Morphological and Functional Effects of a Foot Strengthening Protocol

Study Overview
=================
Brief Summary
-----------------
The principal aim of this study is to investigate the effects of a four-week foot strenghtening protocol combining active voluntary exercises and assisted-active voluntary exercises by neuromuscular electrical stimulation on hallux toe flexion strength in comparison to a standard foot strengthening protocol in a healthy adult recreational active population. The secondary objectives of the study are to investigate the effects of this protocol on lesser toes flexor strength, foot morphology deformation in one, two and three dimensions and kinetic parameters when walking and running.

Official Title
-----------------
Effects of a Foot Strengthening Protocol on Foot Strength, Foot Morphological Deformation and Kinetics Parameters : a Monocentric Randomized Controlled Trial

Conditions
-----------------
Foot Strength Deficit

Intervention / Treatment
-----------------
* Procedure: La Tour Hospital Foot Strengthening Protocol
* Procedure: Standard Literature Foot Strengthening Protocol


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: - Level of weekly physical activity (recreational activity and regular non-competitive runners : at least 1 running session per week) Exclusion Criteria: History of pain or episodes of foot or ankle sprains during the past 6 months; Foot or leg fractures during the past year; Severe deformity of the foot or leg; Self-declared disability due to neuromuscular impairment of the lower limbs; Neurological or vestibular deficit that could hinder balance (diabetes mellitus, radiculopathie lumbosacral, soft tissue disorder such as Marfan or Ehlers-Danlos syndrome) ; Any absolute contraindication to neuromuscular electrical stimulation (NMES) (cardiac pacemaker, epileptic disorders, pregnancy defibrillator); Participation in an exercise program specifically designed to strengthen the ankle or foot during the last 6 months

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomized Controlled Trial
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental group<br>The foot strengthening protocol will last 4 weeks with 2 sessions per week and is composed of 3 exercises targeting forefoot and midfoot region strength as well as enhancing plyometric capabilities of the foot complex. | Procedure: La Tour Hospital Foot Strengthening Protocol<br>* First exercise : NMES forward lean doming. Doming exercise assisted by NMES placed on the IFM. 8 sec of contraction (6 sec rest) moving the trunk forward. 12 repetitions, 3 sets. Progressive increase of the intensity of NEMS during 4 weeks and increase of body load while decreasing the number of repetitions. Second exercise : MTP joint flexion. Isometric MTP joint flexion contractions. 4 contractions of 5 sec (10 sec rest), 3 sets. Progressive increase of the number of MVIC during 4 weeks and of increase body load while keeping the same intensity. Third exercise : Foot-ankle rebound. Multiple jumps with only plantar flexion. Keeping the knee stiff and straight and pushing off the ground with only ankle and MTP plantar flexion by a forefoot contact with the ground. 10 seconds of jump (1 min of rest) during 5 sets. Progressive increase of body load while keeping the same intensity.<br>|
| Active Comparator: Control group<br>The standard literature foot strengthening protocol will last 4 weeks with 3 sessions per week and is composed of one exercise targeting the strength of the foot medial arch. | Procedure: Standard Literature Foot Strengthening Protocol<br>* During the 1st week, the participants will perform the Short foot exercise (SFE) during 3 series of 10 repetitions of 5 seconds of contractions in sitting position. 1 minute of rest will be give between series. During the 2nd week, the participants will perform the SFE during 3 series of 15 repetitions of 5 seconds of contractions in sitting position. 1 minute of rest will be give between series. During the 3rd week, the participants will perform the SFE during 3 series of 15 repetitions of 5 seconds of contractions in standing bipedal position. 1 minute of rest will be give between series. During the 4th week, the participants will perform the SFE during 3 series of 15 repetitions of 5 seconds of contractions in standing unipedal position. 1 minute of rest will be give between series. The progression of the exercise during the protocol will be based on passing from a sitting position to a unipedal standing position.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Hallux flexion strength | Hallux flexion strength will be assessed by a MicroFET2 Handheld Digital Dynamometer in hook lying position. The strength will be normalized by bodyweight (N/kg). | All measures will be collected on both feet 1 week prior the treatment and 1 week after the last intervention session | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Lesser toe flexion strength | Lesser toe flexion strength will be assessed by a MicroFET2 Handheld Digital Dynamometer in hook lying position. The strength will be normalized by bodyweight (N/kg). | All measures will be collected on both feet 1 week prior the treatment and 1 week after the last intervention session | 
| Change in Foot morphological deformation | Foot morphological deformation in 1, 2 and 3 dimensions will be assessed thanks to the Arch Height Index Measurement System (AHIMS, JAKTOOL Corporation, Cranberry, NJ) by measuring the change of the total foot length, foot width, truncated foot length, dorsal arch height, navicular height measurements in a sitting position (10% of bodyweight) to a standing position (95% of bodyweight). The percentage of loading during the measurement will be checked by performing the measurement of force platform. | All measures will be collected on both feet 1 week prior the treatment and 1 week after the last intervention session | 
| Change in Running and walking kinetics : Time parameters | Running kinetic parameters when walking and running will be assessed with an instrumented treadmill (Zebris FDM-THQ, ZebrisMedicalGmbH, Germany). The variables collected will be mean contact time (s), mean flight time (s), and the duration (s) on 7-foot regions (heel 1, heel 2, midfoot, forefoot 1, forefoot 2, forefoot 3, toes) will be assessed during 40 seconds of acquisition at self-selected speed during walking and running. | All measures will be collected on both feet 1 week prior the treatment and 1 week after the last intervention session | 
| Change in Running and walking kinetics : Force parameters | Running kinetic parameters when walking and running will be assessed with an instrumented treadmill (Zebris FDM-THQ, ZebrisMedicalGmbH, Germany). The variables collected will be mean vertical force (N) and peak force (N) on 7-foot regions (heel 1, heel 2, midfoot, forefoot 1, forefoot 2, forefoot 3, toes) during 40 seconds of acquisition at self-selected speed during walking and running. | All measures will be collected on both feet 1 week prior the treatment and 1 week after the last intervention session | 
| Change in Running and walking kinetics : Distance parameters | Running kinetic parameters when walking and running will be assessed with an instrumented treadmill (Zebris FDM-THQ, ZebrisMedicalGmbH, Germany). The variables collected will be step length (cm) and step width (cm) during 40 seconds of acquisition at self-selected speed during walking and running. | All measures will be collected on both feet 1 week prior the treatment and 1 week after the last intervention session | 
| Change in Running and walking kinetics : Stiffness parameter | Running kinetic parameters when walking and running will be assessed with an instrumented treadmill (Zebris FDM-THQ, ZebrisMedicalGmbH, Germany). The variable collected will be mean kleg (Kn/m) during 40 seconds of acquisition at self-selected speed during walking and running. | All measures will be collected on both feet 1 week prior the treatment and 1 week after the last intervention session | 
| Change in Running and walking kinetics : Frequency parameter | Running kinetic parameters when walking and running will be assessed with an instrumented treadmill (Zebris FDM-THQ, ZebrisMedicalGmbH, Germany). The variable collected will be step frequency (step/min) during 40 seconds of acquisition at self-selected speed during walking and running. | All measures will be collected on both feet 1 week prior the treatment and 1 week after the last intervention session | 
| Change in Running and walking kinetics : Pressure parameter | Running kinetic parameters when walking and running will be assessed with an instrumented treadmill (Zebris FDM-THQ, ZebrisMedicalGmbH, Germany). The variable collected will be the maximal pressure (N/cm²) on 7-foot regions (heel 1, heel 2, midfoot, forefoot 1, forefoot 2, forefoot 3, toes) during 40 seconds of acquisition at self-selected speed during walking and running. | All measures will be collected on both feet 1 week prior the treatment and 1 week after the last intervention session |