Differences in Ankle Sprain Risk Factors, Anterior Talofibular Ligament, Calcaneofibular Ligament and Lower Leg Muscles' Size Among Athletes With and Without Ankle Sprain Injury History: A Retrospective Study

This study aims to comprehensively explore the relationship between changes in muscle architecture and connective tissue structure in athletes with ankle sprains and the intrinsic biomechanical risk factors observed in these individuals. The main goal of the research is to compare the risk factors associated with ankle sprains, characteristics of lower extremity muscle architecture, and structural features of the anterior talofibular ligament (ATFL) between athletes with and without a history of ankle sprains. Additionally, the study seeks to identify intrinsic factors that may lead to lateral ankle sprains and to investigate the link between these factors and structural changes related to chronic ankle instability. Overall, the study aims to contribute scientifically to the early detection of sprain risk in athletes and the development of personalised preventative intervention strategies.

The hypotheses of the study are as follows:

Hypothesis 1: In athletes with a history of ankle sprains, the strength of the muscles surrounding the ankle differs from that of their uninjured ankles and ankles of the athletes without a history of sprains.

Hypothesis 2: Athletes with a history of ankle sprains have a different level of proprioception (position sense) compared to athletes without a history of sprains.

Hypothesis 3: Athletes with a history of ankle sprains have different muscle and ligament sizes compared to their uninjured legs and the legs of athletes without a history of sprains.

Hypothesis 4: Dynamic balance differs between athletes with a history of ankle sprains and those without a history of ankle sprains.

Study Overview

• Status: Completed
• Conditions: Muscle Size; Chronic Instability of Ankle Joint; Dynamic Balance

Detailed Description

Ankle instability exhibits a significant propensity to evolve into a chronic condition. Chronic ankle instability (CAI), defined by enduring residual symptoms following a sprain, recurrent sprains, and perceived instability, occurs in approximately 10% to 40% of cases. According to research conducted by Van Rijn and colleagues, between 5% and 33% of patients continued to experience pain one year subsequent to an ankle sprain, and one-third of the participants reported at least one re-sprain three years thereafter (4, 6).

Research indicates that a minimum of 73% of individuals who have sustained an ankle sprain exhibit persistent symptoms, including pain, a sensation of instability, proprioceptive disturbances, and impairments in neuromuscular control (7, 8). This condition presents a significant risk of both re-injury and the development of CAI. A history of multiple sprains and recurrent feelings of instability are identified as CAI, and the ongoing nature of this condition increases joint damage and the likelihood of osteoarthritis (9). The treatment and prevention of these injuries are costly and hinder athletes' return to training and competition (10).

Numerous intrinsic risk factors have been identified in the literature concerning the incidence and recurrence of lateral ankle sprains. These risk factors include a previous sprain history, gender, height, body weight, anatomical foot posture, alignment abnormalities (e.g., pes cavus, genu varum), joint laxity, joint range of motion, muscle strength, proprioception, reaction time, and postural control (11). Current studies show that, although there are differences in performance levels between genders, there is no significant difference in exposure to injury risk (12, 13). Conversely, it is stated that a direct relationship exists between height, body weight, ankle laxity, muscle strength, and postural control and lateral sprains (7). When assessed in terms of muscle strength, weakness in the ankle and hip muscles is an important risk factor for the development of LAS. Research shows that athletes with more than 15% strength asymmetry, especially during the pre-season, face a higher risk of sprain compared to those without such asymmetry. Postural balance disorders are also regarded as a significant intrinsic risk factor in the development of LAS. In conclusion, ankle sprains are common injuries among athletes and can lead to significant functional impairments. Identifying intrinsic risk factors for these injuries and implementing targeted preventive strategies through individual assessments are essential for both injury prevention and reducing the development of OAS. A review of current literature shows that there are limited studies that thoroughly examine changes in the architecture and functional performance of the muscles around the ankle in athletes who have experienced recurrent ankle sprains. This study aims to comprehensively explore the relationship between changes in muscle architecture and connective tissue structure in athletes with ankle sprains and the intrinsic biomechanical risk factors observed in these individuals.

• Study Type: Observational
• Enrollment (Actual): 60

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye)
    • Medipol University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

This study is a retrospective, cross-sectional investigation conducted to evaluate the relationship between intrinsic risk factors, including muscle and ligament sizes, dynamic balance, postural stability, proprioception and ankle instability in athletes diagnosed with chronic ankle instability (CAI). Participants will be equally recruited into the group with athletes who have a lateral ankle sprain history (LAS Group) and the Control group, with consideration for gender stratification (groups will have the same number of males and females).

Description

Inclusion Criteria:

1. At least 5 years of active participation in any sport.
2. Age between 18 and 35.
3. A history of at least two clinically diagnosed LAS episodes with inflammatory symptoms like pain and swelling.
4. The last sprain occurred at least 3 months before the study start, and the participant has fully returned to their sport.
5. No previous surgeries affecting

Exclusion Criteria:

1. Any history of ankle fracture.
2. Surgery or systemic disease impacting sensorimotor function in the lower limb.
3. Neurological disorders.
4. Recent (within a month) acute injury to the lower extremity.
5. Visual or vestibular issues that impair balance or coordination.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Control group; The control group will include athletes who have no history of ankle injuries.
Ankle Instability Group; The group will consist of athletes diagnosed with chronic ankle instability (CAI).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dynamic Balance Assessment	The Y balance test, a short and practical variation of the star balance test, will be used to assess dynamic stability. Athletes will perform the Y balance test according to the test procedures defined by Plisky et al. Three white bands, each 125 cm in length, will be affixed to the ground to form a Y shape, with the small angle at 90° and the two larger angles at 135°, and centimeter-scale markings will be added to the bands by hand.Participants will be positioned at the center of the apparatus with the second phalanges of the extremity being tested in the coronal plane and the metatarsophalangeal joints in the sagittal plane, both aligned with the midline. Participants will be asked to stand with their hands at the level of the iliac crest, adjacent to their bodies, and with the foot to be measured on the ground, to reach out with the other foot in the anterior, posteromedial, and posterolateral directions, once in each direction, and to lightly touch the final point they can reach.	15 minute
Postural Stability Assessment	Athletes' postural stability and center of pressure (CoP) assessments will be performed using the Prokin force platform (Prokin PK 252). The Prokin PK 252 is a proprioceptive system used for static and dynamic balance assessment and training. In this study, the "Static and Dynamic Stability Assessment Program" will be used to provide detailed and accurate data on participants' static standing posture through the stabilometry platform and sensors placed on the body [47]. During the test, participants' standing position will be determined with their feet shoulder-width apart, and their foot positions will be aligned at equal distances from the origin point, using the lines on the platform's x and y axes as references.First, a single-leg static stability test will be performed. This test will be administered in two sub-tests: with eyes open and with eyes closed.	20 minute
Muscle and Ligament Size Assessment	Muscle and ATFL thickness will be measured using an HS60 ultrasound system (Samsung Medicine, Gangwon-do, Korea) with a 5-13 MHz linear probe. Muscle cross-sectional area (MCA) of the ankle muscles will be assessed under two conditions: resting and maximal voluntary contraction (MVC), using B-mode ultrasound. All measurements will be taken by a physical therapist experienced in musculoskeletal ultrasound. Participants will lie on a medical bed with legs fully extended, the ankle in a neutral position, and muscles relaxed during imaging.	1 hour
Proprioception Assessment	An ankle joint position sense test will be administered to assess deficiencies in ankle proprioception. An electronic goniometer will be used to assess ankle joint position sense. The reliability of this test among recreational athletes with ankle instability has been reported as ICC = 0.94-0.98 [45]. Athletes will be seated with their knees flexed at 90°, and their eyes will be closed to eliminate visual cues. The ankle subtalar joint (STJN) will be held in a neutral position, and the goniometer will be set to zero. The ankle will be passively moved through 10° dorsiflexion, 10° eversion, 15° plantar flexion, or 15° inversion, and then returned to the neutral position [46]. Participants will then be asked to actively perform these movements as closely as possible to the previous movements. Three repeated measurements will be taken for each test angle, and deviations from the target angle will be recorded.	15 minute
Muscle Strength Assessment	Isometric muscle strength measurements of the tibialis anterior, peroneus longus and brevis, gastrocnemius, and gluteus medius muscle groups will be performed using a MicroFET digital handheld dynamometer. Measurements will be conducted with participants positioned supine, side-lying, and prone on an examination table [34]. For each muscle group, participants will be asked to perform three maximal voluntary contractions lasting 5 seconds each, with a 1-minute rest between contractions. All measurements will be conducted by the same examiner, and all three recorded values will be used for data analysis.	15 minute

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Foot and Ankle Ability Measure (FAAM)	Athletes' physical functions will be assessed using the Turkish version of the Foot and Ankle Ability Measure (FAAM). FAAM is a self-report measurement tool developed to assess the physical functions of individuals with musculoskeletal problems related to the foot and ankle. The FAAM consists of a total of 29 items, including a 21-item Activities of Daily Living (ADL) subscale and an 8-item Sports subscale. The Sports subscale provides a sports-specific subclass to assess the ability to perform sports-related activities. Each question is scored using a 5-point Likert scale ranging from 0 (unable to perform) to 4 (able to perform without difficulty). The maximum score for the ADL subscale is 84, while the maximum score for the Sports subscale is 32. Total scores are calculated as percentage scores ranging from 0% to 100%, with a higher score indicating a higher level of function [48].	15 minute
Cumberland Ankle Instability Tool (CAIT)	Cumberland Ankle Instability Tool Developed in 2006, the Cumberland Ankle Instability Tool 17 (CAIT) was the first to provide a numerical value measuring the level of ankle instability based on individuals' perceptions [41]. The CAIT scale, designed to assess functional ankle instability levels, consists of 9 questions; the maximum total score is 30 and the minimum is 0. A lower total score indicates more severe functional ankle instability. Test-retest reliability was found to be excellent at 0.96. The CAIT is the first tool to validly and reliably assess functional ankle instability. In the study, the cutoff score was set at 27.5, with a sensitivity of 82.9% and a specificity of 74.7%. Finally, the CAIT score has the potential to predict the risk of re-sprain in individuals with functional ankle instability. Individuals with a sprained ankle and a low CAIT score have a higher likelihood of re-sprain, while those with a high CAIT score have a lower likelihood of re-sprain [42].	10 minute

Collaborators and Investigators

• Sponsor: Yeditepe University

Study record dates

Study Major Dates

• Study Start (Actual): May 15, 2025
• Primary Completion (Actual): May 15, 2025
• Study Completion (Actual): May 15, 2025

Study Registration Dates

• First Submitted: May 5, 2026
• First Submitted That Met QC Criteria: May 5, 2026
• First Posted (Actual): May 12, 2026

Study Record Updates

• Last Update Posted (Actual): May 12, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: risk factors; dynamic balance; chronic ankle instability; muscle size; ligament size
• Other Study ID Numbers: MedipolU

Drug and device information, study documents

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