Altered Disc Compression in Children With Idiopathic Low Back Pain

Abstract

Study Design This study is a repeated measures design to measure the lumbar spine’s response to common backpack loads in children with idiopathic low back pain (ILBP) using upright MRI. Objective The purpose of this study is to analyze the lumbar spine’s response to backpack loads with upright MRI in ILBP children in order to compare their results to previously published normal child data under the same conditions. We hypothesize that typical backpack loads will have a different effect on the lumbar spine of normal and ILBP children. Summary of Background Data Research in normal children shows that backpack loads compress the lumbar IVDs, increase lumbar coronal deformity, and increase pain. Methods Fifteen pediatric and adolescent patients with ILBP were selected. Patients were excluded if a spinal deformity, an underlying pathology, or known injury was identified. A 0.6T upright MRI scanner imaged the subjects while supine and standing wearing 0 kg, 4 kg, and 8 kg backpacks. IVD height, lumbar lordosis, lumbar coronal deformity, and pain score were recorded after each condition and compared using ANOVAs. We compared the above variables between ILBP and normal subjects using generalized least squares models. Results The cohort’s mean age was 13 ± 3 years. The 4 kg and 8 kg backpacks only compressed the L5-S1 IVD relative to upright with no load. Subjects experienced increasing pain with increasing load. Load had no effect on lumbar lordosis or lumbar coronal deformity. Compared to normal children, ILBP children experience significantly less disc compression at T12-L1 to L4-5, less lumbar lordosis, and more pain with increasing load. Conclusions In ILBP children, increasing backpack load compresses only the L5-S1 IVD. Compared to normal children, ILBP children experience less lumbar IVD compression, less lumbar lordosis, and more pain due to increasing load suggesting altered mechanisms for load tolerance in ILBP children.

Correlations between Muscle Activities and Strap Length and Types of School Bag during Walking

“…All subjects walked on a treadmill with no bag, and while carrying a shoulder bag or backpack at the height of the iliac crest, 10 cm lower than the iliac crest, or 20 cm lower than the iliac crest 11 ) . The weight of the bag was set at 10% of the body weight of each subject 2 , 9 , 12 , 13 ) . The order of the tasks was carried out at random to prevent a carry over effect.…”

“…The correlation between pain and backpack weight per body mass index among girls was positive and significant, but negative and not significant among boys. The L4–L5 and L5–S1 intervertebral disc compress, particularly anteriorly, when transitioning from the supine to the upright position when carrying a 10% body weight backpack 9 ) . Al-Khabbaz et al 10 ) reported that the rectus abdominis muscle activity increased progressively and disproportionately as the backpack load increased.…”

“…While backpacks have been studied in a number of studies 3 , 8 , 9 , 10 ) , there is a paucity of study on the effects on muscle activities of strap length and type of school bag during walking. Therefore, the purpose of the current study was to examine correlations between muscle activities and strap length and the type of school bag during walking.…”

Perinatal factors associate with vertebral size and shape but not lumbar lordosis in 10‐year‐old children

“…A study of 13‐year‐olds found that increasing backpack load did not change lumbar lordosis in either those with idiopathic low back pain or controls, but they noted that children with low back pain experienced significantly less lumbar lordosis with backpack load compared with controls but that it was unclear whether this related to their back pain (Shymon et al. ). These uncertainties indicate the need for a better understanding of the factors affecting the development of the lumbar lordosis.…”

Effect of Backpack Strap Patterns on Gait Parameters in Young Adults at Self‐Selected Normal and Fast Walking Speeds

“…The deleterious effect of backpack carriage on both children [1,2], and adults [3,4] alike has been a subject of growing interest and research. Findings from these studies and others indicate that backpack carriage may alter posture [1,3], may cause back pain [5] and increased exertion [4], and may have adverse effects on the cardiopulmonary system [6].…”