Setting Your MVC Goal

If you don’t know where you want to go, you’ll never get there

What is MVC?

MVC stands for maximum voluntary contraction, a measure of muscle strength. “Maximum strength is defined as the highest voluntary force possible under dynamic concentric, dynamic eccentric, or isometric muscle action conditions, and is limited by muscle fiber recruitment and frequency of action potentials.”¹

MVC is often measured via maximum voluntary isometric contraction testing (MVICT), using tools such as the Quantitative Muscle Assessment (QMA) System.

Maximum contraction can be measured by force (e.g., QMA) or via surface electromyography (sEMG), which is referred to as microvolt scaling. This technique measures the electrical activity from subcutaneous motor units rather than force.

How does mTrigger utilize MVC?

It’s important to distinguish between MVC and MVIC. While MVIC normative data is limited², and research is ongoing³, mTrigger leverages real-time sEMG data for practical and functional application.

Real-time biofeedback is far more accessible and motivating during rehab than clinical-grade EMG setups. While EMG can vary between sessions and individuals, the spatial and temporal awareness mTrigger provides is invaluable — and more adaptable.

How do I set and monitor my MVC in the mTrigger System?

sEMG values vary naturally, and MVC should be treated flexibly. This is due to:

• External factors: humidity, skin conductivity, muscle fatigue
• Internal factors:
  • Exercise load/resistance — more effort = higher neuromotor activity
  • Electrode placement — ensure consistent and accurate targeting (see our guide)
  • Goal difficulty — increasing goals over time encourages motivation and progress (read more)

Two ways to set your MVC in mTrigger:

1. MVC Setup Protocol (in Settings):
   • Run a 30-second protocol capturing 3 x 5-second max contractions.
   • Adjust difficulty or set Channel 2 goals relative to Channel 1.
2. Manual Setup in Train Mode:
   • Connect mTrigger and set initial goal to 1000 μV.
   • Have the patient perform several reps of the intended exercise.
   • Adjust the goal based on observed average contraction.

Helpful MVC Reminders

• The feedback bar scales to the MVC goal. Adjusting the goal changes how contraction levels are visualized.
• You can pause sessions to adjust difficulty on the fly.
• Try to keep activation in the green “success” zone for motivation.
• Patients may fatigue faster than expected — that’s okay!

MVC for Relaxation & Inhibition Training

If using mTrigger for downregulation or relaxation training:

• Relaxation: Set MVC at resting tone and guide the patient to reduce activation. Audio feedback helps here.
• Inhibition:
  • Channel 1 = target muscle, Channel 2 = monitor muscle
  • To compare levels: Match Goals ON
  • To minimize Channel 2 activation: Lower goal to ~500 μV, Match Goals OFF
  • If MVC differs across channels: set each goal manually (Match Goals OFF)

TIP: If a target muscle is hard to monitor (e.g. transverse abdominus), consider placing electrodes on a compensator muscle instead to drive proper engagement.

Now that you’re armed with that knowledge, get in there and set some goals!
If you don’t know where you want to go, you’re never going to get there.

References

1. Kraemer et al. “Progression models in resistance training for healthy adults: ACSM position stand.” Read here
2. Meldrum et al. “Maximum voluntary isometric contraction: Reference values and clinical application.” Read here
3. Al-Qaisi. “Electromyography analysis: Comparison of maximum voluntary contraction methods.” Read here

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