Turning over any book of System Anatomy, you'll encounter a simple, often misread concept.——The muscles start and end. beginners tend to remember the hard back, to take the "start" as near to the end of the torso and to "stop" as far away from the end of the torso. This violent spatial classification actually masks the fineness of the logic attached to skeletal muscles.
Anatomical definitions of starting points are not based on absolute spatial position but on movement trends during muscle contraction. The starting point is usually defined as the end attached to the relatively fixed bone, referred to as the " fixed point" in biomechanical science; the stop point is the end attached to the relative moving bone, the "move point". Say it, whoever moves, stop.
Take the bicep. When you stand up and raise the dumb bell, the long head and short head start is as steady as Tarzan, and the end point on the corrosive bone is pulled to the gillbone, at which point it moves. But what if you're holding a single bar up? The gillbone is relatively fixed and the torso and shoulderbones are pulled up. At this point, the original stop point became a fixed point, and the starting point became a moving point. This role interchange of starting points has a special term in anatomy: reverse starting points.
Since the starting point is relative, why does the standard anatomy always mark the near end as the starting point? This is not stereotyped, but is based on a pattern of human force in normality. Most limb muscles perform routine movements (e.g. walking, scratching), providing stability to the torso and near-end bones and performing fine exercise at the far end. Thus, by default, the textbooks are defined as the starting point, which is in line with the default movement logic of evolution.
However, looking at the beginning of single muscles is prone to a mechanical dead end. Modern anatomy studies have increasingly emphasized that the starting point of muscles is not an endless boundary, but rather an integration into the wider membrane continuum. The endpoint of the bicep is not only the death of a corrosive cortex, but it is interwoven with the deep dysentery of the forearms, which indirectly transmits the contractionary force to the finger. The starting point is more like a critical node in a tension network than an isolated anchor.
Understanding the dynamic nature of the starting point is far more valuable than reciting a bunch of dry bones. Next time you see those red and white marks on the autopsy model, think about it: who's moving this muscle right now?
Participation in discussions
What's with the reverse stop? It feels a little entangled.
It's true that the membrane continuum is critical, and many of the rehabilitation trainings are doing so now, and can't just stare at a single muscle.
Feels okay.
It's really pointless to remember those things with backs.
怎么课本不这么写啊!害我之前浪费那么多时间死磕。
那练背的时候这个逻辑也适用吗?
围观一下。