Beware of Smartphone Thumb

by Dr. Joel Kerr

March 16, 2018

Excessive smartphone use is a hot button (pun intended) within sports injury clinical practice especially among gripping sports like tennis.

Do your thumbs hurt and are you unsure of the cause? Do you own the latest smartphone device on the market? Too much typing on personal digital assistive devices (PDA) such as your Android Phone, Blackberry®, or iPhone® and mobile phones could cause repetitive strain injuries (RSI) to your thumbs. Have you noticed that this discomfort has affected your ability to hold your tennis racquet? Has the power and precision of your forehand and backhand been affected by the repetitive use of your smartphone?

Repetitive strain injuries can lead to pain in multiple structures of your thumbs. These may include over use of the joint at the base of the thumb, and more typically overuse of the tendons on the side of the wrist and thumb.

The joint at the base of the thumb is not designed for excessive mobility, instead it is for stabilization for pinching and gripping. Personal computer keyboards are designed with this in mind as the main function of the thumb during typing is with the space bar, while our more mobile fingers perform the typing. As most smartphones keys are small, you are likely to press the keys with more force versus a larger keyboard, while the smaller keys also make it difficult to navigate around. If you persist in typing a lot of information with your thumbs you are at risk of injury.

Potential Diagnosis

DeQuervain's Tenosynovitis

DeQuervain's Tenosynovitis is a potential diagnosis for excessive smartphone use. This condition involves inflammation of the tendons that attach to and are responsible for movement of the thumb (abductor pollicis longus and extensor pollicis brevis). With this injury all movements of the thumb are usually uncomfortable and may cause difficulty with grasping objects.

Treatment: Manual Therapy

Therapists at The Health Institute will use various manual therapy techniques and modalities to address the pain, inflammation, muscle tension, adhesion, and any other contributing factors. These can include: Medical Electro-Acupuncture, Functional Range Release Active Release®, Techniques®, hydro/cyro-therapy and more. Passive treatment sessions eventually taper into more active sessions as the pain subsides. Exercises are given to strengthen inhibited (weakened) muscles and stretch short and stiff muscles to help counteract the damage done while disproportionately using such devices.

Warm up exercise to prevent Smartphone Thumb.


The thumb joint and the muscles that move it are not designed for repetitive rapid movement. It is highly recommended that you perform a dynamic warm up for Smartphone Thumb consisting of opening and closing your hand, spreading your fingers apart and holding for 10 seconds. Lastly, building the endurance of the smaller muscles of the thumb by using an elastic band around the thumb and index finger. One then performs resistance movements in abduction (thumb away from the index finger-see image below). Also, alternate fingers and thumbs so you are not using the same digits all the time. Ideally, if you must type an extended message, rest your thumbs and use a PC keyboard.

Dr. Joel Kerr is the Founder, President and Director of Therapy at The Health Institute. He is a sport injury focused chiropractor with emphasis on exercise prescription and manual therapy. Dr. J, as his patients so affectionately call him, is a graduate from the University of Toronto, Physical Education and Health program. Dr. J successfully completed the Medical Acupuncture diploma from McMaster University Medical School and is a certified acupuncturist. In 2010 Blog TO Dr. J was voted as one of the top trainers in Toronto. Most recently in 2016, Dr. J was recognized by Nike as an Elite Trainer. Dr. J can be reached at his office number at 416-546-5077 or email: