Effects of backpack load on critical changes of trunk muscle activation and lumbar spine loading during walking.
This study investigated the effects of carrying a backpack while walking. Critical changes featuring the disproportionality of increases in trunk muscle activation and lumbar joint loading between light and heavy backpack carriage weight may reveal the load-bearing strategy (LBS) of the lumbar spine. This was investigated using an integrated system equipped with a motion analysis, a force platform and a wireless surface electromyography (EMG) system to measure the trunk muscle EMG amplitudes and lumbar joint component forces. A predictive goal programming model was developed to determine the most critical changes in trunk muscle activation and lumbar joint loading. Results suggested that lightweight backpack carriage at approximately 3% of body weight (BW) might reduce the peak lumbosacral compression force by 3% during walking compared with no load condition. The most critical changes in both trunk muscle activation and lumbosacral joint loading were found at a backpack load of 10% of BW. Practitioner Summary: This study investigated the effects of backpack load on the LBS of lumbar spine while walking. A backpack load of 3% of BW might reduce the peak lumbosacral compression force by 3 and 10% of BW induced the most critical changes in LBS of lumbar spine.
['Li|Simon S W|SSW|', 'Chow|Daniel H K|DHK|http://orcid.org/0000-0001-9333-4920']
D000071596:Abdominal Oblique Muscles D000328:Adult D004576:Electromyography D006801:Humans D017770:Lifting D008159:Lumbar Vertebrae D008297:Male D018482:Muscle, Skeletal D064170:Paraspinal Muscles D017568:Rectus Abdominis D064171:Superficial Back Muscles D016138:Walking D016474:Weight-Bearing D055815:Young Adult D021801:Zygapophyseal Joint
Trunk muscle activation lumbar joint loading backpack carriage load-bearing strategy goal programming