TY - JOUR
T1 - The effect of backpack load on the gait of normal adolescent girls
AU - Chow, Daniel H.K.
AU - Kwok, Monica L.Y.
AU - Au-Yang, Alexander C.K.
AU - Holmes, Andrew D.
AU - Cheng, Jack C.Y.
AU - Yao, Fiona Y.D.
AU - Wong, M. S.
PY - 2005/5/15
Y1 - 2005/5/15
N2 - Concerns regarding the effects of load carriage have led to recommendations that backpacks be limited to 10-15% of body weight, based on significant changes in physical performance. However, gait responses to backpack loads are not entirely consistent and there is a particular lack of data regarding load-bearing gait in adolescent females. Gait patterns of 22 normal adolescent girls were recorded at backpack loads of 0, 7.5, 10.0, 12.5 and 15.0% body weight. Temporal-distance, ground reaction force and joint kinematic, moment and power parameters were analysed by repeated measures ANOVA with factors of backpack load and side (left or right). Walking speed and cadence decreased significantly with increasing backpack load, while double support time increased. Kinematic changes were most marked at the proximal joints, with a decreased pelvic motion but a significant increase in the hip sagittal plane motion. Increased moments and power at the hip, knee and ankle showed increasing demand with backpack load. Parameters showed different responses to increasing load, and those that suggested a critical load indicated this to be approximately 10% body weight. While this may be due to a change in gait due to increased demand, further work is required to verify this and also to examine the cumulative effects of backpack load on the musculoskeletal system, which may be more appropriate in determining recommended load limits.
AB - Concerns regarding the effects of load carriage have led to recommendations that backpacks be limited to 10-15% of body weight, based on significant changes in physical performance. However, gait responses to backpack loads are not entirely consistent and there is a particular lack of data regarding load-bearing gait in adolescent females. Gait patterns of 22 normal adolescent girls were recorded at backpack loads of 0, 7.5, 10.0, 12.5 and 15.0% body weight. Temporal-distance, ground reaction force and joint kinematic, moment and power parameters were analysed by repeated measures ANOVA with factors of backpack load and side (left or right). Walking speed and cadence decreased significantly with increasing backpack load, while double support time increased. Kinematic changes were most marked at the proximal joints, with a decreased pelvic motion but a significant increase in the hip sagittal plane motion. Increased moments and power at the hip, knee and ankle showed increasing demand with backpack load. Parameters showed different responses to increasing load, and those that suggested a critical load indicated this to be approximately 10% body weight. While this may be due to a change in gait due to increased demand, further work is required to verify this and also to examine the cumulative effects of backpack load on the musculoskeletal system, which may be more appropriate in determining recommended load limits.
KW - Adolescent idiopathic scoliosis
KW - Backpack
KW - Gait
UR - http://www.scopus.com/inward/record.url?scp=21844465389&partnerID=8YFLogxK
U2 - 10.1080/00140130500070921
DO - 10.1080/00140130500070921
M3 - Article
C2 - 16087499
AN - SCOPUS:21844465389
SN - 0014-0139
VL - 48
SP - 642
EP - 656
JO - Ergonomics
JF - Ergonomics
IS - 6
ER -