Effect of a Foot Muscle Strengthening Program in Mobile Older Adults Adults (STIFF3)

Background of the study:

Falling is highly prevalent among older adults and has serious societal impact. Falls occur mainly during walking as a result of altered gait and/or the inability to maintain balance. The plantar intrinsic foot muscles (PIFM) have a role in these dynamic functions. When these muscles atrophy, as happens with advancing age, strengthening these muscles may be beneficial in order to improve or retain gait performance.

Objective of the study:

To investigate the effect of adding PIFM strengthening exercises to fall prevention programs compared to fall prevention programs alone on maximum gait speed in mobile older adults. The secondary objective is to also investigate the effect on: foot muscles' size, foot function during gait, balance during gait, discomfort during or after the training, self-reported mobility limitations, physical activity level, fall incidents during the intervention, fear of falling, foot plantar pressure during gait, static balance, toe flexor strength, physical functioning, foot morphology, foot posture.

Study design:

An investigator-blinded parallel randomized controlled trial (RCT), with a 12-week PIFM strengthening intervention period and pre- and post-intervention laboratory measurements.

Study population:

Older adults (>65 years) who are free of any known condition or disease that interferes with the execution of the exercise program.

Intervention:

Both the control and the intervention group continue with the regular exercise therapy to prevent falling. On top of this, the intervention group is delivered a 12-weeks exercise program consisting of foot strengthening exercises prescribed for 5 daily sessions a week, of which 1 supervised, 20 minutes per session.

Primary study parameters/outcome of the study:

The post-intervention difference between the intervention and control group in maximum gait speed.

Secondary study parameters/outcome of the study:

The post-intervention difference between the intervention and control group in foot muscles' size, foot function during gait, balance during gait, discomfort during or after the training, self-reported mobility limitations, physical activity level, fall incidents during the intervention, fear of falling, foot plantar pressure during gait, static balance, toe flexor strength, physical functioning, foot morphology, foot posture.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness:

The burden for the participant consists mainly of 1) the time spent and effort put in engaging in the exercise therapy, 2) any discomfort (e.g., fatigue) or pain (e.g., cramp, muscle soreness) during or after the exercises, 3) the time that is spent on the measurement occasions (home visits: 1 x 1 hour (+ 1 x 30 minutes for the intervention group); laboratory: 2 x 3 hours), 4) the necessity of travelling to the motion analysis laboratory, 5) the inconvenience of wearing the activity monitor attached to the skin of the thigh for 7 days, and 6) questionnaires may unintentionally make the subject aware of declined health conditions.

Study Overview

• Status: Terminated
• Conditions: Fall Risk
• Intervention / Treatment: Other: Foot strengthening training

• Study Type: Interventional
• Enrollment (Actual): 34
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Netherlands
  • Eindhoven, Netherlands
    • Fontys Hogeschool

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years and older (Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• be 65 years of age or over;
• be able to ambulate 10 meter without using a walking aid;
• engage in a functional exercise program delivered to a group of older adults by an educated or certified physical therapist or trainer (e.g., fall preventive exercise program, senior fit programs);
• report to have 1) fear of falling OR 2) experienced a fall in the previous 12 months OR 3) difficulties with mobility, gait, or balance;
• be able to arrange their own transport to the movement analysis laboratory.

Exclusion Criteria::

• The respondent is a minor or legally incompetent adult;
• Self-reported presence of any disorder interfering with the execution of the exercises.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Foot strengthening training; 12-week foot strengthening training in addition to an already joined functional exercise program. The foot strengthening training is supervised and progressing and consists of isolated and functional exercises. Participants keep a training diary.	Other: Foot strengthening training; a 12-weeks exercise program consisting of foot strengthening exercises prescribed for 5 daily sessions a week, of which 1 supervised, 20 minutes per session on top of the regular exercise therapy to prevent falling
No Intervention: Control; The control group continues the functional exercise program as usual. The subjects in this group are asked to keep a diary in which the subjects weekly report other physical activities, fall incidents and mobility related discomfort. The trainer calls the participants in the control group every week to pay attention to these topics.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum gait speed	The post-intervention difference between the intervention and control group in maximum gait speed.	12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Foot muscles' morphology derived from ultrasound imaging		12 weeks
Lower extremity biomechanics during gait assessed with 3D motion and ground reaction force capturing		12 weeks
Spatiotemporal gait parameters assessed with 3D motion and ground reaction force capturing		12 weeks
Balance during gait assessed with 3D motion and ground reaction force capturing		12 weeks
Self-reported mobility limitations		12 weeks
Weekly time spent in physical activities	in bouts of at least 10 minutes duration that is experienced by the participant at least as moderate intense (≥5 on a 10-point scale of how hard one feel he or she is exercising). From this it is deduced whether the participant meets the WHO recommendation on aerobic physical activity for health	12 weeks
Fall incidents during the intervention		12 weeks
Fear of falling assessed by the (Falls Efficacy Scale-International) FES-I questionnaire		12 weeks
Foot plantar pressure during gait assessed by a 2-meter pressure plate		12 weeks
Static balance assessed by a force plate during single leg stance		12 weeks
Isometric toe flexor strength assessed by a pressure plate during maximal toe press		12 weeks
Physical functioning assessed by the Short Physical Performance Battery (SPPB)		12 weeks
Foot arch characteristics assessed by a 3D foot scanner		12 weeks
Health related quality of life assessed by SF-36		12 weeks

Collaborators and Investigators

• Sponsor: Lydia Willemse
• Collaborators: KU Leuven; Tilburg University; Fontys University of Applied Sciences

Study record dates

Study Major Dates

• Study Start (Actual): November 8, 2022
• Primary Completion (Actual): July 18, 2024
• Study Completion (Actual): July 18, 2024

Study Registration Dates

• First Submitted: July 26, 2022
• First Submitted That Met QC Criteria: September 5, 2022
• First Posted (Actual): September 7, 2022

Study Record Updates

• Last Update Posted (Actual): June 6, 2025
• Last Update Submitted That Met QC Criteria: June 3, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: older adults; mobility; falling; foot exercises
• Other Study ID Numbers: STIFF 3

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Re-use of the data will be on request and on condition that all Principle Investigators agree and provided the requirements of the ethical committee are met

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No