CAI Group Research Articles

Contralateral cutaneous reflex modulation during gait in individuals with and without chronic ankle instability

IntroductionChronic ankle instability (CAI), a common seqeula to ankle injury is characterized by a variety of sensorimotor deficits extending beyond the previously injured limb. Cutaneous reflexes have been identified as a potential contributor to these functional limitations with recent studies identifying alterations in reflex patterns following sural nerve stimulation among those with CAI. To date, no studies have measured cutaneous reflexes of the unaffected limb in this population, therefore, the objective of this study was to measure contralateral cutaneous reflexes during gait in individuals with unilateral CAI and healthy controls. MethodsMuscle activity of 6 lower limb muscles was measured in nineteen participants while receiving random, non-noxious sural nerve stimulations during a walking task. ResultsControl reflex patterns were generally well-aligned with previous literature while CAI patterns varied from controls in several muscles throughout the gait cycle. Namely, a lack of lateral gastrocnemius facilitation during late stance and medial gastrocnemius inhibition at midstance. Additionally, a lack of significant BF facilitation throughout contralateral swing was noted. These results indicate reflex alterations extend beyond the affected limb in those with unilateral CAI indicating changes at the spinal level following lateral ankle sprains (LAS). Considering the symptom variability in CAI, the lack of significant reflexes exhibited by the CAI group may be due to increased variability in motor output between subjects or between stimulation trials. ConclusionsThese findings highlight the importance of identifying reflex alterations arising from LAS and subsequently treating these limitations through rehabilitation targeting systemic neural pathways rather than local deficits.

Task-specific differences in lower limb biomechanics during dynamic movements in individuals with chronic ankle instability compared with controls

BackgroundChronic ankle instability (CAI) has been associated with lower limb deficits that can lead to altered biomechanics during dynamic tasks. There have been contradictory findings in terms of ankle and hip joint biomechanics to date, influenced by the variety of movement tasks and varying definitions of the CAI condition. Research QuestionHow do biomechanical variables of the lower extremity differ during walking, running, and jump-landing in individuals with CAI compared with those without CAI? MethodsThirty-two individuals (17 CAI and 15 controls) participated in this retrospective case-control study. Sagittal and frontal plane ankle and hip joint angles and moments, and mediolateral foot balance (MLFB) were calculated during the tasks. Statistical parametric mapping (SPM) was used for the whole trajectory analysis to detect group differences. Discrete variables, including initial contact (IC) and peak angles and moments, were additionally compared. ResultsNo differences were found between groups during walking. During running, the CAI group exhibited a lower plantar flexor moment (p < 0.001) and more laterally deviated MLFB (p = 0.014) during mid-stance when compared to controls. Additionally, participants with CAI had a significantly greater peak plantar flexion angle in early stance (p = 0.022) and a reduced peak plantar flexor moment (p = 0.002). In the jump-landing, the CAI group demonstrated an increased hip extensor moment (p = 0.008), and a greater peak hip adduction angle (p = 0.039) shortly after ground contact compared to the control group. SignificanceDifferences in ankle and hip biomechanics were observed between groups during running and jump landing, but not during walking. These differences may be indicative of impairments in the sensorimotor system or of learnt strategies adopted to try to minimise instability and injury risk and can help to inform future intervention design.

Gait kinematics and kinetics in patients with chronic ankle instability and healthy controls: A statistical parametric mapping analysis

BackgroundChronic ankle instability (CAI) is associated with changes in gait biomechanics which may be related to chronic dysfunction. Traditional statistical models may be limited in their ability to assess the complex 3D movement of the lower extremity during gait. Multivariate analysis of the lower extremity kinematics may reveal unique biomechanical differences associated with CAI. Research Question: Do patients with CAI differ from healthy controls in their lower extremity biomechanics and GRF when comparing 3D biomechanics? MethodsThirty-nine young, active adults participated in this study. Data was collected using a 3D motion analysis system while patients walked and jogged. Statistical parametric mapping (SPM) was used to explore 3D GRF, kinematics and kinetics of the of the lower extremity of CAI and healthy patients. ResultsDuring walking, patients with CAI had greater inversion from 68–100% of gait cycle (p < 0.001, mean difference=3.2°). During jogging, patients with CAI had greater inversion from 20–92% (p < 0.001, mean difference=4.6°). Greater plantar flexion moments were found from 65–71% (p = 0.05, mean difference=347.4Nm/kg) and greater eversion moments were found from 95–100% (p = 0.03, mean difference=74.6Nm/kg) in the CAI group. No differences in GRF were found.Significance:Greater inversion may present a potentially injurious position. A faulty position of the rearfoot may require greater muscle function in order to correct the position of the joint resulting in greater eversion moments at the ankle. However, this kinetic change does not appear to correct the ankle position.

Differences in postural control between healthy and subjects with chronic ankle instability

IntroductionChronic ankle instability (CAI) is characterized by the occurrence of repetitive inversion mechanism of the ankle, resulting in numerous ankle sprains. CAI occurs in approximately 70% of patients with a history of a lateral ankle sprain. Many causes of functional ankle instability have been postulated and include deficits in proprioception, impaired neuromuscular-firing patterns, disturbed balance and postural control. ObjectiveThe purpose of this study was to compare postural control behaviour in subjects with chronic ankle instability and healthy subjects, using the traditional linear and nonlinear variables for the centre of pressure (CoP) displacement, during one-leg stance on stable and unstable surfaces. Methods16 CAI subjects and 20 healthy subjects were evaluated with the single leg stance on a stable surface and an unstable surface, for 60 s with a force plate. The traditional linear variables like CoP displacement, CoP amplitude and CoP velocity were calculated. Variability of CoP displacement was also submitted to nonlinear analysis and the approximated entropy, sample entropy, correlation dimension and Lyapunov exponent were calculated. ResultsOn the stable surface, no differences between groups for all the traditional variables were found but the correlation dimension of CoP mediolateral displacement had lower values on the CAI group with statistical significance (p < 0.05). On the unstable surface, no differences were found neither with linear variable neither with variability nonlinear analysis. ConclusionCorrelated dimension of CoP displacement during one-leg stance on a stable surface was the only variable that show significant differences between the two groups. The lower values of this variable in the CAI subjects may implicate a balance control system with more difficulties to adapt to the environment and the task demands. More studies are needed to better understand CAI subjects balance control.

Quantitative analysis with load–displacement ratio measured via digital arthrometer in the diagnostic evaluation of chronic ankle instability: a cross-sectional study

BackgroundArthrometry has been introduced to evaluate the laxity of ankle joint in recent years. However, its role in the diagnosis of chronic ankle instability is still debatable. Therefore, we assessed the diagnostic accuracy of a digital arthrometer in terms of sensitivity and specificity.MethodsAccording to the inclusion and exclusion criteria proposed by the International Ankle Consortium, we recruited 160 uninjured ankles (control group) and 153 ankles with chronic ankle instability (CAI group). Ankle laxity was quantitively measured by a validated digital arthrometer. Data of loading force and joint displacement were recorded in a continuous manner. Differences between the control and CAI groups were compared using 2-tailed independent t test. A receiver operating characteristic curve analysis was used to calculate area under a curve, sensitivity and specificity.ResultsLoad–displacement curves of the two groups were depicted. Differences of joint displacement between the control and CAI groups were compared at 30, 45, 60, 75, 90, 105 and 120 N, which were all of statistical significance (all p < 0.001) with the largest effect size at 90 N. Statistical significance was found in the differences between the two groups in load–displacement ratio at 10–120 N, 10–40 N, 40–80 N and 80–120 N (all p < 0.001), with the largest effect size at 10–40 N. Load–displacement ratio at the interval of 10–40 N had the highest area under a curve (0.9226), with sensitivity and specificity of 0.804 and 0.863, respectively, when the cutoff point was 0.1582 mm/N.ConclusionThe digital arthrometer measurement could quantitively analyze the ankle laxity with high diagnostic accuracy. The load–displacement ratio would be a reliable and promising approach for chronic ankle instability diagnosis.Level of evidence level II.

Effect of prior immunotherapy on the efficacy of chemotherapy in advanced non-small cell lung cancer: A retrospective study.

BackgroundThe effect of the sequential combination of chemotherapy and immune checkpoint inhibitors (ICIs) remains unclear. Here, we evaluated the efficacy of different chemotherapy regimens administered after ICIs in advanced non‐small cell lung cancer (NSCLC), compared to the same regimens administered without previous ICIs.MethodsWe retrospectively included all patients treated between 2015 and 2019 for an advanced NSCLC, receiving a salvage chemotherapy just after ICI (CAI group) comparing them to ICI naive patients (CWPI group) undergoing the same chemotherapy at Bordeaux University Hospital. The primary outcome was the time to treatment discontinuation (TTD), and secondary endpoints were overall survival (OS) and overall response rate (ORR).ResultsA total of 152 patients were included, with 34/23 (CAI/CWPI) receiving paclitaxel/bevacizumab (PB), 24/11 paclitaxel (P), 27/12 gemcitabine (G) and 6/15 pemetrexed (PE). Characteristics were comparable, except for CAI treated with PB (more patients with an ECOG PS ≤1 [p <0.001]). Median number of lines received was higher in CAI for all groups. There was no difference between CAI and CWPI for TTD, OS and ORR. However, PB was associated with a nonsignificant increase in OS in the CAI group (HR = 0.65; 95% CI: 0.38–1.2, p = 0.17].ConclusionOur data showed no difference in TTD, OS and ORR regardless of chemotherapy, but a trend towards an increased OS with PB when given after an ICI, while patients received chemotherapy later in the CAI group. This suggests that a sequential combination of ICI followed by chemotherapy could be an interesting strategy in advanced NSCLC for selected patients.

COMPUTER-ASSISTED INSTRUCTION ON STUDENTS’ ACADEMIC ACHIEVEMENT AND ENGAGEMENT IN SCIENCE

This study determined the students’ academic achievement and engagement in science. A quasi-experimental research design was utilized. The study results showed that students exposed to CAI obtained “fairly satisfactory” results in the post-test, while those exposed to non-CAI showed “needs improvements” both in the pretest and post-test. Moreover, for students’ engagement in science, the CAI group had a high engagement level for affective, cognitive, and behavioral domains. In contrast, the non-CAI group had moderate engagement before and after the intervention. The students’ academic performance in science exposed to CAI is significantly higher than those exposed to non-CAI. Also, there is a significant difference in students’ engagement level for a cognitive domain in favor of CAI. It is concluded that CAI as a science learning tool enhances the students’ cognitive engagement.

Screening of Antimicrobial Resistance Genes and Epidemiological Features in Hospital and Community-Associated Carbapenem-Resistant Pseudomonas aeruginosa Infections.

IntroductionResearching carbapenem-resistant isolates enables the identification of carbapenemase-producing bacteria and prevents their spread.MethodsP. aeruginosa isolates were recovered from Medicine Faculty of Recep Tayyip Erdoğan University and identified by conventional methods and the automated Vitek 2 Compact system. Antimicrobial susceptibility experiments were performed in accordance with CLSI criteria and the automated Vitek 2 Compact system. The PCR method was investigated for the presence of β-lactamase resistance genes. PFGE typing was performed to show clonal relation among samples.ResultsSeventy P. aeruginosa isolates were isolated from seventy patients. Of the patients, 67.1% had contact with the health service in the last 90 days and 75.7% of the patients had received antimicrobial therapy in the previous 90 days. Twenty-four isolates were carbapenem resistant, 2 isolates were multidrug-resistant except colistin, and none of the samples had colistin resistance. The gene encoding β-lactamase or metallo-β-lactamase was found in a total of 36 isolates. The blaVEB and blaPER genes were identified in 1 and 5 isolates alone or 17 and 13 isolates in combination with other resistance genes, respectively. The blaNDM was the most detected metallo-β-lactamase encoding gene (n=18), followed by blaKPC (n=12). blaIMP and blaVIM were detected in 5 and 1 isolates, respectively. Also, the association of blaVEB-blaPER and blaVEB-blaKPC-blaNDM was found to be very high. Much more resistance genes and co-occurrence were detected in hospital-acquired samples than community-acquired samples. No difference was found between the community and hospital-associated isolates according to PFGE results. Simultaneously from 6 patients, other microorganisms were also isolated and 5 of them died.ConclusionThe average length of stay (days) was found to be significantly higher in HAI group than CAI group. The death of 5 patients with fewer or no resistance genes showed that the co-existence of other microorganisms in addition to resistance genes was important on death.

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.

Neuromuscular control of the ankle during pre-landing in athletes with chronic ankle instability: Insights from statistical parametric mapping and muscle co-contraction analysis

ObjectiveThe present study aimed to compare the neuromuscular control of the muscles around the ankle between athletes with CAI and without history of any ankle sprain (Non-CAI) by using statistic parametric mapping (SPM) and co-contraction analyses. DesignCross-sectional study; Setting: Laboratory; Participants: 40 athletes (20 CAI, 20 Non-CAI) were pair-matched for age and gender. Main outcome measuresNeuromuscular control was examined using surface electromyography (EMG) amplitude and muscle co-contraction 200 ms before foot-contact with the ground during a jump-landing task. ResultsThe EMG amplitude of tibialis anterior, peroneus longus, and gastrocnemius medialis were analyzed using statistic parametric mapping. The CAI group exhibited decreased EMG amplitude of peroneus longus during preparation for foot-contact. There were no significant co-contraction differences between groups. ConclusionsOur findings demonstrate that SPM combined with the co-contraction provides a comprehensive EMG analysis to detect the differences of neuromuscular control between athletes with and without chronic ankle instability. Additionally, this finding indicates that CAI contributed to altered neuromuscular control during the pre-landing phase, which may contribute to re-injury mechanisms.

Verbal Encouragement Improves Star Excursion Balance Test Performance In Patients With Chronic Ankle Instability

PURPOSE:The Star Excursion Balance Test (SEBT) is a common dynamic balance test. Functional limitations on the SEBT are associated with CAI, but psychological constraints such as kinesiophobia or a lack of confidence may affect performance. The purpose of this study was to investigate the effects of verbal encouragement (VE) on maximum reach distance performance between CAI and healthy participants on the SEBT and to explore the role of kinesiophobia with this functional. METHODS:Thirty-four individuals: 17 CAI (10 F/7 M; age= 21.06±3.19yr; height=171.2±11.9 cm; weight=67.7±10.8 kg) and 17 healthy controls (10 F/7 M; age=19.41 ±1.23yr; height=169.35±6.36 cm; weight=64.89±8.76kg) volunteered. Independent variables included condition (VE vs No VE) and group (CAI vs Healthy). The Fear Avoidance Beliefs Questionnaire (FABQ) was administered. Participants completed 3 SEBT trials per condition, starting with No VE followed by VE to eliminate the effect of heightened motivation with a randomized order. Analysis of Variance (ANOVA) examined group differences and whether VE affected performance for Anterior (ANT), Posteromedial (PM), and Posterolateral (PL) reach distances. FABQ was compared between the CAI and Healthy groups using a t-test; all alpha levels were <.05 a priori. RESULTS:With No VE, a significant group-by-condition interaction was observed in both the ANT (CAI: 66.90 ± 5.50 vs Healthy:70.65 ± 4.52) and PM (CAI: 77.60 ± 7.70 vs Healthy: 81.89 ± 8.25 reach directions, which diminished with VE: ANT (CAI: 70.43 ± 4.52 vs Healthy: 71.77 ± 5.10) and PM (CAI: 85.41 ± 7.19 vs Healthy: 86.45 ± 8.71), showing that the two groups behaved similarly with VE. There was no statistically significant interaction (p=0.48) for the PL reach direction without VE (CAI: 73.60 ± 7.84 vs Healthy: 75.16 ±11.72) or with VE (CAI: 80.18 ±9.79 vs Healthy: 80.06 ± 11.93). The CAI group had significantly higher FABQ scores (10.53 ±9.45) than the healthy group (0.41 ± 1.70) (p<.001). CONCLUSIONS: The CAI group had lower performance on the SEBT without VE, but with VE, the scores were comparable to healthy controls. Clinicians and researchers should acknowledge the impact that motivation and psychological stresses have on functional performance in patients with pathologies such as CAI.

Decreased ankle and hip isometric peak torque in young and middle-aged adults with chronic ankle instability

ObjectivesTo compare ankle, knee and hip isometric peak torque between young and middle-aged adults with CAI, copers and un-injured controls. DesignCross-sectional. SettingResearch Laboratory. ParticipantsOne hundred fifty-six young and middle-aged adults with or without CAI volunteered. Main outcome measuresA handheld dynamometer measured isometric dorsiflexion, plantarflexion, knee extension, hip extension and hip abduction peak force during a 5 s trial. Average peak torque was calculated and normalized to body mass. ResultsA significant Age by Injury interaction for dorsiflexion suggest middle-aged un-injured controls (p < 0.001) and copers (p < 0.001) had lower isometric peak torque compared to their young adult counterparts, but there were no differences between young and middle-aged adults with CAI (p > 0.05). Significant Injury main effects suggest the CAI group had decreased plantarflexion (p = 0.004) and hip extension (p = 0.010) strength compared to un-injured controls, but not copers (p > 0.05). Significant Age main effects for all primary outcome measures were observed, indicating peak torque decreased with age (p < 0.05). ConclusionsRegardless of age, isometric ankle and hip peak torque was lower in participants with CAI compared to un-injured controls, but not copers. These findings provide further evidence towards the impact of CAI in both young and middle-aged adults.

Post-cervical compared with cervical insemination in gilts: Reproductive variable assessments

The aim with this study was to compare cervical (CAI; 3 × 109 spermatozoa/90 mL) and post-cervical (PCAI; 1.5 × 109 spermatozoa/45 mL) artificial insemination (AI) techniques for frequency of incidences (unsuccessful or difficult probe passage, backflow, metritis and bleeding), values for reproductive variables and duration of the procedure in gilts. There were 644 gilts (255–270 days old, weighing 150 ± 5 kg) randomly assigned to PCAI (n = 320) and CAI (n = 324) groups. In total, there were 957 and 958 artificial inseminations performed in the CAI and PCAI groups, respectively (2–4 AIs/gilt). The frequency of unsuccessful or difficult PCAI probe passage/AI was 14.6% (140/958), therefore, there was a 85.7% probe passage success/AI rate (818/958). The semen backflow frequency/AI was less with PCAI than CAI (4.3% compared with 8.2%, P < 0.001). With the PCAI group, there were only a few cases of bleeding (11/958: 1.1% /AI) with no difference between the CAI and PCAI groups (P = 0.224). In gilts (n = 72) where there was not passage of the PCAI probe (72/320; 22.5%) there was use of CAI, (M, mixed group). For the CAI, PCAI and M groups, there were similar values for positive pregnancy diagnosis, farrowing rates and prolificacy (P > 0.05). The average duration for AI was shorter in the PCAI (2.34 ± 0.809 min) than CAI (4.77 ± 1.059 min) group, and it was longer in the M group (7.48 ± 2.454 min; P < 0.050). The PCAI procedure, therefore, is recommended for AI of gilts.

Gait kinematics & kinetics at three walking speeds in individuals with chronic ankle instability and ankle sprain copers

BackgroundIndividuals with CAI have demonstrated a more inverted foot position during walking when compared to a healthy control group. Copers are individuals who have had an ankle sprain but learn to cope and return to pre-injury levels of function and may be a better comparison group than healthy controls because they have had the same initial injury. Research questionA controlled laboratory study was performed to simultaneously analyze differences in lower extremity walking gait kinematics, kinetics, and surface electromyography (EMG) between individuals with CAI and copers at a preferred walking speed (PWS), 120% preferred walking speed (120WS), and standardized walking speed (SWS) of 1.34 m/s. MethodsThirty-six (18 coper, 18 CAI) physically active individuals participated. Three-dimensional kinematics and kinetics at the ankle, knee, and hip and EMG amplitude for fibularis longus, tibialis anterior, medial gastrocnemius, and gluteus medius muscles were analyzed. Ten consecutive strides from each speed were analyzed using statistical parametric mapping (SPM). A 2 × 3 group by speed ANOVA and post-hoc t-tests were used to compare differences between the coper and CAI groups. ResultsThe CAI group had more ankle inversion at IC (PWS: MD = 4.2°, d = 1.08; 120WS: MD = 5.0°, d = 1.28; SWS: MD = 6.6°, d = 1.37) and greater peak inversion throughout swing at all three walking speeds (PWS: MD = 4.2°, d = 0.89; 120WS: MD = 4.4°, d = 0.91; SWS: MD = 6.2°, d = 1.21). The CAI group had greater peak hip adduction during swing (PWS: MD = 4.5°, d = 0.96; 120WS: MD = 4.1°, d = 1.04; SWS: MD = 3.6°, d = 0.98). SignificanceThe CAI group demonstrated greater ankle inversion at IC and during the swing phase and greater peak hip adduction during the swing phase compared to the copers. As the speed increased, ankle inversion in the CAI group also increased which could be linked to greater risk of recurrent sprains. Therefore, modeling gait training programs after the coper mechanics may be advantageous.

Quantitative evaluation method for clarifying ankle plantar flexion angles using anterior drawer and inversion stress tests: a cross-sectional study

BackgroundChronic ankle instability (CAI) may result from repeated, frequent ankle sprains during sports activities. Manual examination for CAI is conducted; however, quantitative methods for the evaluation of CAI have not been established, and the reproducibility of the amount of stress is low. This cross-sectional study aimed to use a stress device and ultrasound for the quantitative evaluation of the change in the length of the anterior talofibular ligament (ATFL) during simulated anterior drawer and ankle inversion stress tests.MethodsQuestionnaires were provided to 160 healthy college students (86 men, 74 women; 320 ankles). We extracted two groups from them: control subjects without a history of ankle injury (n = 64 ankles) and subjects with CAI (n = 54 ankles). We calculated the change in the length of the ATFL with anterior drawer and inversion stress tests at ankle joint plantar flexions of 0°, 20°, and 45° using ultrasound images.ResultsThe anterior length change rates were significantly higher in the CAI group than in the control group at ankle joint plantar flexions of 20° and 45° in men (P < 0.05). The inversion length change rates were significantly higher in the CAI group at ankle joint plantar flexion of 20° in men (P < 0.05). No significant between-group difference in the anterior and inversion length change rates was observed in women.ConclusionsStress ultrasound revealed greater length changes in the ATFL in the CAI group than in the control group. The stress test may be useful at ankle joint plantar flexion of 20° for men.

Isometric Hip Strength and Dynamic Stability of Individuals With Chronic Ankle Instability.

Compared with individuals who have a history of lateral ankle sprain (LAS) without markers of chronic ankle instability (CAI; LAS copers) and healthy people, those with CAI often exhibit neuromuscular impairments and dynamic-stability deficits at the hip. However, the influence of hip-strength deficits on dynamic stability remains unknown. To compare isometric hip strength and dynamic stability in individuals with or without CAI and examine the degree of dynamic-stability variance explained by isometric hip strength. Case-control study. Research laboratory. Sixty individuals (47 women, 13 men; age = 23.7 ± 4.6 years, height = 166.6 ± 7.7 cm, mass = 70.8 ± 15.7 kg) separated into CAI, LAS coper, and control groups based on previously established criteria. Group differences in resultant vector time to stabilization (RVTTS) and isometric hip-extension, -abduction, and external-rotation strength were determined using 1-way analyses of covariance that controlled for sex and limb (dominant or nondominant) tested and Cohen d effect sizes (95% confidence intervals). Backward linear regressions and Cohen f2 effect sizes (95% confidence intervals) determined the amount of RVTTS variance explained by isometric hip strength. Significance was set a priori at P < .05. The CAI group had less isometric hip-extension strength than LAS copers ( P = .02, d = 0.72 [0.06, 1.34]) and controls ( P = .01, d = 1.19 [0.50, 1.84]) and less external-rotation strength than LAS copers ( P = .03, d = 0.78 [0.13, 1.41]) and controls ( P = .01, d = 1.02 [0.34, 1.65]). No group differences existed for RVTTS ( F2,57 = 1.16, P = .32) or abduction strength ( F2,57 = 2.84, P = .07). Resultant vector time to stabilization was explained by isometric hip strength for LAS copers ( R2 = 0.21, f2 = 0.27 [0.22, 0.32], P = .04) but not for the CAI ( R2 = 0.12, f2 = 0.14 [0.06, 0.22], P = .22) or control ( R2 = 0.10, f2 = 0.11 [0.03, 0.19], P = .18) groups. Participants with CAI had decreased isometric hip strength, but that did not equate to dynamic-stability deficits. Clinicians should include hip-muscle strengthening in rehabilitation protocols for patients with CAI, yet these gains may not enhance dynamic stability when landing from a jump.

Quantitative magnetic resonance imaging (MRI) analysis of anterior talofibular ligament in lateral chronic ankle instability ankles pre- and postoperatively

BackgroundThe aim of this study was to quantitatively evaluate and characterize the dimension and signal intensity of anterior talofibular ligament (ATFL) using 3.0 T MRI in the mechanical ankle instability group pre- and postoperatively.MethodsA total of 97 participants were recruited retrospectively in this study, including 56 with mechanical chronic ankle instability (CAI group) and 41 without ankle instability (Control group). All the subjects accepted MRI preoperatively. Among the 56 CAI patients, 25 patients, who accepted modified Broström repair of ATFL, underwent a MRI scan at follow-up. The ATFL dimension (length and width) and signal/noise ratio (SNR) were measured based on MRI images. The results of the MRI studies were then compared between groups.ResultsThe CAI group had a significantly higher ATFL length (p = 0.03) or ATFL width (p < 0.001) compared with the control group. The mean SNR value of the CAI group was significantly higher than that of the control group (p = 0.006). Furthermore, the mean SNR value of the ATFL after repair surgery (8.4 ± 2.4) was significantly lower than that of the ATFL before surgery (11.2 ± 3.4) (p < 0.001). However, no significant change of ATFL length or ATFL width were observed after repair surgery.ConclusionsCAI ankles had a higher ATFL length or width as well as higher signal intensity compared with stable ankles. After repair surgery, the mean SNR value of the ATFL decreased, indicating the relaxed ATFL becomes tight postoperatively.

Hip strength and star excursion balance test deficits of patients with chronic ankle instability.

To examine isometric hip strength in those with and without CAI, and determine the degree of Star Excursion Balance Test (SEBT) variance explained by isometric hip strength. Single-blinded, cross-sectional, case-control study. Thirty individuals with CAI, 29 lateral ankle sprain (LAS) copers, and 26 healthy controls participated. We assessed dynamic postural control with the SEBT anterior (SEBT-ANT), posteromedial (SEBT-PM), and posterolateral (SEBT-PL) reaches, and isometric hip extension (EXT), abduction (ABD) and external rotation (ER) strength with hand-held dynamometry. The CAI and LAS coper groups' involved limbs and randomly selected limbs in controls were tested. Separate Kruskal-Wallis tests compared SEBT scores and isometric hip strength between groups. Backwards linear regression models determined the degree of SEBT variance explained by isometric hip strength. Statistical significance was set a priori at P<0.05. The CAI group had lower SEBT-ANT scores compared to LAS copers (P=0.03) and controls (P=0.03). The CAI group had lower ABD compared to LAS copers (P=0.03) and controls (P=0.02). The CAI group had lower ER compared to LAS copers (P=0.01) and controls (P=0.01). ER (R2=0.25, P=0.01) and ABD (R2=0.25, P=0.01) explained 25% of the CAI group's SEBT-PM and SEBT-PL variances, respectively. The CAI group had deficient dynamic postural control and isometric hip strength compared to LAS copers and controls. Additionally, the CAI group's isometric hip strength significantly influenced dynamic postural control performance. Future CAI rehabilitation strategies should consider hip muscular strengthening to facilitate improvements in dynamic postural control.

EFFECTS OF REDUCED PLANTAR CUTANEOUS SENSATION ON GAIT KINEMATICS IN INDIVIDUALS WITH OR WITHOUT CHRONIC ANKLE INSTABILITY

BackgroundChronic ankle instability (CAI) is associated with repetitive lateral ankle sprains, exhibiting postural-control deficits and altered gait biomechanics. Plantar cutaneous receptors have been theorized to affect postural control, but their...

ANKLE BIOMECHANICS AND JUMP PERFORMANCE IN HEALTHY AND CHRONIC ANKLE INSTABILITY INDIVIDUALS DURING LANDING: A TRIPLE BLIND RANDOMIZED CLINICAL TRIAL OF ANKLE TAPING EFFICACY

BackgroundClinicians regularly utilize ankle taping procedures to prevent ankle sprains during practice/competition. Though many different ankle taping applications are employed, the effect of these on biomechanics and performance is unknown.ObjectiveTo...