ELSEVIER International Journal of Industrial Ergonomics 21 (1998) 23 34

Inle r natior, al Jourtaal og

Industrial Ergonomics

The evaluation of a hand-handle interface tool (HHIT) for reducing musculoskeletal discomfort associated with the

manual handling of gas cylinders

J. Devereux*, P. Buckle, M. Haisrnan Ergonomics Research Unit, Rohens &stitute. Uniz,ersity o/'Surrev, Guildfbrd, Surrey GU2 5XH. UK

Received 28 February 1996: received in revised form 20 Jul 3 1996: accepted 15 November 1996

Abstract

This paper reports the evaluation of a tool designed by the workforce to reduce the physical strain imposed by the manual handling of gas cylinders. The design of this tool had not been subject to ergonomics during its participatory design. The aim of this case study was to assess the potential benefits of using such a manual handling tool for gas cylinder deliveries and to investigate any potential problems associated with the use of the tool. Question- naires, diaries, video observations, goniometer and force measurements were used in the workplace and the laboratory to assess the tool with respect to usability and any musculoskeletal discomfort on 20 male delivery drivers. The tool showed few benefits for delivering gas cylinders underground and the tool may increase physical strain. It is recommended that participatory groups use expert ergonomic knowledge and methods to redesign the job as a priority measure before designing and implementing tools that attempt to reduce the physical strain of manual handling gas cylinders.

Relevance to industry

This case study shows that a participatory approach to designing tools and implementing methods to reduce physical strain should use expert ergonomics at all stages of the participation process.

Keywords. Manual handling; Tools; Physical work; Participatory ergonomics; Musculoskeletal discomfort; Evaluation

1. Introduction

Previous studies have shown that the manua l handl ing of gas cyl inders weighing between 16-

* Corresponding author. Tel. (11483 259203; fax: 01483 503517

99 kg results in a high degree of physical s t ra in on the ca rd iovascu la r system and the musculoskele ta l system (Wester l ing and Ki lbom, 1981; H a i s m a n et al., 1994; Devereux et al., 1995). Wester l ing and K i l b o m (1981) showed that for four subjects d rag- ging gas cylinders, hear t rates exceeded 160 beats per minute for an average of 5 min on several

0169-8141,/98/$19.00 Copyright i?~ 1998 Elsevier Science B.V. All rights reserved PII S01 69-81 4 1 ( 9 7 ) 0 0 0 2 2 - X

24 J. Devereux eta/. ," h~ternational Journal q/'lndustrial Ergonomics 21 (1998) 23 34

occasions, the overall work being equivalent to 35% of maximal oxygen uptake during cycle ergometry. The average heart rate during occupa- tional activities was 99 beats per minute. Elec- tromyographic measurements revealed 30 70% of handgrip maximum voluntary contraction when dragging cylinders with a mass of 34 and 76 kg, respectively. A more recent investigation compared a manual handling tool with a trolley for manual handling cylinders with a cylinder mass of 16 kg empty and 22 kg full using physiological and sub- jective measures (Haisman et al., 1994). This study on delivery workers showed comparable maximum heart rates with the study by Westerling and Kilbom (1981). The use of a trolley gave a bigger physiological advantage (lower heart rate and lower perceived exertion) compared to the manual handling tool but a trolley could not be used in cellar deliveries requiring the use of stairs. Fig. 1. shows a worker using a trolley. A large part of the compressed gas industry involves delivery to public houses where the gases are used to help the dispens- ing of beer and other beverages. In the United Kingdom the storage of these beverages, and there- fore the compressed gases, is usually below ground. Manual handling delivery drivers distributing gas cylinders designed a manual handling tool termed the hand-handle interface tool (HHIT) and is shown in Fig. 2. The design arose as a result of some of the workforce recognising the need to reduce the physical strain during manual handling

Fig. 1. A worker using a trolley for the manual handling of gas cylinders.

tasks. Fig. 3. shows how gas cylinders are typically carried during work deliveries. Fig. 4a and Fig. 4b show how the HHIT alters body posture during manual handling tasks. The HHIT was designed by the workforce and there was no ergonomics input at the design stage. A small group of delivery drivers and line managers formed a participation group and assessed the HHIT prototype. Modifica- tions were made to the HHIT but further trials were not undertaken. Ergonomists were eventually called upon to conduct a usability evaluation of the modified HHIT. The aims of this ergonomic evalu- ation were to: (1) assess the potential benefit for workers of using the HHIT for gas cylinder hand- ling; (2) assess possible problems in the use of the

~160

225

< . . . . /~ 25

tt 'V 5

.>mm< 30

End Elevation Side Elevation

Fig. 2. Side and end elevations of the hand handle interface tool (HHIT) which is used for the manual handling of gas cylinders weighing 16 kg empty-22 kg full. All dimensions are in mm drawing is not to scale.

J. Devereux et al. / hlternational Journal o f lndustrial Ergonomics 21 (1998) 23 34 25

Fig. 3. A worker carrying two cylinders without the aid of any manual handling tools.

HH1T, including musculoskeletal discomfort; (3) in the event of a majority acceptance of the handles, develop a concept of use which could form the basis of an operational instruction.

2. Methods

Expert walkthroughs were performed over a period of 5 days by an ergonomist delivering gas cylinders with four different delivery workers in different geographical locations. This provided a representative assessment of the work tasks and the work environments encountered by the delivery drivers. The H H I T was not used by the ergonomist or delivery drivers during the expert walkthroughs. Cylinders were handled in the typical manner shown in Fig. 3. In order to evaluate the H H I T 21 male delivery workers were selected from two geo- graphical locations (user groups A (N = 9) and B (N = 13)). The maximum and minimum age was 48 and 27 years, respectively, and the mean age was 35 years _+ 6.6 ( + 1 SD). The maximum and min- imum current job experience was 5 and 1 year, respectively. The average experience in the current job was 3 years _+ 1.5 ( _+ 1 SD). User group A and user group B performed gas deliveries using the H H I T for 2 weeks and 4 weeks, respectively. Sub- jects were instructed to use the H H I T as often as possible for deliveries during the H H I T interven- tion but the use of other cylinder handling

Fig. 4. [at A worker holding the HHIT using a forward grip and carrying a gas cylinder. (b) A worker holding the HHIT using a reverse grip and carrying two gas cylinders.

methods, sometimes used for deliveries, such as ropes and trollies could not be controlled. Data on H H I T usability and musculoskeletal fatigue and discomfort were collected during and after the H H I T intervention for each user group. It was not

26 J. Devereux el al. /hlternational Journal o f Industrial Ergonomics 2l (1998) 23 34

possible to collect baseline data on musculoskeletal fatigue or discomfort before group A and group B began using the HHIT.

During the HHIT intervention, two subjects were video recorded while performing manual handling tasks over the whole day in order to observe worker behaviour. Self-report diaries were completed daily over the 2 and 4 week intervention periods to obtain subjective response data with minimal likelihood of recall bias (Van der Beek et al., 1994). The diary asked subjects to rate gas cylinder positioning, cylinder carrying; musculos- keletal fatigue and discomfort and overall accepta- bility of the HHIT against a five-point likert scale with markers at l:very bad and 5:very good (see Appendix A).

For each group, a comparative questionnaire using a dichotomous scale was used at the end of the HHIT intervention period to elicit information concerning the performance of the work task with and without using the HHIT (see Appendix B). Comparisons of musculoskeletal fatigue and dis- comfort, difficulties in task performance, task per- formance time, task assistance and HHIT acceptance were measured. Semistructured inter- views were conducted for four subjects from each group 3 weeks after the end of the intervention to elaborate on any benefits or reasons for rejecting the HHIT.

A self-report discomfort questionnaire using a dichotomous scale was completed to assess mus- culoskeletal discomfort without using handles (i.e. musculoskeletal discomfort before the HHIT intervention), discomfort using handles during the intervention, and discomfort using handles com-

pared to 3 weeks after the end of the intervention (see Appendix C).

Laboratory studies were conducted by two ergo- nomists to evaluate the angle subtended between the long axial plane of a cylinder and the horizontal plane during static and dynamic motion while carrying a gas cylinder using the HHIT. A goniometer was used to measure static posture angles. Angles measured during dynamic motion were measured from photographs. Each ergonom- ist grasped a HHIT using a forward and reverse grip at different times with an empty gas cylinder attached (cylinder mass 16 kg). Three measure- lnents per ergonomist were taken during dynamic and static postures when using a forward and reverse grip. The average angle subtended between the long axial plain of the cylinder and the horizon- tal plane was calculated for the forward and reverse grip. A force gauge was used to assess the forces during the lifting of a gas cylinder using the HHIT and during the dragging of a gas cylinder without the HH1T (since dragging gas cylinders is the man- ual handling technique used by the delivery drivers when trollies and the HHIT are not used). The force gauge was calibrated against a fixed weight before and after the experiment.

3. Results

3.1. Results J?om the diary, and comparative questionnaire

Data collected using the diary are shown in Table 1. The median for each diary question was

Table 1 Median scores and the number of entries from the 5:very good

diary questionnaire for groups A and B using the HHIT. Score is from l:very bad to

Item Group A IN = 9) Group B (N - 12)

Entries Median Entries Median

Cylinder positioning 79 3 123 3.25 Cylinder carrying easy/quick 79 3 143 4 Musculoskeletal fatigue 79 3 143 4 M usculoskeletal discomfort 79 3 141 4 Overall acceptability 79 3 139 4

J. Devereux et al. / International Journal Of In&~strial Ergonomics 2 l (1998) 23-- 34

Table 2 Summary of results from the comparative questionnaire for groups A [N = 91 and B (N = 121 using the HHIT

27

Task advantage Task disadvantage Musculoskeletal Musculoskeletal Time t a k e n Acceptability using the HHIT using the HHIT fatigue discomfort to perform task

Up and down large stair Harder through Reduced in the Increased in the cases doorways' neck, shoulders wrist [or 2,,'8

corridors and lower back subjects for for 3/6 group A group A

Medium deliveries on Difficulty in HHIT No differences for No differences for horizontal ground Stowage Harder group B group B

down steep stair cases

No improvement 5:8 subjects wanted for group A the HHIT issued

for group A

Quicker for 4/12 9'12 subjects subjects for wanted the HHIT group B issued for group B

calculated as the measure of central tendency for each group. Overall, group B rated the H H I T as more usable compared to group A. One subject from group B was removed as the subject believed that the H H I T may incur an injury to himself during the intervention.

Summarized in Table 2 are the data for groups A and B obtained from the comparative question- naire. Combining the data for both groups, the H H I T assisted deliveries when carrying cylinders up and down large staircases and covering a walk- ing ("medium") distance between 9 and 27 m over horizontal ground. The H H I T made deliveries harder when carrying cylinders through narrow doorways and corridors, and down steep spiral staircases. There were only slight changes in mus- culoskeletal fatigue and discomfort. The perceived time taken for making deliveries were unaltered for most subjects. Fourteen out of 20 subjects wanted the H H I T issued for deliveries where the use of the tool was considered practicable.

3.2. Video observation and interview data f o r work behaviour assessment

3.2.1. Carlying cylinders

Generally, subjects adopted a forward grip when carrying cylinders (see Fig. 4a). However, a reverse grip (see Fig. 4b) was sometimes preferred when carrying cylinders down staircases in order to avoid the bot tom edge of the cylinder clipping each step. A forward grip was used for carrying gas cylinders

up staircases. Use of the reverse grip may be in- fluenced by arm length and body stature. Walking "medium" distances over horizontal ground using the H H I T seemed to reduce the physical strain in the arms and shoulders compared to dragging or lifting gas cylinders over such a distance. Video and interview data showed that there was less elbow flexion and reduced shoulder girdle elevation when using the H H I T compared to dragging the gas cylinders.

3.2.2. Handling o['cvlinders into and out o f storage positions

Subjects using the reverse grip reported in the interview that a high degree of strain was felt in the wrist when placing cylinders. Video data showed that during the placing of gas cylinders using the reverse grip, the wrist is in ulnar deviation with an external load of either 167 Newtons or 225 Newtons being exerted upon the hand/wrist. Using a forward grip, placing a cylinder in an upright position requires radial deviation of the wrist in combination with elbow flexion, shoulder flexion, and flexion of the trunk in the sagittal plane. Cylin- der momentum was considered by workers to be useful for reducing the muscular strain on the wrists and upper limbs during a cylinder positioning task. However, cylinder positioning accuracy was com- promised and a large mechanical 'braking' force was required to bring the cylinder to an abrupt halt. Cylinders are typically stored vertically in racks and are bunched closely together. Using the

28 ~ Devereux et al. /International .Journal ~?f lndustrial Ergonomics 2l (1998) 23 34

HHIT, subjects were not able to accurately place the cylinders into the racks. Sliding a cylinder between two other cylinders was also a problem because of interference from the ring on the HHIT. Cylinders placed tightly in a rack were not accessible using the HHIT. In order to over- come this, a cylinder had to be removed from the rack before the H H I T could be attached and picked up.

3.2.4. Handling cTlinders it? napv'ow and restricted

spaces

Carrying a cylinder with the H H I T was difficult in narrow spaces. Collisions of gas cylinders into obstacles were frequent as the momentum of the cylinder was difficult to control when changing direction of movement. This was considered by some workers to be unprofessional and so the H H I T would not be used in restricted spaces.

3.2.3. Handling cylinders on staircases

The opinion of some subjects in group A was that approximately 9 out of 10 staircases are nar- row and require axial trunk rotation while carry- ing cylinders down such staircases. Without using the HHIT, one cylinder would typically be carried in front and one behind the subject on narrow staircases. Using the H H I T on a narrow staircase, abduction occurs at both shoulder joints and so the hands collide into the walls. It becomes difficult to axially rotate the trunk with- out increasing instability. Some subjects carried the gas cylinders directly in front of them down stair- cases. Using the HHIT , carrying cylinders in front of the trunk downstairs caused major discomfort in the upper limbs and created an unbalanced posture.

3.3. Musculoskeletal discomfort

Fig. 5. shows the results obtained from a discom- fort questionnaire which was completed three weeks after the H H I T intervention. Eighteen out of 22 questionnaires were returned. The graph shows musculoskeletal discomfort experienced without us- ing the H H I T before the intervention and musculos- keletal discomfort during the H H I T intervention. The number of subjects reporting discomfort in the neck, wrist/hands, knees and shoulders decreased slightly when the H H I T was used, however, discom- fort increased in the lower back. There was no change in the number of subjects reporting discom- fort for the upper back, elbows and ankles/feet. The small number of subjects has precluded a meaningful statistical analysis of these data.

12 . . . .

l0

8

6

Z 4

Neck Shoulders Upper back Elbows Low back Wrist/hands Hips/thighs Knees Ankles/feet

Musculoskeletal Sites

[ I Di . . . . fort without HHIT ~ Discomfort with HHYr

67

II 44

3 3 ~ ~

o~ 22

Fig. 5. Results from the discomfort questionnaire showing the number of subjects experiencing discomfort in regions of the musculos- keletal system. Discomfort without handles represents discomfort before the HHIT intervention. Discomfort with the HHIT represents discomfort during the intervention.

,~ Del,ereux et al. / blternational Journal o/Industrial Ergonomics 21 (1998) 23 34 29

3.3.1. Laborato~ findings Holding the HHI T using a reverse grip, the angle

subtended between the horizontal plane and the axial plane of a cylinder was approximately 60" in a static posture and when in motion. As the angle increases to 90 ~ during the placing of a gas cylinder the greater is the ulnar deviation at the wrist joint. Holding the H H I T using a forward grip, an average angle of 64 ~' was subtended between the horizontal plane and the axial plane of the cylinder in a static posture. However, this angle approximates to 50 -55 when movement is involved. As the angle increases to 90':' during the placing of a gas cylinder, the greater is the radial deviation of the wrist joint. Therefore, there is a greater change in wrist posture using a forward grip on the HHIT to place gas cylinders in a vertical position.

Without using the HHIT, the gas cylinders are typically dragged along the ground. Experiments conducted in the laboratory measured the resultant load force at the hand at 98 N when dragging one empty gas cylinder weighing 157 N on a smooth surface in the same manner as demonstrated by workers on video. Using the HHIT, the total weight of a gas cylinder is exerted upon the hand/wrist. The weight of the HHIT itself increases the total weight by 9.8 167 N. The total weight of the HHIT and a full gas cylinder would approxim- ately equal 225 N.

4. Discussion

The case study showed that there were few bene- fits gained from using the hand-handle interface tool (HHIT) to manual handle gas cylinders com- pared to the normal method of dragging gas cylin- ders with a mass of 16-22 kg. Manual handling tasks were made easier using the HHIT on large staircases and horizontal ground which is in agree- ment with a previous study (Haisman et al., 1994). The HHI T did create greater difficulty where there were obstacles, narrow doorways and narrow stair- cases to negotiate. The picking up and placing of cylinders using the HHIT resulted in a high load applied to the hand/wrist region due to the full weight of the cylinder and tool acting through this joint while in extremely deviated wrist postures. An

underlying trend of musculoskeletal discomfort was present before the H H IT intervention and dur- ing the HHIT intervention for the same group of subjects which may suggest that the HHIT had limited effectiveness for reducing musculoskeletal discomfort. However, the small differences in mus- culoskeletal discomfort before and during the inter- vention may be due to the fact that subjects may have used the HHIT for only some of the deliveries each day. Other handling aids like ropes and trol- lies were also used by the subjects for deliveries during the H H IT intervention. The use of these manual handling tools and performing normal cy- linder handling during the intervention may have limited any reductions in musculoskeletal discom- fort. The data regarding discomfort from the com- parative questionnaire and the discomfort question- naire differ. The data from the comparative ques- tionnaire shows relative changes in the perceived intensity of discomfort whereas the discomfort ques- tionnaire shows the absolute number of reports of discomfort. Discrepancies in the data may be due to the fewer returns from the discomfort questionnaire affecting the interpretation of the data, especially for such a small sample size. Secondly, the question in the comparative questionnaire was open ended and, therefore, may not have motivated subjects to pro- vide sufficient detail. Thirdly, the discomfort ques- tionnaire may be subject to recall bias as it was administered 3 weeks after the end of the interven- tion and manual handling activities during that peri- od may have altered subjects' perceptions of musculoskeletal discomfort.

Using the HHIT, the total weight of a gas cylin- der plus the additional weight of the H H IT is acting upon the hand/wrist. The usual method of cylinder transportation is by holding the cylinder by the valve guard and dragging it along the ground. The resultant force acting upon the hand/wrist using the dragging method is less than the total weight of the cylinder and HHIT. The resultant force will vary due to the weight of the cylinder (full or empty) and the coefficient of friction of the ground surface. It is not possible to drag a gas cylinder using the HHIT. The greater load acting upon the musculoskeletal system when using the HHIT may increase the prevalence of musculoskeletal fatigue and discom- fort with extended use.

30 .I. Devereux et al. / baernational Journal o/lndustrial Ergonomics 2 l (l 998) 23- 34

The distribution of gas cylinders requires low- to-moderate average strain interspersed with fre- quently very intense physical demands. Static muscle contractions are usually exerted by the muscles of the upper extremity and the trunk dur- ing carrying and dragging of gas cylinders which results in localised muscle discomfort (Westerling and Kilbom, 1981; Haisman et al., 1994).

The HHIT was designed and modified by a par- ticipatory group involving workers, engineers and management. The HHIT was an attempt to reduce the physical strain of the manual handling of gas cylinders. Worker participation provides a flexible problem solving resource which can improve sub- sequent work performance problems (Imada, 1991). Participatory ergonomics has been defined as the workers active involvement in implementing ergo- nomics knowledge, methods and procedures in the workplace (Nagamachi, 1995). This case study shows that workers can be a major problem solving resource, however, without expert ergonomic in- volvement in the design and evaluation process participatory ergonomics may result in a sub- optimal design solution for reducing human user costs with respect to usability and musculoskeletal discomfort.

Additionally, attempts to reduce the workload upon the musculoskeletal system by providing tools (microergonomics) without attempting to ad- dress job redesign and organisational change issues (macroergonomics) in the participatory process may reduce the effectiveness of participatory ap- proaches to solving manual handling problems. An ergonomics input is required at the earliest stages of the participation process to address the macroer- gonomics of the work system as a priority and microergonomics as a secondary approach for re- ducing human user costs during manual handling.

5. Conclusion

The main focus for participatory ergonomic groups should be on redesigning the work task and

work organization instead of introducing possible coping strategies like tools (Putz-Anderson, 1988). A participatory approach improves the probability of implementing change successfully as delivery drivers are more likely to support change with which they have been involved and instigated (lmada, 1991). End user participation also creates a flexible problem solving resource that can solve future work problems and can be a motivating factor especially in a work organization where there is a flat hierarchical structure and little scope for promotion. The HHIT was designed by workers and did not have any ergonomics input at the design stage. It is important that a professional ergonomics input should not be neglected during a participatory approach for designing and evalu- ating tools for manual handling.

References

Devereux, J.J., Buckle, P., Haisman. M.F., 1995. A hand handle interface tool (HHIT) for reducing human user costs within a manual handling work system. Book of Abstracts Proceed- ings of the Prevention of Musculoskeletal Disorders Confer- ence (PREMUS 95), Sept 2428, Montreal. IRSST, Montreal, pp. 399 400.

Haisman, M.F., Ridd, J., Fernandez, A.F., Lamey, S., 1994. Manual handling of gas cylinders during filling and delivery. Contemporary Ergonomics: Proceedings of the Ergonomics Society's 1994 Annual Conference, 19 22 April, University of Warwick. Taylor and Francis, London. pp. 224 229.

Imada, A.S., 1991. The rationale and tools of participatory ergonomics. In: N. Kageyu, A. Imada IEds.), Participatory Ergonomics. Taylor & Francis, Bristol, pp. 30 49.

Nagamachi, M., 1995. Requisites and practices of participatory ergonomics. International Journal of Industrial Ergonomics 15 (5}, 371 378.

Putz-Anderson, V.~ 1988. Cumulative trauma disorders: a man- ual for musculoskeletal diseases of the upper limbs. Taylor & Francis. New York, pp. 85 112.

Van der Beek, A.J., Braam, I.T., Douwes, M., Bongers, P.M., Frings-Dresen, M.H.W., Verbeek, J.H.A.M., Luyts, S., 1994. Validity of a diary estimating exposure to task. activities, and postures of the trunk. International Archives Occupation Environment Health 66, 173 178.

Westerling, D., Kilbom, A... 1981. Physical strain in the handling of gas cylinders. Ergonomics 24 (8), 623 632.

Appendix A. Cylinder handling trial handle assessment daily questionnaire Robens Institute, University of Surrey

Please answer the following questions every day you use the handles: Name: Please assess the use of the handle for carrying cylinders using a scoring system of 1 to 5 points (1 is Very Bad up to 5 Very Good) on the following features: Note: the higher the score the more favourable to the carrying handles

Week beginning?

Feature Day 1 Day 2 Day 3 Day 4 Day 5

Is positioning easy/quick

Is carrying easy/quick

Physical fatigue sensations

Discomfort sensations

Overall acceptability

Comments: Week beginning?

Feature Day 1 Day 2 Day 3 Day 4 Day 5

Is positioning easy/quick

Is carrying easy/quick

Physical fatigue sensations

Discomfort sensations

Overall acceptability

Comments:

Appendix B. Cylinder handle trial comparative questionnaire, Robens Institute, University of Surrey

Date: Please answer the following questions at the end of the User Trial: 1. Personal details

Name: Age: Experience of this work: Weight: Height:

years

2. Cylinder carrying with detachable handles

a. Have you used the handles for carrying cylinders in the past month? If Yes did you use the handle?

Yes/No Daily//not every day/whenever possible

b. Were the handles easy to use? If No, state the problem

Yes/No

c. Were the handles helpful in carrying cylinders? If Yes, under which situations If No why was this?

Yes/No

d. Did you experience physical fatigue when using the handles'? If Yes, state the body region affected and possible cause

Yes/No

e. Did you experience discomfort when using the handles? If Yes, state the body region affected and possible cause

Yes/No

f. Where there any situations where the handles caused you difficulty? If Yes, please describe the situation

Yes/No

3. Cylinder handling without handles

a. Have you handled cylinders without using handles? Yes/No

b. Did you experience physical fatigue when carrying cylinders without handles? Yes/No

c. Did you experience discomfort when carrying cylinders without handles? If Yes, state body region affected and possible cause.

Yes/No

4. Comparison handles versus no handles

a. Have you carried cylinders with and without using handles? Yes/No

b. Is the task easier with or without handles? (Delete one) With/without handles Any particular reason for your view?

c. Do the handles enable the task to be performed quicker? Yes/No

d. Did the handles reduce any physical fatigue normally experienced for this task'? Yes/No If No, why was this?

e. Did the handles reduce any body discomfort experienced with this task'? Yes/No

f. Which aspects of the job were helped by using handles?

g. Were the handles ever a handicap? Yes/No If Yes please give examples.

h. Do you think the handles should be issued for cylinder carrying'? Yes/No

i. Could the design of the handle be improved? Yes/No If Yes, please state any design changes required.

5. Other comments

Thank you for completing this questionnaire

Appendix C. Discomfort Questionnaire Robens Institute, University of Surrey

Name: Service Centre:

This short questionnaire is part of the cylinder handle investigation and focuses on any discomfort experienced before using the handles (column A), any discomfort experienced during use of the handles in the trial (column B), and whether the handles caused greater or less discomfort (column C).

The picture shows the parts of the body referred to in the questionnaire. Limits are not sharply defined, and certain parts overlap. You should decide for yourself in which part you have or have had your trouble (if anyl.

Discomfort includes aches, pains, numbness, swelling, tingling, and stiffness. It is important that you tick a box for columns A, B, and C on every row.

- NECK

PER BACK

E,BOWS

LOW BACK

HIPS/THIGHS

~ " ' ~ KN EES

ANKLES/FEET

A B C

Discomfort without Discomfort using using handles handles (before the trial) (during the trial)

Discomfort when using handles compared to now?

Neck Yes [] No [] Yes [] No [] Greater [] Less [] No Change [] Shoulders Yes [] No [] Yes [] No [] Greater [] Less [] No Change [] Upper back Yes [] No [] Yes [] No [] Greater [] Less [] No Change [] Elbows Yes [] No [] Yes [] No [] Greater [] Less [] No Change [] Low back Yes [] No [] Yes [] No [] Greater [] Less [] No Change [] Wrist/Hands Yes [] No [] Yes [] No [] Greater [] Less [] No Change [] Hips/Thighs Yes [] No [] Yes [] No [] Greater [] Less [] No Change [] Knees Yes [] No [] Yes [] No [] Greater [] Less [] No Change [] Ankles/Feet Yes [] No [] Yes [] No [] Greater [] Less [] No Change []

Please make any comments regarding discomfort and the use of the handles.