Ankle Strengthening in Athletes With Chronic Ankle Instability

Evaluation of the Effectiveness of Multiaxial Ankle Strengthening Training in Athletes With Chronic Ankle Instability

Chronic ankle instability (CAI) is a common complication following an ankle sprain, affecting joint stability and leading to decreased muscle strength and poor neuromuscular control. These symptoms can significantly impact athletes' sports performance. Rehabilitation training for CAI majorly involves strengthening or balance training. Few studies have discussed treatment plans that combine the above two training, and the effectiveness of combined training is similar to that of single training content. Due to the lack of machines to train ankle strength, thera-bands were often used for ankle strengthening. However, the resistance thera-bands provide is limited and may need more for athletes requiring high-intensity training. In recent years, a local company has developed a multiaxial ankle training system for machine-based ankle strengthening. This machine allows for training the ankle joint in various directions while sitting and can provide greater training resistance. As this machine has recently been developed and there is seldom evidence for its use in training, this project aims to discuss the effectiveness of using the ankle training machine in athletes with chronic ankle instability. This study will compare the differences in muscle strength, morphology, muscle material properties, balance ability, and functional performance of athletes after a six-week combined training program with thera-band or the multiaxial ankle training system for providing resistance. Thereby establishing a training plan for athletes suffering from chronic ankle instability.

Study Overview

• Status: Completed
• Conditions: Athletes; Chronic Ankle Instability, CAI
• Intervention / Treatment: Other: Strengthening

• Study Type: Interventional
• Enrollment (Actual): 14
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Taiwan
  • Taichung, Taiwan
    • China Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Unilateral CAI: Cumberland Ankle Instability Tool (CAIT) score ≤ 24
• Age between 18 and 28 years
• Engages in sports training at least 3 days a week, for more than 1 hour each session
• Able to perform training and assessment movements

Exclusion Criteria:

• Bilateral CAI
• Less than 6 months since the first ankle sprain
• Acute ankle sprain within the last 6 weeks
• Foot or ankle surgery within the last 3 months
• Neuromuscular diseases.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: multiaxial ankle training system; These subjects will train their ankle strength by the multiaxial ankle training system	Other: Strengthening; All subjects will recieve an ankle muscle strenghening training program twice a week for six weeks.
Active Comparator: thera-band; These subjects will train their ankle strength by thera-band	Other: Strengthening; All subjects will recieve an ankle muscle strenghening training program twice a week for six weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle Morphology	Using ultrasound to measure the muscle morphology of the peronous longus, gastrocnemius, tibialis anterior.	At enrollment (1st. week), midterm of training (3rd. week) and the end of training at 6 weeks
Y-Balance Test	This test is divided into three directions: anterior, posteromedial, and posterolateral. Each direction has a commercial measuring tape attached at 135 degrees, 90 degrees, and 135 degrees, respectively. The subject stands in the middle of the three measuring tapes, with the test foot's toe placed at the intersection point. The subject then stands on one leg with the test foot, extends the non-weight-bearing foot to touch the measuring tape in the target direction without touching the ground, and returns to the starting position while maintaining balance.	At enrollment (1st week), midterm of training (3rd. week) and the end of training at 6 weeks
Countermovement Jump	Before the test, wireless EMG sensors are attached to the tibialis anterior, The test is performed on a force plate. The subject stands on the force plate, bends both knees to 90 degrees, and jumps as high as possible.	At enrollment (1st. week), midterm of training (3rd. week) and the end of training at 6 weeks
Triple Hop Test	The subject stands with both feet at the starting point in front of the force plate, then stands on one foot and performs three consecutive forward hops, with the first hop landing on the force plate.	At enrollment (1st. week), midterm of training (3rd. week) and the end of training at 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ankle muscle strength	Measuring muscle strength of dorsiflexion, plantarflexion, inversion and eversion by hand-hold dynamometer.	At enrollment (1st. week) and the end of intervention at 6 weeks
Muscle tension	The maximum values for muscle tension of tibialis anterior, lateral gastrocnemius, and peroneus longus muscles are evaluated by the MyotonPRO.	At enrollment (1st. week), midterm of training (3rd. week) and the end of training at 6 weeks
Muscle stiffness	The maximum values for muscle stiffness of tibialis anterior, lateral gastrocnemius, and peroneus longus muscles are evaluated by the MyotonPRO.	At enrollment (1st. week), midterm of training (3rd. week) and the end of training at 6 weeks
Muscle elasticity	The maximum values for muscle elasticity of tibialis anterior, lateral gastrocnemius, and peroneus longus muscles are evaluated by the MyotonPRO.	At enrollment (1st. week), midterm of training (3rd. week) and the end of training at 6 weeks
Muscle stress relaxation time	The maximum values for muscle stress relaxation time of tibialis anterior, lateral gastrocnemius, and peroneus longus muscles are evaluated by the MyotonPRO.	At enrollment (1st. week), midterm of training (3rd. week) and the end of training at 6 weeks
Muscle creep	The maximum values for muscle creep of tibialis anterior, lateral gastrocnemius, and peroneus longus muscles are evaluated by the MyotonPRO.	At enrollment (1st. week), midterm of training (3rd. week) and the end of training at 6 weeks
Eyes Open/Eyes Closed Single-Leg Stance Test	This test includes static single-leg stance with eyes open/closed on stable/unstable surfaces, using a force plate to record the center of pressure changes during the test. The starting posture is single-leg stance with hands on hips and the non-test foot lightly touching the inner ankle of the weight-bearing foot. The subject maintains stable standing for 30 seconds. If instability occurs, hands and feet can leave the body to maintain balance, but the test foot must not move. If the other foot touches the ground, the test is considered a failure. For the unstable surface test, a soft pad is placed on the force plate, and the subject stands on the pad.	At enrollment (1st. week), midterm of training (3rd. week) and the end of training at 6 weeks
Muscle activation during countermovement Jump	The wireless EMG sensors are attached to the tibialis anterior, peroneus longus, and lateral gastrocnemius muscles to capture muscle activation during the activity.	At enrollment (1st. week), midterm of training (3rd. week) and the end of training at 6 weeks
Foot and Ankle Ability Measure (FAAM)	The Foot and Ankle Ability Measure (FAAM) is a self-reported functional assessment for the ankle joint, divided into two domains: Activities of Daily Living (FAAM-ADL) and Sports (FAAM-Sports), with 21 and 8 items, respectively. Subjects rate the difficulty of performing each activity based on their perception, with 4 points for no difficulty and 0 points for unable to perform.	At enrollment (1st. week) and the end of training at 6 weeks

Collaborators and Investigators

• Sponsor: China Medical University Hospital
• Collaborators: National Science and Technology Council, Taiwan
• Investigators: Principal Investigator: Chia-Ming Chang, Ph.D., China Medical University, China

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2024
• Primary Completion (Actual): December 20, 2024
• Study Completion (Actual): January 31, 2026

Study Registration Dates

• First Submitted: January 21, 2025
• First Submitted That Met QC Criteria: January 24, 2025
• First Posted (Actual): January 30, 2025

Study Record Updates

• Last Update Posted (Actual): March 20, 2026
• Last Update Submitted That Met QC Criteria: March 19, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: balance training; chronic ankle instability; strengthening; progressive training; ankle training machine
• Additional Relevant MeSH Terms: Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Therapeutics; Physical Therapy Modalities; Patient Care; Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Physical Conditioning, Human; Exercise; Resistance Training
• Other Study ID Numbers: CMUH112-REC1-116(AR1); NSTC 113-2410-H-039-015 - (Other Grant/Funding Number: National Science and Technology Council, Taiwan)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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