1. Introduction
The OMRON Pocket Pain Pro TENS Unit Muscle Stimulator (Model PM400) is a compact and portable device designed to provide drug-free pain relief. It utilizes Transcutaneous Electrical Nerve Stimulation (TENS) technology to help alleviate chronic, acute, and arthritis-related pain in various body areas, including the lower back, arms, legs, shoulders, and feet.
This manual provides essential information for the safe and effective use of your OMRON Pocket Pain Pro. Please read it thoroughly before operating the device and retain it for future reference.
2. Important Safety Information
WARNING: Consult your physician before using this device if you have a cardiac pacemaker, implanted defibrillator, or other implanted metallic or electronic device. Do not use if you have a heart condition, are pregnant, or have any other medical condition that may be affected by electrical stimulation.
Statements regarding dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease or health condition. This device is intended for pain relief only.
Use this unit only with the leads, electrodes, and accessories recommended by OMRON to avoid damage to the unit and ensure user safety.
- Do not apply pads over open wounds, rashes, or inflamed skin.
- Do not use while driving or operating machinery.
- Keep out of reach of children.
- Discontinue use and consult a physician if you experience any adverse reactions.
3. Package Contents
Verify that all items are present in your OMRON Pocket Pain Pro package:

Image: The OMRON Pocket Pain Pro box contents, showing the TENS device, two Long Life Pads, electrode cords, two AAA batteries, a plastic pad holder, an instructional manual, and a quick start guide.
- 1 TENS Device (OMRON Pocket Pain Pro PM400)
- 2 Standard Long Life Pads (1 pair)
- 1 Pad Holder
- 1 Set of Electrode Cords
- 2 AAA Batteries
- 1 Instructional Manual (this document)
- 1 Quick Start Guide
4. Product Overview
The OMRON Pocket Pain Pro is designed for intuitive operation. Familiarize yourself with the device components:

Image: The OMRON Pocket Pain Pro TENS unit, showing the main control unit and two connected Long Life Pads. The control unit features power, intensity adjustment, and program selection buttons, along with LED indicators for intensity levels.
Device Components:
- Main Unit: Houses the controls, battery compartment, and TENS technology.
- Long Life Pads: Self-adhesive electrode pads that deliver electrical stimulation. Reusable up to 150 times.
- Electrode Cords: Connect the pads to the main unit.
- Control Buttons: Power On/Off, Intensity Up/Down, Set/Start, and Program Selection.
- Intensity Indicator: LED lights showing the current intensity level.
5. Setup Instructions
5.1. Battery Installation
- Locate the battery compartment on the back of the main unit.
- Open the battery cover.
- Insert two AAA batteries, ensuring correct polarity (+/-).
- Close the battery cover securely.
5.2. Connecting the Pads
- Connect the electrode cords to the main unit's output jack.
- Attach the other end of the electrode cords to the Long Life Pads. Ensure a secure connection.
- Peel the protective film from the adhesive side of the Long Life Pads. Retain the film for storage.
6. Operating Instructions
6.1. Applying the Pads
Ensure your skin is clean and dry before applying the pads. Place the pads directly on the skin in the area where you are experiencing pain. Avoid placing pads over joints that bend frequently, such as the knee cap, or directly over the heart or head.

Image: Two OMRON Long Life Pads are shown applied to a person's knee, demonstrating proper placement for pain relief.
6.2. Powering On and Selecting a Program
- Press the Power button (⑁) to turn on the device.
- The device offers 3 pre-set body pain programs and 2 massage-like modes:
- Body Pain Programs: Arm/Shoulder, Lower Back, Leg/Foot
- Massage-like Modes: Knead, Steady
- Press the "Set/Start" button to cycle through the available programs until you reach your desired setting.

Image: The OMRON Pocket Pain Pro TENS unit in use, with pads on a knee. Text overlays indicate the three pain modes (Arm/Shoulder, Lower Back, Leg/Foot) and two massage-like modes (Knead, Steady), each with 10 adjustable intensity levels.
6.3. Adjusting Intensity
Each program and mode has 10 adjustable levels of power intensity. Start with the lowest intensity and gradually increase it until you feel a comfortable, yet effective, stimulation. Avoid increasing the intensity to an uncomfortable level.
- Use the Up (▲) and Down (▼) arrow buttons to adjust the intensity.
- The LED indicators on the device will show the current intensity level.
6.4. Session Duration
A typical session lasts 15 minutes. The device will automatically shut off after the session is complete. You can manually turn off the device at any time by pressing the Power button.
6.5. How TENS Technology Works

Image: An infographic explaining TENS technology. It states that TENS blocks pain signals to the brain, increases circulation to targeted areas, and stimulates the body's natural painkillers, providing drug-free relief for chronic, acute, and arthritic pain.
Transcutaneous Electrical Nerve Stimulation (TENS) technology delivers gentle electrical nerve stimulation to the skin near the source of discomfort. Scientific theory suggests that this technology may:
- Block pain messages from reaching the brain.
- Increase blood circulation to targeted areas.
- Stimulate the body's natural painkillers (endorphins).
This process helps to reduce muscle and joint pain, stiffness, and numbness.
7. Maintenance and Care
7.1. Cleaning the Pads
The Long Life Pads are reusable up to 150 times. To maintain their adhesive quality and hygiene:
- After each use, gently wipe the adhesive surface of the pads with a damp cloth. Do not use harsh chemicals or abrasive cleaners.
- Allow the pads to air dry completely before reattaching them to the plastic pad holder.
- If the pads lose their stickiness, they may be gently rinsed under cold water and air-dried. Replace pads when they no longer adhere well to the skin.
7.2. Device Cleaning and Storage

Image: The OMRON Pocket Pain Pro TENS unit and its pads are shown next to a shoulder bag, highlighting its compact and portable design for easy transport.
- Wipe the main unit with a soft, dry cloth. Do not immerse the device in water or use liquid cleaners.
- Store the device and pads in the provided plastic holder in a cool, dry place, away from direct sunlight and extreme temperatures.
- Remove batteries if the device will not be used for an extended period to prevent leakage.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No sensation or weak sensation |
|
|
| Device does not turn on |
|
|
| Pads lose stickiness quickly |
|
|
| Electrode cord breaks |
|
|
9. Specifications
- Model: PM400
- Power Source: 2 AAA batteries (included)
- Product Dimensions: 7.1 x 2.5 x 3.5 inches
- Weight: 8 ounces (with batteries)
- Technology: Transcutaneous Electrical Nerve Stimulation (TENS)
- Programs: 3 pre-set body pain programs (Arm/Shoulder, Lower Back, Leg/Foot), 2 massage-like modes (Knead, Steady)
- Intensity Levels: 10 adjustable levels
- Pad Lifespan: Long Life Pads reusable up to 150 times
- Manufacturer: Omron Healthcare, Inc.
- Date First Available: November 11, 2016
10. Warranty and Support
For warranty information, product support, or to purchase replacement parts (such as Long Life Pads or electrode cords), please visit the official Omron website or contact Omron customer service.
A digital version of this user manual is available for download: OMRON Pocket Pain Pro User Manual (PDF).
11. Product Videos
No official product videos with seller creator type were provided in the available data to embed in this manual.







