Backrest Height Research Articles

Designing School Tables and Chairs based on Anthropometry of Elementary School Students in Surabaya

Introduction: School tables and chairs are needed amongst many other facilities which support the teaching and learning activities. Uncomfortable tables and chairs can cause health problems. The purpose of this study is to design school table and chair sizes in accordance with anthropometry of elementary school students, so the tables and chairs do not cause health problems for children. Methods: The population used in this study was 72 students of elementary school students in Surabaya, and the sample size was 61 students. The sampling method used in this research was a simple random sampling. The anthropometric data measured were shoulder height in the sitting position, elbow height in the sitting position, popliteal-buttock length, knee height, popliteal height, shoulder width, and distance from elbow to fingertips. Meanwhile, the dimensions of tables and chairs measured were chair height, chair width, back length, back height, table height, table width, and underneath desk height. Results: The results of the research show that the sizes of existing tables and chairs are mismatched with student anthropometry. There are 7 dimensions of proposed table and chair sizes which are based on anthropometric data. Specifically, the chair height is 33.25 cm, chair width is 33.25 cm, backrest length is 46.50 cm, backrest height is 49.60 cm, table height is 56.85 cm, table width is 39.05 cm, and underneath desk height is 47 cm. Conclusion: The sizes of existing tables and chairs still need improvement in all dimensions based on the students’ anthropometric measurements.Keywords: anthropometry, chair, elementary school students, table

Effect of shed geometry on starting mark of woven fabric

This paper aims to analyze the formation of starting mark on loom and the effect of shed geometry formed by warp yarns under various conditions. The actual cause of starting mark in woven fabric is variable pick spacing and cloth-fell displacement due to the relaxation nature of the warp yarn and fabric and the loom’s dynamic characteristics after restarting. Herein, nine woven fabrics of different constructions, compositions are used on an air-jet loom with a series of settings. Three shed angles were selected for specific warp yarn count, and other loom settings like heald frame height, back-rest height and depth, air pressure, take-up correction, automatic start offset, stop position were triggered to change the shed geometry, and then the effect of starting mark on fabric was checked. The pick spacings were then measured from fabric using a projection microscope, whereas various plots were generated utilizing the obtained data to check the pick spacing variation after a certain period of loom stoppage and restarting. Finally, the experimental results were analyzed with standard deviation, coefficient of variation % analysis using the IBM SPSS statistical program.

Office Chair Backrest Height Affects Physiological Responses to Sitting

OCCUPATIONAL ABSTRACTProlonged static sitting has been associated with a number of negative health consequences. In prior work investigating office seating designs, the main focus has been on lumbar supports and backrest recline angles. To date, however, there is very limited information on the impact of backrest height on physiologic responses to sitting. Thus, the primary focus of this study was to assess muscular and postural responses to changing backrest height, across various postures, in a standardized office chair. The use of a Tall backrest resulted in significantly more lumbar spine flexion and lumbar erector spinae muscle activation but facilitated a more neutral neck posture. Results from this investigation demonstrate that office chair backrest height influences both posture and muscle activity responses and thus should be a consideration when designing office seating.

Investigating the influence of seating area design and enclosure on the seat-dip effect using scale model measurements

The low-frequency attenuation in the direct sound due to the concert hall seats, i.e., the seat-dip effect, is studied with the help of a scale model comprising an adjustable seating area and an enclosed box. More particularly, different seat underpass sizes and floor raking angles are studied, and the results are averaged over multiple source positions. With the measurements on the seating area only, the main seat-dip frequency is found to depend on the seat back rest height, and on the degree of obstruction of the seat underpass. The attenuation bandwidth is found to depend mainly on the floor raking. The differences become less clear when seating area is enclosed by concert hall walls and ceiling because the early reflections from the concert hall geometry compensate the low-frequency attenuation in the direct sound. In addition, the low frequencies below the main seat-dip frequency are found to increase in the presence of unobstructed seat underpasses, and such seats are recommended for the maximal bass response in a concert hall.

SINIF MOBİLYALARI VE ÖĞRENCİ VÜCUT ÖLÇÜLERİ ARASINDAKİ UYUMUN ARAŞTIRILMASI: İZMİR ÖRNEĞİ

The aim of the research is to determine the anthropometric measures of school children aged 12-13, who live in Izmir, Turkey, in order to propose anthropometrically appropriate school furniture (desk and chair), and to compare findings with the available classroom furniture produced according to Standards of Classroom Furniture, published by Republic Of Turkey General Directorate of Primary Education to determine potential mismatches. A total of twelve anthropometric data were collected by convenience sampling from 393 (207 male and 186 female) students. The data were analyzed with the aid of the SPSS v13 software on a desktop computer. Descriptive statistics for each anthropometric dimension are given as mean, standard deviation and 5th and 95th percentile values for male and female in mm. The obtained anthropometric data used for calculating classroom furniture dimensions, sitting height, seat depth, seat width, backrest height and desk height. Mismatches were found when the findings were compared with the Standards of Classroom Furniture, published by Republic Of Turkey General Directorate of Primary Education.

CONSIDERATIONS OF ANTHROPOMETRICS IN THE DESIGN OF LECTURE HALL FURNITURE

An anthropometric survey of Federal University of Technology Owerri students was carried out in order to determine the anthropometric data needed for proper design of seats used in the classroom. A total of four hundred students, of different gender and level were involved in the survey and their anthropometric measurement were taken and recorded with the help of anthropometric tools. The anthropometric measurements taken were, Stature, sitting height, sitting shoulder height, Popliteal height, Hip breadth, Elbow rest height, Buttock popliteal length, Buttock knee length, Thigh clearance, Sitting eye height, Shoulder breadth and Knee height. The data obtained were analysed using SPSS, Excel and Minitab statistical packages to get the mean, standard deviation and percentiles. Comparing the dimensions of the existing furniture with the anthropometric measures obtained revealed that the existing furniture are not ergonomically suitable for the students. Using the results of the analysed anthropometric data, a model classroom seat was suggested which takes into consideration the seat height, seat depth, seat width, backrest height, armrest height and backrest angle.

Associations Between Whole-Body Vibration Exposure and Occupational and Personal Factors in Drill Operators in Indian Iron Ore Mines

Heavy earth-moving machineries used in open-pit mines intensively expose the drill operators to whole-body vibration and shocks and thus to musculoskeletal disorders. The roles of an individual, machine, and rock-related factors in their exposure remain poorly understood. This cross-sectional study investigated their role among 39 drill operators from Indian iron ore mines. It shows that 70% of the operators were exposed to high levels of vibration, above the limit values recommended by ISO 2631-1. Multiple linear regression models showed that the whole-body vibration and shock exposures were strongly associated with operator’s age, drill machine model, rock’s hardness, uniaxial compressive strength, and density. The role of body mass index was close to significance (p = 0.08). Univariate analyses found that drill’s age, seat pad thickness, and seat backrest height were also strong predictors. These results help in identifying risky operators, materials and occupational situations, and in implementing appropriate prevention and intervention to reduce and monitor the exposures and health risk.

Ergonomic considerations for designing truck drivers' seats: The case of Bangladesh.

Objectives: The purpose of this work was to investigate the fitness of the existing truck seats for Bangladeshi truck drivers and suggest a guideline for drivers' seats based on their anthropometry. Methodology: In this study, eight anthropometric measurements of 120 Bangladeshi truck drivers and seven seat dimensions of ninety trucks of three brands namely, TATA, ASHOK LEYLAND, and ISUZU were considered for investigating the considerable mismatch between seat dimensions and drivers' anthropometry. The data were analyzed using two-sample t-tests to identify the relationship between existing seat dimensions and drivers' anthropometry. Results: The results showed a mismatch in seat dimensions and anthropometric measurements for nearly all truck brands and the existing seat dimensions were found to be inappropriate for Bangladeshi drivers. For all the truck brands, the percentage mismatch of seat height, seat depth, seat width, backrest height, and steering wheel clearance varied between 71% and 98%, 23% and 79%, 33% and 84%, 28% and 65%, and 53% and 100% respectively. Subsequently, an attempt was made to provide ergonomically correct seat dimensions for Bangladeshi truck drivers. Further, generalized equations to design the appropriate seat dimensions were developed using the least square regression technique. The recommended seat height, depth and width, backrest height, and steering wheel clearance were found to be appropriate for 82%, 79%, 76%, 98%, and 100% of drivers respectively. Conclusion: The analysis and results of this study can be useful in developing guidelines for design and manufacture of truck driver seats in Bangladesh.

A preliminary review of Indonesian national standard of chair and desk for junior high school level

This study was a preliminary review to evaluate the dimensions of Indonesian national standard of chair and desk for junior high school level. The furniture was evaluated for seat height, seat depth, seat width, backrest height, desk height and underneath desk height. A number of 301 students were measured for their dimensions. Six equations were used to evaluate the match or mismatch between students’ dimensions and dimensions of chair and desk. Results showed mismatch between students’ dimensions and the dimensions of chair and desk as issued by the National Standardization Agency of Indonesia. The results of this preliminary review could be a basis for a larger study which covers more samples and geographical areas.

Ergonomics assessment of locally fabricated passenger seats in trotro vehicles in Accra, Ghana

Abstract Trotro vehicles constitute one of the major means of transportation in Ghana by way of ferrying people and goods. Most trotros are originally brought into the country as load carrying vehicles, which are then converted into passenger vehicles. Locally designed seats are then fabricated and secured into the vehicles. The study explored the ergonomic evaluation of the locally fabricated passenger seats with anthropometric measures of passengers and also compared the seat dimensions to required standards. The study was undertaken at seven selected bus stations in Accra, the capital city of Ghana. The study composed of 307 volunteer passengers comprising 175 females and 132 males with ages spanning from 18 to 60 years. The dimensions of ninety locally fabricated seats were collected from ninety randomly selected trotro vehicles. Ergonomic assessment was performed to determine match or mismatch between the anthropometric measures and vehicle seating dimensions. In addition, the fabricated seat dimensions were compared to both local and international vehicle seat standards. High mismatches indicating that the passenger seats were probably too deep or too high were observed for seat height – popliteal height, seat depth – buttock popliteal length, and seat breadth – hip breadth. A low mismatch was observed between the sitting height and backrest height for 99.4% of participants. Only four and ten out of the ninety seats complied with specified standard seat length and backrest to backrest distance, respectively. The high prevalence of mismatch is a possible indication that most locally fabricated seats do not adequately accommodate majority of passengers. Furthermore, it appears that anthropometric measures and standard vehicle seat dimensions are not considered during seat design, with potential health ramifications pertaining to the safety, comfort and sitting posture of passengers.

The Effect of Backrest Roller on Warp Tension in Modern Loom

The Backrest roller is one of the key parts of the weaving machine. In this study, the effect of the various position of backrest and dropper has been assessed. The tension is measured by using the integrated tension measuring device of the loom. The tension can be found on the display board. The effect of backrest position can be described in two different ways viz. keeping constant dropper position (distance between dropper line and backrest roller) and keeping constant dropper depth (distance between held frame and dropper line). If dropper position (distance between backrest roller to dropper line) is kept constant then the backward movement of backrest roller will entail low tension. The reason behind this is, the dropper weight will be moved toward the backrest roller and will lose its influence on warp tension. But if dropper depth is kept constant (i,e dropper line is kept intact) then the backward movement of backrest will require more tension as the influence of dropper will more on warp length. On the other hand, when backrest height is lowered then, the downward movement of backrest roller will need low tension and upward movement of backrest roller will need more tension. As the warp length and lap angle increases with the backrest height. In this paper, the whole phenomenon is explained with illustration.

Evaluation of the Indonesian National Standard for elementary school furniture based on children's anthropometry

In Indonesia, National Standardization Agency of Indonesia issued the Indonesian National Standard SNI 12-1015-1989 and SNI 12-1016-1989 to define the type of furniture dimensions that should be used by children in the elementary school level. This study aims to examine whether the current national standards for elementary school furniture dimensions issued by National Standardization Agency of Indonesia match the up-to-date Indonesian children's anthropometry. Two types of school furniture, small type (Type I, for grade 1–3) and large type (Type II, for grade 4–6), were evaluated in terms of seat height, seat depth, seat width and backrest height of a chair as well as the height and underneath height of a desk. 1146 students aged between 6 and 12 years old participated in the study. Seven anthropometric measurements were taken including stature, sitting shoulder height, sitting elbow height, popliteal height, buttock-popliteal length, knee height and hip breadth. Based on the standard school furniture dimensions and students' body dimensions, numbers of matches and mismatches between them were computed. Results indicated a substantial degree of mismatch between children's anthropometry and the standard dimensions of school furniture. The standard seat height was not appropriate for students among different grades with the mismatch percentage ranging from 63.4% to 96.7% for Type I and 72.7% to 99.0% for Type II. For desk height, the standard dimensions were not appropriate for students among different grades with the mismatch percentage ranging from 32.3% to 88.9% for Type I and 67.7% to 99.0% for Type II. Apparently, the current standards are out of date and need to be updated. Four different sizes of school furniture were hence proposed to accommodate the variation in students' anthropometry from Grade 1 to Grade 6. The proposed standard dimensions (PrS) of school furniture cover a slightly broader range of age and present a higher cumulative fit than the current standard dimensions (CrS). In addition, a better strategy for sizing can be also developed to fit chairs and desks to a larger number of students.

Discomfort of seated persons exposed to low frequency lateral and roll oscillation: Effect of backrest height

Backrests influence the comfort of seated people. With 21 subjects sitting with three backrest heights (no backrest, short backrest, high backrest) discomfort caused by lateral, roll, and fully roll-compensated lateral oscillation was investigated at frequencies between 0.25 and 1.0 Hz. With lateral oscillation, the short backrest reduced discomfort at frequencies less than 0.63 Hz and the high backrest reduced discomfort at frequencies less than 1.0 Hz. With roll oscillation, the high backrest reduced discomfort at frequencies less than 0.63 Hz, but increased discomfort at 1.0 Hz. With fully roll-compensated lateral oscillation, the short backrest reduced discomfort at 0.4 Hz and the high backrest reduced discomfort at 0.5 and 0.63 Hz. As predicted by current standards, a backrest can increase discomfort caused by high frequencies of vibration. However, a backrest can reduce discomfort caused by low frequencies, with the benefit depending on the frequency and direction of oscillation and backrest height.

Incorporating Malaysian's Population Anthropometry Data in the Design of an Ergonomic Driver's Seat

An ergonomically designed driver's seat is crucial in ensuring quality, comfort and safe driving. The increase in road accidents every year is mostly linked to drivers’ fatigue. Therefore, posture comfort is an important aspect in driver's seat design. The aim of this study is to design a driver's seat which is suitable for Malaysians. There are three main objectives in this study; firstly, to investigates the comfort level and safety system of the existing driver's seat, secondly, to identify and determine parameters which may affect comfort and the driver's seat safety system, and lastly, to develop and design an ergonomic driver's seat. Anthropometric data of drivers should be used during the driver's seat design stage. Critical dimensions of the driver's seat and anthropometric data must be taken into consideration in order to optimize the comfort level and safety of the seat. Previous studies showed that the evaluation of driver's seat discomfort should include both objective and subjective evaluations. The seat discomfort will negatively affect the driver's performance. All information pertaining to the driver's seat design was obtained through research on the related subjects. In the data collection phase, the objective evaluation method was used in determining the seat's dimension while subjective evaluation was used to gather information on the drivers’ experience. Anthropometric data from 1405 male and female subjects were collected and stored in a database. Meanwhile, subjective evaluation on driver's seat discomfort was conducted on 100 male and female respondents. The SPSS software was used to analyse the data. Every parameter that affects the safety and comfort of the driver's seat were then used to design a new driver's seat. The parameters that were taken into account are backrest height, cushion width, cushion length and adjustability. These parameters were then matched with the Malaysian drivers’ anthropometric data. Finally, the dimensions of the new driver's seat were determined: 520mm cushion width; 380mm cushion length, 480mm backrest width, 407.5mm backrest height and 180mm adjustability.

Teenagers anthropometric measurement and furniture mismatchment

In the varied spheres of life various anthropometric mismatches are seen but are unknowingly being used and the physical problems arising from these are treated as if they were due to some medical problems, for example the height of some counters are such that interactions between the man behind the counter and visitor are obstructed. Writing stands, counter plat forms, which are sometimes used as writing surfaces in post offices and banks, are too high making it difficult to write anything. Anthropometry deals with the measurements of the human external body dimensions in static and dynamic conditions. Designs without due consideration to the body dimensional requirements of intended users do not serve their purpose and have less user acceptance value. There are numerous medical problems that have resulted because of the use of articles that do not match the anthropometry of the users. Lack of foot space may also be a problem for all workers. In this study the desk height, desk depth, length of desk, chair depth, chair breadth for girls and combined group was noted to be less than required. Inclusive of these dimensions the back rest height and breadth was less than required by the boys, result in uncomfortable feeling and pain due to use of furniture.

Teenagers opinion regarding existing school furniture and musculo-skeletal problems

Teenagers spend a large part of their school days in the classroom, and yet the effect of the design of school furniture on their behavior and health has received comparatively little attention. The desk height, desk depth, length of desk, chair depth, chair breadth for girls and combined group was noted to be less than required. Inclusive of these dimensions the backrest height and breadth was less than required by the boys resulting in uncomfortable feeling and pain due to use of furniture. The furniture used by teenagers was opined as comfortable and uncomfortable the results of these opinions are given in the Fig. 1 and 2. It is clear from the figures that 47.3 and 50 per cent girls and boys felt that the desk height was comfortable while (52% to 49%) girls and boys said that they experienced uncomfortable due to desk height. The Table 1 depicts the frequency of musculo-skeletal problems faced by the teenagers. It is clear from the table that 62.7 per cent boys and 46.7 per cent girls never experienced fatigue. While the fatigue was rarely felt by 47 per cent girls and 34 per cent boys. Frequency of fatigue experienced sometimes was at par in girls and boys (3.33 %). Frequent fatigue was felt by of meager per cent of girls (2.2).

Design of combine harvester seat based on anthropometric data of Iranian operators

Harvesting operation with agricultural combines imposes excessive physical loads on the operators and the poorly designed seats may be an important contributory factor in this regard. This aims of this field study were to evaluate the possible mismatch between seat dimensions of existing harvesting combines and anthropometric characteristics of 200 Iranian operators and to propose seat dimensions based on anthropometric principles. The anthropometric dimensions of each individual operator were compared to the relative seat dimensions using the equations proposed in the literature. The results showed a considerable mismatch for different seat dimensions including upper backrest width (100%), seat height (97%), armrest height (83.7%), seat width (52.8%), lower backrest width (40.6%) and seat depth (39.5%). This meant that the existing combine seats were too high, too narrow and too shallow and had armrests and backrests which did not match with body dimensions of the majority of the operators. It was shown that compared to the existing designs, the new proposed dimensions (including seat height = 400 mm, seat width = 450 mm, seat depth = 410 mm, armrest height = 290 mm, backrest height = 420 mm, upper backrest width = 360 mm and lower backrest width = 400 mm) better matched to the operator's anthropometry, with the match percentages ranging from 77% to 100%. Relevance to industryThe design and manufacturing of agricultural machinery should be made based on the anthropometric characteristics of actual users to avoid unnecessary demands on them. This study provide additional data on the operator's anthropometry that can be used as a starting point for designing more appropriate agricultural machinery or used by other researchers in the field.

Investigation of ergonomic parameters of easy chairs in Moratuwa furniture manufacturing establishments

Sitting on a comfortable seat helps to relax the body and reduce energy consumption. but on the otherhand prolonged sitting slackens abdominal muscles and may cause back ache. Application of medicaland ergonomic principles in the design of a seat can maximize advantages and minimize disadvantagesin sitting.In Sri Lanka the demand for a furniture depends on the customer perception to comfort and beauty ofthe product. The present study aimed to find out whether the easy chairs manufactured in the MoratuwaFurniture Manufacturing Establishments were ergonomically designed for the Sri Lankan users.The investigation was initiated with the identification of easy chair designs in the Moratuwa FurnitureManufacturing Establishments. A representative sample of two popular easy chair designs, the KuluPutuwa and the Meda! Putuwa, was then selected.The different design parameters of these twochairs were measured. It was observed that there were differences in the dimensions of the majordesign parameters of the chairs between companies.Sri Lanka has no specific standards for designing offurniture. Hence design standards were developedfor easy chairs in the present study based on available anthropometric data for Sri Lankan users andother published anthropo:netric data on seat designs.The different design parameters of Kulu Putuwa and Medal Putuwa were then compared with thosedeveloped ergonomic standard values. It was observed that only the back rest height of the easychairs was ergonomically acceptable in all the companies surveyed. Seat height, seat depth. seatwidth and ann rest height were lower than the accepted standard values. Such improper dimensionsshould result in discomfort and body pain. The angle of rake and angle of tilt, which indicate theinclination of the back rest, were significantly lower in the sampled chairs. The inclination of the backrest was iower than the req u ired 115°- 120°, wh ich should resu It in low back stress and static musculartension, which may lead to development of back injuries.In order to improve the ergonomic parameters of the Medal Putuwa, a prototype chair was designed.Seat height, seat depth, seat width, arm rest height, of the prototype char was lower and it had higherangIe of ti It and angle of rake. The designed prototype chair was evaluated against a normal controlchair, and the users rated the ergonomically designed chair was much better compared with thecentro I in terms of comfort.The present study reveals the need for Sri Lanka to have specific standards based on the body sizesof users, for des ign of furn iture. This wi IIenable the production of ergonomically correct and aestheticallyacceptable quality furniture in Sri Lanka.

Investigation of ergonomic parameters of easy chairs in Moratuwa furniture manufacturing establishments

Sitting on a comfortable seat helps to relax the body and reduce energy consumption, but on the other hand prolonged sitting slackens abdominal muscles and may cause back ache. Application of medical and ergonomic principles in the design of a seat can maximize advantages and minimize disadvantages in sitting. In Sri Lanka the demand for a furniture depends on the customer perception to comfort and beauty of the product. The present study aimed to find out whether the easy chairs manufactured in the Moratuwa Furniture Manufacturing Establishments were ergonomically designed for the Sri Lankan users. The investigation was initiated with the identification of easy chair designs in the Moratuwa Furniture Manufacturing Establishments. A representative sample of two popular easy chair designs, the Kulu Putuwa and the Medal Putuwa, was then selected. The different design parameters of these two chairs were measured. It was observed that there were differences in the dimensions of the major design parameters of the chairs between companies. Sri Lanka has no specific standards for designing of furniture. Hence design standards were developed for easy chairs in the present study based on available anthropometric data for Sri Lankan users and other published anthropometric data on seat designs. The different design parameters of Kulu Putuwa and Medal Putuwa were then compared with those developed ergonomic standard values. It was observed that only the back rest height of the easy chairs was ergonomically acceptable in all the companies surveyed. Seat height, seat depth, seat width and arm rest height were lower than the accepted standard values. Such improper dimensions should result in discomfort and body pain. The angle of rake and angle of tilt, which indicate the inclination of the back rest, were significantly lower in the sampled chairs. The inclination of the back rest was lower than the required 1150-1200, which should result in low back stress and static muscular tension, which may lead to development of back injuries. In order to improve the ergonomic parameters of the Medal Putuwa, a prototype chair was designed. Seat height, seat depth, seat width, arm rest height, of the prototype char was lower and it had higher angle of tilt and angle of rake. The designed prototype chair was evaluated against a normal control chair, and the users rated the ergonomically designed chair was much better compared with the control in terms of comfort. The present study reveals the need for Sri Lanka to have specific standards based on the body sizes of users, for design of furniture. This will enable the production of ergonomically correct and aesthetically acceptable quality furniture in Sri Lanka.

Effect of Backrest Height on Wheelchair Propulsion Biomechanics for Level and Uphill Conditions

Yang Y-S, Koontz AM, Yeh S-J, Chang J-J. Effect of backrest height on wheelchair propulsion biomechanics for level and uphill conditions. ObjectiveTo evaluate the effect of backrest height on wheelchair propulsion kinematics and kinetics. DesignAn intervention study with repeated measures. SettingUniversity laboratory. ParticipantsConvenience sample included manual wheelchair users (N=36; 26 men and 10 women) with spinal cord injuries ranging from T8 to L2. InterventionParticipants propelled on a motor-driven treadmill for 2 conditions (level and slope of 3°) at a constant speed of 0.9m/s while using in turn a sling backrest fixed at 40.6cm (16in) high (high backrest) and a lower height set at 50% trunk length (low backrest). Main Outcome MeasuresCadence, stroke angle, peak shoulder extension angle, shoulder flexion/extension range of motion, and mechanical effective force. ResultsPushing with the low backrest height enabled greater range of shoulder motion (P<.01), increased stroke angle (P<.01), push time (P<.01), and reduced cadence (P=.01) regardless of whether the treadmill was level or sloped. ConclusionsA lower cadence can be achieved when pushing with a lower backrest, which decreases the risk of developing upper-limb overuse related injuries. However, postural support, comfort, and other activities of daily living must also be considered when selecting a backrest height for active, long-term wheelchair users. The improvements found when using the low backrest were found regardless of slope type. Pushing uphill demanded significantly higher resultant and tangential force, torque, mechanical effective force, and cadence.