Use an external screen or keyboard.
Shoulder joints above hip joints, relatively straight back, thighs horizontal, lower legs vertical, and ankles neutral.
Objectifying intensity, frequency, and duration using tools like scales, tape measures, and dynamometers.
It prevents dangers such as crossing legs, which can block blood supply.
The recommendation is 500 mm, accounting for seat breadth greater than hip breadth and clothing corrections.
Eustress refers to the optimal range of stress loading that is neither too high nor too low, preventing injury.
Ergonomic interventions aim to address work limitations that affect productivity, focusing on anthropometrical and biomechanical characteristics of the body.
There is a high rate of complaints related to neck pain, particularly in the neck/shoulder region, often linked to tension and mouse usage.
They were often performed on cadavers and soldiers, which are not representative of the general population, and primarily included male and Caucasian samples.
Start from existing information to determine if there is an existing PDA for the job description, review PDA templates, and gather preliminary information if necessary.
Product design, clinical assessment, and prediction of medical outcomes.
Solutions include using a mouse designed for a neutral wrist, gel pads for forearm support, and wrist splints to maintain a neutral position.
The seat band should be at knee height.
MSDs represent 1 in 3 lost time injuries and have the highest associated costs among work-related diseases due to high chronicity rates.
Summarize data in a spreadsheet or report and submit the initial PDA/PDD for verification by the employee and/or management.
In the middle position, COM is directly over ischial tuberosities, supporting 25% of body weight; in anterior, it supports more than 25%; in posterior, it supports less than 25%.
Postural, Neuromuscular, and Vascular.
Main risk factors include posture, repetition, prolonged work without breaks, and static contractions.
Keep body close to the work surface, maintain similar posture as seated work, use a foot rail, and alternate between seated and standing work.
A certification corresponds to a bachelor’s degree that includes human health and ergonomics courses.
Muscle fatigue is defined as a reduction in the ability to exert force in response to voluntary effort.
It refers to the health risks associated with prolonged sitting, recently compared to smoking.
No evidence has been found linking computer work to shoulder tendonitis or elbow epicondylitis.
Mental stress and physical load contribute to muscular tension, leading to musculoskeletal disorders.
Laptops have smaller and lower screens, leading to added load on the upper back and hunched posture.
Static (structural) refers to fixed measurements like the distance between shoulder and fingertips, while dynamic (functional) refers to the distance a person can reach in a certain direction.
Exercise balls, sit-stand stools, and sit-stand computer workstations are recommended.
Disruption to mitochondrial cells impairs their capacity to produce ATP.
Seat width, seat back angle, backrest height and curvature, seat pan inclination, and arm rests.
They help accommodate different body types and promote better posture while sitting.
Back pain, neck pain, forearm pain, and wrist tendonitis.
It can lead to the adoption of new, sub-optimal postures and movement strategies, increasing the risk of secondary injuries.
The work surface height should be set at approximately 50mm below elbow height to prevent shoulder strain and optimize finger movement.
No, anthropometrics depend on generation and the country from which the data is taken.
Clothing corrections can add leeway, such as 65 mm for clothing, impacting the overall clearance recommendations.
The purpose of an ergonomics intervention is to modify aspects of work so that it better fits the worker, respecting anatomy and biomechanics, minimizing health risks, and optimizing productivity.
It can lead to neck rotation issues.
People change shape as they get older.
Bernardino Ramazzini is the founder of occupational/industrial medicine, known for his studies on occupational diseases and advocacy for protective measures for workers.
Work environment, equipment, and workflow into and out of the workstation must be verified.
Overuse injuries occur from repeated applications of stress that are lower than the magnitude required to cause traumatic injury.
Designing to account for that which is accountable, ensuring adequate space for the largest user (95th percentile).
Technology has allowed for more precise measurements, such as DEXA scans, aiding in the advancement of norm classification.
It should be adequate for the smallest user (5th percentile), ensuring that seat height does not exceed the lower leg of the 5th percentile user.
An 'ergonomic' keyboard design reduces radial and ulnar wrist deviation and allows motion to pivot around the elbow joint.
Potential problems include forearm pronation, wrist extension, repeated wrist deviations, and direct pressure on wrist bones.
It occurs when blood flow is suddenly restored to an oxygen-deprived area, potentially causing structural damage due to neutrophil action and inflammatory processes.
The most common pain reported is at the base of the right thumb, known as De Quervain’s.
By determining essential vs. non-essential functions and quantifying various tasks and sub-tasks along with their duration.
It leads to contractures and reduces the efficiency of cross-bridge detachment due to lower ATP levels.
A branch of human sciences dealing with body measurements such as height, weight, and body fat.
Kinesiologists specialize in movement and optimize function through physical activity, while occupational therapists focus on restoring function related to work through therapy.
New challenges include population diversity, an aging workforce, and people living with chronic diseases, as well as the fluid nature of work environments like open concept workplaces and remote work.
The main concerns include sedentarism/static work, musculoskeletal disorders (MSDs) affecting the neck, back, wrist, and forearm, as well as psychological and visual stress.
Set the screen at an optimal distance and change font size.
84% of people surveyed reported pain in at least one body part.
Improvement in processing times, less workload, and higher satisfaction.
Different ethnic groups, such as Asians, Caucasians, and Africans, have distinct morphological traits.
Preserve lordosis, facilitate adjustability, ensure safety from tipping, include a swivel base, casters on base, and breathable fabric.
Noise, lighting, vibration, and temperature.
Anterior, middle, and posterior sitting positions.
Keep the pitch angle of the head as small as possible.
Keep LOSA small and line of sight about 15 degrees below horizontal.
Leaning forward increases pressure on legs and feet, while leaning back puts more pressure on ischial tuberosities.
1. Determine job function, 2. Verify job function, 3. Identify job function in detail, 4. Quantify physical demands of each job function, 5. Record all processes.
They trigger the actions of chaperone cells that block important proteins' roles in tissue stress situations, which can be impaired during higher-energy tasks.
Tension neck syndrome, cervicalgia, and cervical syndrome.
It is important because workers are specialized, and their bodies are their main work tool; injury can lead to loss of income.
It assumes that 68% of the population falls within one standard deviation.
A gaze angle of 10-20 degrees below horizontal is recommended.
The two aspects are the amount of stress loading and the rate of stress loading.
Posture, manual material handling, reaching, dexterous work, and environmental factors like noise and temperature.
Fatigue results in reduced capacity to generate maximal force, reduced velocity of contraction and relaxation, reduced power output, and increased agonist/antagonist co-activation.
Sitting provides stability for tasks requiring high visual and motor control, consumes less energy, and places less stress on lower extremity joints.
Low back pain and sciatica can be aggravated by prolonged sitting and poor posture.
It leads to overused muscles undergoing hypertrophy while underused muscles weaken, causing muscle pain and reduced circulation.
It suggests that small/weak motor units are recruited first during low-force tasks, and if force demand increases, larger/stronger units are recruited, leading to structural damage in chronic muscle pain cases.
Sex, age, ethnicity, and generation.
To ensure that the duties and tasks in the job description match the actual job being performed.
PDA stands for Physical Demands Analysis, a systematic procedure to describe the physical and environmental characteristics of job tasks.
Characteristics include mass production/consumption, standardization/interchangeable parts, specialization of labor, energy from machines, use of machines, and use of assembly lines.
Breadth is a straight line, point to point, mediolateral horizontal measurement.
Identifying the limiting user, such as a clumsy person, to determine the minimum acceptable performance.
The Association of Canadian Ergonomists (ACE) regulates the field of ergonomics in Canada.
Little possibility for frequent breaks, stress from work scheduling, and factors like gender, sedentary lifestyle, obesity, smoking, and diabetes.
The metabolic mechanisms include the buildup of H+ and increased levels of phosphate substrates.
The primary focus of an ergonomist is to adapt work to prevent dysfunction or facilitate return to work, ensuring that the work respects human needs as much as possible.
135 degrees.
Use a thigh-back angle of 135 degrees and a tibial pad to counterbalance shear force.
Work can be adapted spatially and temporally, education can be provided to inform workers, and tools can be offered that can be used beyond the intervention.
Finalize the template report based on on-site data collection, distribute for sign-off by necessary people, and file & back up the information for reference.
Ergonomics is the science of improving human performance and well-being in relation to the task, equipment, and environment, aiming to match people physically with the products and work systems they use.
Proper sagittal alignment reduces torque at joints and muscle force requirements, leading to less stress on the neck.
High job demands, low social support, low job control, and low job satisfaction.
Internal staff such as managers, supervisors, health and safety personnel, as well as trained experts or certified ergonomists.
Texting elicits higher neck extensor and thumb muscle activity, but lower activity in trapezius and wrist extensors.
Place the computer screen at 90 degrees from windows or strong light sources to obtain optimal light and reduce glare.
Industries include auto manufacturing, meatpacking, assembly, wholesale, carpentry, and music.
Biological tissue being anisotropic means that its mechanical properties depend on the direction of the load applied.
Higher work intensity leads to a steeper curve for recovery, meaning longer rest periods are needed to achieve full recovery.
Physical factors (80%) such as force, movement repetition, posture, lack of rest, vibration, and extreme temperatures, along with organizational/psychosocial factors (20%) like lack of influence over one’s job and low social support.
Determine the purpose and tasks, verify job purpose and tasks through observation and interviews, classify essential and non-essential tasks, and quantify physical demands using measurements and templates.
Standing resulted in more lower limb blood flow, while seated work led to more neck and shoulder discomfort.
Difficulties and health problems associated with specific job tasks.
The 'forward head' posture, where the neck is flexed and the head is protracted.
Height is a straight line, point to point, vertical measurement.
Acute inflammation involves increased movement of plasma and leukocytes from blood to injured tissue.
Unilateral texting elicits higher forearm muscle load compared to bilateral texting.
The Cinderella hypothesis suggests that most evidence is derived from biopsies of symptomatic neck/shoulder muscles.
Joint deviation occurs when working with a joint in a non-neutral posture, with neutral posture defined by anatomical position as zero deviation.
Rotator cuff tendinitis, impingement syndrome, and rotator cuff tears.
Pain, tingling, numbness, clumsiness, thenar atrophy, weakness in opposition movement, and numbness or tingling while gripping, especially at night.
Consider measurement techniques such as average measures, absolute values, and min/max range.
Significant associations were found between time spent browsing and right thumb pain, as well as total time spent using the device and pain in the right shoulder/neck.
The purpose of a PDD, or Physical Demands Description, is to provide a clear description of the physical demands of a job rather than an analysis.
The recommended horizontal distance is 50-100 cm.
Very tall people, while ensuring that the door is not excessively tall for the majority of the population.
A vicious cycle of injury, chronic inflammation, fibrosis, and tissue breakdown can occur, leading to pain and loss of motor function.
Principal heights include stature, eye height, shoulder height, elbow height, hip height, knuckle height, and fingertip height.
Upper limb measurements include shoulder-fingertip length, elbow-fingertip length, standing overhead reach, and forward reach.
Overuse injuries such as lateral/medial epicondylitis and tennis/golfer’s elbow.
Swelling increases pressure in the narrow carpal tunnel, leading to local venous congestion and edema, which can create a vicious cycle of increased pressure and inflammation.
On average, males are larger than females, and separate data are usually used for men and women.
Try to avoid prolonged static postures and adjust according to symptoms.
The study investigates the optimal biking intensity and its effects on performance and neck and upper limb characteristics.
More commonly seen in endurance sports or certain metabolic conditions.
It leads to a high prevalence of neck pain and headaches, and can also affect the upper limbs.
They provide information for hiring/training, help modify jobs for health/safety, and support both proactive and reactive injury prevention.
Intrinsic factors relate to an individual’s ability to withstand loading, while extrinsic factors relate to the nature of loading imposed.
Tight shoulder muscles.
Vibration can increase the force applied on tissues, constrict blood vessels, cause soft tissue injury, and potentially lead to nerve damage.
'Ergon' means work and 'Nomos' means natural law.
It affects the sizes of tanks, aircraft, equipment, and clothing, necessitating adaptations in workstation design.
The name 'ergonomics' was proposed by Hugh Murrell in 1949 and officially accepted in 1950.
The goal is to quantify specific risks associated with a work task in response to a specific issue or complaint.
Curvature is a point to point measurement following a contour, usually open.
Thoracic hyper-kyphosis is most frequently associated with head protraction and protracted shoulders.
Thoracic outlet syndrome.
Tendons (tendinitis), nerves (carpal tunnel syndrome), and the neurovascular system (vibration syndrome).
It is thought to be due to occupational factors (higher risk jobs) and/or anatomical factors (smaller carpal tunnel).
Standing and walking resulted in less neck and shoulder discomfort, lower EMG amplitude, and improved performance compared to seated work.
Techniques include interviews, observations (visual, pictures, videos), and measurements (semi-quantitative and quantitative).
The first applications of ergonomics emphasized the health and productivity of soldiers.
There is evidence of a positive relationship between neck pain and high quantitative job demands.
There is evidence of lesions in vertebral fossils and pathologies in dinosaur bones, as well as acknowledgment of injuries in historical writings and artwork.
Wolff’s law states that a tissue adapts to the level of stress imposed on it, gaining strength through hypertrophy with increased stress and losing strength through atrophy when stress is removed.
To compress the humerus head into the glenoid fossa to prevent dislocation.
Carpal tunnel release surgery.
A condition affecting the neck and shoulder area, often linked to pain and fatigue in symptomatic computer workers.
Depth is a straight line, point to point, anterior-posterior horizontal measurement.
Increased activity with pain and fatigue, potentially linked to vascular and neuromuscular mechanisms.
They help identify positions with the largest injury rates and inform strategies for improving workplace safety.
The mechanical properties of human tissue are determined by the proportion and arrangements of collagen, elastin, minerals, and water.
It is characterized by impaired motor control of one or more fingers, with evidence of overlap in the homuncular representation of digits in the primary somatosensory cortex.
Clearance, reach, and posture.
Inflammation can be good for repairing tissues but increases the possibility of damage to blood vessels due to increased pressure.
Pathomechanisms include postural issues, neuromuscular factors, and vascular problems.
Sitting dimensions include sitting height, sitting eye height, sitting shoulder height, thigh thickness, buttock-knee length, buttock-popliteal length, and knee height.
The shoulder joint is a ball and socket joint that is very mobile but lacks stability.
It results from a discrepancy between the size of the tendon and the entrance to the tendon sheath, often due to localized inflammation or a nodular swelling on the tendon.
Distance is a straight line, point to point measurement between body landmarks.
The motivation can be influenced by the perceived impact of changes, cooperation from workers, and the feasibility of the changes.
PDA is a systematic procedure for describing job tasks, while PDD is a more current term emphasizing description over analysis.
The rotator cuff muscles: infraspinatus, subscapularis, teres minor, and supraspinatus.
Shaking the hand, medication, and using a wrist splint.
Circumference is a closed measurement that follows a body contour.
It can be aggravated by working with the arms in front of the body, such as during computer work.
Mechanical adaptations are affected by mode, direction, rate, frequency, distribution, and energy of the loading.
CTS is caused by acute or chronic trauma that leads to swelling between bones and the flexor retinaculum, compressing the median nerve.
BlackBerry thumb, which involves tendinitis and/or synovitis of the extensor pollicus brevis and abductor pollicus longus.
