Postural balance asymmetry and subsequent noncontact lower extremity musculoskeletal injuries among Tunisian soccer players with groin pain: A prospective case control study

BackgroundRecent studies reported postural balance disorders in patients and soccer players with groin pain (GP) compared to controls. Since postural balance asymmetry identified after an initial injury contributes for subsequent injuries, identification of this asymmetry in soccer players with GP may highlight the risk of sustaining subsequent noncontact lower extremity musculoskeletal injuries in these players. Therefore, the aims of this study were to (i) examine static and dynamic unipedal postural balance asymmetry in soccer players with GP compared to healthy ones, and (ii) quantify the risk of subsequent noncontact lower extremity injuries in these players.Research questionDo soccer players with GP exhibit higher static and dynamic unipedal postural balance asymmetry, and higher risk of sustaining subsequent injuries compared to controls?MethodsIn this prospective case control study, 27 soccer players with non-time loss GP (GP group: GPG), and 27 healthy ones (control group: CG) were enrolled. Static and dynamic unipedal postural balance asymmetry were evaluated with a force platform using symmetry index (SI), and Y-balance test (Y-BT), respectively. Additionally, subsequent noncontact lower extremity musculoskeletal injuries were tracked for 10 months.ResultsThe GPG revealed higher (p < 0.01) SI in eyes closed condition, higher (p < 0.001) side-to-side asymmetry in anterior, posteromedial and posterolateral reach distances and in composite Y-BT score compared to CG. They showed lower (p < 0.001) composite score for injured limb and higher (p < 0.001) side-to-side asymmetry in posteromedial reach distance compared to the cut-off values of 89.6 % and 4 cm, respectively. Moreover, GPG exhibited higher odds (OR= 7.48; 95 % CI = 2.15, 26.00; p < 0.01) of sustaining subsequent injuries compared to CG.SignificanceThe Y-BT should be instituted into existing pre-participation physical examinations to screen for soccer players with non-time loss GP at an elevated risk of sustaining subsequent injuries. This could help coaches and clinicians make valid return to play decisions.     

Postural balance impairment in Tunisian second division soccer players with groin pain: A case-control study

ObjectiveTo compare postural balance outcomes between soccer players with and without groin pain (GP).DesignCase-control study.SettingLaboratory.ParticipantsFifty-four soccer players, 27 with GP (GP group: GPG) and 27 healthy ones (control group: CG).Main outcome measuresStatic and dynamic postural balance were assessed with a force platform and Y-balance test (Y-BT), respectively. Hip abduction, internal rotation (IR), external rotation (ER) and total rotation (TR) of both limbs were evaluated.ResultsThe GPG exhibited significant higher centre of pressure values in the bipedal posture only on the foam surface in eyes opened and closed compared to controls. Besides, they had lower anterior, posteromedial and posterolateral reach distances and composite Y-BT score on the injured limb (IL) compared to non-injured limb (NIL) and dominant-limb (DL) of the CG. Moreover, they showed lower abduction, IR, ER, and TR on the IL compared to NIL and DL.ConclusionsDynamic unipedal postural balance disorder could be one of the limiting factors of performance in soccer players with non-time loss GP. Hence, postural balance data in these players could enable sport coaches and physical therapists to better understand the mechanisms contributing for performance decrease.     

Improvement of lower-extremity stability by rotational leg press training

BackgroundsPrevious reports revealed that balance and stability are essential for human physical activity. The present study aimed to evaluate the comparative outcome of a novel beginning movement load training (BMLT) versus conventional leg press training in terms of improvement of lower-extremity stability.Research questionDoes the leg press training improve the stability of lower extremities?MethodsTwenty adult, asymptomatic and active amateur basketball players were enrolled in this study and randomized in equal numbers into a BMLT group (study group) and a conventional leg press training group (control group).ResultsThe results after eight-week course of training showed that conventional leg press training had an opposite effect on dynamic stability in the left leg (p = 0.015) and backward movement of the right leg (p = 0.038). The athletes in the study group revealed superior dynamic stability maintenance in both legs backwards (p = 0.001), the left leg (p = 0.013), the right leg backwards (p = 0.022) and overall stability (p = 0.002).SignificanceThe study group showed better postural stability in terms of the medial/lateral index (p = 0.017), and the athletes in the control group exhibited a significant inability to maintain postural stability in the medial/lateral aspect after the training (p = 0.016). Rotational BMLT lower-extremity press training yielded superior enhancement of dynamic stability and maintenance of center of gravity and postural stability.     

The effects of stroboscopic balance training on cortical activities in athletes with chronic ankle instability

ObjectivesTo investigate the effect of a 6-week stroboscopic balance training program on cortical activities in athletes with chronic ankle instability.DesignRandomized controlled trial. Setting: Single-center.ParticipantsThirty-nine participants were assigned to the strobe group (SG, n = 13), non-strobe group (NSG, n = 13), and control group (CG, n = 13).Main outcome measuresCortical activity and balance velocity were evaluated while the athletes were on the HUBER balance device. Electroencephalographic measurements of cortical activity were made at the transition from bipedal stance to single-leg stance.ResultsThe SG showed significant increases in Cz theta and alpha values and COP-v (center of pressure velocity) between pretest and posttest (p < 0.001, p = 0.003, p < 0.001). Posttest Cz theta was significantly higher in the SG compared to the CG (p = 0.009) and posttest Cz alpha was significantly higher in the SG compared to the NSG (p = 0.039) and CG (p = 0.001). Posttest COP-v was significantly higher in the SG than in the CG (p = 0.031) and NSG (p = 0.03).ConclusionsStroboscopic training may be clinically beneficial to improve balance parameters in athletes with CAI, and may have utility in sport-specific activity phases of rehabilitation to reduce visual input and increase motor control.     

Dynamic balance is impaired after a match in young elite soccer players

PurposeThe aim of this study is to assess the effect of actual match effort on dynamic balance abilities in young elite soccer players.MethodsSeventeen Under 15 male players who compete at national level participated in the study. Their dynamic balance was assessed by having them jump starting with both feet on the ground in a standing position and land on one foot only. Their vertical time to stabilization (vTTS) and postural sway were calculated before and after 35 min of an unofficial match. Postural sway was assessed on the basis of center-of-pressure (COP) trajectories. Parameters considered were sway area, COP displacements in the antero-posterior (AP) and medio-lateral (ML) directions and COP path length.ResultsAfter the match, a significant increase in vTTS (p = 0.007) COP path length (p = 0.001) and COP displacements in ML (p < 0.001) was observed. Such effects involve both non-dominant (vTTS, path length) and dominant limb (COP displacements).ConclusionsThe physical effort associated with the match induces significant impairments of players' dynamic balance abilities. On the basis of such findings, coaches might consider integrating training sessions with specific balance exercises as well as performing injury-prevention routines even when players are fatigued, to better adapt them to match conditions.     

Shoulder functional status in rugby union players with and without history of shoulder problems

ObjectivesTo assess the effects of (1) rugby union practice, (2) history of injury managed nonoperatively, and (3) history of injury managed operatively on shoulder functional status in male rugby union players.DesignCross sectional study.SettingClinical.Participants86 male athletes were assigned into four groups: multisport athletes, rugby union players without shoulder problems, with history of shoulder injury managed nonoperatively and with history of shoulder injury managed operatively.Main outcome measuresSI-RSI questionnaire, maximal isometric glenohumeral internal and external rotator strength, unilateral seated shot put test, upper quarter Y balance test.ResultsHealthy players presented higher internal (p = 0.03) and external (p = 0.04) rotator strength than multisport athletes. History of shoulder injury managed nonoperatively did not impair physical abilities but limited player’s psychological readiness (p < 0.001). After 4.5-months, shoulder stabilization surgery impaired maximal muscle strength and upper quarter body stability and mobility (p < 0.001 for all).ConclusionsThe shoulder functional status in rugby union player presented increased glenohumeral rotator strength when compared to non-collision sport athletes. In rugby union players, psychological concerns remained in the long-term after a shoulder injury managed nonoperatively, and psychological and physical readiness seemed not be reached at 4.5 months postoperatively to respond to rugby union practice demand.     

Brain and muscle activation patterns during postural control affect static postural control

BackgroundPrevious studies have reported existence of coordinated brain and muscle activity patterns that affect postural control. However, differences in these activity patterns that affect postural control are still unclear. The purpose of this study was to clarify brain and muscle activity pattern affecting postural control.Research questionDoes the difference in brain and muscle activity patterns during postural control affect postural control ability?MethodNineteen healthy men (mean age: 24.8 ± 4.1 years, height: 171.8 ± 5.5 cm, and weight: 63.5 ± 12.5 kg) performed a postural control task on a balance board, and their brain and muscle activities and body sway during the task were measured using functional near-infrared spectroscopy, surface electromyography, and three-dimensional accelerometry. Hierarchical cluster analysis was conducted to extract subgroups based on brain and muscle activities and postural control, and correlation analysis was performed to investigate the relationship between brain activity, muscle activity, and postural control.ResultsTwo subgroups were found. Subgroup 1 (n = 9) showed higher brain activity in the supplementary motor area (p = 0.04), primary motor cortex (p = 0.04) and stable postural control in the mediolateral (p < 0.01) planes, and subgroup 2 (n = 10) showed higher muscle activity in the tibialis anterior (p < 0.01), a higher shank muscles co-contraction (p = 0.02) and unstable postural control. Furthermore, the supplementary motor area activity is negatively correlated with body sway of mediolateral plane (r = −0.51, p = 0.02), and tibialis anterior activity is positively correlated with body sway on the mediolateral plane (r = 0.62, p = 0.004).SignificanceHigher brain activity in motor-related areas, lower activity in the lower limb muscles and lower co-contraction of shank muscles were observed in stable postural control. These results will facilitate the planning of new rehabilitation methods for improving postural control ability.     

The effects of visual cognitive tasks on landing stability and lower extremity injury risk in high-level soccer players

BackgroundVisual cognition plays a pivotal role in sports. It is widely recognized that there is an intriguing coupling that they could affect each other through interaction between visual cognition and motor control, but few studies linked the effects of visual cognitive tasks on landing stability to postural control and injury risk.Research questionWhether visual cognitive tasks affect the landing stability and lower limb injury risk of professional soccer players?MethodsThe current study used a three-dimensional Multiple Object Tracking (MOT) task to simulate visual cognitive difficulties experienced in soccer matches. Fifteen male high-level soccer athletes (height: 181.43 ± 7.36 cm, weight: 75.37 ± 10.67 kg, training years: 10.07 ± 2.98 yr) from our school team were recruited and completed a landing action from a high platform with and without MOT tasks. Vicon infrared high-speed motion capture system and three-dimensional force measuring platform were used to collect various outcomes simultaneously.ResultsThe Time to Stabilization (TTS) during landing was significantly prolonged, while the Medial-Lateral Stability Index (MLSI), Anterior-Posterior Stability (APSI), Dynamic Postural Index Stability Index (DPSI), the trajectory lengths, and envelope area of COP during landing were also increased during MOT dual-task.DiscussionThe decline of these indicators reflected the deterioration in postural stability and greater requirements for maintaining balance which could increase the risk of injury in soccer athletes. We advocate that adequate visual attention and visual information processing might play critical roles in maintaining dynamic balance through the supraspinal neural network.     

The effects of gluteus medius and tibialis anterior kinesio taping on postural control,knee kinematics,and knee proprioception in female athletes with dynamic knee valgus

ObjectivesThis study aimed to investigate the effects of Kinesio taping on postural control, kinematics, and knee proprioception in female athletes with dynamic knee valgus (DKV).Design: a single-blind randomized clinical trial.Participants40 female athletes between the age of 18 and 28 years with DKV in single-leg drop landing (>13°) participated in this study. They were randomly classified into the Kinesio taping (KT) and placebo control (PC) groups.Main outcome measuresAll the evaluations and measurements were performed on each subject in the pre-test and post-test stages (with an interval of 72 h). The dynamic balance (Y balance test), proprioception (Knee position sense error), and knee kinematics (flexion and DKV angles) of the subjects were measured, prior and post gluteus medius and tibialis anterior KT.ResultsThe results of study demonstrate that the DKV angle and knee position sense error significantly decreased and YBT increased in the KT group from pre-test to post-test (p < 0.05). Nevertheless, there was no significant difference in knee flexion angle (p > 0.05).ConclusionThe results of the present study indicated that KT improves dynamic balance and proprioception and reduces the DKV angle. Therefore, KT is recommended for female athletes with DKV.     

Dynamic reach deficits in those with chronic ankle instability: A systematic review and meta-analysis

ObjectiveThe purpose of this review with meta-analyses was to determine the dynamic reach differences 1) between chronic ankle instability (CAI) and uninjured individuals, 2) between the limbs of an individual with CAI, and 3) between the uninvolved CAI limb and the healthy control limb across all possible reach directions of the Star Excursion Balance Test (SEBT).MethodsPubMed, CINAHL, SPORTDiscus, and Scopus databases were searched up to October 2021. Data were extracted from the retained studies and underwent methodological quality assessment and meta-analysis using random-effect models.ResultsAfter screening, 33 articles were included for the analyses. In all possible SEBT reach directions, the CAI group demonstrated significantly decreased normalized dynamic reach distances relative to the uninjured control group (SMDs: −0.66 to −0.48, p ≤ 0.05). Similarly, the involved CAI limb demonstrated significantly decreased normalized dynamic reach distances relative to the uninvolved CAI limb (SMDs: −0.61 to −0.33, p ≤ 0.05). However, no differences were noted between the uninvolved CAI limb and the healthy control limb (SMDs: −0.22 to 0.09, p ≥ 0.13).ConclusionsOur findings were that the involved limb of those with CAI has dynamic postural deficits relative to (i) an uninjured control group and (ii) relative to their uninvolved limb. However, the uninvolved limb of the CAI group does not differ from an uninjured control group in any reach direction.     

Neuromuscular training reduces lower limb injuries in elite female basketball players. A cluster randomized controlled trial

The study was a two‐armed, parallel group, cluster randomized controlled trial in which 15 teams (160 players) were assigned to either an experimental group (EG , 8 teams n = 86), which warmed‐up with bodyweight neuromuscular exercises, or a control group (CG , 7 teams, n = 74) that performed standard tactical‐technical exercises before training. All injuries during the 2015‐2016 regular season were counted. Epidemiologic incidence proportion and incidence rate were also calculated. Countermovement jump (CMJ ) and composite Y‐Excursion Balance test (YBT ) were used to assess lower limb strength and postural control. A total of 111 injuries were recorded. Chi‐square test detected statistically significant differences between EG and CG (32 vs 79, P  = .006). Significant differences in the injuries sustained in the EG (21 vs 11, P  = .024) and CG (52 vs 27, P  = .0001) during training and matches, respectively, were observed. Significant differences in post‐intervention injuries were observed between in EG and CG during training (21 vs 52, P  < .0001) and matches (11 vs 27, P  = .006). Significant differences in epidemiologic incidence (0.37 vs 1.07, P  = .023) and incidence rate (1.66 vs 4.69, P  = .012) between the EG and the CG were found. Significant improvement in CMJ (+9.4%, P  < .0001; d  = 1.2) and composite YBT (right: +4.4%, P  = .001, d  = 1.0; left: +3.0%, P  = .003; d  = 0.8) for the EG was noted. Significant differences in post‐intervention CMJ (+5.9%, P  = .004) and composite YBT scores (right, +3.7%, P  = .012; left, +2.3%, P  = .007) between the EG and the CG were observed. Including bodyweight neuromuscular training into warm‐up routines reduced the incidence of serious lower limb injuries in elite female basketball players.     

The effect of ankle Kinesio™ taping on ankle joint biomechanics during unilateral balance status among collegiate athletes with chronic ankle sprain

ObjectivesTo determine the effects of ankle Kinesio-taping (KT) on postural sway, lower limb ROM, and muscle activity during a unilateral balance tasks.DesignCase control study design.SettingData were collected at the human movement analysis laboratory.Participants30 collegiate athletes with chronic ankle sprain (11 females and 19 males, 23.91 ± 2.58 years).Main outcome measureHip, knee and ankle joints ranges of motion (ROMs); postural sway area and velocities in both anteroposterior and mediolateral directions; and muscular activity amplitudes (% peak) of lateral and medial gastrocnemius, tibialis anterior and peroneus longus in a 20s single leg balance test in two non-taped (control) and KT (intervention) conditions.ResultsSignificant decrease observed in ankle lateral ROM (p = 0.048, d = 0.52), mediolateral postural sway velocity (p = 0.029, d = 1.25), and peroneus longus activity amplitudes (p = 0.042, d = 0.55) after KT application.ConclusionAcute application of KT among athletes with chronic ankle instability could provide lateral mechanical support to the ankle, potentially decreasing the velocity of frontal plane sway, and decreasing the magnitude of muscle activation. These data suggest that KT may be beneficial for improving static joint stability among individuals with chronic ankle sprain, and thus could be considered an option to allow safe return-to-activity.     

Patellar tendinopathy with intratendinous alteration on MRI may be related to patellofemoral dysplasia

Patellar tendinopathy (PT ) is a frequent overuse injury of the extensor knee apparatus, whereas as up to 30% of the athletes might suffer from persisting symptoms during their entire career. In the present case‐control study, 47 patients (30.8 ± 11.4 years) with PT with intratendinous alteration (PT ita) of a minimum of ≥25% of the axial surface on MRI and minimum Blazina score of II (pain during without limiting sports activity) were included; MR images were analyzed for trochlear geometry, patellar height/tilt, and tibial tubercle‐trochlear groove distance (TT ‐TG ). The control group (CG ) comprised 87 age‐ and gender‐matched patients without history of anterior knee pain or lateral patellar instability. It was hypothesized that patients with PT might be related to patellofemoral dysplasia. It was found that the patella was significantly higher in patients with PT compared to the CG (patellotrochlear index [PT ‐I]: 0.33 vs 0.37, P  = .014; Insall‐Salvati index [InSa]: 1.18 vs 1.07, P  = .004). PT ‐I was above the cut‐off value in 10.6% of PT knees (CG 5.7%, P  = .27), and InSa in 42.6% (CG 21.8%, P  = .012). TT ‐TG was significantly higher in patients with PT compared to CG (12.0 mm vs 9.9 mm, P  = .002); however, TT ‐TG was only pathologic (>20 mm) in one patient. The trochlear facet ratio was above the cut‐off value in 55.3% of PT patients and 23% of CG (P  < .001), and was significantly greater in patients with PT (0.39 ± 0.09) than CG (0.48 ± 0.1, P  < .001). Knees with PT have significantly more morphological characteristics of patellofemoral instability, which needs to be considered especially in recurrent or treatment‐refractive cases.     

Dynamic postural stability differences between male and female players with and without ankle sprain

ObjectivesTo evaluate dynamic stability index (DSI) differences between males and females for different jump directions. To examine both preseason DSI differences between players with and without a history of ankle sprain, and between players with and without an ankle sprain during the subsequent season.DesignProspective cohort design.SettingLaboratory.Participants47 male (22.9 ± 3.9 y) and 19 female (21.5 ± 2.9 y) sub-elite and elite team sport players.Main outcome measuresAnkle sprain history was collected using an injury history questionnaire. DSI of a single-leg hop-stabilization task measured preseason was collected using force plates and calculated using a Matlab program. Ankle sprains were reported during the subsequent season.ResultsMale players demonstrated larger DSI than female players on forward medial/lateral stability index (MLSI) and vertical stability index (VSI), diagonal VSI, and lateral anterior/posterior stability index (APSI) and VSI. Forward, diagonal and lateral dynamic postural stability indices (DPSI) were larger for males (p < 0.001). No significant differences were found between players with and without a previous ankle sprain nor between players with and without an ankle sprain during the subsequent season.ConclusionMale players showed larger DSI scores than female players, indicating lower dynamic stability. Sex-specific training sessions or prevention programs should be developed.     

Atypical adaptive postural responses in children with developmental coordination disorder: Implications for rehabilitation

BackgroundAdaptive postural control is an important yet underexamined area in children with developmental coordination disorder (DCD). This study compared adaptive postural responses between children with DCD and those with typical development.MethodsThis was an exploratory cross-sectional study. Fifty-two children with DCD (aged 6–9 years) and 52 age- and sex-matched children with typical development participated in the study. Their adaptive postural (motor) responses were assessed using the Adaptation Test (ADT) on a computerized dynamic posturography machine. The sway energy score (SES) for each ADT trial and the average SES of five trials for both toes-up and toes-down platform inclination conditions were recorded.ResultsThe SESs were lower in the DCD group than in the control group in ADT toes-up trial 1 (p = 0.009) and on average (p = 0.044). In the control group, the SES decreased from trial 1 to trial 2 for both the ADT toes-up (p = 0.005) and toes-down conditions (p < 0.001).SignificanceAdaptive postural responses were absent in children with DCD, and these children used less force (i.e., sway energy) to overcome postural instability. Therefore, both adaptive balance and neuromuscular training should be factored into rehabilitation programs for children with DCD.     

Development of a preliminary multivariable diagnostic prediction model for identifying active spondylolysis in young athletes with low back pain

AimsThe primary aim of this study was to develop a diagnostic cluster of common clinical findings that would assist in ruling out an active spondylolysis in adolescent athletes with low back pain (LBP).DesignRetrospective case-series.SettingHospital-based sports medicine clinic.PatientsOne thousand and twenty-five adolescent athletes with LBP (age 15.0 ± 1.8 years, 56% female) were reviewed. Active spondylolytic injuries were identified in 22% (n = 228) of these patients.Main outcome measurepresence or absence of active spondylolysis on advanced imaging.ResultsThrough logistic regression analysis, pain with extension (p < 0.001), difference between active and resting pain ≥3/10 (p < 0.001), and male sex (p = 0.002) were identified as significantly associated with active spondylolysis. The clinical cluster had a sensitivity of 88% (95% CI 83%–93%) to help rule out active spondylolysis. The negative likelihood ratio was 0.34 (95% CI 0.23–0.51) and the negative predictive value was 90% (95% CI 86%–93%). Diagnostic accuracy of the cluster was acceptable (area under the curve = 0.72 (95% CI 0.69, 0.76; p < 0.001).ConclusionThis study found a cluster of three patient characteristics that may assist in ruling out active spondylolysis in adolescent athletes with LBP.     

Evaluation of postural control in children with increased femoral anteversion

BackgroundFemoral anteversion is defined as the angular difference between the axis of the femoral neck and the transcondylar axis of the knee and the most common cause of an in-toe gait in children.Research questionDoes increased femoral anteversion (IFA) adversely affect postural stability and balance in healthy children?MethodsSixteen children with IFA aged 10–15 years and an age-matched control group of 16 children who were growing typically were included. Postural stability (PS), limits of stability (LoS), and the modified clinical test of sensory integration of balance (mCTSIB) were used to evaluate postural control by "Biodex Balance System® (BBS)" and Balance Error Scoring System (BESS), which is a visual observation of instability in 3 stance positions under 6 different conditions, were performed for all cases. SPSS v.20 program was used for data analysis. Independent Samples T-test or Mann Whitney U test were used for between-group comparisons depending on the distribution properties of the data. The significance level was set at p < 0.05.ResultsA significant difference was found between the groups for overall and anterior/posterior stability index in PS (p < 0.05), all parameters of LoS (p < 0.05) and mCTSIB (p < 0.05). Also there was a significant difference between the BESS firm surface (p = 0.007), BESS foam surface (p < 0.001), and total surface scores (p < 0.001).SignificanceThe results indicate that the children with IFA were significantly more unstable in all parameters of BBS and BESS when compared to their healthy peers. This shows that postural stability and balance are impaired in healthy children with IFA. To the extent of our knowledge, this study is the first to examine the postural control problems associated with IFA in healthy children.     

Trunk muscle size and function in volleyball players with and without injuries to the head,neck and upper limb

ObjectiveTo investigate trunk muscle size and function in elite and community volleyball players with and without a history of head, neck or upper limb injury.DesignCross-sectional observational study.SettingVolleyball training camp or training sessions.Participants86 volleyball players (elite = 29; community = 57).Main outcome measuresInformation regarding history of head, neck or upper limb injuries was collected by self-report questionnaires. Trunk muscle size (multifidus, transversus abdominis, internal oblique and quadratus lumborum) and voluntary contraction (multifidus, transversus abdominis, internal oblique) were assessed using ultrasound imaging.ResultsFor trunk muscle size, no significant differences were found between elite and community volleyball players with and without a history of injury (all p > 0.05). A significant difference was found for voluntary contraction of the multifidus and transversus abdominis muscles for elite and community volleyball players with and without a history of injury (all p < 0.05).ConclusionA difference in trunk muscle contraction but no change in trunk muscle size in players with a history of head, neck or upper limb injuries may represent an altered muscle recruitment pattern rather than a deficiency in trunk muscle strength. Prospective studies are required to determine if these adaptations are compensatory (and protective) or predispose players to further injuries.     

Ankle muscle activation during the limits of stability test in subjects with chronic ankle instability

ObjectiveTo study postural control and muscle activity during the limit of stability test (LOS) in subjects with chronic ankle instability.DesignObservational study.SettingUniversity laboratory.Participants10 healthy subjects were included in the control group and 10 subjects in the CAI group (age between 18 and 30 years, with history of the multiple ankle “giving way” episodes in the last six months and score ≤24 in the Cumberland Ankle Instability Tool).Main outcome measuresA computerized dynamic posturography equipment was used for assessing the LOS. The electromyography activity of tibialis anterior (TA), soleus (SOL), medial gastrocnemius (MG) and peroneus longus (PL) was registered.ResultsSubjects with CAI had a greater activation in TA to forward (p < .01), forward affected (p = .001), backward affected (p = .007) and backward directions (p < .01); in PL to forward affected (p < .01) and affected directions (p = .001); in MG to forward (p = .023) and affected directions (p < .01) and in SOL to the affected direction (p = .009). We observed restricted excursions and less directional control in subjects with CAI.ConclusionsSubjects with CAI exhibited poorer ability to move their center of gravity within stability limits. In addition, they have an altered ankle muscle activity during LOS test toward the affected ankle joint.