What is the rotation?The rotational movement occurs as a movement on the human body, including the foot and forearm.
At the foot, the movement takes place in the anterior chamber of the lower ankle, which is formed by three tarsal bones. One of the three, the navicular, rotates around the other two in this movement, so that the inner edge of the foot is turned upwards. This process is purely descriptive. A pure rotation can not be performed actively in this joint because the executing muscles are unable to do so due to their course. Therefore, always other components of motion are coupled to the rotational movement. Fixation of the two proximal tarsal bones allows isolated rotation to be carried out passively, for example during movement examinations.
The rotational movement on the upper extremity is a movement between the two forearm bones. The spoke turns around the ulna so that the two bones are parallel to each other in the end position. In the countermovement, the pronation creates a strong crossover. By coupling the wrist and the carpal bones, the hand is taken by the rotation of the forearm bones. During the rotation the palm shows increasingly to the body, at the pronation shows the back of the hand to the body.
Function & Task
The rotation on the foot is involved in all free movements that are directed inwards. It is an important component of the schwungbeinphase. The stronger the orientation to the middle of the body and the faster the execution, the greater its importance. In many sports activities such activities occur.
A typical example is martial arts movements, which involve getting your opponent off his legs with a leg swing or a diagonal kick. In football, a pass or a flank with the Innenrist is very much characterized by the rotation and the power development of the executive muscles, the supinators. The effect the ball gets is predominantly a transfer of the energy of the supinatory foot position to the ball movement.
All body-directed activities of the hand, which take place in the upper and front area, are functionally possible only through the participation of the rotational movement. Their interaction with adduction and flexion in the shoulder joint as well as flexion in the elbow allow the hand to reach almost any point of the head and upper trunk.
Perhaps the most important activity performed in this way is the food. But other actions in everyday life, such as hair washing, nose brushing, scratching the head or neck, as well as the lifting of objects and the drawing to the body, are characterized by these components of movement.
In sports, movements of the arms, which are carried out from the bottom outside to the top inside, are often associated with a rotation. Characteristic movements with these components are the forehand strokes of the racquet sports tennis, squash and badminton. Especially in badminton, the rotation is the decisive impulse for the acceleration of the ball. The same trajectory with a strong supination component of the hand can also be observed in boxing when top hooks are hit. The biceps as flexor and strongest supinator is used in its full strength.
All of the arm and hand over head movements involve rotation as a pre-stretch component for the following striking or throwing motion, such as throwing a stone or volleying in volleyball.
Diseases & complaints
As with all movements, rotation can be affected by a decrease in muscle activity or other processes that restrict the amplitude of movement. The effects on vital functions such as eating and walking are often blatant. The affected people can no longer perform these movements completely or not at all, thus losing their independence.
In addition to the systemic disorders such as muscular dystrophy or amyotrophic lateral sclerosis, there are often special injuries and conditions that hamper the functions.
On the foot, fractures may be in the area of the tarsal bones or ligament injuries. They are often caused by unfavorable movements due to the influence of external forces. A typical injury mechanism is the so-called "supination trauma" in which the foot kinks inwards, which often leads to bone fractures and tears of the outer ligaments.
Herniated discs or peripheral nerve lesions can lead to a so-called Fußheberschwäche. The rotational movement is affected when the tibial nerve is damaged. A particular form of influencing the movement on the foot typically arises as a result of a stroke. It develops on the affected side a hemiplegia with a spasticity of the leg with a strong tendency to stretch and Supinations. The leg is guided very strongly inwards when walking over a circular movement in the hip joint and the foot can not be put on properly. The result is the so-called Wernicke-Mann gait pattern.
In the upper limb, the damage to the arm nerves can negatively affect the functions on the hand. In addition to disc herniations in the cervical spine, peripheral damage to the median nerve or the radial nerve is often responsible for negative effects on the rotational movement.
Forearm fractures have a direct effect on the movement possibilities of the forearm bones. Typical injuries of this type are the wrist fractures with the involvement of the ulna and the radius and the fracture or dislocation of the proximal radius head.
The rotational movement as a rotational movement is not possible even after medical care, or until complete consolidation of the bone is not allowed.