The Therapeutic Effect of Targeted Intrinsic Foot Muscles Exercises in Plantar Fasciitis

A reduction of intrinsic foot muscle sizes has been identified in patients with chronic plantar fasciitis. Weaker intrinsic foot muscles has been suggested to decrease the medial longitudinal arch height and subsequently increase extra tensile stress in the plantar fascia, resulting in the chronicity of the condition. Therefore, it is speculated that atrophic intrinsic foot muscles may be a significant risk factor of developing chronic plantar fasciitis. The purpose of this study is to investigate the effect of an 8-week targeted intrinsic foot muscles exercise regimen on the intrinsic foot muscle size, symptomatic relief, and foot function improvement in long-distance runners with chronic plantar fasciitis.

Study Overview

• Status: Recruiting
• Conditions: Pain; Plantar Fasciitis, Chronic
• Intervention / Treatment: Other: targeted intrinsic foot muscle exercises

Detailed Description

Distance runners are defined as running with more than 20km per week for more than 2 years. All recruited participants have > 1 year of plantar fasciitis. The diagnosis were made based on clinical symptoms and the thickness of plantar fasciitis > 4.0mm at the medial tubercle of heel by ultrasound imaging.

Arm 1: The purpose of this arm of the study is to determine if a 8-week targeted foot muscle exercise regimen, instructed with real-time ultrasound, affect the intrinsic foot muscle size, symptomatic relief, and foot function improvement of distance runners with plantar fasciitis. 32 participants will be recruited in this arm.

Arm 2: This group will not engage in any training, but will serve as a comparator for the intervention arm.

• Study Type: Interventional
• Enrollment (Anticipated): 64
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Hong Kong
  • Sha Tin, Hong Kong
    • Recruiting
    • CUHK-ORT Sports Injury Research Laboratory
    • Contact: On Yue LAU, Phd candidate; Email: fannielauoy@link.cuhk.edu.hk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 56 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. A weekly mileage of at least 20km
2. Have running experience of at least 2 years prior to the experiment

3. if they reported tenderness on palpation of the medial calcaneal tuberosity and exhibited one of the following complaints:

   • Plantar heel pain > 1 year
   • Pain on visual analog scale of equal to or greater than 4 out of 10
   • pain on the first step in the morning or after prolonged sitting,
   • pain on prolonged standing and/or walking
   • pain when running

Exclusion Criteria:

1. Contraindications to MRI scans
2. had undergone surgery to the plantar fascia or
3. local steroid injection within the last 3 months or

4. Any of the following conditions:

   • systemic arthritis,
   • neurologic conditions
   • any coexisting painful musculoskeletal condition of the lower limb.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Targeted intrinsic foot muscles exercise regimen; 4 targeted intrinsic foot exercise will be performed at least 5 times per week, once in the laboratory, and four times at home. The participants will be followed up weekly at the laboratory visit. The real-time ultrasound imaging of intrinsic foot muscles will be used as guided visual biofeedback to instruct all participants to execute all exercise movement in a correct manner. If the participant misses a session, he/she is expected to replace the lost session within the same week.	Other: targeted intrinsic foot muscle exercises; 4 targeted intrinsic foot muscle exercises
No Intervention: Control; continue normal physical activity,

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
muscle thickness (MT) of Abductor Hallucis (AbH), Flexor hallucis brevis (FHB), Flexor digitorum brevis (FDB), quadratus plantae (QP)	ultrasound measurement	baseline
muscle thickness (MT) of Abductor Hallucis (AbH), Flexor hallucis brevis (FHB), Flexor digitorum brevis (FDB), quadratus plantae (QP)	ultrasound measurement	week 4
muscle thickness (MT) of Abductor Hallucis (AbH), Flexor hallucis brevis (FHB), Flexor digitorum brevis (FDB), quadratus plantae (QP)	ultrasound measurement	week 8
muscle thickness (MT) of Abductor Hallucis (AbH), Flexor hallucis brevis (FHB), Flexor digitorum brevis (FDB), quadratus plantae (QP)	ultrasound measurement	week 12
cross sectional area (CSA) of Abductor Hallucis (AbH), Flexor hallucis brevis (FHB), Flexor digitorum brevis (FDB), quadratus plantae (QP)	ultrasound measurement	Baseline
cross sectional area (CSA) of Abductor Hallucis (AbH), Flexor hallucis brevis (FHB), Flexor digitorum brevis (FDB), quadratus plantae (QP)	ultrasound measurement	week 4
cross sectional area (CSA) of Abductor Hallucis (AbH), Flexor hallucis brevis (FHB), Flexor digitorum brevis (FDB), quadratus plantae (QP)	ultrasound measurement	week 8
cross sectional area (CSA) of Abductor Hallucis (AbH), Flexor hallucis brevis (FHB), Flexor digitorum brevis (FDB), quadratus plantae (QP)	ultrasound measurement	week 12
Visual Analog Scale (VAS) pain at first steps in the morning	measuring 100 mm in length marked from 0 (absence of pain) to 100 mm (worst imaginable pain)	baseline
Visual Analog Scale (VAS) pain at first steps in the morning	measuring 100 mm in length marked from 0 (absence of pain) to 100 mm (worst imaginable pain)	week 4
Visual Analog Scale (VAS) pain at first steps in the morning	measuring 100 mm in length marked from 0 (absence of pain) to 100 mm (worst imaginable pain)	week 8
Visual Analog Scale (VAS) pain at first steps in the morning	measuring 100 mm in length marked from 0 (absence of pain) to 100 mm (worst imaginable pain)	week 12
Visual Analog Scale (VAS) worst pain of the day	measuring 100 mm in length marked from 0 (absence of pain) to 100 mm (worst imaginable pain)	baseline
Visual Analog Scale (VAS) worst pain of the day	measuring 100 mm in length marked from 0 (absence of pain) to 100 mm (worst imaginable pain)	4
Visual Analog Scale (VAS) worst pain of the day	measuring 100 mm in length marked from 0 (absence of pain) to 100 mm (worst imaginable pain)	8
Visual Analog Scale (VAS) worst pain of the day	measuring 100 mm in length marked from 0 (absence of pain) to 100 mm (worst imaginable pain)	12
Foot and Ankle Ability Measure (FAAM)	Higher scores represent higher levels of function, with 100% representing no dysfunction.	baseline
Foot and Ankle Ability Measure (FAAM)	Higher scores represent higher levels of function, with 100% representing no dysfunction.	week 4
Foot and Ankle Ability Measure (FAAM)	Higher scores represent higher levels of function, with 100% representing no dysfunction.	week 8
Foot and Ankle Ability Measure (FAAM)	Higher scores represent higher levels of function, with 100% representing no dysfunction.	week 12
Foot posture index	Pronated postures are given a positive value, the higher the value the more pronated. Supinated features are given a negative value, the more negative the value the more supinated. For a neutral foot the final score should lie somewhere around zero	baseline
Foot posture index	Pronated postures are given a positive value, the higher the value the more pronated. Supinated features are given a negative value, the more negative the value the more supinated. For a neutral foot the final score should lie somewhere around zero	week 4
Foot posture index	Pronated postures are given a positive value, the higher the value the more pronated. Supinated features are given a negative value, the more negative the value the more supinated. For a neutral foot the final score should lie somewhere around zero	week 8
Foot posture index	Pronated postures are given a positive value, the higher the value the more pronated. Supinated features are given a negative value, the more negative the value the more supinated. For a neutral foot the final score should lie somewhere around zero	week 12
Navicular Drop test	Supinated foot (<5mm); Neutral foot (5-9mm); pronated foot (>9mm)	baseline
Navicular Drop test	Supinated foot (<5mm); Neutral foot (5-9mm); pronated foot (>9mm)	week 4
Navicular Drop test	Supinated foot (<5mm); Neutral foot (5-9mm); pronated foot (>9mm)	week 8
Navicular Drop test	Supinated foot (<5mm); Neutral foot (5-9mm); pronated foot (>9mm)	week 12

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postural control	three 10-seconds eyes opened trials and three 10-seconds eyes closed trials with single-leg stance	baseline
Postural control	three 10-seconds eyes opened trials and three 10-seconds eyes closed trials with single-leg stance	week 4
Postural control	three 10-seconds eyes opened trials and three 10-seconds eyes closed trials with single-leg stance	week 8
Postural control	three 10-seconds eyes opened trials and three 10-seconds eyes closed trials with single-leg stance	week 12

Collaborators and Investigators

• Sponsor: Chinese University of Hong Kong

Study record dates

Study Major Dates

• Study Start (Anticipated): August 30, 2022
• Primary Completion (Anticipated): March 30, 2023
• Study Completion (Anticipated): August 30, 2023

Study Registration Dates

• First Submitted: July 7, 2022
• First Submitted That Met QC Criteria: July 8, 2022
• First Posted (Actual): July 13, 2022

Study Record Updates

• Last Update Posted (Actual): July 13, 2022
• Last Update Submitted That Met QC Criteria: July 8, 2022
• Last Verified: July 1, 2022

More Information

Terms related to this study

• Keywords: training; Strengthening; intrinsic foot muscle
• Additional Relevant MeSH Terms: Foot Diseases; Musculoskeletal Diseases; Fasciitis; Fasciitis, Plantar
• Other Study ID Numbers: IFM exercise PF

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No