Lateral ankle sprain results in positional faults in the fibula which are thought to limit accessory motion in the ankle, leading to hypomobility and negatively influencing sensorimotor function and postural control. Although it has been shown that fibular reposition taping (FRT) is effective in the prevention of recurrent lateral ankle sprain, its ability to produce significant changes in balance measures in patients with chronic ankle instability is inconclusive.
This study aimed to determine whether a FRT intervention affects balance performance in patients with chronic ankle instability.
Randomized controlled trial.
Sixty individuals with chronic ankle instability were randomly allocated to three groups: FRT, sham taping, or no intervention (control group). Kinesiotape was applied and then re-applied on 3 occasions per week for 2 weeks. Static and dynamic balance were measured with three functional tests before and 1 day after the last session of intervention with the tape removed: single-leg stance test, single-leg hop test for distance, and modified Star Excursion Balance Test (mSEBT).
The results of ANCOVA showed that there were no significant differences between the three groups except for mSEBT reach distance in the posterolateral direction, which was significantly greater in the FRT group than the control group (p = 0.03).
Applying FRT for 2 weeks did not significantly affect static or dynamic balance measures in individuals with chronic ankle instability, hence its clinical efficacy to influence balance remains uncertain in this population.
Clinical trial registration number
Two weeks Fibular reposition taping did not improve balance in chronic ankle instability patients.
No difference was seen between sham and Fibular reposition taping groups in balance measures.
No difference was seen between control and Fibular reposition taping groups in static balance.
Ankle sprains are common in both the general ( ) and the physically active population ( ). After the acute symptoms have resolved, chronic ankle instability (CAI) is a common, persistent sequela of ankle sprain, characterized by three main aspects: 1) a history of at least one significant ankle sprain, 2) a history of ankle joint ‘giving way’ and/or recurrent sprain, and/or ‘feelings of instability’, and 3) poor disability status based on specific questionnaires ( ). According to recent reports, CAI develops in 32–74% of individuals with previous lateral ankle sprains ( ).
It has been reported that postural sway deficits accompany CAI ( ). Recreational and sports activities require postural control and balance ( ). Various factors can be involved in postural control alterations, one of which is arthrokinematic changes ( ). Arthrokinematic restrictions caused by lateral ankle sprains decrease the ability to achieve full ankle dorsiflexion range of motion, and restrictions in this range of motion have been shown to affect postural control negatively ( ). One arthrokinematic alteration linked with inversion ankle sprains is anterior and inferior shift of the fibula relative to the talus ( ). It is believed that positional faults in the fibula restrict accessory motions in the ankle, leading to hypomobility and a negative influence on sensorimotor function ( ). To manage fibular positioning faults, suggest that fibular reposition taping (FRT) may be as a possible way to enhance postural control in patients with CAI through mechanical realignment of the fibula and restoration of pre-injury arthrokinematics.
Kinesiotaping (KT) is a popular taping method; unlike traditional athletic tape, KT has elastic properties similar to the skin and stretches to 40–60% of its initial length, so is mechanically less restrictive ( ). The KT is usually worn for a few days, allowing the individual to carry out activities of daily living and exercises ( ). Due to the adhesive strength on the skin, KT is reapplied every 2 or 3 days ( ). In addition, the cotton material of KT makes it permeable to air and water ( ). A metaanalysis by concluded that KT was superior to other taping methods in improving ankle functional performance in healthy individuals and patients with ankle instability. The exception was the measure of vertical jump height where KT had no effect whereas athletic taping and placebo taping had a negative effect. Two proposed mechanisms for KT appear to be related to the correction of fibular malposition and consequent improvements in balance: 1) repositioning the subluxed joint by reducing abnormal muscle tension ( ), and 2) improved proprioception through the stimulation of cutaneous mechanoreceptors ( ).
Although FRT was shown to be effective in preventing recurrent lateral ankle sprain in a study by , the current evidence for the ability of FRT to provide clinically significant changes in balance measures in patients with CAI is inconclusive. Two studies reported immediate significant improvement in dynamic balance following FRT application ( ; ); however, other studies concluded that there were no changes in static or dynamic balance after FRT application ( ; ; ).
While immediate effects have been tested, to the best of the authors’ knowledge no randomized controlled trials have investigated FRT as a more prolonged therapeutic intervention in patients with CAI. Hence there is lack of evidence regarding the cumulative effects of FRT. The purpose of this study was to determine whether applying FRT using KT for 2 weeks improved balance performance in patients with CAI. The hypothesis was that FRT using KT would have superior effects on balance performance compared to sham taping and no intervention in patients with CAI.
Materials and methods
This randomized controlled trial was conducted from July 2018 to October 2018. The protocol of the study was approved by the Medical Ethics Committee of “X” University of Medical Sciences (ethics code: “X”.REC.1397.142) and was registered prospectively in the “X” Registry of Clinical Trials (code: IRCT20171122037576N2).
Participants and setting
Patients were recruited from outpatient physiotherapy clinics affiliated with “X” University of Medical Sciences and also through flyers distributed at university dormitories. The inclusion and exclusion criteria were based on the International Ankle Consortium Position Statement ( ). Three inclusion criteria were used. 1) A history of at least one significant ankle sprain, with the first sprain occurring 12 months before the study, associated with inflammatory symptoms such as pain, swelling, etc. and interrupting desired physical activities for at least 1 day. 2) Self-reported ankle joint giving way and/or recurrent ankle sprain (at least 2 episodes in the 6 months before the study), and/or feeling of instability confirmed by a Cumberland Ankle Instability Tool (CAIT) score <24( ). 3) A score of <90% in the daily activities section and <80% in the sport activities section of the Foot and Ankle Ability Measure (FAAM) questionnaire ( ). The exclusion criteria were: 1) recent ankle sprain in the previous 3 months, 2) a history of previous surgery in the musculoskeletal system of both lower extremities, 3) a history of fracture needing realignment in each of the lower limbs, and 4) acute injury to other lower extremity joints which interrupted desired physical activities for at least 1 day. Before participation in the study, all eligible patients signed an informed consent form approved by the Ethics Committee.
An experienced physiotherapist carried out all taping interventions. The taper met with the research team to practice the taping technique in order to ensure consistency. Each participant was assigned the same clinician for all sessions.
The Intervention group received FRT taping, applied as previously reported ( ; ). Manual posterior glide was applied to the distal fibula and maintained while a strip of adhesive KT was applied to fix the posteriorly-directed position of the fibula. The FRT method included two 20-cm lengths of KT applied obliquely beginning at the distal end of the lateral malleolus ( Fig. 1 ). The second reinforcing strip was applied in the same manner to reinforce the first one. Patients in the sham taping group received the same layers of adhesive gauze and KT but with no tension or manual mobilization of the fibula. The control group received no treatment between the baseline and post-intervention assessments. All participants were asked to continue their routine lifestyle during the intervention period.
All data were collected at the Faculty of Rehabilitation Sciences of “X” University of Medical Sciences. The primary outcome was dynamic balance and the secondary outcomes were static balance, and function. Static balance was assessed with the Single Leg Stance Test (SLST), dynamic balance was evaluated with the modified Star Excursion Balance Test (mSEBT), and function was recorded with the single hop test. The same investigator supervised all test procedures under the same conditions. The test order was randomized. Participants were allowed to practice the tests 3 times before the main assessment ( ). After participants became familiar with the tests, they performed 3 repetitions for each one. There was a 30-s rest period between each repetition, and a 1-min rest interval between the different tests.
Modified Star Excursion Balance Test: This modified and simplified version of the SEBT is tailored to three directions: anterior, posteromedial and posterolateral. The aim of the test is to evaluate dynamic balance, and it was reported to be a reliable measurement instrument for this outcome ( ). The angle between the anterior axis and two posteromedial and posterolateral axes was 135°, and the angle between the posteromedial and posterolateral axes was 90°. To perform the test, the patients stood on their affected leg with their heels at the center of the meeting point of all three axes of the Y pattern, and with their hands on their hips. They reached as far as possible with their sound limb along each arm of the Y pattern, lightly touched the line with the distal most portion of their reaching foot without shifting weight to or resting this foot on the floor, and then returned their reaching limb to the starting position at the center of the Y and reassumed bilateral stance. Knee flexion and minimal stance foot movements were allowed, as were controlled trunk movements. Each patient repeated each trial direction 3 times with sufficient rest between trials. The distances reached were recorded in centimeters, and then divided leg length to obtain normalized scores. Leg length in centimeters was measured from the prominent tip of the anterior superior iliac spine to the prominent tip of the ipsilateral medial malleolus. Each patient was allowed 6 practice trials to become familiar with the testing maneuver prior to the main trials.
Single Leg Stance Test: This test was used to investigate static balance ( ). The patients were asked to stand on their affected leg with their hands on their waist and the other leg flexed, without touching the weight-bearing leg. They were then asked to hold this position for 30 s with their eyes closed. During each trial the investigator noted the number of errors as follows: the times that the sound leg touched the floor or the weight-bearing leg, the numbers of foot displacements on the floor from the starting position, the numbers of hand separations from the waist, and the numbers of eyes openings. All patients performed 3 trials, and the mean number of trial errors was calculated for further analysis.
Hop test: The aim of this test was to investigate balance during a single hop as far as possible on the affected leg. The test was considered valid when the participant made a controlled, stable landing. No limitations on trunk or arm movements were imposed during the trials. The distance between initial and final heel placement was recorded in centimeters. Each patient performed 3 correct trials, and the mean distance was recorded for further analysis. As in the SLST, each patient was allowed 3 practice trials to become familiar with the test maneuver prior to the main trials.
Sample size calculation
Based on data of mSEBT from a previous study ( ) and assuming 85% power and α = 0.05, we estimated the sample size as 52 (17 participants per group) with G*Power software v. 3.1.7. In anticipation of an overall attrition rate of 15%, we increased the final sample size to 60 (20 in each group).
The patients were randomly assigned to three groups (FRT, sham taping, or control) at a 1:1:1 ratio using a block permutation method (block size of 3).
The allocation procedure was concealed from the examiner by using sequentially numbered opaque, sealed and stapled envelopes. The person responsible for randomization was different from the examiner and therapists. All interventions were carried out by expert therapists who were different from the persons who performed the examinations and randomization. The group codes were not broken until the statistical analysis was completed.
The data were analysed with SPSS software (version 21; SPSS, Inc., Chicago, IL). Descriptive statistics were summarized as the mean and standard deviation. The normal distribution of data was confirmed by Shapiro–Wilk test. The mean differences between pretreatment and posttreatment values were used for statistical analysis. Differences between the three groups were identified with analysis of covariance (ANCOVA). If the ANCOVA results were significant, Bonferroni correction was applied for post hoc comparisons. A p value less than 0.05 was considered statistically significant. The Effect size calculation for significantly different measure was performed using Cohen’s d.
Of the 60 patients who enrolled in the trial, 58 completed the study and data were analysed per protocol. The flow diagram is shown in Fig. 2 . The demographic and clinical characteristics of the participants are summarized in Table 1 . There were no differences between study groups in demographic characteristics. The results of ANCOVA showed no significant differences between groups in the single-leg stance test or single hop test scores. For the mSEBT, ANCOVA showed no significant differences in the anterior or posteromedial directions but a significant difference between groups in the posterolateral direction (p = 0.033) ( Table 2 ). Post hoc analysis revealed that posterolateral reach distance in the mSEBT increased in the FRT group compared to the control group (p = 0.011). The size of effect (Cohen’s d) for between FRT and control group comparison was 1.06.