Shockwave therapy was first used mostly in urology to break down kidney and gallstones. Later the shockwave became more popular in a physiotherapy when it was found the therapy was effective also in treatment of muscle and tendon injuries. Still, in physiotherapy shockwave is relatively new, though in the early 2000 century single machines were also used by physiotherapists. There was more rapid increase in number of machines in 2014. Shockwave is purely mechanical treatment and doesn´t contain electricity or heat. The machine produces pressure waves, resulting in mechanical, nervous and biological effects. Usually the main goal is to reduce pain and increase joint range of motion in subacute an chronical soft tissue injuries. Especially when containing degenerative changes in attachement areas. In those cases shockwave may offer good alternative to surgery or corticosteroid injection.
Shockwave- i.e. pressure wave treatment is also called: Extra corporeal shock wave therapy (ESWT), radial pressure waves (RPW) and radial shockwave. Focused form differs a bit and it belongs outside this text. The machine contains main unit and a treatment head. Compressor produces pulsed pressure to treatment head, which makes small piece of metal to move back and forth at the end of the treatment head. By pressing the treatment head against the skin, the pressure wave is moved into the tissue where it spreads radially and effects 4cm (maximally 6cm) in depth. The therapist can choose the size of the probe (metal) and choose the power, frequency and number of hits. Those are the most essential adjusts of the machine.
EFFECTS OF TREATMENT
Theory behind shockwave is partially known. Treatment belongs to regenerative medicine, where the main goal is to promote healing by regeneration. Important mechanism is mechanotransduction, where mechanical stimulus is converted to biochemical responses inside and between the cells. Shockwave:
- Promotes vasodulation and neovascularisation e.g. by releasing nitric oxide. This increases oxygenation in the tissue.
- Stimulates formation of collagen and tenocytes and their remodelling parallel to load. This makes tissue more durable
- Controls chronic inflammation by e.g. increasing activity of mast cells, which belong to inflammation process The inflammation is increased for a while, giving better opportunities to heal after inflammation
- Produces competitive stimulus against original pain (gate control theory)
- Loosens tight musles and connective tissue structures
- Mobilizes scar tissue by remodelling and resorption
- Stimulates gliding of soft tissue structures, like tendons
- Increases metabolism e.g. by increaring permeability of cell membrane
- Breaks calcifications especially through biochemical effects
- Releases trigger points e.g. by opening calcium pump, which restores normal metabolism and relaxes the muscle
- Decreases content of substance P, which is a mediator of pain
- Promotes healing of non-union fractures by activating osteoblasts, which make new bone
INDICATIONS (WHEN TO TREAT)
Shockwave is an effective method especially in treatment of tendon insertion areas and tight fascia structures. For example in plantar fascitis about 90 % benefits from shockwave treatment. In muscular injuries shockwave is used to break down scar tissue and promote the metabolism and circulation in the area. Treatment of triggerpoints relaxes muscle and alleviates pain. Also bone fractures with poor healing are indications of shockwave. The method is an option especially in chronical soft tissue injuries where traditional physiotherapy has not been succesful. The most typical indications are:
- Tight and painful neck muscles
- Low back pain
- Shoulder pain
- Tennis & golf elbow
- Scar tissue after muscle tear
- Pain in the area of tuber ischiadicum
- Greater trochanter pain
- Runner´s knee
- Jumper´s knee
- Shin splint
- Achilles tendinopathy
- Plantar fascitis
CONTRAINDICATIONS (NO TREATMENT)
Shockwave has minimal risks and drawbacks. Because of mechanical nature the therapy is considered as stimulating, less breaking. In good quality machines therapeutic work doesn´t exeed 0,63mJ/mm2, which is under tissue tolerance. In practice treatment can´t break healthy tissue above injured tissue, if the machine is good quality and treatment follows normal guidelines. Relative or absolute contraindications are:
- Acute injuries
- Vein thrombosis
- Coagulation disorder
- Pace maker
- Metal in treatment area
- Open wounds
- Tumors in treatment area
Shockwave treatment begins with examination. Ultrasound may help in locating the injury place and type. For example in minor tear, the treatment can be initiated more carefully, perhaps later. In larger tear, ultrasound can give reason for sending the patient to doctor for more thorough examination.
Before shockwave therapy some gel is spread on skin to reduce friction and enhace maxium power to enter the tissues. Patient can feel some pain but it is tolerable. If pain is too big, therapist can easily lower the power. Extra tool is a massage probe which can be connected to the machine. Massage type of treatment is more convinient and can be used e.g. to relax painful muscle tissue. Typical dosage is around 2000 (1000-5000) hits, for example 1o Hz frequency, 5-10 min. Duration of treatment depends especially on size of treatment area. Treatment can be combined to movement as well (see youtube video).
Shockwave has often immediate effect on pain and joint range of motion. Treatment can cause some soreness, redness etc afterwards, which usually goes away soon. One of targets of treatment is to cause controlled inflammation, but NSAID should be avoided if pain is not too big. It´s adviced to avoid hard exercise afterwards for treated area at least for a couple of days. Typically treatment is done once a week, 3-6 times. Muscles can be treated more often, 2-3 times a week. For example in tendon injuries it may take 6-12 months to receive maximal result, because slow metabolism and circulation in tendon make regeneration slow. During regeneration extercises are recommended to strenghten the tendon and causes should be eliminated too.
EFFECTIVENESS OF SHOCKWAVE
According to studies 65 – 95 % of pain patients benefit from Shockwave. Shockwave is a good therapy method when it´s used in right purposes. Studies are collected e.g. in following pages: