Assessments of Sensorimotor Deficits Used in Randomized Clinical Trials With Individuals With Ankle Sprains and Chronic Ankle Instability: A Scoping Review

Postural Control Deficits During Static Single-leg Stance in Chronic Ankle Instability: A Systematic Review and Meta-Analysis

CONTEXT

Postural control deficits arising from injured ankles are central to chronic ankle instability (CAI) and its persistent symptoms. This is usually measured by recording the center of pressure (CoP) trajectory during static single-leg stance using a stable force plate. However, existing studies have produced conflicting results on whether this mode of measurement adequately reveals the postural deficits in CAI.

OBJECTIVE

To determine whether postural control during static single-leg stance is impaired in CAI patients when compared with uninjured healthy controls.

DATA SOURCES

Literature databases, PubMed, Embase, Web of Science, Cochrane Library, Scopus, CINAHL, and SPORTDiscus, were searched from inception to April 1, 2022, using ankle-, injury-, and posture-related terms.

STUDY SELECTION

Two authors independently performed the step-by-step screening of article titles, abstracts, and full texts to select peer-reviewed studies investigating CoP trajectory during static single-leg stance using a stable force plate in CAI patients and healthy controls. A total of 13,637 studies were reviewed, and 38 studies (0.003%) met the selection criteria.

STUDY DESIGN

Meta-analyses of descriptive epidemiological study.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

CoP parameters, sway directions, visual condition, and numerical data (means and standard deviations) were extracted.

RESULTS

The injured ankles of CAI patients had higher standard deviations of sway amplitude in both anterior-posterior and medial-lateral directions (standardized mean difference [SMD] = 0.36 and 0.31, respectively) under conditions of open eyes than controls. Higher mean sway velocity in anterior-posterior, medial-lateral, and total directions (SMD = 0.41, 0.37, and 0.45, respectively) with closed eyes was also found.

CONCLUSION

CAI patients had deficits of postural control during static single-leg stance, and these deficits were identified by the CoP trajectory. Further methodological explorations of CoP parameters and corresponding test conditions are required to enhance the sensitivity and reliability of postural deficit assessments in CAI using force plates.

Insufficient recovery of proprioception in chronic ankle instability after surgical restabilization: A systematic review

Surgical repair or reconstruction of the lateral ligaments for patients with chronic ankle instability (CAI) could, logically, restore the proprioception of ankle through retensing receptors. To validate this hypothesis, seven databases were systematically searched, and thirteen studies comprising a total of 347 patients with CAI were included. Although five studies reported improved proprioceptive outcomes after surgeries, the other five studies with between-limb/group comparisons reported residual deficits at final follow-up, which does not consistently support proprioceptive recovery after existing surgical restabilization for CAI. More controlled studies are needed to provide evidence-based protocols to improve proprioceptive recovery after ankle restabilization for CAI.

The Accuracy of Ankle Eccentric Torque Control Explains Dynamic Postural Control During the Y-Balance Test

Background

The Y-Balance Test (YBT), especially the posteromedial (PM) reach direction (PM-YBT), is able to identify dynamic postural control deficits in those who have ankle instability. However, there still exists a need to understand how sensorimotor function at the ankle explains the performance during the PM-YBT.

Hypothesis/Purpose

The purpose of this study was to determine whether the ability to accurately control eccentric ankle torque explained PM-YBT performance. It was hypothesized that eccentric dorsiflexion/plantarflexion torque control would be positively related to the maximum reach distance (MRD) of PM-YBT.

Study Design

Cross-sectional study.

Methods

Twelve healthy subjects performed the PM-YBT, maximum voluntary isometric contractions (MVIC) for both dorsiflexion and plantarflexion muscle strength, and then the torque control testing of the ankle. The torque control testing provided a target torque level on a screen in front of the subject and passive rotations of the ankle joint in the sagittal plane at 10 deg/sec between plantarflexion to dorsiflexion. Subjects were then instructed to eccentrically contract the dorsiflexors and plantar flexors to generate torque while the ankle joint rotated. The accuracy of torque control during eccentric dorsiflexion and plantarflexion by calculating absolute errors, the area between the target torque and the produced torque were evaluated. Tibialis anterior and soleus muscle activities were simultaneously recorded during testing. A step-wise linear regression model was used to determine the best model predicted the MRD of the PM-YBT (PM-MRD).

Results

A step-wise linear regression developed a model explaining only eccentric dorsiflexion torque control predicted higher PM-MRD score (R2 = 44%, F1,10 = 7.94, β = -0.67, p = 0.02).

Conclusion

The accuracy of torque control during eccentric dorsiflexion predicts better performance in the PM-YBT.

Level of Evidence

3b.

Inertial Sensor-Based Assessment of Static Balance in Athletes with Chronic Ankle Instability

The Balance Error Scoring System (BESS), a subjective examiner-based assessment, is often employed to assess postural balance in individuals with chronic ankle instability (CAI); however, inertial sensors may enhance the detection of balance deficits. This study aimed to compare the BESS results between the CAI and healthy groups using conventional BESS scores and inertial sensor data. The BESS test (six conditions: double-leg, single-leg, and tandem stances on firm and foam surfaces, respectively) was performed for the CAI (n = 16) and healthy control (n = 16) groups with inertial sensors mounted on the sacrum and anterior shank. The BESS score was calculated visually by the examiner by counting postural sway as an error based on the recorded video. The root mean square for resultant acceleration (RMS_acc) in the anteroposterior, mediolateral, and vertical directions was calculated from each inertial sensor affixed to the sacral and shank surfaces during the BESS test. The mixed-effects analysis of variance and unpaired t-test were used to assess the effects of group and condition on the BESS scores and RMS_acc. No significant between-group differences were found in the RMS_acc of the sacral and shank surfaces, and the BESS scores (P > 0.05), except for the total BESS score in the foam condition (CAI: 14.4 ± 3.7, control: 11.7 ± 3.4; P = 0.039). Significant main effects of the conditions were found with respect to the BESS scores and RMS_acc for the sacral and anterior shank (P < 0.05). The BESS test with inertial sensors can detect differences in the BESS conditions for athletes with CAI. However, our method could not detect any differences between the CAI and healthy groups.

Effects of Conservative Interventions on Static and Dynamic Balance in Individuals With Chronic Ankle Instability: A Systematic Review and Meta-analysis

OBJECTIVE

To determine which conservative interventions are effective for static and dynamic balance in patients with chronic ankle instability (CAI).

DATA SOURCES

PubMed, Cochrane Library, Web of Sciences, and CINAHL databases were searched up to March 20, 2022.

STUDY SELECTION

Randomized controlled trials investigating the effects of conservative interventions on static and/or dynamic balance in patients with CAI compared with those of different conservative interventions or controls were included.

DATA EXTRACTION

Two independent reviewers extracted the data. Certainty of the evidence was assessed using the GRADE approach.

DATA SYNTHESIS

Forty-eight studies (1906 participants) were included. Whole-body vibration training (WBVT) was significantly more effective than controls for both static (standardized mean difference, 1.13; 95% confidence interval [CI], 0.58-1.68; moderate-certainty evidence) and dynamic balance (0.56; CI, 0.24-0.88; low-certainty evidence). Balance training (BT) and joint mobilization were significantly more effective than controls for dynamic balance (0.77; CI, 0.41-1.14; and 0.75; CI, 0.35-1.14, respectively), but not for static balance (very low to low-certainty evidence). Adding other interventions to BT had no significant effect on either type of balance compared with that of BT alone (moderate to low-certainty evidence). Strength training (ST) and taping had no significant effect on either type of balance (very low- to low-certainty evidence). Multimodal interventions were significantly effective in improving dynamic balance (0.76; CI, 0.32-1.20; low-certainty evidence). Adding transcranial direct current stimulation to ST was significantly more effective for dynamic balance than ST (0.81; CI, 0.08-1.53; moderate-certainty evidence). The effects on balance were not significantly different among BT, ST, and WBVT (very low- to low-certainty evidence).

CONCLUSIONS

The significantly effective interventions reviewed may be treatment options for balance impairments associated with CAI. However, interventions should be chosen carefully, as much of the certainty of evidence is very low to low.