Kotz currents are a medium-frequency alternating current, about 2500 Hz, delivered in short bursts, which causes strong muscle contractions. They are used to strengthen muscles weakened after an injury, surgery or immobilisation, most often the quadriceps muscle of the thigh. Research does not confirm that they are better than other types of electrical stimulation. In Rydułtowy the treatment costs 15 PLN.
Below we explain what Kotz currents are, who they can help, what research really says about them, what the treatment involves and who should not have it.
In brief
- Kotz currents are a type of electrical muscle stimulation with a medium-frequency current (about 2500 Hz), also known as Russian stimulation.
- They are used to strengthen muscles, not to relieve pain.
- The results of Kotz’s first studies from the 1970s have not been confirmed by later research.
- The treatment costs 15 PLN; a physiotherapy consultation 180 PLN.
- The clinic is open Mon–Fri 7:00–20:00, private visits only (not covered by NFZ, the Polish public health fund).
Contents
What are Kotz currents and where does the name come from?
The name comes from the Russian doctor Yakov Kotz, who used this current with athletes in the 1970s. An alternating current with a frequency of about 2500 Hz is divided into bursts, usually 50 times per second. Thanks to its medium frequency, it passes through the skin’s resistance more easily, so it allows a strong muscle contraction with less discomfort than some low-frequency currents.
Kotz currents belong to the same group as other forms of electrical stimulation: their aim is to cause a muscle contraction, not to block pain. We compare the other therapeutic currents and their uses in our post electrotherapy – types of currents.
When are Kotz currents used?
Kotz currents are used when a muscle has a working nerve but has lost strength: after a knee injury or surgery, after immobilisation in a cast or brace, or when a limb has been protected for a long time because of pain. Most often this concerns the quadriceps muscle of the thigh, which weakens quickly after a knee injury and can be “switched off” despite the patient’s efforts.
A typical example is the period after anterior cruciate ligament reconstruction, when the patient has difficulty fully tightening the thigh – we describe it in our post on rehabilitation after ACL reconstruction. Kotz currents are not used to stimulate completely denervated muscles, because their parameters are not suited to this.
Are Kotz currents effective?
To be honest: Kotz currents cause a strong contraction and can help strengthen a weakened muscle, but they are not a “miracle method”. The very large strength gains in athletes that Kotz spoke of have not been confirmed by later research. Comparisons indicate that this current is no better than other forms of electrical stimulation and can feel less comfortable.
The best documented use is electrical stimulation of the quadriceps as an addition to exercise after knee surgery, regardless of the exact type of current. That is why we treat Kotz currents as support for training when the muscle cannot tighten strongly on its own. We do not promise a specific gain in strength – progress is assessed at subsequent visits.
What does the treatment involve and what does it feel like?
The physiotherapist sticks electrodes over the muscle and gradually increases the intensity until a clear, strong contraction appears. Contractions lasting a few seconds alternate with longer breaks. The patient feels strong muscle tension and tingling under the electrodes. The intensity is set at the highest level the patient tolerates well, and it is worth actively tightening the muscle yourself during each impulse.
The treatment should not hurt – a sensation that is too strong or burning must be reported straight away. The limb is usually stabilised so that the contraction is safe for the operated or injured joint. After the treatment the muscle may feel tired, as after a workout. The parameters and number of treatments are chosen individually by the physiotherapist.
Who cannot have Kotz currents?
Kotz currents are not used in people with a pacemaker or an implantable cardioverter-defibrillator, over the abdomen and pelvis during pregnancy, over a tumour, with venous thrombosis in the treated limb, with fever and acute infection, on damaged skin or around the front of the neck. Caution is needed with freshly repaired tendons or ligaments, epilepsy and sensory disturbances.
Tell the physiotherapist about implants, medication you take and heart conditions before the first treatment. You will find a full overview in our post contraindications to physical therapy modalities.
Physical therapy modalitiesKotz currents, electrical muscle stimulation, TENS, iontophoresis and other physical treatments chosen after an examinationPLN 15 per treatmentPrices valid from 08.2026.
When should you see a doctor first?
Electrical stimulation will not solve a problem whose cause is unknown. See a doctor first if, after an injury, the knee is very swollen, gives way or locks, if you cannot stand on it, and also if there is fever and redness of the joint. Pain and swelling in the calf after surgery or immobilisation may indicate thrombosis and require an urgent visit.
Sudden weakness in an arm or leg, a drooping corner of the mouth and speech problems are symptoms for which you must call 112 immediately. Muscle weakness that increases without an injury also requires a medical diagnosis first.
Good to know: after knee surgery, bring the surgery report and the orthopaedic surgeon’s recommendations to your first visit – especially those concerning weight-bearing on the leg and range of movement.
Summary
Kotz currents are electrical stimulation with a medium-frequency current (about 2500 Hz), which causes a strong contraction and helps strengthen a muscle weakened after an injury, surgery or immobilisation. Research does not confirm that it is better than other forms of electrical stimulation, and it works best as an addition to exercise. In Rydułtowy the treatment costs 15 PLN.
Frequently asked questions
Can Kotz currents replace exercise?
No. Kotz currents can help “wake up” a weakened muscle and make it easier to tighten, but they cannot replace active exercises, which teach the muscle to work during movement, when walking or climbing stairs. The best results are described when electrical stimulation is an addition to training led by a physiotherapist and continued at home.
Can Kotz currents be used after a knee replacement?
Often yes, but the decision is made individually. Kotz currents are an alternating current with no direct-current component, so metal in the joint does not usually rule out the treatment, unlike galvanisation. The physiotherapist takes into account wound healing, swelling and the operating surgeon’s recommendations. We describe more about recovery in our post on rehabilitation after a knee replacement.
How many Kotz current treatments are needed?
The number of treatments is set individually by the physiotherapist after the consultation. It depends on how weak the muscle is, the stage of healing after the injury or surgery, tolerance of the current and how quickly the patient regains control over the muscle. When the muscle starts to work well on its own, electrical stimulation is usually stopped, and further improvement comes from exercise.
Is a referral needed for Kotz currents?
No referral is needed for private treatments at the “W zdrowym ciele” clinic, and the clinic has no contract with the NFZ. After surgery, however, it is worth bringing the hospital discharge summary and the doctor’s recommendations on weight-bearing on the limb. Before the first treatment, the physiotherapist takes a medical history, assesses the muscle and checks for contraindications to electrical stimulation.
Sources
- Mika T., Kasprzak W. (eds.), Fizykoterapia (Physical therapy), Wydawnictwo Lekarskie PZWL, edition.
- Ward A.R., Shkuratova N., Russian electrical stimulation: the early experiments, Physical Therapy, 2002.
- Hauger A.V. et al., Neuromuscular electrical stimulation is effective in strengthening the quadriceps muscle after anterior cruciate ligament surgery, Knee Surgery, Sports Traumatology, Arthroscopy, 2018.
About the author: Tatiana Grabowska, MSc – master’s degree in physiotherapy, licence to practise number PWZFz 11646 (Polish physiotherapist licence). Since 2013 she has run the “W zdrowym ciele” physiotherapy and rehabilitation clinic in Rydułtowy; she has about 12 years of professional experience.
- Consultation180 PLN
- Referralnot needed
- ReceptionMon–Fri: 7.00–20.00
