**3. Ergonomic regulations at workplace**

requirements of the job [24]. A more general and comprehensive assessment should be done if the person is to be placed in a new job [24]. The physical condition is investigated from many directions and the most appropriate ones are identified from the various types of job opportunities available [24]. If the objective assessment of the functional capacity is to determine the disability status, then an evaluation method should be chosen where the evaluator can collect the

Functional capacity evaluations, such as all other tests performed in the field of rehabilitation, are generally planned according to the test and measurement standards established by the American Physical Therapy Association [32]. Functional capacity assessments are crucial to ensure reliable and valid results and to be safe and practical in practice [24, 30]. Reliability is stated as the most important factor that evaluations are standardized [24, 30]. Reliability studies of functional capacities for many different purposes have been accelerated after 1990, and clinicians have drawn attention to the importance of reliable assessment methods [33]. Reliability studies of newly produced evaluation methods continue at a rapid pace [33].

Lechner et al. [34] and Brouwer et al. [35] found that functional capacity evaluation protocols were reliable for people with low back pain and other musculoskeletal disorders. Lechner et al. evaluated 50 persons aged between 18 and 65 who had musculoskeletal discomfort and who spent at least 20 hours per week with the so-called Physical Work Performance Evaluation [34]. The reliability of interpersonal reliability when using the evaluation method of 11 physical therapists was found to be very high [34]. Gross and Battie [36] found that test–retest reliability of the results of functional capacity evaluation during lifting was high in people with low back pain. An evaluation system called 'Isernhagen Work System' was used in this study [36]. The authors state that when evaluating the operational definition, the safe and maximum performance detection is reliable when well explained to the evaluators [36]. Many types of validity were tested in the field of functional capacity assessments [30, 33]. Less validity studies were conducted compared to reliability studies [37]. The first study to question the validity of functional capacity assessment studies was conducted by Smith et al. [38]. In this study, 125 prisoners in prison were evaluated by 'Smith Functional Capacity Assessment Method', medical history was taken, and 'Patient Activity Questionnaire' was applied. According to these test results, the chances of returning to work were determined. One year after being released from prison, a questionnaire was sent to these persons, and their employment status was questioned. From the responses, it was determined that the results of the tests in the prison estimated the work situation to be 86%. Matheson et al. [39], who tested the predictive validity of functional capacity assessments, attempted to determine the return to work after 6 months without evaluating the individuals with chronic musculoskeletal system. In this study, a low lift was tested, and a 2% chance of returning to work for each added pound weight was found to increase by 2%. Lechner et al. [40] also tested the predictive validity of the 'Physical Business Performance Assessment', a functional capacity evaluation method, on 30 people with musculoskeletal dysfunction. As a result of this study, the results of functional capacity assessment were well validated in determining the chances of returning to work after vocational rehabilitation [40].

Compared to other assessments, functional capacity evaluations take longer [24, 30]. This can vary from a few hours to a few days, depending on the measurement protocol used [24, 30].

desired information [24].

76 Occupational Therapy - Therapeutic and Creative Use of Activity

The study of ergonomics and work posture in workplaces has gained importance in recent years. Ergonomics is an interdisciplinary scientific discipline that scientifically examines and relates the relationship between people, the equipment and working environment they use to the field of application [41]. In order to harmonize the person, machine and work with each other in the best way, it examines the physiological, biological, anatomical and other specialties of the human being and enables the machine and work to be designed according to these characteristics [41]. This science helps to understand how human abilities and limitations are understood and how it can bring about performance in a safe, effective, comfortable and healthy way in relation to the environment [42, 43]. If a building is anthropologically, physiologically, sociologically and psychologically compatible, it must be able to perform daily activities [42, 44]. Effective and successful 'harmonization' guarantees high productivity, avoidance of disease and injury risk and increased satisfaction in the work [44]. In order to achieve these, technical and health teams must be in a successful cooperation [44].

Ergonomists should consider the special requests of the persons who will use the building during the construction, arrangement, or repair of a building, so that the space is useful, safe and effective [42]. Factors such as lighting, heat, noise, ventilation, cleanliness, humidity, as well as working hours and break times are examined in the field of ergonomics [11]. While arranging the environment of a disabled or elderly person, ergonomists find solutions by evaluating every field and activity [42]. Ergonomic problems that occur during the working life of people with physical disabilities should be solved with the participation of many disciplines. Ergonomics is a multidisciplinary approach which addresses many disciplines as engineers, physicians, psychologists, physiotherapists, ergotherapists, architects, home economists and other disciples who have knowledge about anatomy, biomechanics, psychology, physiology, engineering principles, anthropometry, and kinesiology and the ones who solve stress factors at home, school, and workplace [17, 45].

**5.** When standing, both feet should be loaded equally, and the foot supports should be ad-

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**6.** Work activities should be arranged such that the joint movements are in the middle of the

**7.** When muscle force is required for the work, the force applied should be along the relevant limb and should be performed by the contraction of the most suitable large muscles.

**8.** Work should not be performed at the heart level or above the heart level, especially when using force above the heart level. Even at the light work, the upper extremities need to be

**9.** If there is a continuous force application, arms or legs should be used without having to

**10.** Rest periods should be provided at all workloads including environmental load, informa-

Ergonomic arrangement of a workplace is done by making the work suitable for the person to be worked on. Although the employee is selected according to his/her ability according to the work to be done, it is very important that the place to work matches the physical and psychological characteristics of the employee [44, 45]. 'Appropriate Settlement' was first used in 1990 to prevent discrimination against the people with disabilities and to remove the barriers to employment [14]. This term includes [1] provision of assistive equipment necessary for the job to be done, [2] modification to make the business environment fully accessible, [3] arrangement of the workflow, and [4] provision of personal assistance when needed. Unreachable workstations constitute a physical barrier, and if the workspace is not modified, it will prevent the desired work [7, 14]. Some workplaces are affecting the physical condition negatively due to the work they have installed on the person, which can reduce the person's independence both at home and in daily life [1, 14]. The person may not be able to keep the

Providing the necessary tools to do the job is a step in removing the barriers at the workplace [14]. Easy access to computer technology, software that understands speech, ergonomic keyboards, and mouth-controlled mice are frequently used in many disability groups [14]. In fields where computer technology is not used, envelope folding machines, electrical staplers, telephone headsets, and similar equipment can be useful for productivity [14]. Another step in lifting the barriers is to organize the physical work environment both personally and in general [14]. Business areas should be well illuminated, crossing areas should be expanded, maneuvering areas should be separated, and entrances without stairs should be provided [14, 44]. The regulation of the workflow is also important in ensuring accessibility [14, 44]. It should be ensured that the energy of the person is activated by arranging activities that are not necessary for the business [14, 44]. For example, placing frequently used equipment in close proximity, or lowering shelves where heavy items are placed, prevents the occurrence of fatigue and walking

job any longer and then may be forced to another job or not to work at all.

range of motion. This is especially true for the head, neck, and upper limbs.

rested when work has to be done above the heart level.

justed accordingly.

organize on the equipment.

tion load, and length of work.

**3.1. Ergonomics for persons with disabilities**

The main physical problems that may arise as a result of interaction between human, environment, and equipment are musculoskeletal diseases [41]. Work-related musculoskeletal disorders refer to musculoskeletal disorders that affect work environment and work performance significantly. Workplace risk factors are thought to develop work-related musculoskeletal disorders with personal characteristics and social factors [46]. Jobs with multiple risk factors or increased working at high-risk conditions will increase the likelihood of having a musculoskeletal system disorder [44]. Repeated hand tasks with heavy work, heavy lifting, pushing heavy objects, pulling or carrying, long sitting in poor posture, monotonous work, inadequate intermittent rests, vibration, or cooling are the main risk factors [41]. The level of risk generated is determined by the severity of exposure to the risks, frequency, duration, and strength capacity of the person to meet other job requirements [44].

Inadequate working postures in jobs that require intense labour force cause inefficiency as well as musculoskeletal discomfort [41, 44, 47]. One of the aims of the ergonomics is to improve worker postures and balance worker capabilities and work requirements, resulting in improved worker safety, health, and overall productivity of the system [41, 44, 47]. Workplace injuries cause a decrease in one's work capacity and production [41, 44, 47]. While these injuries cause discomfort, reduced work capacity, and production affect economics negatively [44]. Therefore, the role of preventive rehabilitation becomes increasingly important in preventing these injuries and having a healthy musculoskeletal system [44]. One of the mechanisms of injury that is resulted from many risk factors is muscle loading [43, 48]. In poor working posture, degenerative changes occur in the affected joints and in the connective tissue [43, 48]. Repetitive movements and inadequate rest periods cause discomfort caused by muscular loads together with degenerative changes resulting from poor and bad posture [43, 48]. Another mechanism of injury that occurs during exercise is muscle fatigue. Static and dynamic loading resulting in muscular work with maximum capacity leads to muscle fatigue [43, 48].

Points to consider when designing a workplace to avoid work injuries are listed below [49]:

