The spine supports your body, is extremely flexible, and protects the spinal cord - but it's also prone to pain.
Category
🗞
NewsTranscript
00:00This duck is a vertebrate, so are fish and of course mammals like zebras or
00:06whales. We humans are also vertebrates but in some ways we're unlike our
00:13evolutionary relatives. One difference is that when we walk, sit or stand we use
00:18the spine to support our bodies vertically rather than horizontally and
00:22that's not really what it was made for. The spine is made up of 24 individual
00:29vertebrae plus the sacrum which is attached to a tiny tail, a vestigial one.
00:34It's called the coccyx. At first glance individual vertebrae look a little
00:40strange but everything in and on one serves a purpose. The long flanges act as
00:46anchors for ligaments and muscles enhancing their strength. This gives the
00:51spine a huge range of motion. It can stretch, bend, tilt even twist around its
00:56own axis. So everything runs as smoothly as possible. Elastic intervertebral
01:02discs made of connective tissue containing collagen are located between
01:07the vertebrae. But perhaps the most important feature is a hole two to three
01:11centimetres in diameter. When lined up in the spine the holes form a channel for
01:17the spinal cord. Sprouting from the brain stem and running downwards it branches
01:21out between individual vertebrae into the rest of the body. There the nerves
01:25transmit impulses telling the arms and legs to move for example or carrying
01:30sensory impulses like pain back to the brain. When horizontal the body's weight
01:36is distributed evenly among the vertebrae. It's roughly the same system
01:40as used in bridge construction. But when we sit, walk or stand the weight of the
01:46upper body presses down on the spine like a tower. The lower vertebrae in
01:50particular have to cope with a greater load. Bad posture, sudden movements or
01:57lifting heavy loads can damage the intervertebral discs and even push them
02:02into the spinal canal. This can put pressure on the nerves of the spinal
02:06cord and cause severe pain. But taking it easy, lying around or not moving much
02:12isn't good for the spine either. A common cause of back pain and neck tension is
02:18weak or underdeveloped muscles. So it's important to train your back muscles
02:25that can relieve strain on the vertebrae and intervertebral discs. Walking upright
02:31isn't all bad however. It brought evolutionary advantages. The biggest is
02:36that it freed up our hands and they've allowed us to do things that other
02:40vertebrates have never dreamed of.