Cumulative Trauma Disorders (CTDs)

1. Cumulative Trauma Disorders (CTDs) • Cumulative Trauma Disorders – disorders of the softer tissue due primarily to repeated use. Typically in the upper extremities and can range from joint inflammation to muscle soreness • People generally acceptable to these type of problems are: • garment sewing people • computer operators • manual packaging • barbers • carpentry • Human hand composed of tendons, ligaments, nerves, etc. • flexor tendons pass through a tight tunnel called the carpal tunnel

2. CTDs • Causes and Prevention Techniques • Unnatural joint posture – any time a joint assumes an unnatural position CTD risk is increased. See Figure 3.19. • Forceful application – application of force to hinge joints (e.g., wrist) increases injury potential. Pivot joints (elbow) are at a lesser risk. Some evidence suggests that exceeding one-third of workers static muscle strength maybe a causative factor. • Repetition of activity – highly repetitive tasks (less than 30 seconds) pose more risk to the employee • Individual factors – preexisting conditions aggravate conditions such as neuropathy, arthritis, small hand/wrist. • Other – localized pressure and exposure to vibration and cold over time may cause CTDs. • Prevention techniques include administrative and engineering controls (automation, job and workplace design, tool redesign, and work/rest cycles) • Therapeutic approaches include rest, immobility, vitamins, anti-inflammatory drugs and even surgery.

3. CTDs • Forms of CTDs • Bursitis - inflammation of a bursa –padlike sacks found around the joints • Tendonitis – inflammation of the tendons • Telephone operator’s elbow – due to resting elbow on hard surface leading to numbness • Carpal-tunnel syndrome - inflamed tendons, tendon sheaths, swelling, etc.

4. Carpal Tunnel Syndrome Affected area