title: Effect of backpack shoulder straps length on cervical posture and upper trapezius pressure pain threshold.
abstract: [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.
authors: Faculty of Physical Therapy, Cairo University, Egypt.
authors: Osama Ragaa
authors: OR
authors: Abdelraouf
authors: Faculty of Physical Therapy, Cairo University, Egypt.
authors: Hamada Ahmed
authors: HA
authors: Hamada
authors: Faculty of Physical Therapy, Cairo University, Egypt.
authors: Ali
authors: A
authors: Selim
authors: Faculty of Physical Therapy, Cairo University, Egypt.
authors: Wael
authors: W
authors: Shendy
authors: Faculty of Physical Therapy, Cairo University, Egypt.
authors: Hoda
authors: H
authors: Zakaria
keywords: Backpack; Cervical posture; Shoulder straps