Search

Objective: Back pain in adults is common and well studied. In contrast, back pain in children has received comparatively little scientific study, despite recent media attention. The purpose of this study is to see what factors influence the prevalence of back pain in middle school children, with particular attention to the weight of children's backpacks and the availability of school lockers., Methods: A population-based sample of 1540 children ages 11-14 years in a large metropolitan area was studied. A questionnaire was used to determine presence and severity of back pain, availability of lockers, backpack use, use of 1 or 2 straps to carry backpack, activity limitations due to back pain, and use of pain medication for back pain. Gender, age, weight of the child, and weight of his or her backpack were recorded. Results of scoliosis screening were evaluated with regard to the above information. Data were analyzed using the chi test and univariate or multivariate logistic regression analysis as appropriate., Results: Overall, 37% of the children reported back pain. Backpacks were used by 97% of children, hence there were too few students not using backpacks to treat backpack use as an independent variable. Multivariate analysis found back pain associated with use of a heavier backpack (P=0.001), younger age (P<0.001), female sex (P<0.001), and a positive screening examination for scoliosis (P=0.009). Children with lockers available reported less back pain (P=0.016). The use of 1 or 2 straps to carry the backpack did not have a significant association with back pain (P=0.588). Of the children who reported back pain, 34% limited their activity due to the pain, 14% use medication for pain relief, and 82% believed their backpack either caused or worsened their pain., Conclusions: The incidence of back pain in early adolescence approaches that seen in adults. Recommendations for an "acceptable" weight of backpacks cannot be made from this study, as the weights of students' backpacks seem directly proportional to the likelihood of back pain. This study identifies 2 factors associated with self-reported back pain in early adolescents that are amenable to change: availability of school lockers and lighter backpacks. These findings may be useful in advising families and influencing school policies.

A slipped capital femoral epiphysis was created in 12 matched pairs of immature bovine femora using an anterior-to-posterior-directed shear force. All soft tissues, with the exception of the perichondrial ring, were removed before testing. One specimen from each pair was fixed with a single cannulated screw in standard fashion, whereas the contralateral specimen was fixed with a single screw that compressed the physis. The amount of compression achieved was quantified using Fuji film. Standard fixation yielded 1.4 MPa of pressure across the physis; compression fixation yielded 3.2 MPa, a 2.3-fold difference (p = 0.0001). The compression fixation was 47% more stiff than standard technique (p = 0.030), yet the differences in ultimate strength (p = 0.180) and energy absorbed at failure (p = 0.910) were not statistically significant. The stiffness of the compressed specimens remained less than that of the intact femora. Single-screw compression fixation of in vitro bovine femora was significantly more stiff than the current, widely used noncompression fixation technique, yet does not compromise the ultimate strength, energy absorbed, or the technical ease of single-implant fixation.