The effects of backpack type on lumbo-pelvic coordination during trunk bending and return tasks

Abstract

Backpacks with ergonomic features are recommended to mitigate the risk of developing low back pain due to carrying a heavy school backpack. A repeated measure study was conducted on 40 college-age students to investigate the immediate changes in magnitude and timing aspects of lumbo-pelvic coordination when carrying an ergonomically modified vs. a normal backpack relative to no backpack condition during trunk forward bending and backward return tasks. We found a smaller reduction in the thoracic range of rotation, an increase vs. a decrease in pelvic range of rotation and a larger reduction in lumbar flexion for a modified vs. a normal backpack. Furthermore, during the forward bending, a less in-phase motion for the modified backpack was observed. Our results suggest that participants have likely experienced larger spinal loads with the modified backpack; a conclusion that should be investigated in future to determine whether ergonomic backpacks can reduce the risk of low back pain in children. Practitioner summary: Research participants performed trunk bending and return closer to their habitual way under modified versus normal school backpack. From an equilibrium point of view, therefore, individuals are likely experiencing larger spinal loads during activities of daily living with a modified backpack. However, such a conclusion may change when considering stability requirements.

Einfluss des Schulrucksackgewichtes bei Grundschulkindern: Gang, Muskelaktivität, Haltung und Stabilität

“…Auch andere Studien beobachteten bei Schulkindern mit einer Rucksacklast zwischen 8,5 und 20 % des Körpergewichts eine Vorneigung des Oberkörpers mit einer erhöhten vorderen Beckenkippung und ausgeprägter Hüftflexion [ 16 , 21 , 24 ]. Auch bei älteren Jugendlichen und Erwachsenen konnte eine traglastbedingte Rumpfvorneigung beobachtet werden [ 6 , 12 , 30 ]. Dabei intensivierte sich die Rumpfvorneigung mit der Rucksacklast [ 16 , 24 ].…”

Effects of Trunk Postures and Shoulder Flexion Angles on the Muscular Activity of Scapular Upward Rotators

“…Forward bending posture (FBP) is a risk factor that can cause musculoskeletal pain in industrial workers and is particularly known to have a close association with lumber pain [1][2][3]. For this reason, studies related to FBP and lumber pain have continued to be conducted [4][5][6]. However, improper trunk postures can affect muscles in not only the lower back, but also the neck and shoulders [7][8][9].…”