Background: Backpacks are one of the most widely used accessories in modern society. However, previous studies have shown that carrying a backpack can cause various musculoskeletal problems.
Objectives: To investigate the effects of a body-adhesive backpack on craniovertebral angle, sagittal shoulder angle and the muscle fatigue in the upper extremity.
Design: Randomized cross-over design.
Methods: For this study, 36 healthy university students participated in this study. The experiment was conducted three times using common backpack, and body-adhesive backpack condition. The angles of the cervical spine and shoulder joints of the subjects were calculated without the backpack. Electrodes were placed at upper trapezius, lower trapezius, rectus abdominis and erector spinae to check for muscle fatigue. Subjects carried a backpack and walked on a treadmill for 15 minutes at 4 km/h. The muscle fatigue signal was also measured while walking. After walking, the craniovertebral and sagittal shoulder angles were measured again while subjects carried backpack.
Results: As a result of this study, body-adhesive backpack condition showed significant decrease and significant increase in craniovertebral angle and sagittal shoulder angle than common backpack (P<.05). Body-adhesive backpack condition showed significant decrease in upper trapezius, lower trapezius, erector spinae, and rectus abdominis when compared to a common backpack (P<.05).
Conclusion: This study suggests that a body-adhesive backpack is more beneficial in correcting body posture than a common backpack.

INTRODUCTION
SUBJECTS AND METHODS
    Subjects
    Procedures
    Intervention
    Outcome measures
    Data analysis
RESULTS
    Comparison of craniovertebral angle
    Comparison of sagittal shoulder angle
    Comparison of muscle fatigue by types of backpack
DISCUSSION
CONCLUSION
REFERENCES

• Jinkyu Son(Department of Physical Therapy, Daejeon University)
• Ho Kim(Department of Physical Therapy, Daejeon University)
• Wonseob Shin(Department of Physical Therapy, Daejeon University) Corresponding author