Kotz-type muscle stimulation for treating deep muscles

Despite its greater effectiveness, Kotz stimulation has not become as widely adopted as EMS. The reason is simple: until relatively recently, devices suitable for Kotz therapy were many times more expensive than traditional EMS units, so only a few could afford them.

Today, however, the situation has changed fundamentally. Electrotherapy devices that offer Kotz programs alongside classic EMS/NMES have become affordable. The Globus manufacturer has played a major role in this: its Genesy 1500 and Genesy 3000 devices provide extensive professional-level electrotherapy treatment options, including EMS/NMES and Kotz stimulation.

Comparison of EMS/NMES and Kotz stimulation

With EMS, or NMES stimulation, muscles are stimulated with low-frequency impulses (typically between 20–120 Hz), by directly stimulating the motor nerve/motor endplate that innervates the muscle. This technology directly evokes muscle contraction and is particularly useful for improving muscle tone, increasing endurance and during rehabilitation. Its drawback is that, because it passes through the skin, the stimulation often feels more uncomfortable and mainly activates more superficial muscle fibers, making deeper muscle bundles less accessible.

Kotz stimulation is based on using a 2,500 Hz carrier frequency that is "modulated" by lower-frequency impulses. The high carrier frequency penetrates the skin more easily, reducing the unpleasant sensation of current and allowing activation of deeper muscle fibers. The modulating frequency — for example 30, 50 or 80 Hz — determines which type of muscle fibers are engaged and what training effect is achieved. Therefore, the main goal of Kotz stimulation is not merely to increase endurance but to develop strength and enhance athletic performance.

How does Kotz stimulation work?

Very simply:

• The carrier frequency (2,500 Hz) serves to reduce skin resistance and produce a more comfortable sensation of the current.
• Muscle fiber activation and thus the therapeutic effect are determined by the modulation frequency (5-10-30–50–80-100 Hz).

The method is based on a 2,500 Hz carrier frequency that reaches the muscle in the form of modulated, lower-frequency impulses. The modulation frequency is the parameter that actually defines the nature of the muscle contraction. Stimulation around 30 Hz has endurance and tone-improving effects, 50 Hz is ideal for classic strength development, while 80–100 Hz is more suited to activating fast fibers and developing explosiveness.

The ratio of work and rest phases is also an important factor. A 5-second work and 5-second rest pattern is more endurance-oriented; a 10/10 ratio provides a more significant strength-building effect; while 10 seconds of work and 15 seconds of rest allow working at maximal intensity with longer recovery intervals. Thus, the nature of the load can be adjusted depending on the training goal.

Frequencies and effects

The special feature of the Globus Genesy 1500 and Genesy 3000 devices is that, in addition to the classic 50 Hz setting, they offer several modulation frequencies: you can choose from 5, 10, 30, 50, 80 and 100 Hz.

Lower frequencies — for example 5 and 10 Hz — trigger rhythmic, milder contractions that improve circulation and aid recovery.

30 Hz is ideal for stimulating endurance fibers, making it particularly useful for strengthening stabilizing muscles and preventing back pain.

50 Hz is the classic strength-development frequency, striking a balance in activating slow and fast muscle fibers.

80 and 100 Hz mainly target fast fibers, producing stronger but more fatiguing contractions; therefore, these are better suited for improving athletic performance and explosiveness.

Applications

Kotz stimulation can be used for many purposes. In rehabilitation, it plays an important role in strengthening muscles weakened after surgery or injury, for example rebuilding the quadriceps after knee surgery.

It is also outstanding for lumbar stabilization because it effectively activates the deep back muscles, helping to prevent low back pain.

In sport, it supports performance improvement through increased strength and explosiveness, while for aesthetic uses it can help increase muscle firmness and body shaping.

Potential contraindications

Although Kotz stimulation is safe and well tolerated, there are conditions when its use is not recommended. For example, implanted pacemakers or other electronic medical devices are contraindications because the stimulation can interfere with their operation. It is also contraindicated during pregnancy, especially in the abdominal and lumbar regions. It is not recommended for patients with epilepsy, and should be avoided in active cancer. As with all electrotherapy methods, gradual loading and consultation with a professional are important.

Devices that provide Kotz therapy

The great advantage of the Globus Genesy 1500 and Genesy 3000 devices is that they provide not only traditional EMS programs but also Kotz stimulation. These modern devices offer a wide range of modulation frequencies: you can choose from 5, 10, 30, 50, 80 and 100 Hz. This allows the stimulation to be precisely tailored to the intended goal: lower frequencies aid recovery and tone improvement, while medium and high frequencies support strength development and athletic performance.

All this means that with Genesy devices, Kotz stimulation is suitable not only for professional athletes but also excellent for rehabilitation, posture correction or general muscle strengthening.

Product recommendations

The Globus Genesy 1500 electrotherapy device features more than 150 programs, including EMS, NMES, TENS, iontophoresis and Kotz stimulation. Its compact size yet broad therapeutic repertoire make it an ideal choice for both home and professional use.

For those seeking the most comprehensive functionality, the Globus Genesy 3000 electrotherapy device
offers the solution. This model is one of the manufacturer's most advanced devices, containing every available electrotherapy program and advanced configuration options.

Summary

Kotz stimulation is one of the most effective methods for developing muscle strength, activating deeper muscle fibers beyond classic EMS technology. Although it was long expensive and inaccessible, thanks to the Globus Genesy series, affordable and easy-to-use devices are now available. With the Genesy 1500 and 3000 devices, Kotz stimulation is accessible alongside EMS and NMES, so anyone can benefit from this professional technology, whether for rehabilitation, posture correction or enhancing sports performance.