Work-related Musculoskeletal Disorders (WMSDs)

What Causes WMSDs?

Awkward Postures High Forces High Repetition (Frequency) Long Durations

Back CTDs

Back injuries make up nearly half of all CTDs The lumbar region (lowest 5 vertebrae) is most common portion of spine to be injured L5/S1 Disc is particularly susceptible

Mechanical Injuries

Back sprains occur in ligaments Back strains occur in muscles and tendons Both occur when tissue is stretched or compressed beyond its limits due to excessive or repetitive extension, flexion or loading.

Carpal Tunnel Syndrome

CTS occurs due to tendon overuse Synovial Sheaths surrounding tendons swell Space is tight, so swollen sheaths rub against & impinge the median nerve.

Shoulder Bursitis

Caused by impingement of space in shoulder. Inflammation of Bursa sac between skin & rotator cuff Bursa cannot perform its function of lubricating tendons rubbing on bone

Medial Epicondylitis, Golfers Elbow

Caused by repeated flexion of wrist Similar to tennis elbow, but associated with opposite epicondyle Pain on inside of elbow

Lateral Epicondylitis, Tennis Elbow

Caused by repeated forearm muscle contractions to extend wrist. Pain on outside of elbow Small tears in tendons, inflammation or muscle tears.

Thoracic Outlet Syndrome

Compression of nerves & blood vessels passing under the clavicle. Weakness, Tingling or paleness when elevating the arm above the shoulder, Numbness or cool skin near thumb Caused by overuse of hands working above shoulder height

Herniated Disc

Discs of spine are meant to separate & cushion vertebrae Disc herniation means it expands beyond its limits Nearby spinal nerves can be impinged Pain, weakness, numbness in back & legs Caused by excessive lifting that compresses the disc + poor posture

Ganglion Cysts

Fluid Filled on Back of Wrist Fluid often Leaks from damaged tendon synovial sheaths Often a secondary symptom from a tendon issue

The Four Primary Risk Factors

Force Posture Repetition Duration

Over the past 40 years, MSDs have increased dramatically.

Increased Awareness Shift to Service and Technology Jobs Greater Reporting Expanded Workers Comp

High Forces

Increased loading of muscles & bones can tear, stretch, compress, etc. Adds dynamic loading (inertia), too

Awkward Postures

Increases moments. Causes tendons and ligaments to rub & stretch around joints.

Tendonitis

Inflammation of Tendons Tendons connect muscle to bone Causes: repeated overuse, especially in non-optimal postures Symptoms: pain during normal smooth motion of the joint

rotator tendinitis

Inflammation of one or more tendons in the rotator cuff Caused by multiple factors: overuse, poor posture, lifting, acute trauma

Tenosynovitis

Inflammation of the synovial sheath surrounding the tendon

Musculoskeletal Disorder (MSD):

Injuries to the bones, ligaments, tendons and muscles of the body caused by overexertion or repetitive motion.

Long Durations

Long hours of same task limits body's ability to recover & heal

High Repetition (Frequency)

Lots of muscle contraction & joint motion with no time for recovery Can worsen inflammation & microtears into more serious problems

Work-related Musculoskeletal Disorder (WMSD):

MSDs which can be attributed to workplace exposures.

Neck Tension Syndrome

May also be called: Tension Myalgia Chronic Neck Disease Neck-Shoulder Disorder Tension Neck Syndrome

Hand-Arm Vibration Syndrome (HAVS) " White Finger"

Most commonly, blood vessels leading to hand are constricted by exposure to repeated vibration or mechanical stress Numbness, pain, and pale skin in hands & fingers Formerly called: Reynaud's Syndrome Particularly in cold environments Also neurological & musculoskeletal effects.

Neck Tension Syndrome

Neck muscle irritation associated with static sustained muscle contractions or repeated, sustained overhead work. May also involve psychosocial contributors

CTS Pain

Numbness Tingling Pain

Carpal Tunnel Syndrome Causes

Overuse (frequent use of fingers) Posture / joint motion Wrist extension/flexion (as seen in the illustration) Ulnar/radial deviation can have similar effects

Recognizing an MSD

Symptoms Increase over time

Trigger Finger

Tenosynovitis of the index finger Finger does not extend smoothly when relaxing a fist Causes: repetitive gripping.

De Quervains Syndrome

Tenosynovitis of the thumb Causes: overuse of the thumb... picking up a child, lifting grocery bags by loops, texting, etc.

Ruptured Disc

Very similar to herniated disc Disc membrane actually ruptures Fluid in disc forced out and impinges or damages nerves

Other CTD Risk Factors

Vibration Exposure to Cold Mechanical Pressure Lack of Rest Psychosocial Factors

CTD

cumulative trauma disorder

The Humerus (upper arm bone)

divides into two ends as it connects to the elbow

Compression Injuries

includes disc hernias, ruptures, etc.

medial epicondyle

inside endpost

lateral epicondyle

outside endpost

WMSDs are the

primary "ergonomics" problem to most government agencies and industrial organizations