Like the elbow, the knee joint is an example of a hinge joint with added complexity. The condyles of the femur are enlarged rounded areas at the base of the femur and they make up the knee joint with the enlarged flattened area of the upper end of the tibia. On the outer side of the shin lies the fibula, a thin, long bone which does not make up part of the knee nor bear much weight, mainly acting as an area of muscle origin for the muscles which move the foot, ankle and toes. The hinge joint of the knee splits the leg in two, allowing tidy folding in resting or active positions, the necessary shortening of the leg to allow effective walking and the large levels of of propulsive power required.
Posts Tagged ‘back injury’
The Cervical Spine
Our necks are our spines continuing above shoulder level so that our head can be supported and facilitated in its job. The neck is beautifully designed and engineered and performs its highly complex functions automatically without us having to give them any thought. Our heads are very heavy and placed on top of the lever which is the neck, however we can move them or stop moving them very quickly, positioning them at a very specific point within the large ranges of movement the neck can perform. The ears and eyes, some of our most vital organs of sensory input, are placed on the head and the neck has to serve their needs.
Segmental Stiffness of the Low Back
Most of us start off with a beautifully mobile and smooth running back and rarely are we stiff backed unless there is a reason for it. The back is well evolved to do the job it has to do and does this mostly very well. Spinal bones are separated from the vertebrae by discs which are thicker in areas of greater mobility and greater load, allowing more movement. Facet joints at the back of the spine limit and control spinal motion, stopping inappropriate spinal displacement in response to the loads placed on the spine. Muscles are strong, in balance and working in harmony to achieve the movement and stability required.
