Effect of backpack shoulder straps length on cervical posture and upper trapezius pressure pain threshold

Author: Abdelraouf, Osama Ragaa; Hamada, Hamada Ahmed; Selim, Ali; Shendy, Wael; Zakaria, Hoda
Language: English
Published: 2016
Source: PubMed Central (PMC)
Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5080147/
Identification number: ftpubmed:oai:www.ncbi.nlm.nih.gov/pmc:5080147


[Purpose] This study was performed to investigate the effect of the length of backpack shoulder straps on upper trapezius muscle pain threshold and craniovertebral angle. [Subjects and Methods] There were 25 participants, with ages from 15 to 23 years old. Upper trapezius pain threshold and craniovertebral angle were measured for all subjects without the backpack then re-measured after walking on a treadmill for 15 min under 2 conditions: 1) wearing a backpack with short straps; and 2) wearing a backpack with long straps. [Results] there was a significant reduction in upper trapezius pain threshold and craniovertebral angle while carrying a backpack with long shoulder straps, compared to use of a backpack with short shoulder straps or no backpack. [Conclusion] A backpack with short straps is less harmful than a backpack with long straps. This result should be considered in ergonomic design of backpacks to reduce the incidence of various physiological and biomechanical disorders.