There are three main ways of using radial shockwave:
- Destruction of tissue
- Increased biological effects (healing, blood supply etc)
- Pain reduction
Treatments overview:
| RSWT | Head | Power | Frequency | Shocks | How Often | No. of Sessions |
| Destruction | 15mm | 105mj+2.5 bar+ | 4-15hz | 1000-4000 | every 5 days | 1-3 maybe6+ more likely |
| Healing | 15-35mm | 60-90mj1-2 bar | 10-16hz | 1000 x 1 spot4000 larger area | every 7-10 days | 4-6 |
| Pain Relief | 6-35mm | 60-90mj1-2 bar | 15-30hz | 1500 x 1 spot4000 larger area | every 7-10 days | 3 |
Destruction of tissue:
The destruction of cells through spalling, (Delius, 2000, Lokhandwalla & Sturtevant, 2000, Eisenmenger, 2001, Xi & Zhong, 2001, Zhu et al., 2002), spall crack formation (Tan, 2008, Yankelevsky & Avnon, 1998) or tension (Eisenmenger, 2001) normally requires higher shock pressure and slower speeds. Although for the effect of cavitation higher speeds are most definitely favourable.
Head:
Try to stick to 15mm heads either concave or convex as most structures needing destruction are not that deep (spurs, calcifications). Small heads can give far too much energy density to be used for this purpose and they can easily cause skin damage at high pressure.
Power:
The higher the pressure setting normally the better but most patients can’t tolerate high settings initially. Start at low pressure e.g. 60mj or 1 bar for 200 shocks then increase to 90mj or 2 bar for 200 shocks then 105mj or 2.5 bar. Anything at 105mj or 2.5 bar or more should have the desired effect. Weijers (2009) recommended 2.5 bar or above (equivalent of 0.22mj/mm2).
Frequency:
Authors have used as low as 4hz upwards. Normal convention seems to be for 10hz or somewhere around there. If the desired result is mainly cavitation then any frequency from 5hz will work but from 15hz cavitation will be much better (Kiessling et. al., 2015). Remember increasing frequency will decrease depth.
Number of shocks:
Anything from 1000 shocks upwards should be used. 2000 seems to be the number most people go for but figures as high as 4000 have been demonstrated.
How often to treat:
As damage occurs almost instantly it would seem prudent to perform the next session before any repair can occur. Frairia & Berta (2011) say there is a critical window for healing after shockwave therapy, between 6-12 days. On this basis treatment for destruction should be performed every 5 days. In practice I don’t worry too much about the actual time frame. If any heeling occurs it can be broken once more by further shockwave.
How many sessions:
Lots of people say 1-3 but these often don’t lead to full resolution. An average is 6 sessions, although when I first started I noted some prominent bone spurs did not go in 6 sessions. When I asked the community about treatment numbers a very pragmatic therapist told me if the symptoms have been there less than 6 months anything up to 6 sessions will be required. However, if the symptoms are more than 6 months old it will take more than 6 sessions. In my experience it almost always takes more than 6 sessions.
Tissue Healing:
Berta et al. (2009) showed low to medium energy shockwave treatment induces much less cell destruction and more stimulation of cell proliferation. Wang et al. (2001, 2002) and Martini et al. (2003) found the same thing. Whether fibroblasts lived or died was influenced most by the number of shots much more than by energy level. There was also evidence of a suitable energy/shot number ratio to have a minor cytocidal effect. Shock waves had a dose-dependent destructive effect on cells in suspension, as well as having a dose-dependent stimulatory effect on cell proliferation. In addition, a significant increase in proliferation rate was observed with respect to the un-shocked cells (this is probably because of the interconnections through the integrins). In other words, even if you get cell damage some of the effects spill over into the surrounding cells improving healing. To just get healing use lower shock pressures and less shocks to an area.
Head:
Bigger is better for healing. A larger head dissipates the pressure reducing cell damage and increasing the healing effects over a larger area.
Power:
Stay at low pressure e.g. 60mj-90mj or 1-2 bar (Wang et al., 2001, 2002 and Martini et al., 2003).
Frequency:
Generally higher values are used as these cause less pain. Anywhere around 10-16hz will do, most people use 14hz.
Number of shocks:
1000 shocks if stationary. As high as 4000 shocks for a large area (Frairia & Berta, 2011).
How often to treat:
Frairia & Berta (2011) say there is a critical window for healing after shockwave therapy between 6-12 days. On this basis treatment should be performed every 12+ days. Actually most people in the literature have done the treatments every 7-10 days with good effects.
How many sessions:
Don’t be surprised if the patient feels improved after 4 sessions. However the average number of sessions required is 6 at weekly intervals.
Pain:
Maier et al. (2003) showed that after shockwave pain initially increases (for the first 6 hours after shockwave application). This comes from an increase in release of substance P (through C fibre and A-delta fibre depolarisation) and the subsequent inflammatory response from that release. Shockwave mechanically stimulates the release of substance P (Maier et al. 2003). However this initial release is followed by a subsequent decrease in levels of substance P (and hence inflammation) at the 24 hour point as the nerve degenerates (Maier et al. 2003). This reduction in substance P release lasts for over 6 weeks (Maier et al. 2003) and may go on as long as 2 years (Maier et al. 2003).
Head:
Any size head can be used but as pain can be local to very specific points the small 6mm heads are useful for this type of treatment.
Power:
Stay at low pressure e.g. 60mj-90mj or 1-2 bar (Jeon et al., 2012)
Frequency:
Generally higher values are used as these cause less pain. 15-30hz tends to be used as it can also relax the muscles (Nazarov & Gorozhani, 1988).
Number of shocks:
1500 shocks if stationary. As high as 4000 shocks for a large area. (Jeon et al 2012).
How often to treat:
Jeon et al. (2012) performed treatments every 7-10 days with good effects.
How many sessions:
Jeon et al. (2012) recommended 3 sessions.