Kyeongtak Song

Increased Visual Use in Chronic Ankle Instability: A Meta-analysis

PURPOSE The underlying cause of balance impairments in chronic ankle instability (CAI) patients remains unknown, but an altered use of sensory information has been hypothesized as a potential cause. The purpose of this systematic review with meta-analysis was to determine whether CAI patients use somatosensory information to the same extent as uninjured controls during static single limb stance. METHODS We searched PubMed, CINAHL, SPORTDiscus, and Scopus databases from origin to March 2016 using the combination of key words, including postural control, postural stability, single limb stance, single leg stance, single leg balance, single limb balance, and time to boundary (TTB). Eligible studies had to include instrumented single leg stance with both eyes open and eyes closed in healthy, CAI, or both groups as well as report TTB mean and SD values. RESULTS A total of 11 articles were identified. Effect sizes using eyes closed to eyes open standardized mean differences and 95% confidence intervals were calculated for all studies that were included in this investigation. Similarly, pooled estimates for each TTB outcome were compared between the CAI and the uninjured control groups. The mean (95% confidence interval) of the mediolateral TTB (control: -1.50 [-1.71 to -1.29]; CAI: -2.04 [-2.31 to -1.77]), anterioposterior mean (control: -2.19 [-2.43 to -1.96]; CAI: -2.82 [-3.13 to -2.52]), and anterioposterior SD (control: -1.81 [-2.03 to -1.58]; CAI: -2.50 [-2.79 to -2.22]) did not overlap, indicating significant differences between two groups. CONCLUSION On the basis of our systematic review with meta-analysis, it appears that CAI patients do not use somatosensory information to the same extent as uninjured controls and instead upregulate the use of visual information during single limb stance.

Visual Utilization During Postural Control in Anterior Cruciate Ligament– Deficient and –Reconstructed Patients: Systematic Reviews and Meta-Analyses

OBJECTIVE To determine whether anterior cruciate ligament-deficient (ACL-D) individuals and individuals with a reconstructed anterior cruciate ligament (ACL-R) rely more heavily on visual information to maintain postural control. DATA SOURCES PubMed, CINAHL, and SPORTDiscus databases were searched from their earliest available date to May 24, 2016, using a combination of keywords. STUDY SELECTION Articles were included if they reported any instrumented static single-leg balance outcome in both a patient and control sample. The means and SDs of these outcomes must have been reported with both eyes open and eyes closed. DATA EXTRACTION Sample sizes, means, and SDs of single-leg balance measures for each groups eyes open and eyes closed testing conditions were extracted. The methodological quality of included studies was independently evaluated by multiple authors using an adapted version of the Quality Index. DATA SYNTHESIS Effect sizes were calculated by dividing the differences in change between eyes closed and eyes open in the ACL-D and control group and the ACL-R and control group by the pooled SD from the eyes closed trials for each analysis. Significant differences between the ACL-D and control group (effect size, -1.66; 95% confidence interval [CI], -2.90 to -.41) were noted. The ACL-R and control group were not different (effect size, -.61; 95% CI, -2.17 to .95). CONCLUSIONS ACL-D individuals but not individuals with ACL-R demonstrate a greater reliance on visual information during single-leg stance compared with healthy individuals.

Comparative Effectiveness of Plantar-Massage Techniques on Postural Control in Those With Chronic Ankle Instability

CONTEXT   One of the major concerns after an acute lateral ankle sprain is the potential for development of chronic ankle instability (CAI). The existing research has determined that clinician-delivered plantar massage improves postural control in those with CAI. However, the effectiveness of self-administered treatments and the underlying cause of any improvements remain unclear. OBJECTIVES   To determine (1) the effectiveness of a self-administered plantar-massage treatment in those with CAI and (2) whether the postural-control improvements were due to the stimulation of the plantar cutaneous receptors. DESIGN   Crossover study. SETTING   University setting. PATIENTS OR OTHER PARTICIPANTS   A total of 20 physically active individuals (6 men and 14 women) with self-reported CAI. INTERVENTION(S)   All participants completed 3 test sessions involving 3 treatments: a clinician-delivered manual plantar massage, a patient-delivered self-massage with a ball, and a clinician-delivered sensory brush massage. MAIN OUTCOME MEASURE(S)   Postural control was assessed using single-legged balance with eyes open and the Star Excursion Balance Test. RESULTS   Static postural control improved (P ≤ .014) after each of the interventions. However, no changes in dynamic postural control after any of the interventions were observed (P > .05). No differences were observed between a clinician-delivered manual plantar massage and either a patient-delivered self-massage with a ball or a clinician-delivered sensory brush massage in any postural-control outcome. CONCLUSIONS   In those with CAI, single 5-minute sessions of traditional plantar massage, self-administered massage, and sensory brush massage each resulted in comparable static postural-control improvements. The results also provide empirical evidence suggesting that the mechanism for the postural-control improvements is the stimulation of the plantar cutaneous receptors.

Six Sessions of Anterior-to-Posterior Ankle Joint Mobilizations Improve Patient-Reported Outcomes in Chronic Ankle Instability Patients: A Critically Appraised Topic

Clinical Scenario: Chronic ankle instability (CAI) is a complex musculoskeletal condition that results in sensorimotor and mechanical alterations. Manual therapies, such as ankle joint mobilizations, are known to improve clinician-oriented outcomes like dorsiflexion range of motion, but their impact on patient-reported outcomes remains less clear. Focused Clinical Question: Do anterior-to-posterior ankle joint mobilizations improve patient-reported outcomes in patients with chronic ankle instability? Summary of Key Findings: Three studies (2 randomized controlled trials and 1 prospective cohort) quantified the effect of at least 2 weeks of anterior-to-posterior ankle joint mobilizations on improving patient-reported outcomes immediately after the intervention and at a follow-up assessment. All 3 studies demonstrated significant improvements in at least 1 patient-reported outcome immediately after the intervention and at the follow-up assessment. Clinical Bottom Line: At least 2 weeks of ankle joint mobilization improves patient-reported outcomes in patients with chronic ankle instability, and these benefits are retained for at least a week following the termination of the intervention. Strength of Recommendation: Strength of recommendation is grade A due to consistent good-quality patient-oriented evidence.

O8 The relationship between t1ρ magnetic resonance imaging & ultrasonography measurements of the talar cartilage in individuals with chronic ankle instabiltiy

Study Design Correlational study. Objectives To determine if T1ρ MRI is associated with ultrasonography(US) measurements of talar cartilage in those with chronic ankle instability (CAI). Background Recurrent ankle injuries are a leading cause of post-traumatic ankle osteoarthritis (PTAOA). Reduced proteoglycan density (PGD) measured using T1ρ MRI is an early indicator of PTOA. US has been used to monitor joint health in people with knee OA, but the relationship between US and T1ρ MRI in CAI patients remains unknown. Methods and Measures 9 CAI patients participated. T1ρ MRI was performed using a Siemens Magnetom TIM Trio 3T scanner. Segmentation of the T1ρ MRI images was done using ITK-SNAP software. Four regions of interest (ROI): anteromedial (AM), anterolateral (AL), posteromedial (PM), and posterolateral (PL) were identified. Talar cartilage thickness was measured using ultrasound while patients were positioned supine on the examination table. The ultrasound transducer was positioned for a longitudinal view over the medial, middle, and lateral aspect of the talocrural joint. The thickness was measured using the ImageJ software program at the midpoint of each image. Correlations between mean T1ρ relaxation times and cartilage thickness values in each ROI were analysed using Pearson correlation coefficients. Statistical significance was set at p<0.05 for all analyses. Results A significant correlation between T1ρ relaxation time (r=0.786, p=0.012) in the PL ROI and middle talar cartilage thickness was noted and a trend was noted for middle talar cartilage and T1ρ relaxation times in the PM (r=0.647, p=0.060) ROI. No other significant correlations were found. Conclusions Positive correlations between T1ρ relaxation times (higher T1ρ=less PGD density) and greater talar cartilage thickness may be explained by increased water content (swelling) in the cartilage due to greater cartilage breakdown. US measurements may be able to detect early degenerative change in CAI patients but further research is needed.

Comparative Effectiveness of Plantar Massage Techniques on Postural Control in those with Chronic Ankle Instability: 2601 Board #124 June 3, 11

Mechanism(s) that contribute to the development of chronic ankle instability are not understood. Previous investigators have developed a hypothetical model, where neuromuscular alterations that stem from damaged ankle ligaments are thought to affect periarticular and proximal muscle activity. Yet, the retrospective nature of these studies does not allow for a causal link. PURPOSE: To assess temporal alterations in muscle activity of two periarticular muscles and two proximal muscles of the rat hindlimb following an ankle sprain. METHODS: Five (16 weeks-of-age, 400±13.5g) male Long Evans rats were surgically instrumented with fine wire electromyographical (EMG) electrodes that were implanted in the tibialis anterior (TA), gastrocnemius (MG), vastus lateralis (VL), and biceps femoris (BF) muscles. Baseline EMG were recorded while rats walked on a motor driven treadmill (16m/min) and then a closed lateral ankle sprain was induced by overextension of the lateral ankle ligaments. After ankle sprain, the rats were placed back on the treadmill every 24 hours for 7 days of post-sprain EMG data. Altered muscle activity was quantified via changes in muscle onset time, phase duration, and sample entropy that were compared to baseline EMG using two-tailed dependent t-tests. Minimum detectable change (MDC) was also calculated for sample entropy to quantify the change in muscle activity outside of measurement error that reflected true change. RESULTS: Compared to baseline, BF and TA muscles was found to exhibit delayed onset time (ms; BF:baseline:-16.7±54.0; day0:5.23±64.1; TA: baseline:307.0±64.2; day3:362.5±55.9; day6:357.3±39.6, P<0.05) and longer phase durations were observed for the VL and TA (ms; VL:baseline:321.9±92.6; day3:401.3±101.2; day4:404.1±93.0; day5:364.6±105.2, TA:baseline:105.3±14.5; day4:154.9±7.8; day6:141.9±16.2, P<0.05). After sprain, greater sample entropy was found for the VL and TA (VL:baseline:0.69±0.3; day6:0.93±0.4; day7:0.85±0.3; TA:baseline:0.62±0.4; day4:0.90±0.5, P<0.05). MDC analysis revealed increased sample entropy values for the VL and TA. CONCLUSION: Manually inducing an ankle sprain in a rat via overextension of the lateral ankle ligaments alters the coordination of VL and TA muscles that exceeded the MDC of the baseline data.