Our model is widely used as
a device to assess the degree of impairment of vibration
sensitivity in pallanaesthetic patients.
It can be used to diagnose nerve disorders defined as
polyneuropathies, which manifest themselves in the form of
impaired vibration sensitivity. The symptom is found in the
following diseases:
• Diabetes
• Toxic nerve damage
• Alcoholism
• Neuritis of bacterial origin
The Rydel-Seiffer tuning fork generates two different
frequencies: note C = 64 Hz with the weights (as indicated
on the weights) and note c = 128 Hz without the weights
(as indicated on the tuning fork itself). The weights must be
attached at the level of the lowest notch on the arms of the
tuning fork. The mark “C 64” on the weights, the mark “c 128”
on the front of the tuning fork and the gradation must all be
facing the user when the weight is positioned. The knurled
screws are tightened to secure the weights and loosened to
remove them. Once the weights are in place, they must be
tightened firmly.
EASy OF USE:
There are two triangles on the weights, one white and one
black, each featuring a scale from 2 to 8
When the tuning fork is struck against the fingertip of the
thumb (never strike it against objects that are too hard, such
as sheet metal, steel or stone), the arms begin to oscillate and
two triangles become visible on each weight. As soon as the
oscillation decreases, the two triangles gradually move closer
together again and their point of intersection moves upwards.
The scale shows the intensity of the vibrations. This can be
read either from the white triangle or from the black one,
depending on the amount of light available, or depending
on which scale is easier to read. To determine the degree
of insensitivity to vibrations, the tuning fork is touched and
its plastic base is placed against the olecranon or processus
mastoideus.
The patient must then indicate the point at which they stop
feeling vibrations. The vibration intensity at that precise
moment is read on the scale. The following values can be
considered normal:
• Patients below the age of 60: between 6 and 8
• Patients above the age of 60: between 4 and 8
Vibration sensitivity in the foot region can be checked by
placing the tuning fork against the head of the fibula, the
inner malleolus, the head of the metatarsus and the tip of
the hallux. The patient must once again indicate the point
at which they stop feeling vibrations. When a neuropathy is
present, there is generally a symmetrical decrease of vibration
sensitivity at the periphery compared to the proximal
values, especially at the front of the foot. The extent of the
neuropathy can be determined more accurately by placing the
tuning fork at successive points along the edge of the tibia.
Patients with decreased sensitivity due to sensory neuropathy
are especially prone to foot injuries because they usually do
not feel them until it is too late.
The tuning fork cannot be sterilised after use. It must be
cleaned using a dry or slightly oily cloth
