Work profile and functional capacity for formwork carpenters in Hong Kong

Abstract

This study explored the work profile and functional capacities of formwork carpenters at the construction sites in Hong Kong (HK). The major objective was to match the workers' physical demand at work with their physical capacity. Descriptive job nature and physical demands obtained in this study were compared with those in the Dictionary of Occupational Titles (DOT) of United States Department of Labour (USDOL). Workers' physical capacity was compared with a group of sedentary adults, which shed light to the job-demand-induced physical capacities of workers. Thirty male formwork carpenters aged 19-45 underwent a 60-minute face-to-face interview on the perceived job demand based on the DOT Questionnaire and a four-hour functional capacity evaluation (FCE). The FCE included upper extremity functional evaluation on the isometric, dynamic and endurance strength on hand grip, wrist flexion, wrist extension, elbow flexion, and static knuckle-shoulder lifting with the Baltimore Therapeutic Equipment Primus (BTEP), and the dynamic lifting and carrying capacities by VALPAR19. On-site visits were made to consolidate the information obtained from the perceived job demand questionnaire. Another 30 male sedentary adults aged 19-45 were recruited from the Department of Rehabilitation Sciences, Hong Kong Polytechnic University to undergo the exact FCE. Descriptive results from workers revealed similar job tasks of local formwork carpentry as compared to the US. The percentage of agreement of the results obtained from the questionnaire on physical demands included occasional standing (36.7%), walking (46.7%), pushing (73.3%), pulling (63.3%), climbing (66.7%), balancing (66.7%), stooping (53.3%), crouching (50.0%) and reaching (76.7%); frequent lifting (46.7%), carrying (50.0%), handling (60.0%); and near acuity (80.0%). The physical demands that were expressed by workers in HK but not by those in the US included kneeling, fingering, far acuity, and depth perception. No significant differences were revealed in the upper extremity functional capacity between workers and the adults counterparts, except in the dynamic strength of left wrist flexion (t=3.18, df=55, p<=0.01) and wrist extension (t=3.95, df=52, p=0.00); and endurance strength of right wrist extension (t=3.68, df=54, p<=0.01). Results of VALPAR19 on dynamic lifting and carrying capacities showed that a majority of workers managed in lifting a maximum of 'Very Heavy' load (76.7%) when compared with a lower proportion in the sedentary adult group (43.3%). Chi square statistics illustrated a significant difference in the distribution among the 'Medium', 'Heavy', and 'Very Heavy' categories between the two groups (x2=6.48, df=2, p<=0.05). However, no significant difference was found in the endurance of lifting and carrying between the two groups. Due to the prolonged, dynamic nature of the physical demand of formwork carpentry, significant difference was expected in the dynamic and endurance strength of the upper extremity functions between the groups. However, the submaximal physical demand at work did not result in the evaluation of the upper extremity function. The cumulative protocol from the 'maximal strength' subtest of VALPARI9 possibly reflected the endurance strength between the groups while the duration of the 'endurance strength' subtest was suspected to be inadequate to reflect endurance strength function.