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Ergonomics: Health Implications for Dental Hygienists www.ProSpineRehab.com

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Overview: Ergonomics and Health Implications for Dental Hygienists <ul><li>Increase awareness </li></ul><ul><li>Decrease work-related pain and injuries </li></ul><ul><li>Heighten productivity </li></ul><ul><li>Improve musculoskeletal health </li></ul><ul><li>Increase comfort </li></ul><ul><li>Improve quality of life </li></ul><ul><li>Extend careers </li></ul>

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What is Ergonomics? <ul><li>Ergonomics is the study of workers and their relationship with their occupational environment </li></ul><ul><li>How you position yourself, your patient, how equipment is utilized, how the workplace is designed and how it impacts your health </li></ul><ul><li>ERGONOMICS is a way to work smarter, more efficiently with less effort and discomfort to the human body </li></ul>

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Ergonomics in the Dental Health Field <ul><li>Studies show work-related pain in the dental field is not decreasing </li></ul><ul><li>Over half of all dental professionals continue to experience work-related pain </li></ul><ul><li>Why? The physically challenging nature of the work with numerous risk factors </li></ul><ul><li>Risk Factors </li></ul><ul><li>Prolonged Static Postures </li></ul><ul><li>Repetitive Movements </li></ul><ul><li>Working in a confined space </li></ul><ul><li>Challenges with positioning yourself or the patient </li></ul><ul><li>Limitations with the tools and equipment used </li></ul>©2008, Valachi from “Practice Dentistry Pain-Free”

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Reasons for Early Retirement Among Dental Health Professionals <ul><li>Musculoskeletal Disorders (29.5 %) </li></ul><ul><li>Cardiovascular Disease (21.2%) </li></ul><ul><li>Neurotic Symptoms (16.5%) </li></ul><ul><li>Tumors (7.6%) </li></ul><ul><li>Diseases of the Nervous System (6.1%) </li></ul>©2008, Valachi from “Practice Dentistry Pain-Free”

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Ergonomics: The Human Factor <ul><li>People Are Different </li></ul><ul><li>We come in different shapes and sizes yet the workplace is often set up for “ one size fits all ” </li></ul><ul><li>People Have Limitations </li></ul><ul><li>We have physical and mental limits for working </li></ul><ul><li>- The wrist cannot tolerate excessive extension </li></ul><ul><li>- The back cannot tolerate excessive bending or twisting </li></ul><ul><li>- The neck was not meant to be in constant flexion </li></ul><ul><li>- Muscles will fatigue if under constant tension </li></ul>©2008, Valachi from “Practice Dentistry Pain-Free”

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Consequences of Poor Ergonomics <ul><li>Fatigue </li></ul><ul><li>Pain/Discomfort </li></ul><ul><li>Illness/Injury </li></ul><ul><li>Missed days at work </li></ul><ul><li>Errors </li></ul><ul><li>Lower productivity </li></ul><ul><li>Patient dissatisfaction </li></ul>

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Poor Ergonomics: Signs and Symptoms <ul><li>Physical Signs </li></ul><ul><li>Decreased range of motion </li></ul><ul><li>Deformity </li></ul><ul><li>Decreased grip strength </li></ul><ul><li>Loss of muscle function </li></ul><ul><li>Symptoms </li></ul><ul><li>Pain </li></ul><ul><li>Numbness </li></ul><ul><li>Tingling </li></ul><ul><li>Burning </li></ul><ul><li>Cramping </li></ul><ul><li>Stiffness </li></ul>©2008, Valachi from “Practice Dentistry Pain-Free”

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Poor Ergonomics = Musculoskeletal Disorders <ul><li>The World Health Organization definition: </li></ul><ul><li>Musculoskeletal Disorder is “a disorder of the muscles, tendons, peripheral nerves or vascular system not directly resulting from an acute trauma or instantaneous event” </li></ul><ul><li>Two Most Common Causes for Musculoskeletal </li></ul><ul><li>Disorders in the Dental Health Profession </li></ul><ul><li>Cumulative Traumas </li></ul><ul><li>Prolonged Static Postures </li></ul>©2008, Valachi from “Practice Dentistry Pain-Free”

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Cumulative Trauma <ul><li>Repetitive Movements like Scaling and Polishing are Cumulative Traumas </li></ul><ul><li>Vibrations transmitted by dental handpieces or mechanical scalers are Cumulative Traumas </li></ul><ul><li>Cumulative Traumas add up </li></ul><ul><li>These microtraumas cause “ wear and tear ” on the muscles, tendons, and nerve tissue </li></ul>

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Prolonged Static Postures <ul><li>Human body was designed for movement </li></ul><ul><li>Dental hygiene procedures means practitioners must maintain static postures </li></ul><ul><li>Hygienists hold postures that require more than 50% of the body’s muscles to contract to resist gravity </li></ul><ul><li>Muscle overload leads to decreased blood flow and increased pressure on the muscles and joints </li></ul>©2008, Valachi from “Practice Dentistry Pain-Free”

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Flowchart: Static Overload <ul><li>PROLONGED STATIC POSTURES </li></ul><ul><li>Muscle Fatigue and Muscle Imbalance </li></ul><ul><li>Muscle Ischemia, Trigger Points, Muscle Substitution </li></ul><ul><li>PAIN </li></ul><ul><li>Protective Muscle Contraction </li></ul><ul><li>Joint Hypomobility, Nerve Compression, Spinal Degeneration/Herniation </li></ul><ul><li>MUSCULSKELETAL DISORDERS </li></ul>©2008, Valachi from “Practice Dentistry Pain-Free”

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Static Postures leads to Muscular Imbalances <ul><li>Muscles responsible for rotating the body to one side become tighter (shorter), while opposing muscles become weaker (longer) </li></ul><ul><li>Right handed hygienists repeatedly assume NECK ROTATION TO LEFT with SIDE-BENDING TO RIGHT to gain better visibility </li></ul><ul><li>Problems with NECK ROTATION TO RIGHT with SIDE-BENDING TO LEFT </li></ul>©2008, Valachi from “Practice Dentistry Pain-Free”

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Static Postures = Muscle Ischemia <ul><li>As postures deviate from neutral, muscles contract harder to maintain working postures </li></ul><ul><li>During static muscle contraction, the vascular supply to muscle and surrounding tissues is restricted </li></ul><ul><li>Results in depleted nutrient and oxygen supply ( ischemia ) </li></ul><ul><li>Lactic acid and other metabolites accumulates causing pain and tissue damage </li></ul>

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Cumulative Traumas and Prolonged Static Postures Lead to Musculoskeletal Disorders <ul><li>Trigger Points and Myofascial Pain Disorders of Neck </li></ul><ul><li>Degenerative Joint Disease (Arthritis) </li></ul><ul><li>Thoracic Outlet Syndrome </li></ul><ul><li>Tendinitis </li></ul><ul><li>Carpal Tunnel </li></ul><ul><li>Syndrome </li></ul><ul><li>Trigger Finger </li></ul><ul><li>Nerve Entrapment Syndromes </li></ul><ul><li>Lower Back Pain </li></ul><ul><li>Sciatica </li></ul>

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Myofascial Pain: Trigger Points <ul><li>Trigger Points : groups of muscle fibers that are in a constant state of contraction inside a tight band of muscle </li></ul><ul><li>Feels like a knot or a small pea in muscles, and when pressed on can refer pain to distant parts of the body </li></ul><ul><li>Ischemic areas are susceptible to the development of trigger points </li></ul>

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Myofascial Pain: Trigger Points

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Myofascial Pain: Trigger Points

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Static Postures: Degenerative Joint Disease <ul><li>Synovial fluid, which lubricates the joints, is produced each time a joint moves </li></ul><ul><li>Lack of movement and contracted muscles from static postures reduces the synovial fluid production, resulting in joint hypomobility </li></ul><ul><li>This loss of mobility leads to degenerative changes and more musculoskeletal disorders </li></ul>

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Static Postures: Degenerative Joint Disease <ul><li>Symptoms </li></ul><ul><li>Intermittent/chronic pain and stiffness </li></ul><ul><li>“ Creaking” or “cracking” of joints </li></ul><ul><li>Swelling in the joints </li></ul><ul><li>Loss of motion in the joints </li></ul><ul><li>Increased pain with activity or use </li></ul>

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Neck and Shoulder Disorders Thoracic Outlet Syndrome <ul><li>Condition resulting from compression of the nerves, arteries, and veins as they pass through from the neck to the arm (thoracic outlet) </li></ul><ul><li>Possible causes: tight scalenes, cervical rib, tight pectoralis muscle, traumas </li></ul><ul><li>Often misdiagnosed </li></ul>

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Neck and Shoulder Disorders Thoracic Outlet Syndrome <ul><li>Symptoms </li></ul><ul><li>Pain in the neck, shoulder, arm or hand </li></ul><ul><li>Numbness and tingling of fingers </li></ul><ul><li>Muscle weakness/fatigue </li></ul><ul><li>Cold sensation in the arm, hand or fingers </li></ul>

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Cumulative Trauma Injury: Tendinitis <ul><li>When tendons slide back and forth through their sheaths friction is created </li></ul><ul><li>As with any other moving part, enough friction can cause wear and tear along with inflammation </li></ul><ul><li>When tendons or sheaths swell, and there is pain and tenderness </li></ul>

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Wrist Tendinitis <ul><li>Pain, swelling and inflammation on the thumb side of the wrist </li></ul><ul><li>Made worse with grasping and twisting activities (polishing and scaling) </li></ul><ul><li>Occasional “catching” or snapping when moving thumb </li></ul>

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Shoulder Tendinitis <ul><li>Elevated arm postures cause shoulder impingement </li></ul><ul><li>Leads to tendinitis in the rotator cuff </li></ul><ul><li>Pain is usually felt in the front or the side of the shoulder </li></ul><ul><li>Worse with activity </li></ul>

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Carpal Tunnel Syndrome <ul><li>Compression of the Median Nerve as it passes through the Carpal Tunnel </li></ul><ul><li>Caused by pinching and gripping activities with the wrist bent </li></ul><ul><li>Made worse with repetitive flexion and extension activities at the wrists </li></ul>

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Carpal Tunnel Syndrome <ul><li>Symptoms </li></ul><ul><li>“ Pins and needles” in the hands and fingers </li></ul><ul><li>Pain in the thumb, index and middle finger </li></ul><ul><li>Limited range of motion at the wrist </li></ul><ul><li>Pain radiating up the arm </li></ul><ul><li>Decreased grip strength </li></ul><ul><li>More pain at night </li></ul>

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Trigger Finger (Tenosynovitis) <ul><li>Sustained forceful grips and repetitive motion irritates the tendon and tendon sheath (tenosynovium) </li></ul><ul><li>Nodules form in tendon causing warmth, swelling, tenderness of the tendon </li></ul><ul><li>Pain occurs during movement that place tendons in tension </li></ul><ul><li>Fingers lock in “Trigger Position” </li></ul>

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Cubital Tunnel Syndrome <ul><li>Prolonged use of the elbow while flexed or trauma from overuse can compress the Ulnar Nerve </li></ul><ul><li>Pain, numbness, tingling and impaired sensation in the little and ring fingers, side and back of hand </li></ul><ul><li>Loss of fine control </li></ul><ul><li>Reduced grip strength </li></ul>

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<ul><li>Compression of ulnar nerve in Guyon’s canal at the base of the palm </li></ul><ul><li>Caused by repetitive wrist flexing or excessive pressure on palm/base of hand </li></ul><ul><li>Pain, weakness, numbness, tingling, burning in the little finger and part of the ring finger </li></ul><ul><li>Symptoms may worsen at night or early morning </li></ul>Guyon’s Syndrome

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Upper Crossed Syndrome <ul><li>Tight Levator Scapulae Upper Trapezius Scalenes Pectorals </li></ul><ul><li>Weak Middle/Lower Traps Rhomboids Serratus Anterior Deep Neck Flexors </li></ul><ul><li>Elevated shoulders </li></ul><ul><li>Forward head postures </li></ul><ul><li>Jutting shoulder blades </li></ul><ul><li>Neck Pain and Upper Back Pain </li></ul>

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Low Back Pain <ul><li>Low Back Pain is the leading cause of occupational disability in the dental healthcare profession </li></ul><ul><li>Studies show that low back pain is clearly related to seated postures and sitting duration </li></ul>

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Low Back Pain <ul><li>We often think of a back injury as caused by a single event, like lifting a heavy load </li></ul><ul><li>The lower back is vulnerable to Cumulative Trauma </li></ul><ul><li>More lower back injuries result from the cumulative effects of bending, twisting, or excessive sitting </li></ul><ul><li>Working continuously in a seated position places tremendous static load on the back muscles, discs, and joints </li></ul>

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Low Back Pain: The Problem with Sitting <ul><li>With seated postures, pressure in the lumbar disks increases by 50% from standing </li></ul><ul><li>Unsupported sitting causes 2x more axial loading in the spine than standing </li></ul><ul><li>During forward flexion and rotation (a position often assumed by dental hygienists) the pressure increases by 200% </li></ul>

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Low Back Pain: Disc Degeneration, Bulge and Herniation <ul><li>Spinal discs provide for flexibility shock absorption </li></ul><ul><li>Discs are composed of tough outer layer (annulus fibrosis) and gel-like center (nucleus pulposis) </li></ul><ul><li>When weight is applied to the disc, the nucleus expands outward and puts pressure on the annulus fibrosis </li></ul>

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Low Back Pain Disc Degeneration and Herniation <ul><li>Sitting while flexing forward compresses the discs in the front </li></ul><ul><li>Uneven pressure on the disc leads to disc bulging and herniation </li></ul><ul><li>When the disc bulges or herniates backwards the nerves can become pinched </li></ul>

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Low Back Pain: Sciatica <ul><li>Pain from lower back or hip radiating to the buttocks and legs </li></ul><ul><li>Leg weakness, numbness, or tingling </li></ul><ul><li>Commonly caused by prolapsed intervertebral disc pressuring the sciatic nerve </li></ul><ul><li>Worsened with prolonged sitting or excessive bending and lifting </li></ul>

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Low Back Pain: A Vicious Cycle <ul><li>People with back problems seem to be faced with this vicious cycle </li></ul><ul><li>There is considerable evidence that bed rest and passive treatments have limited value </li></ul><ul><li>We now know that activity and the right kind of exercise are critical to treating back pain </li></ul>Stop Moving Back Pain Hurts to Move Stiffness Weakness

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Lower Crossed Syndrome <ul><li>Tight Hip Flexors Lower Back Muscles </li></ul><ul><li>Weak Abdominal Muscles Gluteus Maximus </li></ul><ul><li>Swayback - excessive curve of the lower back </li></ul><ul><li>Anterior Pelvic Tilt - hips tilted forward </li></ul><ul><li>Lower Back Pain </li></ul>

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What is the best position to sit in? Traditional 90 º Sitting Is not It <ul><li>Problems with Traditional 90 ° Sitting </li></ul><ul><li>Looks nice but it’s just not comfortable </li></ul><ul><li>Natural curve of the lower back collapses </li></ul><ul><li>Leads to muscle tension and misaligned vertebrae </li></ul><ul><li>Increases static load on the discs </li></ul><ul><li>Decreases circulation in lower extremities </li></ul>

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What is the best position to sit in? Leg Balanced Sitting <ul><li>Allows for forward and upward postures to transfer some of the body’s support to the feet </li></ul><ul><li>Hip angle of 100 ° to 120 ° </li></ul><ul><li>Knee angle of 110° to 135° </li></ul><ul><li>Forward seat tilt of 45° to 55° from horizontal </li></ul><ul><li>Opposing muscle groups are balanced and curve in lower back is maintained </li></ul>

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Chair Selection <ul><li>Saddle Seat Design </li></ul><ul><li>True waterfall design is an essential feature </li></ul><ul><li>Hydraulic piston assembly for the widest range of motion </li></ul><ul><li>Seat should be adjustable so hips can be slightly elevated beyond parallel without restricting blood flow to the legs </li></ul>

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Ergonomics for Dental Hygienists Workstation Layout <ul><li>Clutter threatens the safety and cleanliness of the dental operatory </li></ul><ul><li>Allows convenient positioning when required </li></ul><ul><li>Provide a clear line of sight to the oral cavity and all required equipment </li></ul>

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Ergonomics for Dental Hygienists Workstation Layout <ul><li>Optimize space for work from 7 o’clock to 1 o’clock position for right handed Hygienists (11° to 5° if Left Handed) </li></ul><ul><li>Instruments should be accessible while seated (within 20 inches of the front of body) </li></ul><ul><li>Hoses should be positioned away from the body </li></ul><ul><li>Over-the-Patient or Over-the-Head equipment is most ergonomic </li></ul><ul><li>Use mobile carts for less commonly used equipment </li></ul>

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Ergonomics for Dental Hygienists Scheduling <ul><li>Scheduling of procedures should be considered. </li></ul><ul><li>Difficult procedures scheduled back-to-back does not allow your body sufficient relaxation time </li></ul><ul><li>Potential strategies </li></ul><ul><ul><li>Increase treatment time for more difficult patients </li></ul></ul><ul><ul><li>Alternate heavy and light calculus patients within a schedule </li></ul></ul><ul><ul><li>Vary procedures within the same appointment </li></ul></ul><ul><ul><li>Shorten patient’s recall interval </li></ul></ul>

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Ergonomics for Dental Hygienists Reduce Physical Effort <ul><li>Avoid bent or unnatural postures </li></ul><ul><li>Minimize sustained effort </li></ul><ul><li>Brief but frequent rest pauses can minimize fatigue and enhance productivity </li></ul><ul><li>Incorporate different activities to shift musculoskeletal demands from one part of the body to another </li></ul>

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Ergonomics for Dental Hygienists Equipment <ul><li>If your air/water syringe has a tightly coiled cord, consider replacing it with a lightweight hose </li></ul><ul><li>Swiveling devices can be placed on a handpiece to reduce torque </li></ul><ul><li>Newer handpieces are much lighter than the older models </li></ul>

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Ergonomics for Dental Hygienists Hand Instruments <ul><li>Look for: </li></ul><ul><li>Hollow or resin handles </li></ul><ul><li>Round, textured grooves, and compressible handles </li></ul><ul><li>Carbon-steel construction </li></ul><ul><li>Color-coding may make instrument identification easier </li></ul>

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Ergonomics for the Dental Hygienists Magnification Systems <ul><li>Should improve neck postures and Provide clearer vision </li></ul><ul><li>Consider additional lighting </li></ul><ul><li>Weight should also be considered </li></ul>

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Ergonomics for Dental Hygienists Gloves <ul><li>Gloves are one of the most overlooked ergonomic items </li></ul><ul><li>Hand-specific gloves allow the thumb to be in a more natural position </li></ul><ul><li>Gloves should not be too tight across the palm or too constricting at the wrist </li></ul><ul><li>The finger length should be adequate to allow for comfortable finger movement </li></ul>

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Preventing Ergonomic Injuries <ul><li>Move </li></ul><ul><li>Change Position </li></ul><ul><li>There is no one “correct” posture best for an entire working day </li></ul><ul><li>The Human Body Needs Change and Mobility </li></ul>

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Preventing Ergonomic Injuries <ul><li>Taking frequent, shorter breaks is preferable to taking longer, fewer breaks </li></ul><ul><li>Change positions before painful symptoms arise </li></ul><ul><li>Remember to go back to neutral postures </li></ul>

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Preventing Ergonomic Injuries Stretching Guidelines <ul><li>Never stretch to the point of pain or discomfort </li></ul><ul><li>Do not bounce or use quick, jerky movements </li></ul><ul><li>Stretch should be performed every half hour </li></ul>

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Suboccipital Muscles <ul><li>Deep muscles at the base of the skull responsible for protraction, rotation, and tilting of the head </li></ul><ul><li>Suboccipitals become shortened with forward head postures </li></ul><ul><li>Common cause for headaches </li></ul>

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Levator Scapulae <ul><li>Primary function is to elevate the scapula </li></ul><ul><li>Also bends the neck to the side </li></ul><ul><li>Tightens up when carrying a bag with a strap or talking on the phone </li></ul>

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Scalenes <ul><li>Functions to stabilize the neck during lateral movements </li></ul><ul><li>Aids in inspiration </li></ul><ul><li>Becomes tight with awkward leaning positions while seated </li></ul>

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Trapezius <ul><li>Upper elevates the shoulders </li></ul><ul><li>Middle retracts the shoulder blades </li></ul><ul><li>Lower rotates the shoulder blade downwards </li></ul><ul><li>Becomes tight with elevated arm postures </li></ul>

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Pectoralis Minor <ul><li>Functions to draw the shoulder blade forward and downward </li></ul><ul><li>Tight in people with a rounded shoulder posture </li></ul><ul><li>Shortened pec minor is a possible cause for Thoracic Outlet Syndrome </li></ul>

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Wrist Flexors/Extensors <ul><li>Prime function is to flex and extend the wrist </li></ul><ul><li>“ Tennis Elbow ” is pain on the lateral side of elbow </li></ul><ul><li>“ Golfer’s Elbow ” is pain on the medial side of the elbow </li></ul>

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Hamstrings <ul><li>Main function is to bend the knee </li></ul><ul><li>Secondary role in extending the hip </li></ul><ul><li>Weak low back and glute muscles increases tightness in the hamstrings </li></ul><ul><li>Prolonged seated postures also causes tight hamstrings </li></ul>

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Iliopsoas <ul><li>Primary function is to flex the hip (bring thigh up towards the abdomen) </li></ul><ul><li>People with chronic lower back pain often have very tight hip flexors </li></ul><ul><li>Commonly shortened with prolonged seated postures </li></ul>

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Piriformis <ul><li>Main function is to externally rotate the hip/thigh </li></ul><ul><li>Shortened in people who sit for long periods of time </li></ul><ul><li>“ Piriformis Syndrome” causes compression of the Sciatica nerve </li></ul>

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Questions and Answers