Effects of Different Backpack Loads in Acceleration Transmission during Recreational Distance Walking

Abstract

It is well established nowadays the benefits that physical activity can have on the health of individuals. Walking is considered a fundamental method of movement and using a backpack is a common and economical manner of carrying load weight. Nevertheless, the shock wave produced by the impact forces when carrying a backpack can have detrimental effects on health status. Therefore, the aim of this study was to investigate differences in the accelerations placed on males and females whilst carrying different loads when walking. Twenty nine sports science students (16 males and 13 females) participated in the study under 3 different conditions: no weight, 10% and 20% body weight (BW) added in a backpack. Accelerometers were attached to the right shank and the centre of the forehead. Results showed that males have lower accelerations than females both in the head (2.62 ± 0.43G compared to 2.83 + 0.47G) and shank (1.37 ± 0.14G compared to 1.52 ± 0.15G; p<0.01). Accelerations for males and females were consistent throughout each backpack condition (p>0.05). The body acts as a natural shock absorber, reducing the amount of force that transmits through the body between the foot (impact point) and head. Anthropometric and body mass distribution differences between males and females may result in women receiving greater impact acceleration compared to men when the same load is carried.

Evaluation of impact-shock on gait after the implementation of two different training programs in older adults

“…The final head accelerations achieved in this study in both training groups and both during dominant and non-dominant leg support, suggest that physical exercise (regardless of its type) is sufficient to increase the head accelerations to more similar levels to those of younger adults. For example, in a sample of men and women aged 24.66 (3.67) years, with a walking speed similar to that of our study (1.3 m/s), Lucas-Cuevas et al (2013) recorded head accelerations of 2.62 (0.43) g in men and 2.83 (0.47) g in women. In our study, the participants' average (dominant and non-dominant leg) head accelerations increased in both groups after training (MCG: +14.91%, IWG: +11.75%), reaching 2.24 g in the MCG and 2.28 g in the IWG.…”

Surface acceleration transmission during drop landings in humans

“…Existing knowledge of in vivo whole-body impact elastic wave reduction largely stems from surface-mounted accelerometer investigations. The majority of studies have attached accelerometers to the tibia and forehead of participants in activities including walking (Forner et al, 1995;Light, McLellan, & Klenerman, 1980;Lucas-Cuevas et al, 2013;Voloshin, Wosk, & Brull, 1981), running (Derrick, Hamill, & Caldwell, 1998;Hamill et al, 1995;Shorten & Winslow, 1992), and landing (Zhang et al, 2008). These studies have consistently reported lower peak accelerations at the forehead compared with the tibia.…”

Effect of backpack shoulder straps length on cervical posture and upper trapezius pressure pain threshold

“…People use these different types of bags to carry the things they require in their daily lives. While carrying a bag and walking, the body is subjected to physical stress owing to the weight of the bag, and the body is either mechanically or physiologically influenced, which affects dynamic balance and changes the posture of the body2, 3 ) . Carrying a backpack in an incorrect manner can cause various biomechanical, physiological and neuromuscular disorders that may reduce physical performance4, 5 ) .…”

“…An ideal bag weight and space between the shoulder straps have been recommended6, 7 ) . Asymmetry of weight distribution in both shoulder straps may cause a spinal deformity with gait abnormalities and scoliosis1, 2 ) . Carrying weight on one shoulder increases energy consumption and leads to alteration in the electromyogram of both arms and legs muscles8, 9 ) .…”