The Acute Effect of Isotonic Versus Isometric Exercise Versus Walking on Pain in Individuals With Plantar Fasciopathy

The Acute Effect of Isotonic Versus Isometric Exercise Versus Walking on Pain in Individuals With Plantar Fasciopathy: a Randomised, Participant-blinded, Cross-over Trial

This study investigates the acute effect of isotonic versus isometric exercise versus walking on pain in individuals with plantar heel pain and an ultrasound-diagnosed plantar fasciopathy. The hypothesis is that isometric exercise will induce greater participant rated pain relief than isotonic exercise and walking during aggravating activity.

Study Overview

• Status: Completed
• Conditions: Plantar Fasciopathy
• Intervention / Treatment: Other: Isometric exercise; Other: Isotonic exercise; Other: Walking

Detailed Description

Participants will be required to attend three sessions (isometric, isotonic, or walking) within a maximum of two weeks. The order in which the participant completes the sessions will be randomised.There will be a minimum of 48 hours between sessions. To account for potential time of day differences in terms of pain, all sessions will be performed within ±1 hour (e.g. if the first session is performed at 10 AM the remaining two sessions will be performed between 9 and 11 AM). After diagnosis, randomisation of the order of which the sessions will be performed, and have their pain during an aggravating activity examined (aggravating activities will be static stance, half squat or heel raise). Subsequently the participants will be instructed in performing either isotonic or isometric heel raise or walking, (determined according to the randomisation) by a physiotherapist.

All statistical analyses will be performed according to a pre-established analysis plan using STATA ver. 14. The assumption of negligible carryover effects is investigated with a preliminary test. The primary analysis will test the presence of a difference in EIH between isotonic and isometric exercise and walking and a 3 X 2 repeated measures ANOVA will be performed. Independent factors will be exercise type (isometric vs. isotonic vs. walking) and time (pre vs. post). If an interaction is found, post-hoc paired t-tests will be performed. The standardised mean difference (effect size) and its confidence intervals will be calculated and presented in a forest plot. Apriori it has been determined that no conclusions will be made favouring either of the exercises nor walking if pain is reduced less than the clinically important difference of 19 mm VAS. In addition, the proportion of clinically relevant pain reductions (i.e. a pain reduction of at least 19 mm VAS) will be calculated. EIH by pain experienced during the aggravating activity before the exercises and walking will also be presented in a plot.

Secondary analyses using a 3 X 2 repeated measures ANOVAs will test if there is a difference in the thickness of the plantar fascia and a difference in PPTs from before to after either of the exercises or walking and a difference in pain experienced during the exercises or walking. If interactions are found post-hoc paired t-tests will be performed. A paired t-test will be performed to investigate potential differences in plantar fascia thickness from before to after the initial PPT and pain aggravating activity are performed. Effect sizes will be calculated for the difference in pressure pain threshold and plantar fascia thickness. The association between thickness of the plantar fascia and the difference in pain from before to after the exercise activities will be investigated using Pearson's correlation coefficient.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Aalborg East, Denmark, 9220
    • Research unit for general practice

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• History of inferior heel pain for at least three months before enrolment
• Pain on palpation of the medial calcaneal tubercle or the proximal plantar fascia
• Thickness of the plantar fascia of 4.0 mm or greater
• Pain during at least one of three pain aggravating activities (static stance, half squat and heel raise)
• Mean heel pain of ≥ 20 mm on a 100 mm VAS [0mm = no pain, 100mm = worst pain imaginable] during the past week

Exclusion Criteria:

• Below 18 years of age
• History of inflammatory systemic diseases
• Pain or stiffness in the 1st metatarsophalangeal joint to an extent where the exercises cannot be performed
• Prior heel surgery
• Pregnancy
• Pain medication
• Corticosteroid injection for plantar fasciopathy within the past six months

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Isometric exercise	Other: Isometric exercise; The isometric exercise is performed standing with the forefoot on a step. The participant is instructed to stand still with the ankle joint in neutral and hold this position. Supporting oneself for balance by placing the hands on a wall or a rail is allowed. The participant performs 5 sets of 45-second isometric holds. The load used is the heaviest possible load that the participant is able to withstand for 1 minute. As with the isotonic exercise, if the participant's body weight is inadequate the participant is fitted with a backpack with books and/or weights.
Active Comparator: Isotonic exercise	Other: Isotonic exercise; The isotonic exercise is performed standing with the forefoot on a step. The toes are maximally dorsi-flexed by placing a towel underneath them. The participant is instructed to perform a heel-raise to a maximal plantar flexion in the ankle joint, and afterwards to lower the heel to maximal dorsi flexion. Supporting oneself for balance by placing the hands on a wall or a rail is allowed. The participant performs 4 sets of 8 repetitions with a load of 8RM. The contraction time is 3s concentric, 2s isometric and 3s eccentric and will be guided by a metronome. If the participant's body weight is inadequate to reach sufficient loading during the exercises the participant is fitted with a backpack with books and/or weights.
Active Comparator: Walking	Other: Walking; The walking will be performed barefoot and the participant will be instructed in walking at a pace similar to the pace they would use when walking around in their home. The duration of the walking session will be four minutes to match the duration during the exercises.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in pain	This is measured during an aggravating task on a 100 mm VAS, where 0 mm is no pain and 100 mm is worst pain imaginable and is also referred to as exercise-induced hypoalgesia (EIH)	Immediately before and after each exercise/walking

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in pressure pain threshold	Measured on the tenderest spot under the heel by an algometer in kPa	Immediately before and after each exercise/walking
Change in thickness of the plantar fascia	Measured by ultrasonography in mm	Immediately before and after each exercise/walking
Pain	Measured on a 100 mm VAS, where 0 mm is no pain and 100 mm is worst pain imaginable.	During each exercise/walking

Collaborators and Investigators

• Sponsor: Aalborg University
• Investigators: Principal Investigator: Henrik Riel, M.Sc., Research Unit for General Practice in Aalborg, Department of Clinical Medicine, Aalborg University

Publications and helpful links

General Publications

• Riel H, Vicenzino B, Jensen MB, Olesen JL, Holden S, Rathleff MS. The effect of isometric exercise on pain in individuals with plantar fasciopathy: A randomized crossover trial. Scand J Med Sci Sports. 2018 Dec;28(12):2643-2650. doi: 10.1111/sms.13296. Epub 2018 Oct 1.

Study record dates

Study Major Dates

• Study Start (Actual): August 24, 2017
• Primary Completion (Actual): October 3, 2017
• Study Completion (Actual): October 3, 2017

Study Registration Dates

• First Submitted: August 15, 2017
• First Submitted That Met QC Criteria: August 28, 2017
• First Posted (Actual): August 29, 2017

Study Record Updates

• Last Update Posted (Actual): October 5, 2017
• Last Update Submitted That Met QC Criteria: October 4, 2017
• Last Verified: October 1, 2017

More Information

Terms related to this study

• Keywords: plantar heel pain
• Other Study ID Numbers: N-20170021

Drug and device information, study documents

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