Study Design
This study is a randomized, controlled, double blind clinical trial with two parallel groups (Fig. 1). The study was approved by the Human Rights Ethics Committee under protocol number CAAE: 30660520.1.0000.5152 and registered in the Brazilian Registry of Clinical Trials (ReBEC) (Registration number: RBR-93xv9t). It is funded by the Coordenação de Aperfeiçoamento Pessoal de Nível Superior (CAPES- Master's Scholarship). Recruitment will begin in September 2020 with a probable end date of July 22, 2021. According to Flowchart (Fig.1) evaluations will be conducted pre-intervention (A0), post-intervention (A1), and 3-4 days after intervention (A2). Variables to be observed are: Amplitude of Motion of Dorsiflexion of ankle in closed kinetic chain and open kinetic chain, postural balance and functional performance.
Participants and Evaluators
Sample calculation was performed using difference of means and standard deviation, based on closed kinetic chain range of motion, of similar works, being RoM of DF in CKC, primary outcome, performed through the Lunge Test (LT), and minimum clinically relevant difference of 3.8 degrees[20], and considering ANOVA statistical test of repeated measurements. Power of the test considered was 80% and alpha of 0.05, being sample size of 28 volunteers per group.
Considering possible sample losses, a total of 64 volunteers, aged between 18 and 40, who have RoM in CKC less than 40º DF ankle will be recruited. If the volunteer has bilateral ankle dorsiflexion limitation, the most affected side will be considered for analysis and intervention.
Exclusion criteria are: presenting musculoskeletal injury in lower limb, rheumatic diseases, cardiovascular diseases, or any other alteration that could harm the volunteer's health or compromise performance of tests.
These individuals will be recruited through posters on campus of the Federal University of Uberlândia (UFU) and by dissemination on social media and local media.
Research will be developed at the Laboratory of Evaluation in Biomechanics and Neurosciences (LABiN) of the Faculty of Physical Education and Physical Therapy of the Federal University of Uberlândia, Minas Gerais, Brazil.
Procedures
All participants will receive a Free and Informed Consent Term.
Volunteers will be submitted to individual physiotherapeutic evaluation containing ankle range of motion, history of injuries and previous treatments, physical activities performed, history of other diseases and, if necessary, special tests for hip, knee and ankle to exclude musculoskeletal changes in lower limbs, these being the eligibility criteria. After selection, all eligible volunteers will be randomized into two groups by a blind (unbiased) researcher not involved with evaluation, intervention and recruitment of volunteers. Volunteers will be informed that they will receive physiotherapeutic intervention, but will not know the difference between treatment groups or study hypothesis, and may therefore be considered blind. Randomization will be carried out by Microsoft Excell® RAND command and placed in a brown sealed envelope, listed sequentially to hide participants allocation. These will be distributed in two groups, intervention A and intervention B, and only a physiotherapist, who will not be involved in evaluations, will be responsible for applying treatment techniques and will be considered blind for evaluations.
Intervention / Control
Sixty-four volunteers will be randomly allocated in 2 groups: (A) Articular Mobilization - Mulligan Concept; (B) Articular Mobilization - Mulligan Concept + Articular Mobilization - Maitland Method. Both groups will be submitted to intervention according to techniques mentioned.
Intervention group A will be submitted to Mulligan mobilization technique - Mobilization with Movement (MWM) - where physiotherapist will manually stabilize with continuous pressure on the Talus in the AP direction and a belt will be passed around the distal region of the leg region of the volunteer and waist of the therapist, where pressure will be applied in the PA direction accompanying the entire range of motion that will be performed with active movements of DF with weight bearing on assessed limb performing a sinking movement and, at the end of active movement, the patient will be guided to perform a final pressure called overpressure. Intervention will be performed in 3 series of 10 repetitions. In addition, the volunteer will be guided to perform self-mobilization by performing oscillatory movements at the end of DF with weight discharge, in 3 series of 10 repetitions per day, aiming at gaining an ankle DF during 3 days [14,18].
Intervention group B will also be submitted to technique cited in group A plus Maitland method technique, which will be applied after intervention A, in grade IV, with volunteer in dorsal decubitus, and foot out of stretcher. Mobilization will occur through a passive oscillatory pressure in AP direction in talus, for 5 series of 1 minute [21,18]. All techniques will be performed by a physiotherapist trained and experienced in clinical applicability of both techniques.
Outcome Measurements
Three outcome measurements will be evaluated, 2-3 days before intervention application (A0), after immediate intervention (A1), and 3-4 days after intervention (A2).
Primary Outcome
The primary outcome corresponds to DF ankle range of motion of in CKC measured through Lunge Test (LT).
Secondary Outcome
Secondary outcome corresponds to passive ankle DF measured in OKC by means of a goniometer, Postural Control which will be evaluated through oscillation of CoP during evaluation of Y Balance Test, which will be carried out on force platform, with functional performance evaluated through Y balance test (YBT) and Triple Hop Test (THT) and, satisfaction evaluated through Medrisk satisfaction questionnaire [22].
Each result measurement is described below:
Range of Motion (RoM)
DF RoM will be measured in CKC performed by LT, this test being of high reliability for measurement of DF (ICC = 0.98) [23]. To this end, a smartphone and an application will be used for acquisition of measurements (ClinometerⓇ), this application having already been validated [24].
Test will be performed with participant barefoot and with weight bearing on member evaluated (Fig.2). A 50 cm line will be fixed on ground and a continuous 60 cm line will be demarcated on wall to perform test [3]. Cell phone device will be positioned 15 cm away from anterior tibial tuberosity [3]. Participants will be positioned with their feet along line on ground, and then will be asked to move maximum DF, thereby bringing knee closer to vertical line drawn on wall, without foot moving from ground (Fig. 2). Once maximum DF is reached, examiner will position inclinometer on reference marked on volunteer's leg. Angle (in degrees) of DF and distance (in cm) from tip of 1st toe to wall will be computed. Participant will return to initial position. Procedure will be repeated 3 times and average calculated for later analysis [4].
RoM will also be measured in OKC by means of goniometry, method validated by Petherick et.al in 1988 [26]. Participant will remain in a ventral decubitus position, knee positioned at 90º and asked to perform ankle DF movement and then evaluator will help to complete maximum DF range passively. The goniometer will be positioned on lateral malleolus with its central axis, fixed arm directed towards lateral epicondyle of knee and mobile axis will be directed towards 5th metatarsal (Fig.3). This procedure will be repeated 3 times and mean calculated for later analysis [26].
Postural Control
Postural control will be evaluated during execution of YBT using force platform.
Postural oscillation will be evaluated through analysis of center of pressure (CoP) displacement with data obtained during execution of YBT, performed during use of force platform (EMGSystem do Brasil® São José dos Campos, SP), with sampling frequency being 500 Hz. Force signals obtained (Fx, Fy and Fz) and the moments of these forces (Mx, My and Mz), will be used to determine CoP oscillation, with direction of CoP oscillation being considered, [+x]- anterior; [+y]- right and [+z]- upper directions will also be used.
Collecting environment will have controlled temperature and noise level minimizing interference in postural control. Participants will be previously oriented as to positions that should be performed during data collection. Volunteer must be initially positioned with face facing posterior direction of platform (-Fy).
During execution of YBT, volunteer will be tested in unipodal support under force platform. Participants will be positioned with foot to be evaluated at intersections of lines, formed by previous, posterior-medial and posterior-lateral directions marked on force platform. Participants will be verbally instructed to perform maximum reaches in three directions, with contralateral limb, with upper limbs positioned at waist level [27] (Fig. 4).
Participants will perform 3 familiarizations, followed by 3 tests for each direction. Test will be invalidated if hands do not remain at waist area, if position of support is not maintained, if heel does not remain in contact with platform during reach, if volunteer unloads body weight onto contralateral limb, or if participant loses balance during test [27].
For kinetic analysis during YBT execution, data will be filtered using Butterworth 2nd order 2.5 Hz low-pass filter applied in direct and reverse direction. Variables will be calculated: average speed (cm/s); anteroposterior peak speed (Y) (cm/s); mid-lateral peak speed (X) (cm/s); anteroposterior displacement amplitude (Y) (cm); mid-lateral displacement amplitude (X) (cm); average displacement (XY) (cm) and reliable ellipse area (cm2)43 for each test displacement direction.
Functional Performance
During execution of YBT, carried out as described above, will also be computed for each direction, anterior, postero-medial and postero-lateral, displacement, in centimeters, performed with contralateral limb to supporting member [27] (Fig. 4). Average displacement (AD) in each direction will be normalized using length of support leg (LS) of individual [27], and composite score (CS) will be calculated.
CS = AD (Ant+Postero-medial+postero-lateral)/3xLS (*100)
To evaluate functional performance of THT, a demarcation will be carried out, consisting of a line 6 meters long and 15 centimetres wide, perpendicular to a starting point [29].
This test is used to measure combination of muscle strength, neuromuscular control, and ability to tolerate sports-related activities[30]. Participant must perform 3 maximum jumps with same leg following trajectory of marked line. Subsequently, the distance between starting line and tip of Hálux at site of last landing must be measured in centimeters [29] (Fig.5). Three (3) repetitions will be carried out for member to be tested and best result will be computed for later analysis.
Satisfaction
At the end of data collection after final reassessment (3-4 after applying technique), the Medrisk [23] satisfaction questionnaire will be presented, which is an instrument used to evaluate patient's satisfaction with physiotherapy treatment, composed of 13 questions with scores from 1 to 5 evaluating quality of service and, 1 question evaluating one’s clinical perception of performance improvement.
Statistical Analysis
The normality test will be performed using the Kolmogorov Smirnov test. If null hypothesis is confirmed, comparison between groups will be performed using parametric tests, however, if null is not confirmed, non-parametric tests will be applied.
For parametric data the effect of treatment will be evaluated by ANOVA two-way test for repeated measurements, considering value of p ≤ 0.05. Data will be evaluated by intention to treat.
Clinical relevance of results will be confirmed by calculating effect size (Cohen' d) of significant differences found between assessments. The following effects will be considered: 0.00-0.49, small; 0.50-0.79, medium and above 0.80, large (Cohen, 1988). Analysis of data will be made by intention to treat [31].