Ankle vs. Hip vs. Combined Strengthening in Chronic Ankle Instability

NCT07606534 | Recruiting

• 1 other identifier: 2025-400
• Study Type: interventional
• Target: 45
• Locations: 1 country
• Sites: 1

Brief Summary

Chronic ankle instability (CAI) is a common condition that can develop after a lateral ankle sprain. Up to 40% of people who sprain their ankle experience a recurrence within a year, and as many as 30% develop persistent symptoms such as ankle "giving way," weakness, or instability. These symptoms can limit daily activities, sports participation, and increase the risk of future sprains. Muscle weakness in both the ankle and hip has been identified as an important factor contributing to CAI. Strengthening these muscles may therefore help improve stability and function. The SHAC study is a randomized controlled trial designed to compare three different strengthening programs in people with chronic ankle instability: (1) an ankle-focused strengthening program, (2) a hip-focused strengthening program, and (3) a combined ankle-hip strengthening program. The goal is to determine which approach leads to the greatest improvement in functional ability, muscle strength, balance, and ankle mobility. A total of 45 participants aged 18 to 35 years with documented chronic ankle instability will be recruited from local sports clubs and the University of Liège. All participants must have a history of at least one ankle sprain that occurred more than 12 months before entering the study, report episodes of ankle instability in the previous six months, and meet specific questionnaire criteria (CAIT \< 24 and FAAM Sport \< 80%). People with recent injuries, previous lower-limb surgery, fractures requiring realignment, neuromuscular conditions, or current pain or swelling will not be able to participate. After the first assessment (T1), participants will be randomly assigned to one of the three groups. Each intervention lasts four weeks and includes three supervised sessions per week. All strengthening exercises are isometric, performed using a handheld dynamometer to measure force accurately. The ankle program includes plantarflexion, dorsiflexion, inversion, and eversion exercises. The hip program includes clamshells, hip external rotation, abduction, and extension. The combined group alternates between hip and ankle exercises. A warm-up and standardized familiarization are performed before each session. All participants will attend two additional assessment sessions: one immediately after the four-week program (T2) and one at a later follow-up time point (T3). During each visit, they will complete functional questionnaires, report their sports participation, and undergo several strength and performance tests. These include hip and ankle muscle strength measurements using a dynamometer, the Heel Rise Test, the modified Y-Balance Test, the Side Hop Test, and a dorsiflexion mobility test. The study aims to identify whether one of the strengthening approaches leads to better functional outcomes for individuals with chronic ankle instability. Understanding these effects may help clinicians design more effective rehabilitation programs for people recovering from ankle sprains and for those experiencing ongoing instability. Participant data will be kept confidential and stored securely in anonymized form for 20 years. Participation is voluntary, and individuals may withdraw at any time without consequences. Results will be presented anonymously in scientific publications and conferences.

Conditions

Chronic Ankle Instability, CAI; Ankle Sprain

Keywords

chronic ankle instability; Ankle strengthening; Hip strengthening; Isometric exercise; Physiotherapy; Rehabilitation; Randomized controlled trial

Outcome Measures

Primary Outcomes (1)

• Cumberland Ankle Instability Tool (CAIT)

  The Cumberland Ankle Instability Tool (CAIT) is a validated patient-reported outcome measure assessing perceived ankle instability. Scores range from 0 to 30, with lower scores indicating greater perceived instability. Change in CAIT score over time will be compared between intervention groups.

  Baseline and week 4 (end of intervention)

Secondary Outcomes (7)

• Foot and Ankle Ability Measure (FAAM) - Sport Subscale

  Baseline, week 4 (end of intervention), and week 8 (follow-up)

• Hip Muscle Strength

  Baseline, week 4 (end of intervention), and week 8 (follow-up)

• Ankle Muscle Strength

  Baseline, week 4 (end of intervention), and week 8 (follow-up)

• Dynamic Postural Balance (Y Balance Test)

  Baseline, week 4 (end of intervention), and week 8 (follow-up)

• Side Hop Test Performance

  Baseline, week 4 (end of intervention), and week 8 (follow-up)

Study Arms (3)

Ankle Strengthening

EXPERIMENTAL

Participants in this arm receive an isometric ankle strengthening program targeting plantar flexion, dorsiflexion, inversion, and eversion. The program is performed three times per week for four weeks, under supervision, using a handheld dynamometer.

Other: Isometric Ankle Strengthening Program

Hip Strengthening

EXPERIMENTAL

Participants in this arm receive an isometric hip strengthening program targeting hip abductors, external rotators, and extensors. The program is performed three times per week for four weeks, under supervision, using a handheld dynamometer.

Other: Hip Strengthening

Combined Ankle-Hip Strengthening

ACTIVE COMPARATOR

Participants in this arm receive a combined isometric ankle and hip strengthening program reflecting usual physiotherapy practice. The program includes the same ankle and hip exercises as the single-intervention arms and is performed three times per week for four weeks, under supervision, using a handheld dynamometer.

Other: Combined Isometric Ankle and Hip Strengthening Program

Interventions

Isometric Ankle Strengthening Program OTHER

This intervention consists of an isometric ankle strengthening program targeting plantar flexion, dorsiflexion, inversion, and eversion. Exercises are performed using a handheld dynamometer. Participants complete three supervised sessions per week for four weeks.

Ankle Strengthening

Hip Strengthening OTHER

This intervention consists of an isometric hip strengthening program targeting hip abductors, external rotators, and extensors. Exercises are performed using a handheld dynamometer. Participants complete three supervised sessions per week for four weeks.

Hip Strengthening

Combined Isometric Ankle and Hip Strengthening Program OTHER

This intervention consists of a combined isometric ankle and hip strengthening program reflecting usual physiotherapy practice. The program includes the same ankle and hip exercises as the single-intervention programs. Exercises are performed using a handheld dynamometer during three supervised sessions per week for four weeks.

Combined Ankle-Hip Strengthening

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Have a history of at least one major ankle sprain that occurred at least 12 months prior to enrolment in the study, was associated with inflammatory symptoms (pain, swelling, etc), created at least one interrupted day of desired physical activity.
• Have had at least two episodes of feeling like an "unstable" ankle in the six months preceding the study.
• The Cumberland Ankle Instability Tool (CAIT) with a score of less than 24.
• The Foot and Ankle Ability Measure (FAAM) Sport scale with a score below 80%.
• Between 18 and 35 years old
• Must be able to understand the study procedures and provide written informed consent

You may not qualify if:

• Have had a recent injury of less than three months prior to enrolment in the study.
• A history of surgery on the musculoskeletal structures of the lower limbs.
• Have a history of fracture of one of the lower limbs requiring realignment.
• Being diagnosed with a neuromuscular disease.
• The appearance of swelling or pain in the lower limb during the experiment.

Sponsors & Collaborators

• University of Liege: lead

Study Sites (1)

University of Liege

Liège, 4000, Belgium

RECRUITING

Related Publications (4)

• Khalaj N, Vicenzino B, Heales LJ, Smith MD. Is chronic ankle instability associated with impaired muscle strength? Ankle, knee and hip muscle strength in individuals with chronic ankle instability: a systematic review with meta-analysis. Br J Sports Med. 2020 Jul;54(14):839-847. doi: 10.1136/bjsports-2018-100070. Epub 2020 Jan 14.

  PMID: 31937576 RESULT

• Wright CJ, Linens SW, Cain MS. A Randomized Controlled Trial Comparing Rehabilitation Efficacy in Chronic Ankle Instability. J Sport Rehabil. 2017 Jul;26(4):238-249. doi: 10.1123/jsr.2015-0189. Epub 2016 Aug 24.

  PMID: 27632874 RESULT

• Gribble PA, Delahunt E, Bleakley CM, Caulfield B, Docherty CL, Fong DT, Fourchet F, Hertel J, Hiller CE, Kaminski TW, McKeon PO, Refshauge KM, van der Wees P, Vicenzino W, Wikstrom EA. Selection criteria for patients with chronic ankle instability in controlled research: a position statement of the International Ankle Consortium. J Athl Train. 2014 Jan-Feb;49(1):121-7. doi: 10.4085/1062-6050-49.1.14. Epub 2013 Dec 30.

  PMID: 24377963 RESULT

• Hertel J, Corbett RO. An Updated Model of Chronic Ankle Instability. J Athl Train. 2019 Jun;54(6):572-588. doi: 10.4085/1062-6050-344-18. Epub 2019 Jun 4.

  PMID: 31162943 RESULT

MeSH Terms

Conditions

Ankle Injuries

Condition Hierarchy (Ancestors)

Leg Injuries; Wounds and Injuries

Central Study Contacts

Aude Aguilaniu Aude, PhD

CONTACT

+32483421291; aude.aguilaniu@uliege.be

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants are randomly assigned to one of three parallel intervention groups: ankle strengthening, hip strengthening, or combined ankle-hip strengthening. All interventions are delivered over a 4-week period with three sessions per week.

Study Record Dates

• First Submitted: March 11, 2026
• First Posted: May 26, 2026
• Study Start: March 2, 2026
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): September 1, 2027
• Last Updated: May 26, 2026

Record last verified: 2026-03

Data Sharing

• IPD Sharing: Will not share

Locations

BE (1)