Abstract Previous epidemiological studies indicated that weight of schoolbag in most countries is far higher than that recommended guidelines. Heavy schoolbags seriously affect the healthy development of the musculoskeletal system of adolescents, which not only leads to abnormal posture e.g. rounded shoulders, hunchback and head forward, but also is one of the main causes of adolescent musculoskeletal diseases such as cervical spondylosis, low back pain and scoliosis. However, adolescents and their parents do not fully understand the harm of heavy schoolbags, let alone the health knowledge regarding the choice and use of schoolbags. Therefore, the review introduces current evidence regarding the association between schoolbag and adolescent musculoskeletal system diseases, as well as schoolbag selection and use, with the aim to arouse the attention of teenagers and their parents and relevant health education departments.

Objective To study the effect of pain on the lumbar and hip joint moments in patients with lumbar disc herniation(LDH)while sitting and standing.Methods Dynamic data from 20 healthy controls and 20 patients with LDH were collected using an AMTI dynamometer.The differences in moments between the lumbar spine and hip joints in the sagittal and coronal planes for the two groups of subjects performing sitting-standing tasks were analyzed using statistical parameter mapping(SPM).Results Compared to the healthy control group,the LDH group showed a significant increase in the maximum lumbar flexion moment and the maximum hip adduction moment from standing to sitting(P＜0.05).SPM analysis showed that during the initial phase of standing(37％-42％),the hip abduction moment of the LDH group was significantly greater than that of the healthy control group(P=0.007).Conclusions Subjects with LDH have an unstable lumbar spine and pelvis during sitting and standing,especially at the stationary stage,which makes it difficult to achieve balance in their body.Therefore,increasing the hip abduction moment is necessary to maintain pelvic stability.During clinical evaluation and treatment,emphasis should be placed on the stable function of the spine and pelvis.