Biomechanics Blog #1

Every morning when I wake up, the first thing I do is brush my teeth. There are several different movements and biomechanics mechanisms that come in to play with even a small activity of daily life that everyone participates in like brushing one's teeth. Once the toothpaste is on the brush, the first movement is flexion of the elbow. The prime mover here is my biceps brachii and the muscle is shortening meaning it is a concentric contraction. This action occurs in the sagittal plane and the medial-lateral or frontal axis. In terms of athrokinematics, there are articulations happening in the humeroulnar joint between the distal convex end of the humorus and the proximal concave side of the ulna. The end of the ulna closest to the trunk is going to glide along the distal end of the humerus towards the front. There are also articulations of the humeroradial joint in elbow flexion, which result in the radial head gliding along the distal humerus anteriorly in a similar way as the ulna.

There is also a great deal of both wrist flexion and extension while holding the toothbrush and performing the task. Wrist flexion is demonstrated for most of the duration of the activity. This flexion occurs in the sagittal plane and the axis of movement is the frontal axis.Wrist extension is a movement that also takes place in the sagittal plane and is classified as having the frontal axis of movement.