| dc.description.abstract | Musculoskeletal conditions are a major burden on individuals, health systems,
social care systems, with indirect cost being predominant. In Kenya, thousands
of masonry workers incur disorders and injuries at their places of work every
year. The Ministry of Labour Directorate of Occupational Health and Safety
Services concedes that workers suffer illness due to exposure to unfavourable
working environments and practices. The dynamics of masonry activities in
building and construction sites are poorly understood. In addition, there is
inadequacy of information by the contractors, investors, policy makers and the
operatives, which compound the already complex situation.
This study set out to establish the relationship between manual handling risk
variables and predictability of musculoskeletal disorders in masonry-related
trades. It sought to identify main ergonomic risk factors among masonry charge
hands and other masonry related activities performed by skilled workers in
superstructure external walling constructions. The research provides data for
use in development of prediction tools in evaluation of ergonomics related
complications. The study in its hypothesis suggested that manual handlingrelated
high-risk factors were directly related to work-related musculoskeletal
disorders, which impair work performance.
Generally, masonry work is physically demanding, involving stocking and laying
of stone, mixing and stocking of mortar and grout, and assembling scaffolds.
Lifting and carrying of materials is common, as well as repetitive motion, high
hand force, reaching overhead, and bending of the back or neck, for certain
tasks. Possible causes of musculoskeletal disorders and the various exposure
assessment methods were explored in an attempt to develop an exposure
matrix for masonry workers. Handling factors such a? posture, force, static
exertion, grip, contact trauma, velocity/acceleration, repetition, duration,
recovery time, heavy dynamic exertion and segmental vibration were given
consideration as independent variables. Musculoskeletal disorders; back pains,
muscle aches and fractures, cuts and lacerations were conceptually defined
and taken as dependent variables for application in the study function.
The study evaluated risk hazards on the construction sites' regular activities to
identify, determine, describe and predict safe ergonomic work operations. This
was on the basis of regular superstructure external walling masonry activities.
The researcher compared regular superstructure external walling masonry
activities on specific low and medium rise building sites against the acceptable
established ergonomic standards such as NIOSH to determine the magnitude of
risk. The research uses ethnographic techniques (observation, questionnaires,
personal and semi structured interviews) to assess masonry workers' activities.
The research analyses depict that the interacting variables of manual handling
influence the form, type and magnitude of the resultant injuries, in the muscular
and the skeletal systems among the masonry operatives. This relationship of
influence determines the safety and comfort levels on any given construction
worksite. Further, the findings were that in manual handling force, grip,
repetition, vibration time and recovery duration were still the main factors
influencing musculoskeletal discomforts/injuries of back pain, muscle aches,
fractures, cuts and lacerations. The conclusions are that different manual
handling risk factors have different contributory effects on the human
musculoskeletal system and hence on the resultant injuries. It thus,
recommends that if manual handling practices are to be made worker-friendly,
then the risk factors must be lowered to safer thresholds and their multiplier
effect managed. This could be through; engineering, administrative and work
practice controls.
The study suggests the use of more expansive and medically oriented
approaches to provide additional insight into the field of masonry material
handling. It closes by outlilling provocative areas of further research hoped to
be beneficial both to the fields-of academia and the construction industry. | en |
