Morphological and Functional Effects of a Foot Strengthening Protocol

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

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.

Study Overview

• Status: Completed
• Conditions: Foot Strength Deficit
• Intervention / Treatment: Procedure: La Tour Hospital Foot Strengthening Protocol; Procedure: Standard Literature Foot Strengthening Protocol

• Study Type: Interventional
• Enrollment (Actual): 28
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Geneve
    • Meyrin, Geneve, Switzerland, 1217
      • Hopital de La Tour, Service de Physiothérapie

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 46 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental group; 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; 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.
Active Comparator: Control group; 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; 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.

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

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Evertor and invertor anke muscles strength	Evertor and invertor anke muscles strength will be assessed by a MicroFET2 Handheld Digital Dynamometer in supine position and with the ankle in neutral 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 Plantarflexor muscles strength	Plantarflexor strength will be assessed by using the Heel-Rise Test according to previous recommendations. The maximal repetitions will be keep for the analysis.	All measures will be collected on both feet 1 week prior the treatment and 1 week after the last intervention session

Collaborators and Investigators

• Sponsor: François Fourchet
• Investigators: Principal Investigator: François Fourchet, PhD, La Tour Hospital, Human Motion Lab

Publications and helpful links

General Publications

• Fraser JJ, Hertel J. Effects of a 4-Week Intrinsic Foot Muscle Exercise Program on Motor Function: A Preliminary Randomized Control Trial. J Sport Rehabil. 2019 May 1;28(4):339-349. doi: 10.1123/jsr.2017-0150. Epub 2018 Dec 4.
• Kim KM, Croy T, Hertel J, Saliba S. Effects of neuromuscular electrical stimulation after anterior cruciate ligament reconstruction on quadriceps strength, function, and patient-oriented outcomes: a systematic review. J Orthop Sports Phys Ther. 2010 Jul;40(7):383-91. doi: 10.2519/jospt.2010.3184.
• Namsawang J, Eungpinichpong W, Vichiansiri R, Rattanathongkom S. Effects of the Short Foot Exercise With Neuromuscular Electrical Stimulation on Navicular Height in Flexible Flatfoot in Thailand: A Randomized Controlled Trial. J Prev Med Public Health. 2019 Jul;52(4):250-257. doi: 10.3961/jpmph.19.072. Epub 2019 Jul 14.
• Taddei UT, Matias AB, Ribeiro FIA, Bus SA, Sacco ICN. Effects of a foot strengthening program on foot muscle morphology and running mechanics: A proof-of-concept, single-blind randomized controlled trial. Phys Ther Sport. 2020 Mar;42:107-115. doi: 10.1016/j.ptsp.2020.01.007. Epub 2020 Jan 13.
• McKeon PO, Hertel J, Bramble D, Davis I. The foot core system: a new paradigm for understanding intrinsic foot muscle function. Br J Sports Med. 2015 Mar;49(5):290. doi: 10.1136/bjsports-2013-092690. Epub 2014 Mar 21.
• Gooding TM, Feger MA, Hart JM, Hertel J. Intrinsic Foot Muscle Activation During Specific Exercises: A T2 Time Magnetic Resonance Imaging Study. J Athl Train. 2016 Aug;51(8):644-650. doi: 10.4085/1062-6050-51.10.07. Epub 2016 Oct 3.
• Fourchet F, Kuitunen S, Girard O, Beard AJ, Millet GP. Effects of Combined Foot/Ankle Electromyostimulation and Resistance Training on the In-Shoe Plantar Pressure Patterns during Sprint in Young Athletes. J Sports Sci Med. 2011 Jun 1;10(2):292-300. eCollection 2011.
• Gaillet JC, Biraud JC, Bessou M, Bessou P. Modifications of baropodograms after transcutaneous electric stimulation of the abductor hallucis muscle in humans standing erect. Clin Biomech (Bristol, Avon). 2004 Dec;19(10):1066-9. doi: 10.1016/j.clinbiomech.2004.03.005.
• Fiolkowski P, Brunt D, Bishop M, Woo R, Horodyski M. Intrinsic pedal musculature support of the medial longitudinal arch: an electromyography study. J Foot Ankle Surg. 2003 Nov-Dec;42(6):327-33. doi: 10.1053/j.jfas.2003.10.003.
• Soysa A, Hiller C, Refshauge K, Burns J. Importance and challenges of measuring intrinsic foot muscle strength. J Foot Ankle Res. 2012 Nov 26;5(1):29. doi: 10.1186/1757-1146-5-29.
• Kelly LA, Kuitunen S, Racinais S, Cresswell AG. Recruitment of the plantar intrinsic foot muscles with increasing postural demand. Clin Biomech (Bristol, Avon). 2012 Jan;27(1):46-51. doi: 10.1016/j.clinbiomech.2011.07.013. Epub 2011 Aug 23.
• Kelly LA, Lichtwark G, Cresswell AG. Active regulation of longitudinal arch compression and recoil during walking and running. J R Soc Interface. 2015 Jan 6;12(102):20141076. doi: 10.1098/rsif.2014.1076.
• Kelly LA, Farris DJ, Lichtwark GA, Cresswell AG. The Influence of Foot-Strike Technique on the Neuromechanical Function of the Foot. Med Sci Sports Exerc. 2018 Jan;50(1):98-108. doi: 10.1249/MSS.0000000000001420.

Study record dates

Study Major Dates

• Study Start (Actual): January 3, 2022
• Primary Completion (Actual): February 11, 2022
• Study Completion (Actual): February 11, 2022

Study Registration Dates

• First Submitted: December 14, 2021
• First Submitted That Met QC Criteria: January 27, 2022
• First Posted (Actual): January 31, 2022

Study Record Updates

• Last Update Posted (Actual): April 20, 2022
• Last Update Submitted That Met QC Criteria: April 19, 2022
• Last Verified: April 1, 2022

More Information

Terms related to this study

• Other Study ID Numbers: 2021-D0041

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

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