Previous research has quantified differences in head and spinal kinematics between children and adults restrained in an automotive-like configuration subjected to low speed dynamic loading. The forces and moments that the cervical spine imposes on the head contribute directly to these age-based kinematic variations. To provide further explanation of the kinematic results, this study compared the upper neck kinetics - including the relative contribution of shear and tension as well as flexion moment - between children (n=20, 6-14 yr) and adults (n=10, 18-30 yr) during low-speed (<4 g, 2.5 m/s) frontal sled tests. The subjects were restrained by a lap and shoulder belt and photo-reflective targets were attached to skeletal landmarks on the head, spine, shoulders, sternum, and legs. A 3D infrared tracking system quantified the position of the targets. Shear force (F(x)), axial force (F(z)), bending moment (M(y)), and head angular acceleration (θ(head)) were computed using inverse dynamics. The method was validated against ATD measured loads. Peak F(z) and θ(head) significantly decreased with increasing age while M(y) significantly increased with increasing age. F(x) significantly increased with age when age was considered as a univariate variable; however when variations in head-to-neck girth ratio and change in velocity were accounted for, this difference as a function of age was not significant. These results provide insight into the relationship between age-based differences in head kinematics and the kinetics of the cervical spine. Such information is valuable for pediatric cervical spine models and when scaling adult-based upper cervical spine tolerance and injury metrics to children.
Take care of your body and self, Keep your mind clear of anger issues, Any sadness, Etc. Be kind! Not just to yourself but others! Helps you seem and appear a kind person to others which can make friends, I have depression but I hope you dont get it and avoid it! <3
This statement is "false" or the second option. Digestion takes places as soon as you put food in your mouth. That's because your saliva has chemicals that starts to break down the food as soon as you put it in your mouth. Then it goes down through your esophagus then through your stomach going through the primary intestines but when it gets to the small intestine that's when it sucks all the nutrient's out of the food that would give the body energy and gets rid of the food that won't.
