What is Flexor Pollicis Longus and What is its Function?

The Flexor Pollicis Longus muscle forms a part of the lower half of the arm which means it is located from the elbow moving downwards. This muscle is believed to be unique and present only in humans. The Flexor Pollicis Longus extends into the hand. The function of this muscle is to facilitate thumb flexion. Flexor Pollicis Longus stems from the bottom half of the radius. The radius is a bone located in the forearm. Bordering thus muscle is the supinator muscle. This muscle also extends from the radius to the top part. This muscle then goes down the side of forearm and gets attached to the interosseus membrane of forearm. This serves as base for attaching other muscles. The Flexor Pollicis Longus muscles moves through the hand as a tendon. It travels through the carpal tunnel which is the point connecting the palm and forearm, and goes into the thumb. This muscle is located between the two muscles which facilitate flexion of the thumb, namely the Flexor Pollicis Brevis and the Abductor Pollicis. Flexor Pollicis Longus terminates at the tip of the thumb. In case if there is any sort of injury to the tendons of the Flexor Pollicis Longus then recovery from such injuries take a significant amount of time to heal due to lack of blood supply to the tendons when compared to other tendons of the body.

Flexor Pollicis Longus Pain

Signs and Symptoms of Flexor Pollicis Longus Pain

Following are the Signs and Symptoms of Flexor Pollicis Longus Pain:

  • Pain at the thumb joint
  • Pain and discomfort at the tip of the thumb
  • Difficulty and pain with gripping or grasping objects
  • Frequent locking and popping of the joints of the thumb
  • Pain and discomfort with holding a pen or a pencil
  • Pain and discomfort with buttoning buttons
  • Pain and discomfort when trying to tie laces of the shoes.

What Can Cause Pain of the Flexor Pollicis Longus Muscle?

Below mentioned are some of the activities that may cause Flexor Pollicis Longus Pain:

  • Frequent and prolonged gripping of tools like people who work in construction or in garages
  • People who are involved with persistent and repetitive writing activities
  • Artists involved with long periods of painting can also lead to pain of the Flexor Pollicis Longus muscle
  • Bank tellers who repetitively spend time counting money also can injure the Flexor Pollicis Longus muscle
  • In some cases people who do a lot of gardening and pull out weeds using the thumb and fingers can also injure Flexor Pollicis Longus muscle.

Risk Factors of Flexor Pollicis Longus Injury

A damaged or injured Flexor Pollicis Longus can contribute to certain medical conditions like:

What is the Treatment for Flexor Pollicis Longus Pain?

When it comes to treating an injured Flexor Pollicis Longus muscle causing pain in the thumb, the most preferred and recommended way is massaging the injured area or using supports or braces. Massaging can be done either using cold therapy or by utilizing heat. Wrist and thumb supports and braces are also quite useful in relieving Flexor Pollicis Longus muscle pain. All these treatments have been explained in detail below:

Cold Therapy for Flexor Pollicis Longus Pain: For treating pain of the Flexor Pollicis Longus muscle using cold therapy, the most recommended treatment is using a Biofreeze gel. This gel has been shown to be quite useful in reliving Flexor Pollicis Longus Pain. This gel tends to cool the inflamed area quickly and prevents development of swelling due to the cooling effect. Studies have shown that this gel can relieve pain twice more than normal gels and its effect lasts more than nine times than any other cooling gel. To use this gel, gently rub it at the injured side both at the front and back starting just at the elbow going down all the way to the tip of the thumb.

Wrist Ice Wrap: When an individual has an injured Flexor Pollicis Longus muscle then just treating the thumb pain is not sufficient but the whole muscle needs to be treated. For this the Ice Wrist Wrap has been shown to be quite beneficial, as it covers the entire muscle and provides compression and helps in healing of the muscle. To begin with, you can start wearing the wrap for about 20 minutes and then gradually increase the time. You can also adjust the wrap so as to cover the thumb as well. Also helpful can be using a frozen wash rag wrapped around the thumb along with using the wrap as this combination will completely cover the muscle and allow it to heal faster. Additionally, Biofreeze gel can also be applied along with using the wrap for additional comfort.

Warm Therapy: Heat can also be used as a form of treatment for pain in the thumb caused due to Flexor Pollicis Longus Injury. Sombra Warm Therapy Gel is widely used as a mode for pain relief. This gel has been proved to relieve pain for long periods of time. This gel warms up the area and helps with inflammation and relieves stiffness and pain. This is normally used for pain caused due to arthritis but can also be used for a Flexor Pollicis Longus muscle pain. This gel needs to be applied in the painful area about three to four times a day. One this that needs to be understood here is that heat and cold therapy do no go along together and hence if you are using cold therapy for pain relief then it is recommended not to use this gel.

Thumb Supports: Using supports for a Flexor Pollicis Longus Pain is definitely not a cure but may afford substantial pain relief and help in stabilizing the muscle. In some cases the pain may be so excruciating that it may be tough to even move the thumb then in such cases thumb brace or support comes to the rescue in relieving pain and providing necessary rest and support to the thumb. It should be noted here that the brace used should be light weight so that it can be easily adjusted and compressible. These supports are especially useful for those who do a lot of writing or pain pictures.

Arm Compression Sleeves: These have also been shown to be quite effective in relieving pain and discomfort caused due to an injury or damage to the Flexor Pollicis Longus muscle. These sleeves provide more support to the muscle and prevent it from any reinjury and also help in recovery. It is mostly used by periople who have significant pain affecting their activities of daily living and athletes along with people who use tools quite often in their work.

Trigger Point Identification: Also of note here is that if you have unrelenting thumb pain then it may be of help in identifying a trigger point in the Flexor Pollicis Longus muscle. It may be difficult to identify it at first but you can consult with your healthcare provider who will help in identifying a trigger point and once it is identified it can help tremendously in completely eliminating pain caused due to a dysfunctional Flexor Pollicis Longus.

Written, Edited or Reviewed By:


Last Modified On: August 22, 2015

Pain Assist Inc.

Pramod Kerkar
  Note: Information provided is not a substitute for physician, hospital or any form of medical care. Examination and Investigation is necessary for correct diagnosis.

Symptom Checker

Slideshow:  Home Remedies, Exercises, Diet and Nutrition

Chakra's and Aura's

Yoga Information Center

Find Pain Physician

Subscribe to ePainAssist Newsletters

By clicking Submit, I agree to the ePainAssist Terms & Conditions & Privacy Policy and understand that I may opt out of ePainAssist subscriptions at any time.

Copyright © 2016 ePainAssist, All rights reserved.

DMCA.com Protection Status