A client is on the table, the transmitter tip is pressed to their heel, and you're staring at a control screen showing 3.5 bar, 10 Hz, 2000. Do you know what each number physically does to the tissue — or are you just copying the preset that "seems to work"? Every radial shockwave machine hides a remarkably simple mechanical system behind those settings, and understanding it makes you dramatically better at choosing energy, frequency, tip and shot count for each presentation. This guide walks through what happens inside the handpiece, step by step, then translates each parameter into clinical decisions.
Inside the Handpiece: A Ballistic System in Four Steps
A pneumatic radial shockwave handpiece is essentially a tiny, precise air cannon. The same principle is used across professional brands — the technology category is often called ballistic or radial pressure wave therapy.
- Compressed air in. The console's built-in compressor delivers a pulse of pressurized air into the handpiece barrel. The air pressure you dial in (1.0–8.0 bar on machines like the MB100B) determines how hard the air pushes.
- The projectile fires. Inside the barrel sits a small cylindrical metal projectile (often called the bullet). The air pulse accelerates it down the barrel toward the transmitter tip.
- Impact. The projectile strikes the back of the transmitter tip — the metal applicator that's in contact with the client's skin through a layer of coupling gel. Its kinetic energy converts into an acoustic pressure wave at the contact surface.
- Radial propagation. The wave radiates outward and downward from the contact point like ripples from a stone in a pond. Pressure is highest at the surface and falls with depth — that's the "radial" part, and it's why the wave covers a broad, superficial volume rather than a focal point deep in the body.
Between shots, the air path reverses (or vents), the projectile returns to its start position, and the cycle repeats — at the frequency you set. This projectile-and-barrel assembly is the heart of the machine, and it's a wear part: manufacturers rate the projectile/tube kit for a finite shot count (commonly cited around 2 million impulses in industry maintenance literature), after which impact consistency degrades. Source: shockwave machine maintenance engineering guide.
What "bar" Really Means
The energy setting in bar controls the air pressure driving the projectile — higher bar means faster projectile, harder impact, more energy entering the tissue and deeper residual pressure.
- 1.0–3.0 bar — low energy. For the first session with a new or anxious client, thin or bony areas (around the knee cap, elbow epicondyles), facial or aesthetic work, and warming up a zone.
- 3.0–5.0 bar — mid energy. The everyday working range for most musculoskeletal presentations: trigger points, shoulder and neck tension, plantar fascia in average body types.
- 5.0–8.0 bar — high energy. For dense tissue, large muscle masses (gluteals, thighs), chronic thick tendons, and clients with higher tolerance who have already adapted through earlier sessions.
The cardinal rule across all clinical protocols: titrate energy up to, but not beyond, the client's pain tolerance. "Strong but bearable" is the target; a client clenching their teeth will tense the tissue, which changes wave transmission and destroys the experience. Many operators start every new client at 1.5–2.0 bar and climb during the first session. For scale, 8 bar ≈ 0.8 MPa of driving pressure at the surface — radial waves peak in the 0.1–1 MPa surface pressure range, versus up to 100 MPa at the focal point of focused machines (see our radial vs. focused shockwave comparison for the full physics).
What Frequency (Hz) Controls
Frequency is simply impacts per second: 5 Hz = five shots per second; 21 Hz = twenty-one.
- Low frequencies (4–8 Hz) deliver distinct, well-separated impacts. They're used for precise work — a localized trigger point, a tendon insertion, anywhere you want the client to feel and feedback on each shot. Most published radial shockwave protocols for conditions like epicondylopathy and patellar tendinopathy work at 4–5 Hz — the slower rate lets the tissue settle between impacts and lets the client give accurate feedback.
- High frequencies (10–21 Hz) blur into a continuous buzzing percussion. They're used for broad scanning, warm-up passes over large areas, and myofascial/relaxation work where you're moving the tip constantly rather than parking on a point.
A common workflow: start at high frequency and low energy to scan the area and locate the most tender point, then switch to low frequency with higher energy for the focused work on that point.
Transmitter Tips: Size and Shape Change the Treatment
The transmitter tip is where the wave enters the body, so its diameter and shape directly determine pressure distribution:
- Small tips (6–9 mm) concentrate energy on a tiny spot — pinpoint trigger points, tendon insertions, small areas between bones. Pressure per unit area is high, so energy settings usually come down.
- Medium tips (15 mm flat or convex) are the workhorses for most tendon and muscle work. The convex version keeps better contact on curved body contours.
- Large tips (20–25 mm) spread energy over a wide zone for large muscle groups, fascia chains, back and thigh work, and aesthetic treatments. Lower pressure per area means clients tolerate higher bar settings.
Practical rules: use the largest tip that still covers the target comfortably; small tips on large muscles waste time and create hot spots; large tips on a precise trigger point dilute the energy. Tips are machined stainless steel (SUS420 on the MB100B's set) and screw onto the handpiece — they're consumables that eventually pit and wear, and a worn tip face changes impact transmission. Replace when you see deep pitting or permanent gel-induced surface damage.
Shot Count and Treatment Rhythm
The impulse counter (typically 100–5,000 shots per session on modern consoles) sets how many impacts the session delivers to a zone. Clinical practice across published rESWT protocols clusters around these impulse counts per indication:
- Trigger points: ~2,000 shots
- Lateral/medial epicondylopathy (tennis/golfer's elbow): ~1,500
- Patellar tendinopathy: ~1,500
- Subacromial/shoulder pain: 1,000–2,000 depending on presentation
- Plantar fascia: 1,500–2,500 depending on area covered
Courses are 3–6 sessions spaced roughly 5–10 days apart — not daily. The tissue response (local circulation, cellular-level repair signaling) continues between visits; stacking sessions too closely gives no benefit and can increase irritation. Clients typically feel the difference 1–3 sessions in, with results building over the course. Always use a generous layer of coupling gel on the tip-skin interface: air gaps scatter the wave, and insufficient gel is the most common cause of "the treatment feels weak" feedback. The MB100B console pairs this shockwave handpiece with a separate vibration massage handle, which many operators use before shockwave to relax the area and after to flush it.
Putting It Together: A Typical Session
- Find the target with palpation; mark the tender zone mentally or on skin.
- Apply coupling gel generously.
- Warm-up/scanning pass: large tip, 15–21 Hz, 1.5–2.5 bar, moving constantly.
- Switch to the appropriate focused tip (6–15 mm), drop to 4–8 Hz, raise energy to tolerance.
- Treat the point(s) with 1,500–2,000 shots total, working outward if the zone is broad.
- Finish with vibration massage or light manual work; advise the client on mild post-session soreness (normal, like a deep massage) and hydrate.
- Re-book 5–10 days out, 3–6 sessions total.
If shots feel weak or inconsistent despite correct settings, the cause is almost always mechanical — worn projectile, dried gel inside the barrel, a loose tip, or air supply issues. Our shockwave troubleshooting guide walks through the full diagnosis ladder.
Frequently Asked Questions
What energy should I use for a client's first session?
Start low — 1.5–2.5 bar — for the first few hundred shots, explain the sensation, then climb gradually to their tolerance. Sensitivity varies hugely by body area and individual; some clients comfortably take 6 bar on the gluteals while 2.5 bar on the lateral elbow is their limit.
Does higher frequency mean deeper treatment?
No. Frequency is shots per second; depth is governed by energy (bar), tip size and tissue density. High frequency feels more comfortable for scanning and broad work; depth comes from energy.
How often should I replace the projectile/tube kit?
Industry maintenance literature rates ballistic projectile kits for around 2 million impulses. Track your shot counter; when impacts sound or feel inconsistent despite correct settings, gel and tip checks, the projectile or barrel is the next suspect. Wear-part replacement is normal service, not a defect.
Why is coupling gel so important?
The pressure wave travels poorly through air. Any gap between tip and skin scatters energy before it enters tissue, so the client feels less and receives less. Use a thick, continuous layer and keep the tip moving or fully seated.
Can I treat directly over bone?
Over bony prominences the sensation sharpens dramatically and there is little soft tissue to absorb energy — lower the bar, use a smaller tip carefully, or work the surrounding soft-tissue attachments. Avoid direct treatment over the spine, major nerves, vessels and joints' open growth plates; follow your device manual's contraindication list.
Disclaimer: All brand names and trademarks mentioned in this article are the property of their respective owners and are referenced for identification and educational purposes only. iTech Aesthetics is an independent aesthetic equipment supplier. This content is intended for trained aesthetic professionals and clinic operators, is provided for informational purposes only, and does not constitute medical advice. Always follow device manuals, manufacturer protocols, and applicable local regulations.
Originally published by iTech Aesthetics — professional aesthetic and physiotherapy equipment for clinics and studios worldwide.