Plantar Fasciosis: 3 Ways to Identify Weakness in the Foot

Written By Brandon Steele

Reading time: 5 minutes

45.6% of plantar fasciitis (PF) sufferers will continue to report symptoms ten years after onset. (1)

Today’s blog will provide three tips to prevent your patients from falling into this statistic.

  1. Identify the most significant overlooked contributor to PF

  2. Learn how to evaluate for this key Weakness

  3. Teach you simple strengthening exercises for PF

 
 

The plantar fascia is a thick, fibrous band serving as a biomechanical force transducer and protector to the vulnerable neurovascular structures on the plantar aspect of the foot. Its primary function is to support the arch of the foot while stationary as well as shock absorption during movement. For a detailed background on the biomechanics and etiology of plantar facia function and related injuries, read THIS prior blog or the Condition Reference in ChiroUp.

Increased speed of pronation and weakness within the foot intrinsic muscles lead to a 20-fold increase in running injuries. (2) Three tests can identify weakness in the foot intrinsic muscles.

1. Toe Strength Dynamometer

The patient is seated with their knee bent 90-95 degrees, the heel on a firm floor, and 2nd thru 5th toes resting on the dynamometer card. Do not place the card beneath the forefoot. The patient is instructed to keep their heel on the ground and grip the card as firmly as possible while the clinician attempts to draw the card out from underneath the patient’s toes. The clinician places their hand over the patient’s foot to monitor compliance and maintain stability. The clinician performs the test three times and records the peak score for each foot. The process is then repeated with the card beneath the great toe on each side.

 
 

2. Paper Grip Test

The barefoot, seated patient places their second through fifth digits on a business card while the clinician attempts to pull the card from beneath the patient’s toes. The inability of the patient to resist removal of the card suggests flexor digitorum brevis weakness- often related to plantar fasciitis.

 
 

Evaluation of the patient’s shoe insoles may provide additional information regarding flexor digitorum brevis strength. Runners with strong flexor digitorum brevis muscles will demonstrate indents beneath their middle toes.

3. The Wink Sign

A standing patient pushes their toes into the floor with as much force as possible. The clinician observes the second through fifth toes.

Strong FDM

The intermediate phalanx plantarflexes, and a visible crease forms between the intermediate and distal phalanx.

 

Weak FDM

The second through fifth toes remain stationary while the distal phalanx plantarflexes.

A negative or absent Wink Sign indicates weakness of the FDB and all the intrinsic muscles of the arch. (3)

Next week we will dig through the research and identify a couple ways to strengthen the foot intrinsic muscles. 

Every patient deserves “best practice” treatment, rehabilitation, advice, and condition-specific education.  As an evidence-informed provider, you must develop processes within your practice to ensure that your patients receive the best possible care.  One of the benefits of ChiroUp is to learn from the top providers around the world.  Check out the Expert Advice section within the ChiroUp condition references to learn more about what the top providers are doing for plantar fasciitis.

Not a member of ChiroUp? Take a gamble on the one product that will ethically transform your practice.  Deliver a service that your patients want to buy—Excellent Clinical Care!  ChiroUp tells your patients WHAT you do and WHY you do it with the research to back it up.  Please take two minutes to start using it today at no charge, no commitment, no termination fees.  Each month we will provide enough value that you can’t imagine practicing without it. 

    1. Hansen L, Krogh TP, Ellingsen T, Bolvig L, Fredberg U. Long-term prognosis of plantar fasciitis: a 5-to 15-year follow-up study of 174 patients with ultrasound examination. Orthopaedic journal of sports medicine. 2018 Mar 1;6(3):2325967118757983

    2. Michaud T, Injury-Free Running Second Edition. (2021)

    3. Michaud T, The Positive Wink Sign: A New Diagnostic Test for Evaluating Toe Flexor Weakness. Accessed 11/5/2021 https://cdn.shopify.com/s/files/1/2565/7146/files/TheWinkSign4.21.pdf?v=1616159825

Brandon Steele

Dr. Steele is currently in private practice at Premier Rehab in the greater St. Louis area. He began his career with a post-graduate residency at The Central Institute for Human Performance. During this unique opportunity, he was able to create and implement rehabilitation programs for members of the St. Louis Cardinals, Rams, and Blues. Dr. Steele currently lectures extensively on evidence-based treatment of musculoskeletal disorders for the University of Bridgeport’s diplomate in orthopedics program. He serves on the executive board of the Illinois Chiropractic Society. He is also a Diplomate and Fellow of the Academy of Chiropractic Orthopedists (FACO).

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