EFFECTS OF SURFACE INCLINATION AND LOAD CARRIAGE AID ON STABILITY AND POSTURE DURING POSTERIOR LOAD CARRIAGE TASK

• Main Author: LUH PUTU LILIS SINTA SETIAWATI, NI
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/39667
• Institution: Institut Teknologi Bandung

Posterior load carriage is an activity that can result in loss of balance (associated with the risk of falls) and posture deviation (associated with the risk of musculoskeletal disorders, MSDs). The activity is carried out on a flat, uphill, and downhill surface without using an assistive device that specifically designed for posterior load carriage activities. This study aims to evaluate the effect of surface inclination and aid types used on the mechanism of maintaining stability and posture adjustment in the lower extremities during posterior load carriage. The experiment was within-subject design involving twelve participants with two independent variables including the surface inclination (+250, -250, and 00) and aid types used (frame backpacks and fabric shawl). Measurements of center of pressure (COP) (root mean square, elliptical area, range, velocity, and sway path of COP in the anterior-posterior and medial-lateral direction, and COP length), posture angle in the lower extremities (ankles, knees, and hips), stability perceptions, and rating of perceived discomfort (RPD) are carried out to evaluate the effect of slope surfaces and assistive devices. Through this research, it can be explained that the greater the slope of the surface results in a decrease in stability and the greater the deviation of the posture. Standing on the uphill surface increases instability and posture deviation in a higher amount compared to downhill and flat surface. Meanwhile, the use of a frame backpack provides better stability in uphill surfaces, however, fabric shawl accommodates better stability in the downhill surface. In the other hand, frame backpack causes a greater deviation of the ankle and left knee angle compared to the fabric shawl. It means that the frame backpack provides better posture than the fabric shawl. This was caused by a larger mass in the frame backpack, even reaching 13 times the fabric shawl mass. Regarding the results of the study, it is recommended to replace the frame material in the backpack by aluminum and the base material by a canvas that initially uses iron. This aims to reduce the mass of the frame backpack. In addition, it is recommended to add a hand grip feature to the backpack sling to help users in regulating balance mechanism when carrying posterior loads on an inclined surface. Those recommendations are generally designed to reduce the risk of falls and MSDs during posterior load carriage tasks.