

• Flexion and extension (hyperextension)

• Lateral flexion (right and left)

• Rotation (right and left)

Nerves

Brachial Plexuses

Brachial Plexuses

• Musculotaneous• Ulnar• Median• Radial