Chronic Ankle Instability Group Research Articles

Differences in lower extremity kinematics during single-leg lateral drop landing of healthy individuals, injured but asymptomatic patients, and patients with chronic ankle instability- a cross-sectional observational study.

The lower-extremity kinematics associated with forward jump landing after an ankle injury is known to differ for patients with Chronic Ankle Instability (CAI), copers (injured but asymptomatic patients), and healthy individuals. However, the differences in the lower extremity kinematics of these groups associated with a Single-leg Lateral Drop Landing (SLDL) are unknown. The purpose of this study is to characterize the lower limb and foot kinematics during SLDL in CAI patients and to compare these characteristics with those of the copers and healthy individuals. This was a cross-sectional observational study. Nineteen participants, each, were selected from the CAI, Coper, and control groups. The lower-extremity kinematics during SLDL was measured using three-dimensional motion analysis over an interval progressing from 200 ms before landing to 200 ms after landing. Either one-way ANOVA or the Kruskal-Wallis test was used to compare the attributes of the respective groups, with each parameter measured every 10 ms. The maximum values and excursions of the parameters were established over time intervals progressing from 200 ms before landing to 200 ms after landing. Significant observations were subjected to post hoc analysis. Compared to the Coper group, the CAI group exhibited significantly smaller hip adduction angles at 160 ms, ankle dorsiflexion angles in the 110-150 ms interval, and maximum ankle dorsiflexion angles after landing. Compared to the control group, the CAI group exhibited significantly smaller excursions of MH inversion/eversion after landing. Our findings confirm the necessity of focusing on the kinematics of hip adduction/abduction and plantar/dorsiflexion during SLDL in evaluating patients with ankle injuries.

Single-legged landing behavior of high school basketball players with chronic ankle instability

ObjectivesAnterior cruciate ligament injury is one of the most serious ligamentous injuries. The purpose is to compare the impact of the ankle joint on the knee during landing between athletes with chronic instability and a control group (coper group) and to verify the effects of the kinetic chain from other joints. DesignProspective study. SettingHigh school basketball. ParticipantsParticipants were 62 female high school basketball players who had participated in team sports for >6 months. Main outcome measuresPlayer joint angles, movements, and moments. ResultsThe knee valgus moment was significantly higher in the chronic ankle instability group than in the coper group (20%–60% [p < 0.01]; 80%–100% [p < 0.05]) during landing motion. The knee valgus moment was also significantly higher during the change from the maximum knee joint flexion position to the maximum extension (p < 0.05). In addition, the landing motions of the chronic instability group may have utilized suboptimal compensatory motor strategy on the sagittal plane, depending heavily on the knee joint's abduction moment. ConclusionsOur findings indicate that the chronic ankle instability group uses a different landing strategy pattern than the coper group by changing the joint moment and joint angle during landing, which may increase the risk of anterior cruciate ligament injury.

Influence of anterior talofibular ligament injury and mechanical ankle anterior displacement on symptoms in individuals with chronic ankle instability.

Repeated ankle sprains can lead to injuries, including those of the anterior talofibular ligament; however, the extent to which these ligament injuries are associated with symptoms of chronic ankle instability remains unclear. To examine the influence of anterior talofibular ligament injury and ankle anterior displacement on symptoms of chronic ankle instability. Case-Control Study. A university laboratory. A total of 426 college students completed a questionnaire survey on the history of ankle sprain. Thirty-four (24 males, 10 females; age = 20.6 ± 0.5 years), 49 (38 males, 11 females; age = 20.2 ± 1.2 years), and 39 (24 males, 15 females; age = 20.1 ± 1.1 years) participants were enrolled in the healthy, coper, and chronic ankle instability groups, respectively. One examiner measured the anterior talofibular ligament delineation using ultrasound and anterior ankle displacement using a capacitance-type sensor device. The Cumberland Ankle Instability Tool was applied to assess pain and perceived instability. The anterior talofibular ligament was normal significantly more frequently in healthy participants and abnormal significantly more frequently in patients with chronic ankle instability (p < 0.001). Anterior ankle displacement was significantly greater in the coper and chronic ankle instability groups than in healthy individuals (p < 0.001), but no significant difference was observed between the coper and chronic ankle instability groups. There was no significant correlation between the anterior ankle displacement and Cumberland Ankle Instability Tool scores (p = 0.709) in participants with previous ankle sprains. Observation of an abnormal anterior talofibular ligament on ultrasonography is associated with anterior displacement of the ankle joint. However, it is assumed that the influence of anterior ankle displacement due to damage to the anterior talofibular ligament on the pain and perceived instability in chronic ankle instability is small.

Chronic ankle instability affects the association between knee joint angle and loading: musculoskeletal simulation study

The purpose of this study was to calculate and compare (1) knee loads, (2) muscle-specific contributions to knee loads, and (3) effects of knee flexion angle on knee loads and muscle-specific load contributions during a forward jump-landing task in people with and without chronic ankle instability (CAI). Eight CAI patients and seven healthy controls performed a forward jump-landing task. We collected 3D kinematics, ground reaction force, and muscle activation and used musculoskeletal modeling. The results showed that only healthy controls exhibited an association between knee flexion angle and knee compressive impulse (r = 0.854, p = .014). The lack of association in CAI group may lead to knee instability and increase knee injury risk in people with CAI.

Changes in dynamic quadriceps angle in patients with chronic ankle instability

Background: Changes in dynamic Quadriceps Angle (Q angle) had been studied in healthy subjects and individuals with other musculoskeletal disorders; however, in chronic ankle instability (CAI), it has not yet been determined. The purpose of this study was to investigate the difference in dynamic Q angle of patients with unilateral chronic ankle instability and those without chronic ankle instability. Methods: One-hundred and four participants with and without chronic ankle instability from both genders aged between 18-30 years, with a BMI range of 17.9-27.3, were enrolled into 2 equal groups; a study group and a control group, with mean values of age of the study and control groups (20.8±2.4) and (20.9±3) years respectively and of BMI (24.1±4.3) and (23.8±2.9) kg/m2 respectively. Dynamic Q angle measurement is carried out using dynamic knee valgus (DKV) through the frontal plane projection angle (FPPA) during single limb squat. Results: A statistically significant difference in FPPA angle was observed between the affected limb of the CAI group and controls (P=0.001). Conclusion: The present study suggested that unilateral CAI display an increased knee valgus, suggesting an additional proximal kinematic alteration and chronic maladaptation in the CAI population.

Neurocognitive Hop Performance in Patients With Chronic Ankle Instability

The purpose of this study was to determine differences in neurocognitive hop function among individuals with chronic ankle instability, ankle sprain copers, and control participants and identify the relationship between the self-reported function and neurocognitive hop performance; 61 participants across control, ankle sprain coper, and chronic ankle instability groups completed the Cumberland Ankle Instability Tool and the Choice-Reaction Hop Test. There was no significant difference in neurocognitive hop performance among groups. However, there was a large correlation between the Cumberland Ankle Instability Tool and the Choice-Reaction Hop Test. Those with chronic ankle instability with worse self-reported disability concurrently demonstrated decreased performance during the Choice-Reaction Hop Test, reflecting poorer neurocognitive hop performance.

MRI Assessment of Tendon Graft After Lateral Ankle Ligament Reconstruction: Does Ligamentization Exist?

Background: No description exists in the literature about the normal evolution of tendon graft after a lateral ankle ligament (LAL) reconstruction. Purpose: To assess the magnetic resonance imaging (MRI) characteristics and the evolution of the tendon graft during different moments in the follow-up after an endoscopic reconstruction of the LAL. Study Design: Cohort study; Level of evidence, 3. Methods: This prospective study included 37 consecutive patients who underwent an endoscopic reconstruction of the LAL with an autograft using the gracilis tendon to treat chronic ankle instability (CAI) resistant to nonoperative treatment (CAI group) and 16 patients without ankle instability (control group). All patients in the CAI group underwent a postoperative assessment at 6, 12, and 24 months using the Karlsson score and MRI examination. Only patients with good and excellent results were included in the study. Graft assessment consisted of qualitative measurements and quantitative evaluations of the reconstructed anterior talofibular ligament (RATFL) and reconstructed calcaneofibular ligament (RCFL), including signal-to-noise quotient (SNQ) and contrast-to-noise quotient (CNQ) measurements in proton density–fat suppressed (PD-FS) and T1-weighted sequences. The analysis of variance test was used to compare the SNQ and the CNQ at different time points for each sequence. Results: The MRI signal at 6 months was increased compared with that of the control group. Next, a significant signal decrease from 6 to 24 months was noted on PD-FS and T1-weighted images. SNQ measurements on PD-FS weighted images for both the RATFL and the RCFL demonstrated a significantly higher signal (P < .01 and P = .01, respectively) at 6 months compared with that of the control group. Subsequently, the signal decreased from 6 to 24 months. Similarly, CNQ measurements on PD-FS weighted images for both the RATFL and the RCFL demonstrated a significantly higher signal (P < .01 and P < .01, respectively) at 6 months compared with that of the control group. Subsequently, the signal decreased from 6 to 24 months. Conclusion: The present study demonstrated an evolution of the MRI characteristics, suggesting a process of graft maturation toward ligamentization. This is important for clinical practice, as it suggests an evolution in graft properties and supports the possibility of creating a viable ligament.

Individuals with chronic ankle instability show altered regional activation of the peroneus longus muscle during ankle eversion.

Individuals with chronic ankle instability (CAI) present muscular weakness and potential changes in the activation of the peroneus longus muscle, which likely explains the high recurrence of ankle sprains in this population. However, there is conflicting evidence regarding the role of the peroneus longus activity in CAI, possibly due to the limited spatial resolution of the surface electromyography (sEMG) methods (i.e., bipolar sEMG). Recent studies employing high-density sEMG (HD-sEMG) have shown that the peroneus longus presents differences in regional activation, however, it is unknown whether this regional activation is maintained under pathological conditions such as CAI. This study aimed to compare the myoelectric activity, using HD-sEMG, of each peroneus longus compartment (anterior and posterior) between individuals with and without CAI. Eighteen healthy individuals (No-CAI group) and 18 individuals with CAI were recruited. In both groups, the center of mass (COM) and the sEMG amplitude at each compartment were recorded during ankle eversion at different force levels. For the posterior compartment, the sEMG amplitude of CAI group was significantly lower than the No-CAI group (mean difference = 5.6% RMS; 95% CI = 3.4-7.6; p = 0.0001). In addition, it was observed a significant main effect for group (F1,32  = 9.608; p = 0.0040) with an anterior displacement of COM for the CAI group. These findings suggest that CAI alters the regional distribution of muscle activity of the peroneus longus during ankle eversion. In practice, altered regional activation may impact strengthening programs, prevention, and rehabilitation of CAI.

Differences in abductor hallucis activity during running in individuals with chronic ankle instability and copers

BackgroundAssessment of neuromuscular dysfunction following a lateral ankle sprain during running typically focuses on the activities of the extrinsic foot muscles. Although the interaction between intrinsic and extrinsic foot muscles has been reported, there are no studies on the activities of intrinsic foot muscles in individuals with chronic ankle instability and ankle sprain copers. Research questionDo copers and individuals with chronic ankle instability (CAI) have different abductor hallucis activity? MethodsThis study included 11 controls, 11 copers, and 16 CAI participants. A wireless surface electromyography system was applied to the abductor hallucis, peroneus longus, tibialis anterior, and medial gastrocnemius muscles. Running was performed on a treadmill (speed of 3.5 m/s). The stance phase is divided into four functional phases. The muscle activities during these phases were calculated using the root mean square standardized by the root mean square during static standing with a double-leg stance. ResultsAbductor hallucis activity was significantly lower during most phases in the coper and control groups than in the CAI group (P < 0.05). There were no differences in the extrinsic foot muscles among the groups (P > 0.05). SignificanceSimultaneous investigations of muscle activity in the abductor hallucis and extrinsic foot muscles identified neuromuscular dysfunction after ankle sprains. Increased activity of the abductor hallucis may be associated with recurrent ankle sprains.

Cortical Activation During Single-Legged Stance in Patients With Chronic Ankle Instability.

Chronic ankle instability (CAI) has been considered a neurophysiological condition, with dysfunctional somatosensory and motor system excitability. However, few researchers have explored the changes in cortical activation during balance tasks of patients with CAI. To compare the cortical activity during single-legged stance among CAI, copers, and uninjured control participants and to compare dynamic balance across groups. Cross-sectional study. Biomechanics laboratory. A total of 22 participants with CAI (median [interquartile range]; age = 34.5 [11.0] years, height = 170.0 [15.8] cm, mass = 67.0 [16.2] kg), 17 copers (age = 27.0 [14.0] years, height = 170.0 [9.5] cm, mass = 66.5 [16.5] kg), and 21 uninjured control participants (age = 25.0 [10.5] years, height = 170.0 [11.0] cm, mass = 64.0 [16.5] kg). Participants performed single-legged stance while cortical activation was tested with functional near-infrared spectroscopy. The peak oxyhemoglobin response of the activated cortex was calculated and compared across groups. The Y-Balance test outcomes and patient-reported outcomes were assessed and compared across groups. The CAI group had worse Y-balance test and patient-reported outcomes than the coper and uninjured control groups. Differences in the peak oxyhemoglobin response were observed for the primary somatosensory cortex (S1; F2,57 = 4.347, P = .017, ηp2 = 0.132) and superior temporal gyrus (STG; F2,57 = 4.548, P = .015, ηp2 = 0.138). Specifically, copers demonstrated greater activation in S1 and STG than the CAI (d = 0.73, P = .034, and d = 0.69, P = .043, respectively) and uninjured control (d = 0.77, P = .036, and d = 0.88, P = .022, respectively) groups. No differences were found in the cortical activation between CAI and uninjured control participants. Copers displayed greater cortical activation in S1 and STG than CAI and uninjured control participants. Greater activation in S1 and STG suggested a better ability to perceive somatosensory stimuli and may represent a compensatory mechanism that allows copers to maintain good functional ability after the initial severe ankle sprain.

Ankle biomechanics of the three-step layup in a basketball player with chronic ankle instability

At present, the effects of chronic ankle instability (CAI) on the biomechanics of the ankle joint in the three-step layup of basketball players are not clear. This work aims to thoroughly investigate the impact of CAI on the biomechanical characteristics of the ankle during the execution of a three-step layup in basketball players. Thirty male basketball players were stratified into distinct groups—namely, a CAI group and a non-CAI group—comprising 15 individuals each, based on the presence or absence of CAI. Demographic attributes, including age, weight, height, and the Cumberland Ankle Instability Tool (CAIT) score, were subjected to rigorous statistical examination within both athlete cohorts. The research employed four Whistler 9281CA 3D force measuring platforms (Switzerland), recording at 1000 Hz, in conjunction with eight camera motion analysis systems (USA), functioning at a frequency of 200 Hz. The study recorded maximal plantarflexion angle, inversion angle, dorsiflexion angle, and peak ankle dorsiflexion moment across the subjects during the distinct phases of push-off, landing, and the ensuing landing period. The findings notably exhibited that within the context of the one-foot push-off phase, the maximum ankle inversion angle was notably diminished in the CAI group as contrasted with the non-CAI group, demonstrating statistical significance (t = − 3.006, P < 0.01). The CAI group exhibited a lesser alteration in ankle inversion angle compared to the non-CAI group. Notably, during the one-foot landing period, the CAI group demonstrated a significantly greater maximum ankle inversion angle in contrast to the non-CAI group (t = 8.802, P < 0.001). Furthermore, the CAI group displayed a substantially larger maximum dorsiflexion angle at the ankle joint compared to the non-CAI group (t = 2.265, P < 0.05). Additionally, the CAI group exhibited a prolonged peak time for ankle dorsiflexion moment as compared to the non-CAI group (t = − 2.428, P < 0.05). Collectively, the findings elucidated a reduction in the maximum ankle joint inversion angle during the one-foot push-off phase in individuals with CAI. Furthermore, increased maximum inversion angle and maximum dorsiflexion angle of the ankle joint were observed during the one-foot landing period, alongside a lengthening of the peak time of ankle dorsiflexion moment. These results contribute valuable insights into the selection of training methodologies for basketball players afflicted by CAI.

Tortuosity Angle of a Calcaneofibular Ligament on Magnetic Resonance Imaging &amp; Stress Radiography

Category: Ankle; Sports Introduction/Purpose: A lateral ankle sprain is one of the most common musculoskeletal injuries for both athletes and non- athletes, causing chronic ankle instability. Talar tilt angle on a radiograph used for diagnosis of chronic ankle instability(CAI), however, there were no reports of instability of calcaneofibular ligament(CFL) itself through an MRI. This study aimed to determine whether measuring tortuosity angles of CFL through oblique coronal imaging of MRI in CAI. We compared CFL’s tortuosity angle with the talar tilt angle, Cumberland ankle instability tool(CAIT), and ankle strength in patients without a history of ankle sprain or not. Methods: From March 2020 to May 2022, Of the total 120 cases, the CAI group (82 patients) took CFL’s tortuosity angle in MRI and talar tilt angle inradiograph. The control group (38 patients) included those without an ankle sprain who visited this hospital due to an Achilles tendon rupture. In the control group, the talar tilt angle could not be achieved due to pain. Results: CFL’s tortuosity angle in MRI showed a significant difference of 76.5 ± 18.3º in the CAI group and 31.9 ± 5.4º in the control group(P &lt; 0.001). The diagnostic cutoff value for CAI was more than 40º of the tortuosity angle. According to the measure of the isokinetic machine(Biodex), the CAI group shows a 22.8% deficit of the eversion strength. The tortuosity angle, talar tilt angle, and manual stress test show significantly different between both groups. However, CAIT and strength defect showed no significant results between both groups. Conclusion: CFL’s tortuosity angle through oblique coronary imaging of MRI, it’s average value was 31º degrees, and we can diagnose as CAI if CFL’s tortuosity angle is more than 40º.

Relationship of Chronic Ankle Instability With Foot Alignment and Dynamic Postural Stability in Adolescent Competitive Athletes.

Competitive adolescent athletes should be aware of the early signs of chronic ankle instability (CAI) and the connection between the condition and performance. To investigate whether CAI is related to foot alignment and morphology as well as dynamic postural stability after a jump landing among adolescent competitive athletes with and without a history of a lateral ankle sprain and CAI. Cross-sectional study; Level of evidence, 3. Between July 2020 and August 2021, adolescent competitive athletes (N = 85; n = 49 boys; n = 36 girls) were classified into 3 groups using Cumberland Ankle Instability Tool (CAIT) scores: healthy athletes (n = 55), coper athletes (n = 19), and athletes with CAI (n = 11). Results of foot alignment assessments involving the leg-heel angle (LHA) and navicular height, intrinsic foot muscle morphology, dynamic postural stability index (DPSI), and other parameters were compared among the 3 groups. The relationship between the CAIT score and the LHA and dynamic postural stability and instability were examined using multiple linear regression. Compared with the healthy group, the CAI group had a significantly greater LHA (8.73°± 3.22° vs 6.09°± 3.26°; P < .05), higher DPSI (0.336 ± 0.046 vs 0.298 ± 0.035), and higher vertical stability index (0.303 ± 0.048 vs 0.264 ± 0.037; P < .05 for all). Multiple regression analysis showed that the LHA (β = -0.228; P = .033) and DPSI (β = -0.240; P = .025) were significantly associated with the CAIT score . Valgus rearfoot alignment and poorer dynamic postural control were associated with CAI among adolescent athletes.

The morphology of osseous structure in subtalar joint with chronic ankle instability

BackgroundOsseous structures have been demonstrated as risk factors for chronic ankle instability (CAI). Previously, the researchers only focused on the osseous structures of ankle, but ignored the osseous structures of subtalar joint(STJ). Accordingly, the aim of our study was to investigate the morphological characteristics of STJ osseous structures in CAI. Methods52 patients with CAI and 52 sex- and age- matched control subjects were enrolled from The Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University. The lateral radiographs of ankle in weight-bearing were used to compare the diversity of the two groups. Specifically, The Length of calcaneus, Calcaneal facet height and Absolute foot height, Böhler's angle, Gissane's angle, Calcaneal inclination angle, Talocalcaneal angle, Tibiotalar angle, Tibiocalcaneal angle, Talar-horizontal angle, talar declination angle, facet inclination angle were gauged in the two groups. ResultsThe Böhler's angle, Calcaneal inclination, Talocalcaneal angle, Tibiotalar angle, Talar-horizontal angle, Talar declination angle, Facet inclination angle and Absolute foot height of CAI group were significantly higher than normal control group (P < 0.05). There were no significant differences in Gissane's angle, Tibiocalcaneal angle, Length of calcaneus and Calcaneal facet height between patients with CAI and normal controls (P > 0.05). ConclusionsThe osseous structures of STJ in CAI patients are different from normal people in morphology. Therefore, we should pay more attention to the changes of STJ anatomical parameters in the diagnosis and prevention of CAI. Level of evidenceⅢ.

Decreased rate of torque development in ankle evertors for individuals with chronic ankle instability

BackgroundIndividuals with chronic ankle instability have decreased peak torque during maximum voluntary contraction in ankle evertors/invertors, and hip abductors. However, it is unclear whether individuals with chronic ankle instability and/or copers demonstrate decreased rate of torque development in ankle evertors/invertors, and hip abductors. Methods54 university-aged participants (18 chronic ankle instability, 18 copers, and 18 controls) performed three maximal isometric contractions for ankle evertors and invertors, and hip abductors. Rate of torque development was defined as the linear slope of the torque-time curve during the first 200 ms of each contraction and compared between the three groups using a one-way analysis of variance (α = 0.05). FindingsThe chronic ankle instability group showed 38.1% less rate of torque development than the coper (P = 0.03 and d = 0.84) and 37.1% than the control groups (P = 0.03 and d = 1.03) in the ankle evertors. For the hip abductors, there were moderate effects between the chronic ankle instability group and the copers (P = 0.06 and d = 0.70), and control groups (P = 0.06 and d = 0.75). InterpretationsThe observed between-groups differences in rate of torque development indicate that restoring rate of torque development after lateral ankle sprain may be important to reduce risk of reinjury and development of chronic ankle instability. Clinicians should consider the rate of torque development in the ankle evertors and hip abductors during rehabilitation chronic ankle instability patients.

Collegiate Dancers With Chronic Ankle Instability Possess Altered Strength and saut de chat Leap Landing Mechanics.

Ankle sprains are among the most common injuries in dancers. Following one or more severe sprains, some individuals will experience residual mechanical and functional deficits, otherwise known as chronic ankle instability (CAI). Dancers who suffer from CAI may have weaker musculature surrounding the ankle and altered landing mechanics. The purpose of this study was to compare ankle strength and saut de chat landing mechanics between dancers with and without CAI. Dancers with and without CAI, defined by the Identification of Functional Ankle Instability (IdFAI), participated in the study (CAI n = 8; IdFAI = 18.75 ± 5.50 points; age = 20 ± 1.5 years; training = 15.5 ± 3.5 years) (Control n = 8; IdFAI = 7.13 ± 3.40 points; age = 19 ± 0.6 years; training = 15.9 ± 2.5 years). Strength and leap landing mechanics were measured on the affected ankle for the CAI group and on the preferred landing leg of a leap for the control group. Concentric and eccentric ankle plantar flexion, and subtalar inversion and eversion strength were determined with dynamometry set at an angular velocity of 60°•s-1. Force plates and motion capture cameras were used to calculate lower extremity kinematic and kinetic data as participants performed 3 saut de chat leaps. Independent t-tests were calculated to determine differences between groups. Compared to dancers without CAI, dancers with CAI had lower eccentric plantar flexor strength, landed with higher vertical ground reaction forces, and absorbed greater power at the knee-joint during landing. Whether dancers who are weaker are more prone to injury or ankle-joint injury leads to muscular weakness is unknown. Dancers with CAI appear to lack control during leap landing while concomitantly shifting loads proximally away from the ankle-joint. We encourage dancers with and without CAI to engage in additional training that enhances ankle strength.

Postural control measured before and after simulated ankle inversion landings among individuals with chronic ankle instability, copers, and controls

BackgroundPostural control measured during single-leg stance and single-leg hop stabilization has been used to estimate sensorimotor function in CAI individuals and copers. To date, studies have not used postural control tasks as a way of measuring responses to sudden changes in sensory information after simulated ankle inversion landings. Research questionA cross-sectional study was performed to identify any differences in static and dynamic postural control before and after simulated ankle inversion landings among individuals with chronic ankle instability (CAI), copers, and healthy controls. MethodsNineteen CAI individuals, 19 copers, and 19 controls participated in this study. Participants performed 3 static and dynamic balance tasks before and after simulated ankle inversion landings onto a 25° tilted platform from a height of 30 cm. The main outcome measures were the center of pressure (COP) velocity and range from the single-leg stance, as well as the dynamic postural stability index from the single-leg hop stabilization. The Wilcoxon signed-rank test was used to compare posttest and pretest differences in static and dynamic postural control between groups. ResultsIn the static postural control measures, the CAI group had a higher difference in COP velocity and COP range in the frontal plane (p < 0.05 and p < 0.05, respectively) than the coper group. In the dynamic postural control measures, the CAI group demonstrated a higher difference in the vertical stability index (p < 0.05) than the healthy control group. SignificanceCAI individuals have persistent worse postural control after somatosensory modulation due to their inability to adapt to sudden somatosensory modulation. Relative to CAI individuals, copers may have different abilities not only the integration of somatosensory input about ankle inversion modulation, but also the adaptation of the entire motor control system, preventing recurrent ankle sprains after an initial LAS. Therefore, somatosensory modulation may be the indicator of understanding CAI and coper.

Factors associated with persistent pain in college athletes with a history of lateral ankle sprain

ObjectivesTo determine the factors associated with and prevalence of persistent pain in college athletes with chronic ankle instability (CAI) and with previous lateral ankle sprain (LAS) without CAI. DesignCross-Sectional Study. SettingOnline survey at one university. ParticipantsOf the 385 respondents surveyed online, 140 were identified as having experienced at least one LAS (CAI group: 69, coper group: 24, LAS group not classified as either: 47). Main outcome measuresFactors associated with the presence of pain during activities of daily living (ADL) and sports were identified using multivariate logistic regression analyses. Independent variables were demographics, injury characteristics, the Identification of Functional Ankle Instability (IdFAI) score, the Foot and Ankle Ability Measure Sports (FAAM-Sports) and ADL subscales, and the Tampa Scale for Kinesiophobia-11 score. ResultsThe prevalence of pain during ADL and sports in the three groups was 16.7%–42.0% and 33.3%–56.5%, respectively. FAAM-Sports and IdFAI score were significantly associated with pain during ADL and sports in the CAI group (odd ratio: 0.923 and 1.145), respectively. No significant pain-related factors were found in the coper and LAS groups. ConclusionsLower self-reported function and greater perceived ankle instability may be important factors in pain management in athletes with CAI.

Characteristics of the static muscle stiffness of ankle plantar flexors in individuals with chronic ankle instability.

Individuals with chronic ankle instability (CAI) have deficits in closed kinetic chain dorsiflexion that may perpetuate injury. Determining the characteristics of muscle stiffness in the plantar flexors of individuals with CAI may help in developing appropriate treatments. We aimed to highlight the characteristics of static muscle stiffness in ankle plantar flexor muscles during the passive dorsiflexion of the ankle joint in individuals with CAI. A total of 30 patients were included in the study based on the International Ankle Consortium criteria. The patients were categorized evenly into healthy, coper, and CAI groups (i.e., 10 patients in each group). After measuring the dorsiflexion range of motion (non-weight-bearing/weight-bearing) of the ankle joint, the static muscle stiffness measurements of the medial gastrocnemius, lateral gastrocnemius, soleus, and peroneus longus were obtained. The measurements were performed during the knee joint's extension and 50° flexion and passive dorsiflexion between the range of 40° plantar flexion and 20° dorsiflexion. The dorsiflexion range of motion of the CAI group was significantly smaller than that of the healthy and coper groups in the weight-bearing position. No interaction was observed for muscle stiffness in both the knee flexion and extension positions, and no significant differences were identified among the three groups. The shear modulus of the soleus at 20° ankle dorsiflexion with knee flexion had a significant negative correlation with the weight-bearing range of motion of the ankle. The limitation in the weight-bearing dorsiflexion range of motion in CAI was largely due to factors other than the increased elasticity of the ankle plantar flexor muscles.

Ultrasound Imaging of Subtalar Joint Instability for Chronic Ankle Instability.

The purpose of this study was to develop the assessment of subtalar joint instability with chronic ankle instability (CAI) using ultrasonography. Forty-six patients with anterior talofibular ligament (ATFL) abnormalities and a history of ankle sprain were divided into CAI (21.2 ± 5.9 y/o, 7 males and 17 females) and asymptomatic groups (21.0 ± 7.4 y/o, 9 males and 12 females) on the basis of subjective ankle instability assessed using the CAIT and the Ankle Instability Instrument Tool (AIIT). Twenty-six age-matched feet participated in a control group (18.9 ± 7.0 y/o, 9 males and 17 females). Ultrasound measurements of the width of the posterior subtalar joint facet were obtained at rest and maximum ankle inversion (subtalar joint excursion; STJE). The differences in STJE among the three groups were assessed by one-way ANOVA. The relationship between STJE and subjective ankle instability was assessed using Spearman's correlation tests. The STJE value was significantly greater in the CAI group (2.3 ± 0.8 mm) than in the asymptomatic (1.0 ±0.4 mm) and control groups (0.8 ±0.2 mm) (p < 0.001, effect size: 0.64). STJE had significant negative correlations with CAIT (r = -0.71, p < 0.01), and significant positive correlations with AIIT (r = 0.74, p < 0.01). The cut-off value to distinguish between the CAI and asymptomatic groups was 1.7 mm using the ROC curve.