Chapter 25 - Ergonomics

Identify the volar carpal ligament in the image.

#2 (in between thumb and pinky area near end of wrist)

Musculoskeletal disorders

- Painful conditions that affect both muscles and bones, such as neck or back pain and carpal tunnel syndrome - Tendonitis, bursitis, sprains, strains, and general pains are common symptoms - The early onset of pain should alert you to an imbalance

Cumulative trauma disorders

- Painful conditions that result from ongoing stresses to muscles, tendons, nerves, and joints. - To help prevent CTD's, periodic breaks and alternation of difficult procedures with less stressful procedures are recommended

Normal horizontal reach

- Reach created by a sweep of the forearm with the upper arm held at the side - Keep air-water syringe, hand piece, saliva ejector. and high-volume oral evacuator within a "normal horizontal reach"

What is the goal of ergonomics?

- To help people stay healthy while performing their work more effectively. - This is done by changing the workplace design, modifying instruments, strengthening muscles, taking breaks, using certain products, and providing proper training. - Ergonomic conditions are the safest, most efficient, and easiest way to work

Carpel tunnel syndrome

- With improper motion the tendons can swell and exert pressure on the median nerve. Repetitive and forceful motion can lead to CTS - a condition that causes numbness, tingling, or weakness in your hand. - Braces can be worn that will splint the tendon, preventing movement. This will allow the tendon to rest and recover from the stress of repetitive motion

Identify three categories of risk factors that contribute to increased risk of injury

1) Posture, 2) Repetition, 3) Force

In 1994 the Bureau of Labor Statistics recorded data on workplace-related injuries. How many do you think were the result of overexertion or repetitive motion?

705,800 cases, which accounted for 32% of all cases

Which number identifies the number of carpal bones present in the carpal tunnel area of the hand and wrist?

8

Which consequence is encountered by the dental assistant after wearing the gloves depicted in the figure? (loose gloves)

Difficulty in transferring instruments

Thenar Eminence (THEE-nar EH-meh-nents)

Fleshy mound on the palm at the base of the thumb

Which measure will the dental assistant take to prevent eyestrain?

Focus the eyes at a distance for 20 seconds.

Which hand exercise is being shown in the image? (finger being pulled)

Gently pulling and relaxing each finger

Describe exercises to reduce neck strain

Head rotations which involve tilting the head from right to left and from forward to backward without forcing the motion beyond a range of comfort

Strains

Injuries caused by extreme stretching of muscles or ligaments

Sprains

Injuries caused by sudden twisting or wrenching of a joint with stretching or tearing of ligaments

Which action will a dental assistant perform to reduce eyestrain caused by intense focusing for a long time?

Look up from the task and focus the eyes at a distance for 20 seconds.

Describe exercises to reduce eye strain

Look up from the tasks and focus your eyes at a distance for about 20 seconds to practice using your full range of vision

Identify common symptoms of musculoskeletal disorders

Neck or back pain and CTS

List the symptoms of carpel tunnel syndrome

Numbness, tingling, or weakness in your hand

Which symptom is typically noticed first in carpal tunnel syndrome?

Painful tingling in the hands at night

Discuss exercises that can reduce muscle fatigue and strengthen muscles

Pelvic tilt, hyper extension, knee to chest, sit-ups, suspend from bar, doorway stretch, neck isometric, rubber ball squeeze, rubber band stretch

Neutral position

Position of the body to maintain for a prolonged period, with a natural curvature of the spine. Sitting upright with your weight event distributed

Which action will the dental assistant take to obtain optimal operator positioning?

Position the thighs parallel to the floor.

Maximum vertical reach

Reach created by a vertical sweep of the forearm while the elbow is kept at midtorso level.

Maximum horizontal reach

Reach created when the upper arm is fully extended

Frequent performance of which action is the best way to prevent carpal tunnel syndrome (CTS)?

Resting of the hands

Which reason best explains why a dental assistant should sit with the hips leaning forward while working in a neutral position?

Rotate the pelvis backward

Describe the neutral working position

Sitting upright with your weight evenly distributed

Which injury results from extreme stretching of muscles or ligaments?

Strain

During which situation would the dental assistant find the shoulder shrug helpful to relieve discomfort?

Stress from holding the telephone handsets

Ergonomics

Study of people in their work environment, and how to prevent injuries