Quick Overview

A 2024 systematic review in PLOS ONE analyzed 36 studies on neuromuscular electrical stimulation (NMES) and muscle length. The researchers found that when EMS was applied at a mid-range joint angle (for quads, about 50–70° knee bend), muscles produced significantly higher torque compared to very short positions. Strength gains were also greater when training was done at this optimal length. Shortened positions created more discomfort and less force. For people who train, this suggests EMS may provide a stronger contraction stimulus when used at effective joint angles alongside structured training.

Training Hard but Not Seeing Enough Progress? What This 2024 EMS Study Suggests

Introduction

ORIEMS FIT Research Digest exists for one reason:

To take real university research and explain it in simple, honest language.

No hype.
No exaggerated claims.
No miracle promises.

We translate scientific papers into clear, practical information so you can make informed decisions.

This article is for education only.
It is not medical advice.
It does not diagnose or treat any condition.

Why This Study Matters If You Train Seriously

If you train consistently, track your workouts, eat enough protein, and still feel like results are slower than expected, you’re not alone.

Sometimes the issue is not effort.

Sometimes it is quality of muscle contraction stimulus.

This 2024 systematic review published in PLOS ONE examined how neuromuscular electrical stimulation (NMES) works at different joint angles.

The key question:

Does muscle position change how effective EMS is?

For serious trainees, that question matters.

What Is This Study About?

This paper is a systematic review. That means the researchers collected and analyzed many existing studies instead of running just one experiment.

They examined how muscle length (which changes with joint angle) affects:

• Maximum evoked torque (how much force the muscle produces)

• Perceived discomfort

• Contraction fatigue

• Strength adaptations over time

Who Conducted It?

Researchers from:

• University of Brasília (Brazil)

• Federal University of Rio Grande do Sul (Brazil)

• University of Burgundy Franche-Comté / INSERM (France)

Published in 2024 in PLOS ONE.

DOI:
https://doi.org/10.1371/journal.pone.0304205

Full article:
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0304205

What Type of “EMS” Are We Talking About?

This research focused on NMES (Neuromuscular Electrical Stimulation).

Important distinction:

• NMES / EMS → designed to create visible muscle contractions.

• TENS → typically used for sensory stimulation and does not aim to produce strong muscle contractions.

This study examined force production and strength outcomes, not pain claims.

Who Was Studied?

Across the included research:

• 36 studies were analyzed.

• Most participants were healthy young adults (19–40 years).

• Some studies included older adults.

• A small number involved spinal cord injury participants.

The strongest data were in healthy, resistance-training-age adults.

What Did They Actually Find?

Let’s simplify it.

1. Joint angle changes how strong the contraction is

For the quadriceps (front thigh), researchers found that a mid-range knee angle (about 50–70° of bend) produced significantly higher torque compared to very short muscle positions.

In plain English:

When the muscle was positioned properly, EMS created stronger contractions.

2. Strength gains were greater at optimal muscle length

When training protocols used that mid-range joint position, strength improvements were greater than when shorter muscle positions were used.

This does not mean EMS replaces lifting.

It means:

If you use EMS, positioning can influence the training stimulus.

3. Very short positions caused more discomfort

Shortened muscle positions produced more discomfort for the same electrical intensity.

That matters because excessive discomfort limits how much usable stimulus you can apply.

4. Stronger contractions led to greater fatigue

When the muscle produced more torque, fatigue during repeated stimulation was also higher.

That is expected.

More force = more training stress.

What This Means for Serious Trainees

If you feel stuck, the realistic takeaway is this:

EMS may add value by creating additional high-quality contractions, especially when used at effective joint angles.

It may help:

• Improve muscle activation in lagging areas

• Add contraction stimulus without adding heavy joint loading

• Provide extra work on recovery days

It does NOT:

• Replace progressive overload

• Guarantee muscle growth

• Work without consistent training

Think of it as:

A tool for adding extra contraction stimulus, not a shortcut.

What This Means If You Are Considering Buying EMS

EMS works by stimulating motor nerves to create muscle contractions.

If joint positioning allows higher torque, the contraction may be stronger.

Who it may suit:

• People training consistently who want extra activation work

• Individuals with difficulty feeling certain muscles working

• Athletes looking to add low-impact contraction volume

Who should consult a professional first:

• Anyone with a pacemaker or implanted medical device

• Pregnancy

• Seizure disorders

• Heart conditions

• Recent surgery

• Significant medical conditions

What This Means If You Already Use EMS

1. Position matters more than most people think.
   Adjust joint angle before simply increasing intensity.

2. Consistency is more important than occasional extreme sessions.

3. Expect gradual effects.
   Strength adaptations happen over time.

4. Understand the difference between NMES (muscle contraction) and TENS (sensory stimulation).

Final Thoughts

This 2024 review supports a practical principle:

If EMS is used, muscle length and joint angle influence how strong and tolerable the contraction is.

For serious trainees who feel plateaued, that may provide an additional lever to pull.

Not a miracle.

Not a replacement for hard training.

But potentially an added contraction stimulus when used correctly.

If you want to read the full study:

DOI:
https://doi.org/10.1371/journal.pone.0304205

Journal page:
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0304205

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🔴 Disclaimer

This article is provided for educational purposes only.

It is not medical advice.
It is not a diagnosis.
It is not a treatment recommendation.

ORIEMS FIT does not claim to cure, prevent, or treat any disease or medical condition.

Results discussed are based on research averages. Individual responses vary.

Consult a qualified health professional before using electrical stimulation if you have medical implants, pregnancy, seizure history, cardiovascular conditions, recent surgery, or any significant medical concerns.

This article does not replace professional medical care.

Readers are responsible for their own health decisions.

ORIEMS FIT is not affiliated with the researchers or journal mentioned.

No guarantees of performance or outcome are made.

Use devices according to instructions and safety guidelines.

ORIEMS FIT Research Digest makes complex research from top scientists and universities easy for anyone to understand—clear, simple, and never medical advice, just trustworthy science.

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