The Effect of Foot Core Exercises or Foot Orthotics in Symptomatic Flexible Flatfoot

NCT05840965 | Completed

• 2 other identifiers: B3222022001031S67036
• Study Type: interventional
• Target: 48
• Locations: 1 country
• Sites: 1

Brief Summary

The overall goal of this study is to evaluate the effect of a foot strengthening program (focused on the intrinsic foot muscles) on ankle and foot joint kinematics and kinetics (rearfoot, midfoot, and forefoot) in patients with symptomatic flexible flat feet. The investigators will also evaluate the effect on intrinsic muscle morphology, foot strength, pain and other symptoms. The investigators will compare to the standard conservative therapy, which is foot orthotic therapy.

Conditions

Flatfoot, Flexible

Keywords

Multi segment foot kinetics; Multi segment foot kinematics; Intrinsic foot muscles; Ultrasound

Outcome Measures

Primary Outcomes (5)

• Change in lower limb joint angles (degrees)

  Joint angles will be measured based on the position of passive markers placed on participants' anatomical landmarks all over the lower limbs. The position of those markers will be tracked by 10 infrared high-speed cameras that surround the walkway (sampled at 100 Hertz (Hz) - type T-10, 1 megapixel, captures 10-bit grayscale using 1120 \* 896 pixels, Vicon Motion System Ltd, Oxford, Metrics, UK). The angular positions of the multiple joints that constitute the lower limb (hip, knee, ankle, chopart, lisfranc and metatarsophalangeal) will be assessed during walking, running, and single leg drop jump in the gait laboratory.

  8-week intervention period

• Change in lower limb joint angular velocities (degrees/second)

  Joint angular velocities are also assessed based on reflexive markers placed on anatomical landmarks. This outcome evaluates the rate of change of a certain joint angle over time. Joint angular velocities will be assessed of the multiple joints that constitute the lower limb (hip, knee, ankle, chopart, lisfranc and metatarsophalangeal) during walking, running and a single leg drop jump in the gait laboratory.

  8-week intervention period

• Change in joint moments

  Joint moments will be determined by coupling kinematic data (joint position and velocities) with plantar pressure data from a specially designed pressure plate (sampled at 200Hz, Footscan, dimension 0.5m x 0.4m, 4096 sensors, 2.8 sensors/cm², RsScan International, Olen, Belgium) embedded in the middle of the runway and placed on top of a force plate (sampled at 1000Hz, Advanced Mechanical Technology Inc., Watertown, MA, USA). Kinetic data will be assessed while walking, running and a single leg drop jump in the gait laboratory.

  8-week intervention period

• Change in foot muscle thickness

  The thickness of five intrinsic foot muscles (abductor hallucis, flexor digitorum brevis, flexor hallucis, quadratus plantae and abductor digiti minimi) and three extrinsic foot muscles (peronei, tibialis anterior and flexor digitorum longus) will be measured on images obtained using ultrasonography. To obtain those images, the investigators will scan the muscles in a longitudinal view.

  8-week intervention period

• Change in foot muscle cross-sectional area

  The area of five intrinsic foot muscles (abductor hallucis, flexor digitorum brevis, flexor hallucis, quadratus plantae and abductor digiti minimi) and two extrinsic foot muscles (peronei and flexor digitorum longus) will be measured on images obtained using ultrasonography. To obtain those images, the investigators will scan the muscles in a transversal view.

  8-week intervention period

Secondary Outcomes (5)

• Change in foot muscle strength

  8-week intervention period

• Change in foot Posture Index

  8-week intervention period

• Change in navicular drop

  8-week intervention period

• Change in the OSPRO-YF questionnaire

  8-week intervention period

• Change in the FAOS questionnaire

  8-week intervention period

Study Arms (3)

Asymptomatic flexible flatfoot

NO INTERVENTION

This group undergoes no intervention.

Symptomatic flexible flatfoot: foot core strengthening

EXPERIMENTAL

The investigators put together a specific training program emphasizing the neuromuscular recruitment of the plantar intrinsic foot muscles. This will be colloquially referred to as the "Foot Core Strengthening Program". The most recognized exercise of our program is the short foot exercise. However, as recently other exercises were validated by Gooding et al., we also included following exercises: toe spread out, first-toe extension and second- to fifth-toes extension. Simultaneously, neuromuscular electrical stimulation (NMES) will be provided, as 77% of healthy active people struggle performing contractions of the foot muscles.

Other: Foot muscle strengthening

Symptomatic flexible flatfoot: foot orthotics

ACTIVE COMPARATOR

Custom-made foot orthotics are the current standard of care (SOC) therapy within this population. Patients choose their own health care provider to customize these orthotics. The sole is made of EVA material whose color and hardness is determined by the podiatrist or bandage maker. Digital scans or plaster of Paris cast will be taken of the participant's non-weightbearing foot (placed in a neutral or corrected position) by a certified pedorthist following the prescription of the orthopaedic surgeon. The geometry of the foot orthotic will encompass a total contact principle with respect to the medial arch. The orthotics will be manufactured using ethyl vinyl acetate (EVA) with a shore ranging between 45 and 60

Other: Foot orthotics

Interventions

Foot muscle strengthening OTHER

A specific training program emphasizing the neuromuscular recruitment of the plantar intrinsic foot muscles. This will be colloquially referred to as the "Foot Core Strengthening Program". The exercises are: short foot exercise, toe spread out, first toe extension, second to fifth toe extension. Simultaneously, neuromuscular electrical stimulation (NMES) will be provided, as 77% of healthy active people struggle performing contractions of the foot muscles.

Symptomatic flexible flatfoot: foot core strengthening

Foot orthotics OTHER

Custom-made foot orthotics

Symptomatic flexible flatfoot: foot orthotics

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• For both asymptomatic and symptomatic flexible flatfoot:
• Adults between 18 and 65 years of age, able to run at a self- selected low speed.
• Physically active: min. 1h30 and max 6 h/week
• Foot Posture Index \> 6 AND Navicular drop \> 5 mm
• Informed consent (ICF) obtained
• For asymptomatic flexible flatfoot:
• cfr. supra
• For symptomatic flexible flatfoot:
• Diagnosis made by a physician
• ICF obtained
• Symptomatic =
• Foot pain ( \> 4 on Visual Analog Pain Scale score) OR
• Medial arch pain OR
• Metatarsalgia (general or diffuse hyperkeratosis accepted) OR
• Lateral impingement pain OR

You may not qualify if:

• For both groups:
• \< 18 years, \> 65 years
• Any medical contraindication to physical exertion
• Systemic diseases
• Recent lower limb surgery (\< 6 months)
• Lower limb osteosynthesis material
• Pregnancy
• Pacemaker
• Leg length discrepancy \> 3 cm
• Body Mass Index (BMI) \> 30kg/m²
• Constant ankle pain
• Ankle fractures
• Single hyperkeratotic lesion with nucleus under metatarsal head
• Recent participation in a physical rehabilitation program (\< 3 months)
• Recent orthotics (\< 3 months)

Sponsors & Collaborators

• KU Leuven: lead

Study Sites (1)

KU Leuven

Bruges, West Flanders, 8200, Belgium

Location

MeSH Terms

Conditions

Flatfoot

Condition Hierarchy (Ancestors)

Talipes; Foot Deformities, Acquired; Foot Deformities; Musculoskeletal Diseases; Foot Deformities, Congenital; Lower Extremity Deformities, Congenital; Limb Deformities, Congenital; Musculoskeletal Abnormalities; Congenital Abnormalities; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Study Officials

• Kevin Deschamps, PhD, Pod

  Musculoskeletal Rehabilitation Research Group, Department of Rehabilitation Sciences, KU Leuven

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: The data will be coded (pseudonymization). The subject's name or other identifiers will be stored separately from their research data and replaced with a unique code to create a new identity for the subject. The outcomes assessor will be blind for participants' injury status for the following : * while conducting kinematic and kinetic data processing, * while performing muscle size measurements on the ultrasound images, * while performing statistical analysis (for all outcomes) There will be no blinding while scoring the following outcomes (because these scores are immediately determined in the presence of the participant) : * Foot muscle strength * Foot posture index * Navicular drop
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Physiotherapist, Master of Science

Model Details: Prospective monocentric randomised controlled trial with an asymptomatic control group.

Study Record Dates

• First Submitted: March 3, 2023
• First Posted: May 3, 2023
• Study Start: June 1, 2023
• Primary Completion: December 1, 2024
• Study Completion: December 30, 2024
• Last Updated: February 19, 2025

Record last verified: 2025-02

Data Sharing

• IPD Sharing: Will not share

Locations

BE (1)