Smith B, Ashton K, Bohl D, Clark R, Keller J, Klassen S; Department of Physical Therapy, Wichita State University, Wichita, KS, USA. Barb.Smith@wichita.edu.

PURPOSE: Little data exist concerning how carrying a backpack influences pelvic movement while walking in college females. The researchers examined the differences in pelvic tilt, obliquity and rotation between carrying no backpack, carrying one on the preferred shoulder, and carrying one over both shoulders. SUBJECTS: Thirty female college students ages 18 to 30 years with no history of musculoskeletal disorders to their pelvis, legs, or arms were used as subjects. The average subject age and weight were 23.0 years and 140.2 pounds, respectively. METHODS AND MATERIALS: Subjects were weighed and fitted with a backpack loaded with 15% of their body weight. Then gait was analyzed using the Oxford MetricsÓ VICON Clinical Manager gait analysis system while the subject carried no backpack, a backpack over both shoulders (bilaterally), and a backpack over her preferred shoulder (unilaterally). Three trials were conducted under each condition. ANALYSES: The results of the three trials for each condition and each pelvic motion were averaged. Paired t-tests were used to determine differences in the degrees of pelvic tilt, pelvic rotation, and pelvic obliquity without the backpack and carrying the backpack bilaterally and unilaterally. The alpha level was set at .05/3 (p£ .017) using Bonferroni’s correction. RESULTS: Anterior pelvic tilt was greatest when the backpack was carried unilaterally. Significant differences in tilt occurred between the conditions of no backpack and unilateral backpack and between unilateral and bilateral backpack. Pelvic obliquity was greatest when the backpack was carried unilaterally. Significant differences between all three conditions were found. Pelvic rotation was smallest when carrying a backpack bilaterally. Significant differences were found between the conditions of no backpack and bilateral backpack and between unilateral and bilateral backpack carriage. CONCLUSIONS: These results suggest that college-age females could develop postural deviations depending on how they carry a weighted backpack. FUNDING SOURCE: This research was supported by Kansas Partners in Progress and the DeLano Maggard Scholarship. No author has any potential for material gain as a result of this study.

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