Effect of single and double strap backpacks on lung function.

Area of Science:

• Physiology
• Biomechanics
• Public Health

Background:

• Previous research indicates heavy military loads and body armor negatively impact lung function, causing restrictive ventilatory impairment.
• The effects of lighter loads, such as those carried by students (approx. 6 kg), on lung function remain understudied.
• The impact of different backpack strap designs on lung function has not been previously investigated.

Purpose of the Study:

• To investigate the effects of a 6 kg backpack load on lung function in young adults.
• To compare the lung function changes induced by a single-strap backpack (SSB) versus a double-strap backpack (DSB).
• To assess the impact of backpack design on Forced Vital Capacity (FVC), Forced Expiratory Volume in one second (FEV1), FEV1/FVC ratio, and Peak Expiratory Flow (PEF).

Main Methods:

• Thirteen participants (4 males, 9 females) were recruited for the study.
• Lung function parameters (FVC, FEV1, FEV1/FVC%, PEF) were measured under three conditions: no backpack (control), with a 6 kg SSB, and with a 6 kg DSB.
• Statistical analysis was performed to compare lung function measurements between conditions.

Main Results:

• Both SSB and DSB significantly reduced FVC compared to the no-pack condition (SSB: -3.94%, DSB: -1.97%).
• The SSB resulted in significantly lower FVC and FEV1 compared to the DSB.
• No significant differences were observed in FEV1/FVC% or PEF across all conditions.

Conclusions:

• A 6 kg backpack load can induce a mild, restrictive type of ventilatory impairment.
• The single-strap backpack design appears to have a more pronounced negative effect on lung function compared to the double-strap design.
• These findings suggest that backpack design and load distribution are important factors influencing respiratory mechanics in students.