Linear Vibration vs Pivotal Oscillation

Pivotal Oscillation vs Linear Vibration

Linear vibration and pivotal oscillation are the two dominant motion patterns adopted in the design of whole body vibration plates.

Except for some very rare vibration plate models, all vibration plate models provide either linear vibration or pivotal oscillation, or combined motion of the two.

The mechanics of linear vibration and pivotal oscillation are distinctively different, so are their impacts to human body. Below we discuss each motion pattern in detail and compares them side by side.

Motion Pattern Comparison

Linear Vibration
Eccentric Wheel Device
Pivotal Oscillation
Planar 4-bar Linkage Device
linear vibration
Pivotal Oscillation
High Frequency
Low Amplitude
Low Frequency
High Amplitude
Linear vibration plate drawing
VT003F
vibration plate - Pivotal Oscillation
VT027

Above animations are slow motion vibration (3-4Hz). In reality, a linear vibration plate usually vibrates at the frequency from 15Hz to 40Hz; and pivotal oscillation plates from 5Hz to 15Hz.

How Does a Linear Vibration Plate Work?

linear vibration animation

Linear vibration plate uses eccentric wheel device and supporting springs to produce forced vibration.

The phrase "linear" comes from the attribute of the spring: the spring force and the spring length change has a linear relationship.

Eccentric wheel device is the most widely used method to produce vibration. iPhone adopts a tiny eccentric wheel device to make vibration.

motor-eccentric wheel VT007 Eccentric Wheel & Motor system

In a linear vibration plate, a set of eccentric wheels rotate and create circular centrifugal force. The force drives the exercise platform to move in a vertical oval path. The supporting springs regulate the exercise platform to move mainly in vertical direction and less in horizontal direction.

Linear vibration plate is usually designed to vibrate at a frequency range from 15Hz to 40Hz, and amplitude range below 3mm.

How Does a Pivotal Oscillation Plate Work?

pivotal oscillation animation

Pivotal oscillation plate uses planar 4-bar linkage device to produce its reciprocating movement.

The exercise platform of pivotal oscillation plate moves like a see-saw around a center pivot point ~ literally, pivotal oscillation.

Pivotal oscillation plate is usually designed to oscillate at a frequency range from 5Hz to 15Hz, and ammplitude between 8mm and 10mm.


What is a planar 4-bar linkage?
four-bar linkage system vibration 4-bar Linkage

Planar 4-bar device is used to transfers rotation to reciprocating movement.

In a pivotal oscillation plate, the motor rotates the crank-bar through a belt. The crank-bar is in a round shape so the belt can rotate it. The crank-bar transmits the movement to the coupler-bar and the rocker-bar. The exercise platform is the the rocker-bar. As the crank-bar rotates, the coupler-bar drags rocker-bar (the exercise platform) to move up and down in a see-saw motion.


Pivotal Oscillation is Actually Not Vibration planar four-bar linkage

A pivotal oscillation plate resembles an oil pumpjack, also a 4-bar linkage device. Only the pivotal oscillation plate moves much faster.

Pivotal oscillation is actually not vibration. It lacks the characteristics of vibration, except for its reciprocating movement.

The structure of a pivotal oscillation plate is a rigid system. Its amplitude does not yield to the body weight. Unlike vibration, pivotal oscillation does not have damping effect.

VT027 pivotal oscillation VT027 pivotal oscillation plate drawing


The name

Manufacturers and sellers usually refer pivotal oscillation plates as vibration plates in general.

Pivotal oscillation is distinctively different from linear vibration. It is necessary to distinguish them from each other.

An easy way is just to call a pivotal oscillation type of machine as a pivotal oscillation plate.

Pivotal Oscillation Plate
Lateral Oscillation
lateral oscillation

4-bar linkage device can also be designed to create a left-right type of motion called lateral oscillation.

In fact, lateral oscillation also moves around a pivotal point. It is just that its pivotal point is fixed on the bottom, and it is designed with long coupler-bar. Such an arrangement creates a left-right direction oscillation.

Some manufacturers make vibration plate models that have two 4-bar linkage devices to create both pivotal oscillation and lateral oscillation.

We believe the lateral oscillation type of motion can harm your knee joint cartilage and ligaments.

may harm your knee joints

Attributes Comparison

Linear vibration and pivotal oscillation each has their own unique attributes. Most significant differences are the vibration frequency and amplitude.

Frequency

Vibration frequency indicates how many reciprocating movement in one second. A vibration plate running on 30Hz means its exercise platform move up-and-down 30 times each second.


frequency of linear vibration plate
vibeplate VibePlate 10-60Hz

Linear vibration plates can achieve higher vibration frequency. Most linear vibration plates in the market are designed to run at the frequency range between 15Hz to 60Hz.

Some linear vibration models run on a fixed frequency, while others run on adjustable frequency.

Major brands that offer linear vibration plates are Power Plate and Vibeplate.

Vibration Therapeutic's model VT003F and VT007 offers a low cost alternative for linear vibration. VT003F and VT007 are designed for home use. They feature adjustable frequency from 15Hz to 40Hz and two amplitude settings.

VT007 Linear Vibration Plate
VT007 frequency: 15-40Hz


frequency of pivotal oscillation
pivotal oscillation plate LifePro Waver 4-12Hz

Pivotal oscillation plates are mostly designed to work in the frequency range below 15Hz. The majority of the consumer grade vibration plates available in the market are pivotal oscillation models.

Precision and material constraint make it costly to make a durable pivotal oscillation model to run at high frequency (above 15Hz). The reason is that 1) the small bearings that connect the for bar system can quickly wear out at high rotation speed; and 2) the coupler-bar can reach fatigue much sooner in high speed movement.

pivotal oscillation plate Galileo S25 10-30Hz

German made Galileo brand models are probably the only available pivotal oscillation models that can achieve frequency above 30Hz.

Galileo S25 can achieve a 30Hz high frequency and a 8mm peak-to-peak amplitude (G-force = 7.2).

Another Galileo model S40 can achieve 33Hz and 9.4mm amplitude. Being both high frequency and high amplitude, the model S40 can achieve a G-force of 10.3, probably the highest among all vibration plates available in the market.

Pivotal oscillation plates are sold in many brands or off-brands. Most models are redundant in terms of motion patters and parameters.

Vibration Therapeutic offers VT027 pivotal oscillation plate. The big difference for VT027 is its patented all aluminum twin-coupler design. VT027 is a high performance machine built inside a slim machine body but still offer a large and flat exercise platform.

Pivotal Oscillation frequency
VT027 Pivotal Oscillation plate 5-14Hz

Amplitude

The amplitude of a vibration plate the maximum movement range of its exercise platform.


amplitude of linear vibration
vibration-amplitude
VT003F amplitude: 1.5‑3mm

Linear vibration plates are designed to work at low amplitude, usually less than 3mm. The supporting springs need to maintain a certain rigidity in order to support and stabilize the body weight. The needed rigidity limits the achievable amplitude. At higher frequency, the damping effect of the forced vibration also limits the amplitude.

Nevertheless, low amplitude is desirable for a high frequency vibration plate for the health improvement purposes.

A linear vibration plate can be designed to have adjustable amplitude settings by changing the weight or number of eccentric wheels. For example VT003F are VT007 are designed to offer two amplitude settings (Hi and Lo).


amplitude of pivotal oscillation
amplitude VT027 amplitude 10mm

Pivotal oscillation plate, with its 4-bar linkage structure, can be designed to achieve higher amplitude.

Because of its pivotal motion, the amplitude is zero at the center of the exercise platform, and reaches the highest value at the two sides.

When standing on a pivotal oscillation plate, the user can adjust the distance between his/her two feet to get a different vertical displacement.

Most pivotal oscillation plates on the market have the amplitude between 8mm and 10mm.

Rigid Link, Flexible Link & Power Consumption

    Another major opposite attribute of the two types of vibration plates are

  • Linear vibration plate is a flexible link system.
  • Pivotal oscillation plate is a rigid link system.

flexible link system
power plate Power Plate My3 160W

Linear vibration plate is a flexible link system. Its spring supports allow the vibration amplitude to yield to the body weight. Theoretically for a linear vibration plate, the motor power consumption is nearly constant, irrelevant to the body weight. A linear vibration plate requires a smaller motor because the tolerance requirement for power surge is low.

For example, VT linear vibration plate model VT007 only needs a 80W motor to generate powerful vibration. Even for a large size vibration plate like Power Plate My3, the rated motor power is 160W.

Because of its power consumption is stable regardless of the body weight, a linear vibration plate is less likely to be overloaded and get its motor burned.

 


rigid link system
rigid link of pivotal oscillation plate Steel Frame of VT027

Pivotal oscillation plate is a rigid link system. The planar 4-bar linkage system consists of rigid bars. The oscillation amplitude is fixed, regardless the load (body weight).

User body weight affects the motor power consumption. Extra motor power capacity is needed to accommodate the situation of sudden load increase, such as when the body weight falls on just one side of the platform. Therefore the motor power capacity needs to cover power surge tolerance for the protection of the motor.

For a pivotal oscillation plate that runs max 15Hz frequency and 10 mm amplitude, designed for body weight below 265LB, a 200W motor is sufficient.

The belt that transmits the movement from motor to crank bar is a also flexible link. It provides a layer of protection to the motor for over load. In normal use, the belt holds well. Over time the belt can become loose.

speed compensation

As a protection design, when there is a load surge, the motor will rotate faster to compensate the needed motor power. The speed change is more evident when the machine oscillate at a very low frequency. This design is to protect the motor by reducing the electric current in the rotor coil.

So when you put your entire body weight on one side of a pivotal oscillation plate, the machine will speed up the oscillation. You feel more difference when the frequency is low like 5Hz. Your machine is programmed this way, not a malfunction.

Impact on Human Body

Linear vibration and pivotal oscillation each have its own unique impact on the human body. Their user experiences are very different.

Linear Vibration
Vibration Plate Linear
Pivotal Oscillation
vibration plate - Pivotal Oscillation

Frequency: 15 - 50Hz

Amplitude: 1 - 3 mm

(fast and small movement)

Frequency: 5 - 15Hz

Amplitude: 8 - 12mm

(slow and big movement)

Vibration frequency range matches human tissue natural frequency. The resonance effect induces intensive muscle contraction.

Small range of motion; The muscle is tight.

Vibration energy transmitted deep into tissue. Muscle contraction damps the vibration.

The high amplitude motion swings the body and tissues high, but not enough frequency to effectively induces muscle contraction.

Large range of motion; The muscle is not very tight.

The motion shakes the entire body vigorously. Muscles swing high as a whole piece.

High impact.

Intensive skeletal muscle contraction enhances muscle and bone strength.

Vertical motion transmitted to upper body and head, and cand cause nausea and dizziness for some people.

Low impact.

The alternate movement resembles walking motion, beneficial for gait training.

The see-saw motion does not transmit to the upper body, very relax to use.

Vibration evenly distributed on the entire exercise board, accommodating many exercise poses.

The exercise board swings high on the two sides, but still at the center, limiting exercise posses.

High noise

Low noise

Design Comparison

Linear vibration plates and pivotal oscillation plates can be designed in similar styles.

Pivotal oscillation plates are more towards a long rectangular, in order to get a higher amplitude at the two ends. Some pivotal oscillation plates have the exercise board designed as a slightly curved shape to work better with the pivotal motion.

Linear vibration plates are more toward a short rectangular or round square shape.

Some models of both types are designed with handrails.

Most designs are redundant in terms of motion patterns, parameters and functions.

Linear Vibration Plates

collection of linear vibration plates

Pivotal Oscillation Plates

collection of pivotal oscillation plates
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