Physiotherapy and Recovery Equipment
Smooth, controlled counterbalance for adjustable treatment tables, tilt sections, resistance arms, and recovery devices — engineered for OEM rehab equipment builders and aftermarket supply.
- 1 The Backrest a Recovering Patient Has to Move Alone
- 2 Four Rehab Sections, Four Different Demands
- 3 One Spring or Two on Rehab Equipment
- 4 When to Specify Stainless Steel or Locking Gas Springs
- 5 Specifying Gas Springs for Physiotherapy Equipment
- 6 Why Force Progression Defines a Physiotherapy Gas Spring
- 7 Why Rehab OEMs Source Gas Springs for Physiotherapy Equipment from Newtone
- 8 Frequently Asked Questions
- 9 Conclusion
- 10 Get a Specification or Quote
The Backrest a Recovering Patient Has to Move Alone
Gas springs for physiotherapy equipment have to feel effortless to someone who has lost strength. A patient recovering from a shoulder injury reaches back to raise the backrest of a treatment table, and the section has to rise smoothly under a hand that can’t push hard. If the spring is too stiff, the patient can’t move it; if it’s uneven — light at first, then suddenly hard — it jars a healing joint. The force has to be low, smooth, and the same from one end of the travel to the other.
This page is for OEM engineers building rehab tables, tilt frames, and recovery devices, and for procurement teams sourcing replacement springs for a fielded equipment line. Newtone manufactures gas springs in Turkey and exports to more than 60 countries, so the guidance below comes from sizing real adjustable medical sections, not a generic catalog.
Short answer: rehab sections usually need 80–500 N (18–112 lbf) per spring, but the deciding factor here is the feel — a low force progression so a weakened patient moves the section evenly, plus a lock where the position must hold.
Four Rehab Sections, Four Different Demands
Recovery equipment puts gas springs in places where the patient, not a machine, sets the motion. Each section has a different load and a different reason the feel matters.
Adjustable Treatment Table Backrests
The core case. A patient or therapist raises the backrest by hand, often mid-exercise. Needs a low, even force so a weakened patient can move it, and usually a lock to hold the chosen angle under their weight.
Tilt Tables & Standing Frames
Sections that bring a patient from lying to upright in graded steps. The spring assists a heavy combined load, and a rigid-lock holds each intermediate angle precisely while the patient acclimatizes.
Resistance & Range-of-Motion Arms
Levers and arms the patient pushes against for controlled exercise. Here the force progression is the therapy — a predictable, repeatable resistance through the stroke is exactly what the clinician is dosing.
Footrests, Armrests & Light Sections
Smaller adjustable supports on recovery chairs and devices. Low force, but smooth motion and a clean hold still matter — a footrest that drops on a healing ankle is a setback, not an inconvenience.
One Spring or Two on Rehab Equipment
Decide by section weight and how evenly the patient needs the motion. A single spring suits light, narrow sections; pairing keeps a wide patient-bearing section balanced so it doesn’t twist or pull to one side as it moves.
⬤ Single Spring Setup
- Light section under ~10 kg (22 lb)
- Narrow, centered, rigid panel
- Footrests, armrests, small backrests
- Centered hinge, no lateral pull
- Simpler installation, lower cost
⬤ Paired Spring Setup
- Wide, patient-bearing sections
- Treatment-table backrests, tilt frames
- Load above ~10 kg (22 lb) or offset hinge
- Even motion, no twist under a patient
- Springs force-matched to ±5%, same batch
When to Specify Stainless Steel or Locking Gas Springs
For a dry clinic or gym, a standard build is right. Two situations on recovery equipment justify an upgrade, and both are easy to identify at the design stage.
Stainless Steel for Hydrotherapy and Washdown
Specify a 316L stainless body and rod for hydrotherapy, pool-side recovery equipment, and any device exposed to frequent washdown, high humidity, or disinfectant saturation. Standard steel corrodes in those conditions and the seal fails soon after. For dry indoor clinic and gym use, a black nitrided rod (900–1000 HV, 20–30 µm) with HNBR seals is the right, lower-cost choice — and HNBR handles routine wipe-down well. The stainless steel gas springs range covers the wet-area cases.
Locking and Rigid-Lock for Held Positions
A locking gas spring is essential wherever a section holds a patient at a set angle. A rigid-lock (lock-anywhere) unit holds at any point along the stroke — the right choice for adjustable backrests, tilt tables, and positioning sections a therapist sets and leaves. An end-lock unit holds only at full extension, which suits hold-open service panels rather than patient positioning. The release method depends on the device, so confirm the locking type and the patient load before you commit.
Specifying Gas Springs for Physiotherapy Equipment
| Section / Device | Supported Weight | Recommended Force | Spring Count | Notes |
|---|---|---|---|---|
| Footrest / armrest | 2–6 kg (4–13 lb) | 80–200 N (18–45 lbf) | 1 | Low progression for smooth feel |
| Treatment table backrest | 10–20 kg (22–44 lb) | 200–500 N each (45–112 lbf) | 1–2 | Rigid-lock to hold the set angle |
| Tilt table / standing frame | 20–40 kg (44–88 lb) | 400–900 N each (90–202 lbf) | 2 | Paired; lock each intermediate angle |
| Resistance / ROM arm | Per dosed load | 100–600 N (22–135 lbf) | 1–2 | Progression is the therapy — specify it |
| Hydrotherapy / wet area | Any | Per above | Per above | Stainless steel recommended |
Why Force Progression Defines a Physiotherapy Gas Spring
On rehab equipment the number that matters is not just the peak force — it is how much the force changes from one end of the stroke to the other. A gas spring is naturally higher in force when compressed and lower when extended, and the ratio between those two is the progression, or K-factor. Keep it low and the section feels almost constant to a patient’s hand.
- P1 / F1 — extended-position (open) force, the lowest on the stroke, N (lbf)
- P2 — compressed-position (closed) force, N (lbf)
- K — progression ratio = P2 ÷ P1 (gas springs run 1.05–1.8; standard 1.2–1.4)
- ΔF — total force rise from open to closed, N (lbf)
Worked example. Take a backrest spring with an open-position force P1 = 300 N (67 lbf) and a low progression ratio K = 1.2. The force at the closed end is P2 = 300 × 1.2 = 360 N (81 lbf), so the rise across the whole stroke is ΔF = 300 × (1.2 − 1) = 60 N (13 lbf). A patient feels the force move only from 300 N to 360 N (67 to 81 lbf) across the full travel — gentle and even. Spec the same section with a high-progression spring at K = 1.6 and P2 jumps to 480 N (108 lbf), a 180 N (40 lbf) rise that feels light then stiff. That is the difference between a section a recovering patient can move comfortably and one they fight. Tell us the section weight and the feel you want, and we will match both the gas spring force and its progression, then confirm the right mounting bracket.
Mounting protects that smoothness. Fit the spring with the rod pointing down when the section is closed so oil keeps the seals lubricated and the motion stays quiet over thousands of patient cycles. Keep both pivots in the same plane of motion — gas springs take axial load only, and a side-loaded rod wears unevenly and starts to feel notchy. Position the lower pivot to set the effective moment arm; shifting it changes the assist more than swapping force ratings does.
Why Rehab OEMs Source Gas Springs for Physiotherapy Equipment from Newtone
We are a manufacturer, not a distributor. Every spring is built in our own facility in Turkey, so the force, progression, and tolerance stay under our control rather than a third party’s.
Frequently Asked Questions
It depends on what the spring counterbalances. An adjustable backrest supporting 10–20 kg (22–44 lb) of panel and patient weight typically needs 200–500 N (45–112 lbf) per spring. A light footrest or armrest may need only 80–200 N (18–45 lbf). Because a patient sets these sections by hand, a smooth, low force progression matters as much as the peak value. Share the section weight and geometry and Newtone will size it.
Patients and therapists adjust these sections slowly and by hand, so the force change across the stroke, not just the peak force, defines the experience. A gas spring with a low progression ratio (K-factor near 1.2) feels almost constant from open to closed, which lets a patient with limited strength move a section smoothly. A high progression feels light at first then suddenly stiff, which is wrong for recovery use.
Yes, where a section must hold a set position under a patient. A rigid-lock or lock-anywhere gas spring holds any point along the stroke, which suits adjustable backrests, tilt tables, and positioning sections a therapist sets and leaves. An end-lock unit holds only at full extension, suited to hold-open service panels. The release method depends on the device, so confirm the locking type against the load.
Mount the spring with the rod pointing down in the closed or rest position so oil keeps the seals lubricated and the motion stays smooth and quiet. Keep both pivots in the same plane of motion to avoid side load, which shortens life under repeated use, and use an end fitting that allows slight angular misalignment. The lower pivot position relative to the hinge changes the effective moment arm more than the force value does.
For most clinic and gym environments, no. A black nitrided rod with HNBR seals handles indoor use and routine wipe-down at lower cost. Specify 316L stainless steel for hydrotherapy, pool-side equipment, or any device exposed to frequent washdown, high humidity, or disinfectant saturation, where corrosion would otherwise reach the seals.
Conclusion
On physiotherapy and recovery equipment, the gas spring is part of the therapy, not just hardware. A patient with reduced strength has to move these sections, so the feel — a low, even force progression — matters as much as the peak number, and a reliable lock keeps a set position safe under their weight. Get the progression wrong and a section becomes something the patient fights instead of uses.
Newtone has been supplying gas springs to medical and rehab equipment builders for over two decades. Whether you are designing a new treatment table, a tilt frame, or a recovery device, or replacing a spring that has lost its smoothness, we match the force and the progression to the section and back it with engineering support.
Send us your section weight, hinge geometry, and the feel you want. We will return a force and progression recommendation, a datasheet, and a quote — typically within 5 business hours.
Get a Specification or Quote
Tell us the section type, supported weight, and the motion feel you need. Our team handles the force and progression selection, sample datasheet, and competitive pricing.
