|Author:||Ng, Hon-yan Xavier|
|Title:||Effects of backpack loading on the pulmonary capacities of normal schoolgirls and those with adolescent idiopathic scoliosis|
|Subject:||Hong Kong Polytechnic University -- Dissertations|
Backpacking -- Physiological aspects
Scoliosis in children
Spine -- Wounds and injuries
|Department:||Jockey Club Rehabilitation Engineering Centre|
|Pages:||viii, 130 leaves : ill. ; 30 cm|
|Abstract:||Backpacks are commonly used by school children to carry books to and from school. It has been suggested that the weight of backpack should not exceed 10% of the user's body weight. Many studies have investigated the effects of backpack loading on users as the weight of the backpack may have adverse effects. Carrying a backpack of weight around 10% to 15% of the user's body weight was found to result in significantly increased forward trunk inclination and double support duration during the gait cycle. Pulmonary function parameters of forced vital capacity (FVC) and forced expiratory flow in the first second (FEV1) were significantly decreased when backpack users adopted a kyphotic posture or carried a backpack of over 20% of the users' body weight. A backpack with tighter straps also significantly decreased the user's FVC and FEV1. While a load limit of 10% body weight has been recommended, it was shown that over 80% of school children's backpacks were over this suggested weight. For school children with adolescent idiopathic scoliosis, who are know to have poorer pulmonary function, concerns have been raised as to whether or not the suggested limit of backpack weight is suitable for them. A group of 18 normal schoolgirls and a group of 42 schoolgirls with AIS (21 subjects in mild group and 21 subjects in moderate group) participated in this study. Pulmonary function testing (spirometry) was used to investigate the effects on subjects due to different weights of backpacks (0%, 5%, 7.5%, 10%, 12.5% and 15%). Forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), ratio of FEV1 to FVC, peak expiratory flow (PEF) and mean forced expiratory flow from 25% to 75% of vital capacity (FEF25-75%) were compared among three groups and also between normal schoolgirls and schoolgirls with AIS under different loading conditions. There was no significant difference between the factors of group and backpack weight when comparing among three groups or comparing between normal schoolgirls and schoolgirls with AIS. Schoolgirls without backpack had significantly higher FVC and FEV1 than when carrying a backpack loaded at 5% to 15% of the users' body weight either comparing among the three groups or between normal subjects and subjects AIS. PEF and FEF25-75% in normal subjects were significantly higher than in subjects with AIS. From this study, it was shown that backpacks lighter than 10% of the user's body weight can also affecting user's pulmonary function, especially for subjects with AIS. The suggested loading limit for normal subjects may not be suitable for subjects with AIS.|
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