Neutral Zero Method
The Neutral Zero method is a standardized method for documenting the extent of movement of a joint. The extent of movement is given in degrees of angle. This allows other doctors who have not seen the patient to understand the extent of movement or, if necessary, restrictions in joint movement.
To understand the neutral-zero method, one must first explain the neutral position, which is indicated by 0°. It is the position in which a person stands upright, his arms hang down, thumbs point forward and feet are parallel. The knee joints and elbows are not completely straight, but lie relaxed against the body.
The small angle resulting from this is nevertheless indicated as 0°. In order to understand the information about the freedom of movement of a joint, the direction in which the test is performed must also be mentioned. In the statutory accident insurance, it has become established to indicate first the movements that move away from the body.
These include stretching, outward rotation or outward movement such as spreading an arm. This is followed by the neutral position and then the movements that are directed towards the body: Bending, inward rotation and inward movement such as bringing the upper arm closer. A normal healthy range of motion can look like this: 10°-0°-120.
10° extension in one joint, 0° is the neutral position, 120° flexion of the same joint. A joint often has the ability to move in more directions than forward or backward. So the neutral-zero method must be written down for each direction of movement.
Normally a joint can move in three different axes in space. One speaks of three degrees of freedom. If one or two main directions are blocked, the number of degrees of freedom is minimized. Joints can be divided into real and fake joints.
Joint mobility of the upper extremities
Shoulder joint: It is a ball joint and has three degrees of freedom. In the neutral-zero method, this is indicated as follows: 40° – 0° – 170° in flexion (backward movement) and extension (forward movement) of the upper arm to the upper body 30° – 0° – 40° spreading and approaching the upper arm 60° – 0° – 70° outward and inward rotation Elbow joint: It is a compound joint and consists of an upper arm-elbow joint, an upper arm-spoke joint and an elbow-spoke joint. The first is a hinge joint and can make a flexion or an extension.
The second is a ball joint, but because of its connective tissue attachment it has only two degrees of freedom, inward or outward rotation and extension or flexion. The third is a wheel joint. Together it is a hinge joint and thus has two degrees of freedom.
10° (possible for children and women) – 0° – 150° extension and flexion of the forearm to the upper arm. 90° – 0° – 90° outward and inward rotation. This movement takes place together with the distal Ellen-Speichen joint.
Wrist: The wrist is an egg joint and has the following degrees of freedom: 20-30° – 0° – 30-40° flexing laterally to the ulna or flexing to the radius Head joint: The head joint is the joint between the skull and the cervical spine. It is divided into an upper and lower joint. In technical jargon, they are called Articulatio atlantooccipitalis and Articulatio atlantoaxialis.
The atlantoaxial joint is the lower cervical joint, which is located between the first cervical vertebra (atlas) and the second (axis). It is counted among the wheel joints and is responsible for the rotational movement of the head. The atlanto-occipital joint is located between the first cervical vertebra (atlas) and the base of the skull.
This is an occipital joint that allows the head to tilt forward and backward and is therefore responsible for nodding.
- 40° – 0° – 170° in flexion (backward movement) and extension (forward movement) of the upper arm to the upper body
- 30° – 0° – 40° Spreading and advancing the upper arm
- 60° – 0° – 70° Outward and inward rotation
- 10° (possible for children and women) – 0° – 150° extension and flexion of the forearm towards the upper arm.
- 90° – 0° – 90° rotation outwards and inwards. This movement takes place together with the distal Ellen-spoke joint.
- Stretch 40-60° – 0° – 50-70° backwards by hand and bend forward by hand
- 20-30° – 0° – 30-40° laterally to the ulna bending or spoke bending
