2. Department of basic science, Faculty of Physical Therapy, Cairo University, Egypt.
3. Department of Physical therapy for cardiovascular/respiratory disorders and geriatrics, Faculty of Physical Therapy, Cairo University, Egypt.
Background: Load placement is an important factor in the efficiency of load carriage. Two types of packs have aroused special interest, backpack and front pack. The backpack is one of several forms of manual load carriage that provides versatility and is often used by school children. There is a change in kinematics when the placement of the load was altered.
The purpose: of this study was to investigate the efficacy of backpack and front pack on ventilatory functions.
Methods: A pretest-post test (2×3) design was used in this study. Forty Saudi girls with mean age (10.5±0.9 and 10.5±0.7) years old participated in this study. They were assigned into two groups of equal sizes (group I and group II). Subjects in group I, n=20. Subjects in group II, n=20:- Subjects in group I were assessed without a load (NP)and carrying a load (10% of body weight) in a backpack(BP) while Subjects in group II were assessed without a load (NP) and carrying the same load in a front pack (FP). They were required to the cardiopulmonary laboratory for testing on two separate occasions, they provided three maximally forced expirations under each of the following two conditions: no pack (NP), load carriage (10% of BW) either backpack (BP)or front pack (FP). They rested for 1 min between each individual expiration and for 5 min between each condition. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF) were measured. Paired t-test was used to distinguish between the two groups before and while carrying the packs in each group separately. Unpaired t-test was used to further distinguish between both types of packs.
Results: The results revealed that both front pack and backpack significantly decreased ventilatory functions. Comparing both groups, this decrease was non-significant.
Conclusion: The finding revealed that both types of packs decreased the ventilatory functions, the decrease in ventilatory functions when carrying a front pack is higher than when carrying a backpack, so the backpack has the advantage over the front pack in terms of ventilatory functions.
Keywords: Backpack, Front pack, load carriage, Forced Vital Capacity, Forced Expiratory Volume in 1 s, Peak expiratory flow