{"title":"Isokinetics and CON-TREX MJ dynamometry","seoTitle":"Isokinetics and CON-TREX MJ dynamometry | Physiotherapy PES Luxembourg","metaDescription":"CON-TREX MJ dynamometer for quantitative assessment and isokinetic, isometric or isotonic muscle work at Bascharage. Informations et rendez-vous au Pôle Éq","content":"**Isokinetic testing measures the strength of a joint at constant speed and produces a curve, not an impression. At Pôle Equilibre & Santé, in Bascharage, the [CON-TREX MJ](https://www.physiomed-group.com/en/products/con-trex/mj) (Physiomed) tests and trains the large joints. The detail of this specialty is also on [kine-isocinetisme.lu](https://kine-isocinetisme.lu/).**\n\n## A multi-mode dynamometer (CON-TREX MJ)\n\nYou push: the device maintains the programmed speed and adjusts the resistance. If you release or if pain appears, the resistance drops. Sampling reaches **4,000 Hz**. **Gravity compensation** makes it possible to test or train a segment that is still too weak to lift its own weight.\n\nThe CON-TREX MJ is not only isokinetic. It also offers **isometric**, **isotonic** and **continuous passive motion (CPM)** modes. It is a clinical laboratory dynamometer, not a daily-life movement.\n\nA multi-joint system: knee, hip, ankle, shoulder, elbow, according to the adapters. The surgeon’s instructions take precedence: we do not activate an eccentric shoulder mode the month of a cuff repair if it is forbidden.\n\n## Why these figures matter after an ACL\n\nGrindem et al. (*BJSM*, 2016) showed that a return to sport validated on tests — including quadriceps strength, with a **limb symmetry index (LSI) of about 90 %** — is associated with a lower recurrence risk. Undheim et al. (*BJSM*, 2015) discussed the place of these tests after ACL reconstruction: useful, to be interpreted with pain, swelling, confidence and functional tests, not as a single criterion.\n\nThe CON-TREX is also used in neurological rehabilitation (passive mode, biofeedback, gravity compensation) and to objectify an imbalance. A prosthesis, a tendinopathy, an operated shoulder: as soon as a reproducible figure is needed.\n\n## How a test goes\n\nAlignment of the joint on the axis of the device, range stops, safety devices. After a warm-up, sets at defined speeds (slow for strength, faster for power). Curves live.\n\nA **test** often lasts **twenty to thirty minutes** once installed, more if several joints or modes are needed. **Training** is integrated into rehabilitation: targeted sets. We choose milestones (return, checking a deficit), not a test at every appointment.\n\nThis does not replace the [leg press](/bascharage/equipement/leg-med-press), the [flywheel](/bascharage/equipement/iso-inertiel) or the field exercises of [sports physiotherapy](/bascharage/competence/kinesitherapie-du-sport). Isokinetic testing mainly objectifies in a controlled open chain; life happens in a closed chain, off balance, in fatigue.\n\n## Preparation\n\nSports clothing, trainers, strap skin without oily cream. Remove jewellery that would catch an adapter. Do not be fasting. Avoid a very heavy training session the day before on the same muscle. Mention pain, swelling, fever or a recent instruction from the surgeon.\n\n## After the test\n\nA frank effort, not a fight against the machine. Delayed muscle soreness of 24 to 48 hours is common. Driving and work are generally possible; a match the same evening is not reasonable. A useful result: a readable curve, a deficit that reduces, an argued return decision — including a postponement.\n\n## Contraindications\n\nAcute pain, marked swelling, fever, range instructions still forbidden, chest pain on effort. A fragile knee can be tested within the limits set by the surgeon, thanks to adaptive resistance and the stops.\n\n## Frequently asked questions\n\n\nIs it risky?
\n\nNo: the resistance adapts to your effort, and the range is limited by a triple safety device. It is designed to test even a still-fragile knee, within the limits set by the surgeon.\n\n \n\n\nHow long does a test last, and should I come back often?
\n\nOften about twenty minutes of measurements, plus the set-up. We repeat it at useful milestones (return to sport, a strength plateau), not every week.\n\n \n\n\nWill I have delayed muscle soreness?
\n\nYes, often the next day, especially after a maximal test. It lasts a day or two. This is not a lesion.\n\n \n\n\nHow should I prepare?
\n\nSports clothing, a light meal, no exhausting training the day before on the same muscle. Bring reports and the surgeon’s instructions. Mention any unusual pain on the day: we postpone a maximal test rather than distort the result.\n\n \n\n\nIs the 90 % figure enough to resume sport?
\n\nIt is an important criterion after ACL reconstruction, not the only one. Quality of movement, field tests, confidence and medical advice count equally. Isokinetic testing informs the decision; it does not sign it on its own.\n\n \n\n\nIs a prescription required?
\n\nPhysiotherapy is provided on medical prescription so that it can be reimbursed by the [CNS](https://cns.public.lu/fr/assure/remboursements/prestations-remboursees/prestations-paramedicales/kinesitherapeutes.html). The practice handles the paperwork. Details: [The Consultation](/bascharage/kinesitherapie/consultation-kine).\n\n \n\n\nHow can I book an appointment?
\n\nVia [Doctena](https://fr.doctena.lu/cabinet/Pole_Equilibre_Sante-281318) or on +352 26 65 28 42. Practice at 20B Rue du Bois, 4912 Bascharage — see [Contact & access](/contact).\n\n \n\n## Find out more\n\n- [Sports physiotherapy](/bascharage/competence/kinesitherapie-du-sport)\n- [kine-isocinetisme.lu](https://kine-isocinetisme.lu/) — our dedicated site\n- [The Consultation](/bascharage/kinesitherapie/consultation-kine)\n\n","image":"https://pes-luxembourg.lu/bascharage/wp-content/uploads/sites/2/2022/11/Isocinetisme.png"}