A biomechanical model via Kane’s equation – solving trunk motion with load carriage

Abstract

Carrying a heavy backpack has become a phenomenon among school children and adults. A review of the literature on the effect of carrying backpack loads on the trunk backward and forward lean in children and adults showed that with a load of even less than 15% of body weight, children have to walk with a forward lean of the trunk, whereas adults are in a forward lean position only with a backpack loads of more than 27% of their body weight. Due to these biomechanical studies, a mathematical model of the upper body representing trunk and head inclination angles is developed in this paper. The model was a two-link planar of rigid bodies in two-dimensional space. The objectives of this study were to investigate the motion of the trunk and also to develop the mathematical model so that the joint forces and moments acting on the body can be determined. The equations of motion for this model were written based on Kane's dynamical equation of motion.

The Influence of the Schoolbag on Standing Posture of First-Year Elementary School Students

“…Average height, mass and BMI were typical of 7-year-old children. The shift of center of gravity while the subjects were encumbered with a schoolbag was tested, and the anterior shift concurs with the results of many other studies [30,31,32,33] which measured the anterior shift of the torso in a standing position or during bipedal locomotion. Since the anterior shift of center of gravity while under a load in the form of a schoolbag is a well-known fact, the primary goal of this study was to measure the extent of the shift.…”

“…The age difference could explain different findings because older children could have better postural control, even though they were carrying a heavier load. For example, one study [32] reviewed literature on trunk backward and forward lean and found that younger children had more pronounced lean forward than older children when encumbered with the same load ratio relative to the child’s mass. The authors hypothesized that an undeveloped musculoskeletal system was more prone to postural compensations when encumbered to better regain balanced position (center of gravity above center of base of support).…”

Kinetics Study in Parachute Landing Fall Technique by Comparing Professional and Amateur Malaysian Army Parachutists Using Kane’s Method

“…In addition, Kane's method has also been used to solve the problem of shoulder injury when planting palm oil [29]. Additionally, [30,31] have applied Kane's method for the construction of mathematical models for lifting activities as well as the effects of heavy lifting towards the spine. This shows that many activities have been improved to prevent injuries through mathematical modelling by using Kane's method.…”