Research on the Mechanism of Spinal Stability Under Body Load

In modern society, the prevalence of musculoskeletal disorders and spinal problems has become increasingly concerning, particularly among students and working professionals who regularly carry heavy loads. The growing awareness of health issues related to load carrying has sparked significant research interest in this field. This study investigated the mechanisms of spinal stability under various loading conditions among college students. While backpacks are essential in daily life, their impact on spinal biomechanics and potential injury risks remains a concern. Twenty university students (10 males, 10 females) participated in this research examining the effects of different load magnitudes (0%, 5%, 10%, 20%, and 30% body weight) and carrying durations on spinal stability. Using three-dimensional motion capture, force platform measurements, and surface electromyography, we analyzed participants' postural control and muscle activity during both static stance and dynamic walking conditions at various gradients (0°, 5°, 10°, 20°). Results showed that loads exceeding 20% body weight caused significant alterations in spinal alignment, with forward lean angles increasing by 7-8 degrees at 30% body weight loading. During inclined walking, the combination of slope and load had multiplicative effects, with 30% body weight load at 20° slope resulting in approximately 10-12 degrees more spine forward flexion compared to level ground. Prolonged loading (60 minutes) led to a 30-35% increase in center of pressure sway range, indicating deteriorated postural control. EMG analysis revealed significant muscle fatigue, with erector spinae and multifidus muscles showing primary roles in maintaining spinal stability. Recovery of spinal stability parameters required approximately 30 minutes following heavy load carrying. These findings provide important guidance for establishing evidence-based recommendations for load carrying among college students and emphasize the need for appropriate rest periods and carrying techniques to maintain spinal health.