What is thumb carpometacarpal (saddle) osteoarthritis?
It is precisely this exceptional range of motion that also makes the joint vulnerable. When you grasp a key, open a jar or pick up a small object with a pincer grip, the force is almost always transmitted through this small joint. Over decades it can accumulate the equivalent of tons of load — so it’s no surprise that the cartilage eventually begins to wear, the ligaments that stabilize the joint loosen, and the articular surfaces shift relative to one another.
The condition typically appears after age 50 and is 6–10 times more common in women than in men. Affected people usually report pain at the base of the thumb, reduced grip strength and difficulty with pincer grips. In more advanced cases a visible deformity may develop: the base of the thumb may "stick out" while the rest of the thumb deviates in the opposite direction.
Key idea
Saddle joint osteoarthritis is not simply "wear and tear", but a combined imbalance of the cartilage, ligaments and the muscles that stabilize the joint. That is why effective home treatment targets two directions at once: strengthening the muscles that stabilize the joint (physiotherapy + electrical muscle stimulation) and reducing inflammation (laser, magnetic and ultrasound therapies).
How can the treatments help?
Home therapy devices do not act on their own: each supports a specific biological process. The four mechanisms below show why it makes sense to combine stabilization and anti‑inflammatory approaches. Each contributes in a different way, through different tissues, to help your joint better tolerate everyday loads.
The small muscles around the joint — particularly the so‑called first dorsal interosseous (FDI) and the intrinsic thumb muscles (the thenar group) — act like guy‑ropes tightening a tent canvas. If these weaken, the articular surfaces slide relative to one another and every movement becomes painful. A fluoroscopic study showed that contraction of the FDI muscle can pull the displaced end of the first metacarpal back into place — therefore targeted strengthening of this muscle provides real, measurable mechanical benefit.1,2
Physiotherapy alone is effective: studies show that regular, targeted exercises can significantly reduce pain and improve hand function.3 Electrical muscle stimulation (EMS/NMES) can complement this by reaching tiny muscles that are difficult to contract voluntarily. The two methods together — active exercise plus passive stimulation — work similarly to combining resistance training with manual support: one trains the muscle, the other maintains its tone.
Low‑level laser therapy (LLLT or photobiomodulation) uses low‑intensity red or near‑infrared light at specific wavelengths. The light penetrates the skin to deeper tissues where it acts on cellular mitochondria. It functions like an "internal energy switch" — increased ATP production in cells may help reduce inflammation and support tissue regeneration.
This is particularly relevant for the saddle joint because it lies immediately beneath the skin — only a few millimeters deep — so laser light can reach the target tissues with good effectiveness. According to systematic reviews up to 2025, photobiomodulation shows a promising adjunctive role in hand osteoarthritis, although optimal dosing still needs refinement.4
Pulsed electromagnetic field therapy (PEMF) permeates the hand, affecting the joints and cell membranes. Pulsed magnetic fields can influence ion channel function and thus may help calm inflammatory processes and support cartilage cell metabolism.
In 2025 the first double‑blind randomized controlled trial specifically tested magnetic therapy in patients with thumb carpometacarpal osteoarthritis. Participants wore a PEMF device nightly for 8 hours a day over 4 weeks. Interestingly, pain reduction became statistically significant only after the treatment period, at week 6 — suggesting that PEMF is not a rapid analgesic but a slower‑developing therapy that can produce lasting effects.5,6
Therapeutic ultrasound is a high‑frequency, inaudible sound wave that produces tiny mechanical vibrations and a mild thermal effect in tissues. Think of it as a microscale massage that works the connective tissue around cartilage, ligaments and muscle attachments. This microvibration can aid blood flow, interstitial fluid movement and the clearance of inflammatory mediators.
Specifically for rhizarthrosis, the SUR study (Study of Medical Ultrasound for Rhizarthrosis), launched in 2020, may provide more detailed data in the near future (the trial is still ongoing). For now, ultrasound is considered an accepted, well‑tolerated modality in hand‑OA treatment, especially as part of combined physiotherapy programs.7
What home therapies are available?
The table below provides an overview of what each method targets and how it can fit into a comprehensive home program. Note that the four main pillars act by different mechanisms — therefore they complement rather than exclude one another.
| Method | What it affects | Typical daily duration | When to choose it? |
|---|---|---|---|
| Physiotherapy | Muscle strength, stabilization, joint position | 10–15 minutes | At every stage, the cornerstone of treatment |
| EMS / muscle stimulation | Activation of small stabilizing muscles | 15–20 minutes | When muscles are weak or hard to activate voluntarily |
| Low‑level laser | Cell‑level anti‑inflammatory effects, regeneration | 5–10 minutes | During active inflammatory phases, in treatment cycles |
| Magnetic therapy (PEMF) | Inflammation, cartilage cell metabolism | 30–60 minutes or nightly wear | For chronic, persistent complaints, for long‑term use |
| Therapeutic ultrasound | Soft tissues, microcirculation, joint capsule | 5–8 minutes | Stiff, swollen joints, in treatment cycles |
| TENS (symptomatic only) | Pain relief via nerve fiber modulation | 20–30 minutes as needed | For acute pain as an adjunct — only provides symptomatic relief |
Important distinction
TENS (transcutaneous electrical nerve stimulation) and EMS (electrical muscle stimulation) often operate on the same device, but serve completely different goals. TENS "quiets" pain nerves — it is a symptomatic analgesic and does not contribute to joint stabilization. EMS, on the other hand, contracts muscle and thus actively contributes to long‑term improvement. In the treatment of thumb carpometacarpal osteoarthritis the emphasis is clearly on EMS and anti‑inflammatory physiotherapy modalities.
Guardians of the joint: targeted muscle strengthening
Training the muscles that stabilize the joint is the most important pillar of treatment. A 2024 study in postmenopausal women found that targeted muscle strengthening and proprioceptive training significantly reduce pain and improve hand function.3,8 The exercises below can be done at home for 10–15 minutes daily.
Place your palm on a table with your fingers naturally splayed. Put the index finger of your other hand between your thumb and index finger at the base joint (the "webspace" area). Try to bring your index finger toward the thumb while pressing against the opposing finger so it does not move — the muscle should tense. Hold for 5 seconds, relax to 3. Repeat 10 times, twice daily. This is an isometric strengthening exercise that directly targets the FDI muscle, which stabilizes the joint.
Touch the tip of your thumb sequentially to the tips of your index, middle, ring and little fingers, making an "O" shape at each contact. Move slowly and deliberately, feeling the muscles at the base of the thumb working. Do 10 repetitions in both directions, twice daily. This classic opposition training strengthens the intrinsic thumb muscles (thenar group).
Close your eyes and rely only on sensation to place your thumb in different positions: extended, flexed, toward the center of your palm, sideways. Hold each position for 3–5 seconds. This exercise retrains joint receptors (proprioception), and 2024 studies show it has an outstanding effect on improving hand function.8
Use small (2.5 cm round PALS) electrodes or a motor‑point pen. Place one electrode at the base of the thumb and the other on the palmar pad — these stimulate the intrinsic thumb muscles. Start at low intensity and gradually increase to a visible but not painful contraction. 15–20 minutes, 3–5 sessions per week. EMS is particularly useful when, during physiotherapy, you feel you "cannot find" the muscle — stimulation shows how correct activation feels.
Home therapy devices for thumb carpometacarpal osteoarthritis
There are home devices available for each of the four main technologies. The summary below can help you navigate:
EMS / muscle stimulator devices
Designed to target the muscles that stabilize the joint. Most models include both EMS and TENS functions, so you can address stabilization and pain relief with one device. Look for units that come with electrodes specifically developed for the hand and small joints.
Home low‑level laser devices
For small joints the laser can be directed straight at the painful spot. For home use, 808 nm wavelength, medium‑power devices are most common. A treatment cycle typically lasts 5–10 minutes, daily or every other day.
Magnetic therapy devices
Pulsed magnetic fields can cover a larger area — small joints can be treated with special hand applicators or low‑intensity devices designed for prolonged wear. Ideal for chronic, persistent complaints because effects develop slowly but are durable.
Therapeutic ultrasound devices
Home therapeutic ultrasound devices operate at 1 or 3 MHz; for small joints 3 MHz is appropriate because higher frequency acts on more superficial tissues. Apply with gel using slow circular movements.
Before you start treatment
Before beginning any home therapy, discuss it with your physician. In certain conditions the methods listed below are not recommended or should be used with special precautions.
When should you be cautious?
- Pacemaker or implanted electronic device – EMS, TENS and magnetic therapy are generally not used in these cases because they may interfere with the implant’s function.
- Active malignant tumor in the treatment area – ultrasound and laser thermal effects and circulation‑enhancing actions are not recommended in this situation.
- Pregnancy – pregnancy is a clear contraindication for magnetic, ultrasound and laser therapy on the abdominal and pelvic regions; application on the hand should be subject to medical consultation.
- Acute inflammation or infection – if the base of the thumb is hot, red, swollen and throbbing, this may be an acute inflammatory process. In such cases the cause should first be clarified and most physiotherapeutic treatments are not recommended during the active phase.
- Fresh surgical wound in the treatment area – wait until the surgical wound is fully healed before starting home therapies; your treating physician can give guidance on timing.
- Bleeding disorder or anticoagulant therapy – increased caution is warranted with ultrasound and magnetic therapy; consult your treating physician.
- Epilepsy – electrotherapy devices (EMS, TENS) are explicitly contraindicated over the head; use on the limbs requires medical judgment.
Important note
Home therapy devices are intended to complement conventional medical treatment, not replace it. If your symptoms significantly impair your quality of life, if your condition suddenly worsens, or if you see no improvement after 4–6 weeks of treatment, consult your treating physician or a hand surgeon specialist.
Scientific background
The highlighted studies below form the evidence base supporting the recommendations above. Each is publicly available on PubMed and full texts can be accessed through the cited links.
2024 meta‑analysis — effects of exercises in CMC‑I osteoarthritis
Karanasios and colleagues pooled 14 randomized controlled trials (1280 patients, mean age 62.2 years) and found that exercise‑based interventions significantly reduce pain intensity and wrist‑functional impairment compared with no treatment. The study was published in Healthcare.3
2024 randomized trial — PNF + strengthening in postmenopausal women
Campos‑Villegas and co‑authors compared proprioceptive neuromuscular facilitation (PNF) and strengthening training in postmenopausal women with thumb carpometacarpal osteoarthritis. Both methods contributed to pain reduction and improved function, highlighting the importance of targeted muscle training. Published in J Hand Ther.8
2022 trial protocol — FDI muscle as key stabilizer
Tossini and colleagues’ protocol details why targeted strengthening of the first dorsal interosseous (FDI) may be more effective than traditional training of thumb abductors and extensors. Biomechanical and electromyographic studies support the FDI as a decisive stabilizer at the CMC‑I joint.2
2025 RCT — pulsed electromagnetic field for rhizarthrosis
In the double‑blind randomized controlled trial by Durtschi et al., 61 patients with thumb carpometacarpal osteoarthritis wore a PEMF device nightly for 8 hours over 4 weeks. Mean daily pain intensity was significantly lower in the PEMF group than the sham group at week 6 (P = 0.02), indicating a pain‑reducing effect that outlasts the treatment period. Published in Hand.5
2025 systematic review — comprehensive hand‑OA management
Kjeken and colleagues’ 2025 systematic review evaluated non‑pharmacological, pharmacological and surgical treatments for hand osteoarthritis. Among non‑pharmacological interventions, combinations of exercises and anti‑inflammatory physiotherapy (magnetic, laser) showed the most favorable benefit‑risk profile in the RMD Open analysis.4
Practical advice
Summarizing clinical trials and everyday experience, the following principles are most important if you want to start home treatment.
Start with stabilization
The most common mistake is that patients seek only pain relief (TENS, intensive laser use) and skip stabilizing muscle strengthening. Yet long‑term improvement depends on restoring the function of the muscles surrounding the joint. Plan for at least 6–8 weeks: muscle training effects become tangible in that timeframe. Don’t give up in the first weeks.
Combine methods
An ideal daily/weekly protocol might look like this: morning 10 minutes physiotherapy, during the day 15–20 minutes EMS (3–4 times/week), for painful moments a targeted laser or ultrasound treatment (5–8 minutes), at night magnetic therapy if you have an appropriate device. Monotherapy rarely achieves the effects of a combined approach.
Protect the joint
Alongside treatment, reconsider daily movements. Use an opener for jars, balance a jar in the center of your palm, don’t hold your phone with just two fingers. A simple thumb‑stabilizing orthosis (especially at night) can also provide significant support during active treatment phases.
Frequently asked questions
Analgesic effects (laser, TENS, ultrasound) can be noticed after a few sessions. Improvements in muscle strength and stabilization typically become tangible after 4–6 weeks of regular exercise. For magnetic therapy, the 2025 trial showed a durable effect detectable at week 6 — so plan for longer treatment durations.
Yes — and combined approaches are generally most pragmatic. Stabilization (physiotherapy + EMS) and anti‑inflammatory (laser, magnetic, ultrasound) methods do not exclude each other — they complement one another. You can use 2–3 different methods in a day, but pay attention to appropriate rest intervals between treatments.
TENS is an effective symptomatic analgesic but does not address the cause of pain: joint instability and inflammation. If you treat the complaint only with TENS, the joint can continue to deteriorate and the analgesic effect may wane over time. Therefore TENS is at best an adjunctive symptomatic tool — real improvement depends on muscle strengthening and anti‑inflammatory therapies.
In an acute, touch‑sensitive phase start with the gentlest methods: rest the hand in an orthosis, apply cold packs, and only begin active exercises once pain has subsided. Laser therapy and gentle magnetic therapy can still be used at this stage because they do not require strong touch — which is why they are useful early in treatment.
Current guidelines (EULAR, ACR) state that surgery is considered only if conservative treatment (physiotherapy, physiotherapy modalities, orthosis, medical and injection therapy) fails to improve the condition within 6 months. Targeted, regular home therapy can therefore significantly contribute to postponing or avoiding surgery. However, in advanced cases surgical solutions (trapeziectomy, joint replacement) may be the most appropriate option — this should always be discussed with a hand surgeon specialist.
Both deliver low‑frequency electrical pulses but with different goals. TENS (transcutaneous electrical nerve stimulation) targets pain‑sensing nerve fibers — a symptomatic analgesic. EMS (electrical muscle stimulation) contracts muscle and therefore provides active training, which is important for joint stabilization. Most devices on the market support both modes, covering both objectives with a single unit.
Summary – Quick overview
Sources
- McGee C, O'Brien V, Van Nortwick S, Adams J, Van Heest A (2015). First dorsal interosseous muscle contraction results in radiographic reduction of healthy thumb carpometacarpal joint. Journal of Hand Therapy. PubMed: 26209165
- Tossini NB, Pereira ND, de Oliveira GS, da Silva Serrão PRM (2022). Effect of first dorsal interosseous strengthening on clinical outcomes in patients with thumb osteoarthritis: a study protocol for a randomized controlled clinical trial. Trials. PubMed: 35241133
- Karanasios S, Mertyri D, Karydis F, Gioftsos G (2024). Exercise-Based Interventions Are Effective in the Management of Patients with Thumb Carpometacarpal Osteoarthritis: A Systematic Review and Meta-Analysis of Randomised Controlled Trials. Healthcare (Basel). PubMed: 38667585
- Kjeken I, Bordvik DH, Osteras N, Haugen IK, et al. (2025). Efficacy and safety of non-pharmacological, pharmacological and surgical treatments for hand osteoarthritis in 2024: a systematic review. RMD Open. PubMed: 39793978
- Durtschi MS, Rajakumar V, Kenney DE, Pham NS, Ladd AL, Chou RC (2025). Clinical Efficacy of Pulsed Electromagnetic Field Therapy on Thumb Carpometacarpal Joint Pain: A Double-Blind, Randomized, Controlled Trial. Hand. PubMed: 41015912
- Wu Z, Ding X, Lei G, Zeng C, Wei J, Li J, Li H, Yang T, Cui Y, Xiong Y, Wang Y, Xie D (2018). Efficacy and safety of the pulsed electromagnetic field in osteoarthritis: a meta-analysis. BMJ Open. PubMed: 30552258
- Bock M, Eisenschenk A, Lorenzen H, Lautenbach M (2020). Study of Medical Ultrasound for Rhizarthrosis (SUR): study protocol for a randomized controlled single-center pilot-trial. Trials. PubMed: 32487163
- Campos-Villegas C, Pérez-Alenda S, Carrasco JJ, Igual-Camacho C, Tomás-Miguel JM, Cortés-Amador S (2024). Effectiveness of proprioceptive neuromuscular facilitation therapy and strength training among post-menopausal women with thumb carpometacarpal osteoarthritis. A randomized trial. Journal of Hand Therapy. PubMed: 35948454
