Xiao’ao Xue

BACKGROUND: Acute ankle injury causes damage to joint mechanoreceptors and deafferentation and contributes to proprioception deficits in patients with chronic ankle instability (CAI). We aimed to explore whether deficits of proprioception, including kinesthesia and joint position sense (JPS), exist in patients with CAI when compared with the uninjured contralateral side and healthy people. We hypothesized that proprioception deficits did exist in patients with CAI and that the deficits varied by test methodologies. METHODS: The study was a systematic review and meta-analysis. We identified studies that compared kinesthesia or JPS in patients with CAI with the uninjured contralateral side or with healthy controls. Meta-analyses were conducted for the studies with similar test procedures, and narrative syntheses were undertaken for the rest. RESULTS: A total of 7731 studies were identified, of which 30 were included for review. A total of 21 studies were eligible for meta-analysis. Compared with the contralateral side, patients with CAI had ankle kinesthesia deficits in inversion and plantarflexion, with a standardized mean difference (SMD) of 0.41 and 0.92, respectively, and active and passive JPS deficits in inversion (SMD = 0.92 and 0.72, respectively). Compared with healthy people, patients with CAI had ankle kinesthesia deficits in inversion and eversion (SMD = 0.64 and 0.76, respectively), and active JPS deficits in inversion and eversion (SMD = 1.00 and 4.82, respectively). Proprioception deficits in the knee and shoulder of patients with CAI were not statistically significant. CONCLUSION: Proprioception, including both kinesthesia and JPS, of the injured ankle of patients with CAI was impaired, compared with the uninjured contralateral limbs and healthy people. Proprioception varied depending on different movement directions and test methodologies. The use of more detailed measurements of proprioception and interventions for restoring the deficits are recommended in the clinical management of CAI.

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.

OBJECTIVE: Patients with chronic ankle instability (CAI) may experience ankle force sense deficits due to mechanoreceptor injury and proprioceptive deafferentation in the affected ankles. This study aimed to systematically review the literature and investigate (1) whether patients with CAI have impaired force sense when compared with uninjured contralateral sides or healthy controls, and (2) which characteristics of CAI (e.g., any measurement of CAI symptoms, clinical questionnaires, or functional tests on the injured ankles) are correlated with force sense deficits. TYPE: Systematic review and meta-analysis. LITERATURE SURVEY: PubMed, Embase, Web of Science, Cochrane Library, Scopus, CINAHL, and SPORTDiscus were searched for ankle-related, injury-related, and force sense-related terms from inception to February 2, 2022. METHODOLOGY: The following information was extracted from included articles: demographic data, sample size, selection criteria, methodology, force reproduction test outcomes, and correlations between force sense and other characteristics of CAI. Meta-analyses were conducted for the force sense outcomes, and a narrative review was undertaken for the correlation between force sense deficits and other characteristics of CAI. SYNTHESIS: Eight studies were included. The meta-analyses revealed eversion force sense deficits of the injured ankles in absolute error (magnitude of force reproduction error) at 20% maximal voluntary isometric contractions (MVIC) (standardized mean difference [SMD] = 0.67, 95% confidence interval [CI] 0.23-1.11) and variable error (consistency of force reproduction) at 30% MVIC (SMD = 0.46, 95% CI 0.07-0.85), as compared with healthy controls. None of the included studies reported a significant correlation between these two deficits and other characteristics of CAI. CONCLUSIONS: Patients with CAI have eversion force sense deficits in the magnitude of force reproduction error at 20% MVIC and the consistency of force reproduction at 30% MVIC.