Individuals with chronic ankle instability exhibit altered ankle kinematics and neuromuscular control compared to copers during inversion single-leg landing

ObjectivesThis study compares the ankle kinematics and muscle activities of the individuals with chronic ankle instability (CAI), coper, and control groups in normal and inversion single-leg landings.Designcross-sectional study;SettingBiomechanics laboratory.ParticipantsPhysically active adults with CAI (N = 12); and coper (N = 12) and control (N = 12) groups.Main outcome measuresThe participants performed normal and inversion single-leg landing. The muscle activity 200 ms before and after landing of the tibialis anterior, the medial gastrocnemius, and the fibularis longus (FL) were recorded. The FL latency, sagittal and frontal co-contraction indexes (CCI), ankle inversion angle at the initial contact, and the maximum inversion angle were recorded.ResultsSignificantly longer FL latency, decreased FL muscle activity, frontal CCI, and an increased maximum inversion angle at post-landing were discovered during inversion single-leg landing in the CAI group compared to the coper and control groups. However, no significant difference was observed among the CAI and coper groups during normal single-leg landing.ConclusionThese results suggest prolonged FL latency and altered ankle kinematics suggest an increased risk of recurrent lateral ankle sprains in CAI with inversion single-leg landing.     

In vivo kinematics of functional ankle instability patients during the stance phase of walking

BackgroundPrevious studies showed functional ankle instability (FAI) patients have morphological ligamentous abnormality, despite having no apparent joint laxity.Research questionWhether tibiotalar and subtalar joints hypermobility exists in FAI patients during stance phase of walking, remains controversial.MethodsTen unilateral FAI patients, ten unilateral lateral ankle sprain (LAS) copers and ten healthy controls were included. A dual fluoroscopy imaging system was utilized to capture the fluoroscopic images of tibiotalar and subtalar joint during the stance phase of walking. Kinematic data from six degrees of freedom were calculated utilizing a solid modeling software. The range of motion and joint excursions about six degrees of freedom were compared among the three groups. The correlations between range of motion and Cumberland Ankle Instability Tool (CAIT) scores were assessed utilizing the Spearman’s correlation coefficient (r).ResultsDuring the stance phase, the FAI patients and LAS copers showed larger tibiotalar anterior/posterior translation than the healthy controls (FAI patients, p = .013; LAS copers, p = .002). The FAI patients also showed significantly larger lateral/medial translation (p = .035) and inversion/eversion rotation (p = .003) of subtalar joints than healthy controls. By contrast, the subtalar joints of the LAS copers were not different from those of the healthy controls in the lateral/medial translation (p = .459) and inversion/eversion rotation (p = .091). CAIT scores were negatively correlated with range of motion.SignificanceDuring the stance phase of walking, FAI patients showed significantly larger hypermobility of subtalar joints than healthy controls, contrary to the LAS copers. These findings justify the utilization of dual fluoroscopy imaging system to detect joint hypermobility in FAI patients. Treatment for FAI patients may require stabilization of the subtalar joint.     

Dynamic joint stiffness of the ankle in chronic ankle instability patients

BackgroundWhile Individuals with chronic ankle instability (CAI) exhibit altered ankle joint movement and moments during stance phase of gait, the interaction or dynamic joint stiffness (DJS) between these is not fully understood. Little attention has been placed on DJS during gait, limiting our understanding of how the most common dynamic task during daily life could affect cartilage loading.Research questionDo Individuals with CAI exhibit altered ankle DJS and mechanical energy exerted at the ankle joint during stance phase of gait?MethodsEighty-four physically active individuals, consisting of 42 individuals with CAI (12 M and 30 F) and 42 control (12 M and 30 F) participants were recruited in this study. Three-dimensional gait analysis was conducted. The sagittal ankle joint angle and moment during stance phase of walking gait were obtained. Stance phase was divided into three sub-phases: controlled plantarflexion, controlled dorsiflexion, and powered plantarflexion. Ankle DJS was represented by the slope of the joint moment plotted as a function of the joint angle. The coefficient of determination was calculated to determine how accurately data fit a linear model. Net work was calculated by the difference between work produced and absorbed. Further, sex specific exploratory analyses of DJS and work between individuals with and without CAI were conducted.ResultsLower DJS during the controlled plantarflexion (CPF) sub-phase, work produced, and net work was found in the CAI group. Males with CAI exhibited lower ankle moment changes during controlled dorsiflexion (CDF) sub-phase and work absorbed. Females with CAI exhibited lower ankle moment changes during CPF and CDF sub-phases, lower DJS during the CPF sub-phase, and lower net work.SignificanceIndividuals with CAI have alterations in DJS and work relative to uninjured controls. Females with CAI showed greater DJS related alterations, relative to controls, than their male CAI counterparts.     

Effects of elastic ankle support on running ankle kinematics in individuals with chronic ankle instability and healthy controls

BackgroundIndividuals with chronic ankle instability (CAI) have an increased risk for recurrent injuries. The preventive effects of external ankle supports are not fully understood. This study aimed to examine the effect of elastic ankle support on running ankle kinematics.Methods3D running gait analysis of individuals with and without CAI was conducted at three-minute-running trials at 2.78 m/s with and without elastic ankle support in a randomised order. Ankle kinematics and intra-individual standard deviations (variability) were calculated at each percent of the running gait cycle. Group and ankle support effects were calculated using statistical parameter mapping.ResultsTwenty-seven individuals were analysed (CAI: n = 14, controls: n = 13). When wearing ankle support, CAI individuals showed significantly decreased plantarflexion angles at 43–47 % (p = 0.033) and 49–51 % (p = 0.043) of the running gait cycle compared to normal running. In healthy controls, no differences in ankle angles between both conditions were found. Comparisons between CAI individuals and healthy controls showed statistically significant differences in the plantar-/dorsiflexion angles at 38–41 % (p = 0.044) with ankle support and at 34–46 % (p = 0.004) without ankle support. Significant ankle angle variability differences were found for ankle in-/eversion between CAI individuals and healthy controls (p = 0.041) at 32–33 % of the running gait cycle.ConclusionsElastic ankle support reduces the range of sagittal plane running ankle kinematics of CAI individuals but not of healthy controls. Further research is needed to evaluate the association between ankle support effects and the risk for recurrent ankle sprains.     

Ankle inversion proprioception measured during landing in individuals with and without chronic ankle instability

BackgroundResearch evidence has suggested that a more sensitive ankle proprioceptive testing method with higher ecological validity is needed for assessing proprioceptive deficits in individuals with chronic ankle instability (CAI).Objectives(1) To determine the test–retest reliability of a novel ankle proprioception assessment tool, the Ankle Inversion Discrimination Apparatus for Landing (AIDAL); (2) To assess whether AIDAL scores were sufficiently sensitive to detect proprioceptive deficits in chronic ankle instability (CAI); and (3) To examine whether AIDAL scores correlated with Cumberland Ankle Instability Tool (CAIT) scores.DesignCross-sectional study.MethodsThe AIDAL was purpose-built to assess ankle discrimination in four positions of ankle inversion (10°, 12°, 14° and 16°) upon landing from a 10 cm drop. Area Under the Receiver Operating Curve (AUC) was employed as the ankle proprioceptive discrimination score. Seven-day test–retest reliability was evaluated with 23 university students (12 CAI and 11 non-CAI), and another 36 university students (18 CAI and 18 non-CAI) were in the comparison study.ResultsThe test–retest reliability ICC score for the whole group was 0.763 (95% CI = 0.519–0.892), which showed an excellent reliability level. ICC _(3,1) was 0.701 for the non-CAI group (95%CI = 0.210–0.910) and 0.804 for the CAI group (95%CI = 0.451–0.939). The CAI group performed at a significantly lower level on the AIDAL assessment than the non-CAI group (0.777 ± 0.05 vs. 0.815 ± 0.05, F = 5.107, p = 0.03). The discriminative AUC value for the AIDAL test was 0.756 with a cut point of 0.819 (sensitivity = 0.733, specificity = 0.800). The MDC₉₀ scores for CAI and non-CAI groups were both 0.04. Spearman's correlation showed that the CAIT scores were significantly correlated with the ankle proprioceptive discrimination scores (rho = 0.401, p = 0.015).ConclusionThe AIDAL showed good test–retest reliability for both non-CAI and CAI groups. Measuring ankle inversion proprioception during landing may be important for assessing the outcomes of CAI rehabilitation, as proprioceptive performance obtained from the AIDAL was significantly correlated with severity of functional ankle instability CAIT scores.     

Tibial and calcaneal coupling during walking in those with chronic ankle instability

BackgroundIt is estimated that nearly 2 million individuals sprain their ankle each year in the US. A majority of these are recurrent injuries, which often results in chronic ankle instability. To better understand the cause of instability, previous research has looked at the coupling or coordination between leg and foot motion during locomotion.Research QuestionDetermine the coupling between the tibia and the calcaneus during the stance phase of walking in those without a history of ankle instability compared to those with either moderate or severe instability.MethodsFifty-four individuals between the age of 18-30 years (15 males; 39 females) participated in this study. Each participant’s history of ankle sprains and score on the Cumberland Ankle Instability survey was used to assign them to either a no, moderate or severe instability group. Electromagnetic sensors attached to the tibia and calcaneus recorded three-dimensional movement of their tibia and calcaneus during the stance phase of barefoot over ground walking. The kinematic data was referenced to the subject’s standing position and time normalized to each subject’s stance phase duration. The relative phase (RP) angle and RP variability between tibia internal/external rotation and calcaneal inversion/eversion motion was then calculated. A one-way analysis of variance test was used to determine if significant differences existed between the three groups of subjects on mean RP angle or variability. An alpha level of .05 was used to determine statistical significance.ResultsA significant increase in RP angle and variability was found during the mid-stance phase of walking for those with severe ankle joint instability compared to those with moderate or no instability. Significance. The observed decreased coordination and increased coupling variability observed for those with severe ankle instability suggests either residual ligamentous damage, inadequate sensorimotor control, or both.     

The effect of an ankle brace on the 3-dimensional kinematics and tibio-talar contact condition for lateral ankle sprains

Ten fresh-frozen cadaveric ankles were studied to investigate the effect of an ankle brace (Air-Stirrup) on the three-dimensional (3-D) motion and contact-pressure distribution of the talo-tibial joint with lateral ligamentous injury. Three-dimensional motion and contact-pressure distribution were simultaneously measured under dynamic conditions employing a direct linear-transformation technique and a dynamic-pressure sensor, respectively. Inversion increased significantly upon severing of the anterior talo-fibular (ATF) ligament and calcaneo-fibular (CF) ligaments; however, restoration to the intact level was observed following application of the ankle brace. Internal rotation also increased upon severing of the lateral ligaments in the plantar flexion; however, this difference was not altered by using the ankle brace. The contact area on the articular surface of the talus shifted from posterior to anterior between plantar flexion and dorsal flexion; additionally, a high pressure area was evident in the medial aspect of the talus following severing of the lateral ligaments. Upon application of the ankle brace, however, no significant changes were apparent in the contact condition. The results of this study suggest that stabilization against inversion is the major function of braces in terms of protection of ankle sprains. Ankle sprains, however, often occur in combinations of inversion, plantar flexion and internal rotation; therefore, restriction of plantar flexion and internal rotation may also be an important function of the ankle brace.     

Ankle laxity affects ankle kinematics during a side-cutting task in male collegiate soccer athletes without perceived ankle instability

ObjectivesTo investigate whether ankle joint laxity alone influences lower limb kinematics during a side-cutting task.DesignA cross-sectional study.SettingSports medicine research laboratory.ParticipantsIn total, 66 male collegiate soccer players with history of ankle sprains with no perceived ankle instability were categorised into three groups: no-laxity copers (n = 26), laxity copers (n = 23), and severe-laxity copers (n = 17).Main outcome measuresThe hip, knee, ankle, rearfoot, midfoot, and forefoot kinematic data during the stance phase (0%–100% indicated initial contact to take-off) of a 45° side-cutting task were analysed using one-dimensional statistical parametric mapping.ResultsThe horizontal plane kinematics of the rearfoot differed significantly among the three groups during 30%–91% of the stance phase (P < .05). Severe-laxity copers exhibited a greater external rotation angle than no-laxity copers during 6%–14% and 32%–92% of the stance phase (P < .05).ConclusionOur data suggest that severe ankle joint laxity affects rearfoot horizontal plane kinematics in individuals without perceived ankle instability performing a 45° side-cutting task. These findings could be used by clinicians in developing rehabilitation programs to prevent further ankle sprains in patients with severe ankle joint laxity.     

慢性踝关节外侧不稳定的治疗

目的 回顾慢性踝关节外侧不稳定的治疗,对其结果进行分析和评价.方法 74例患者,其中男43例,女31例;年龄15～63岁,平均39岁.患者至少有半年以上的病史,有两次以上的反复扭伤史.所有患者均行6周以上的保守治疗.41例患者行手术治疗,改良的Brostrom术12例,Myerson法8例,Chrisman-Snook法21例.对其他并发的病理问题需同时处:其中腓骨肌腱滑脱加固术6例,跟腱挛缩延长术9例,跟内翻截骨外移术8例,距骨骨软骨损伤清理打孔13例.结果 本组74例患者,通过术前的保守治疗,21例功能性不稳定的患者症状缓解,53例合并功能性不稳定和机械性不稳定的患者中,10例症状缓解,2例不愿意手术治疗,41例行手术治疗.手术治疗的患者在术后的随访中,有随访资料的39例;33例未手术的患者中,有随访资料的28例.共随访6～91个月,采用Roos功能结果评分法进行结果评判.术后踝关节功能评分的平均值为86.24,保守治疗的患者踝关节功能评分的平均值为97.34.结论 本组74例患者,通过术前的保守治疗,21例功能性不稳定的患者症状缓解,53例合并功能性不稳定和机械性不稳定的患者中,10例症状缓解,2例不愿意手术治疗,41例行手术治疗.手术治疗的患者在术后的随访中,有随访资料的39例;33例未手术的患者中,有随访资料的28例.共随访6～91个月,采用Roos功能结果评分法进行结果评判.术后踝关节功能评分的平均值为86.24,保守治疗的患者踝关节功能评分的平均值为97.34.     

Fibular taping does not influence ankle dorsiflexion range of motion or balance measures in individuals with chronic ankle instability

ObjectivesTo determine the effects of fibular taping on ankle dorsiflexion range of motion (ROM) and dynamic balance in individuals with chronic ankle instability (CAI).DesignSingle-blind, randomized crossover.MethodsTwenty-three individuals (age = 23.4 ± 2.5 years, height = 171.6 ± 12.4 cm, mass = 71.5 ± 13.1 kg) with CAI were allocated to either a fibular taping intervention or sham taping intervention (tape applied without tension) over the course of two visits. Weight-bearing ankle dorsiflexion ROM and components of the Star Excursion Balance Test (SEBT) were measured before and after intervention.ResultsThere was not a significant change in ankle dorsiflexion ROM when comparing the taping interventions (F_1,43 = 1.03, P = .32), but both interventions resulted in a small increase (F_1,43 = 8.07, P = .007) in dorsiflexion ROM (pre = 36.7° ± 6.9°, post = 37.7° ± 6.2°). This increase in ROM did not exceed the established minimal detectable change for dorsiflexion ROM. Fibular taping with tension produced an increase (F_1,41 = 5.84, P = .02) (pre = 69.0 ± 9.1%, post = 70.6 ± 8.6%) in posterolateral reach distance when compared to taping without tension (pre = 72.7 ± 11.0%, post = 71.4 ± 9.6%), but this increase did not exceed the established minimal detectable change. There was not a significant change in dynamic balance between groups for the anterior (F_1,41 = 2.33, P = .14) and posteromedial (F_1,41 = .41, P = .53) reach directions.ConclusionsAlthough small changes in ankle dorsiflexion ROM and posterolateral reach distances were observed, these changes did not exceed established minimal detectable change values for these measures. These results suggest that the benefits of fibular taping are not related to an increase in ankle dorsiflexion ROM or dynamic balance.     

Anatomical repair of lateral ligaments in patients with chronic ankle instability

In a prospective study, 19 patients with chronic ankle instability underwent clinical and radiographic reexaminations 36 months after anatomical reconstruction. In addition, dynamic pedography was conducted and peroneal reaction time measured on a tilting platform for an evaluation of functional aspects. Prior to this examination, 32 patients had been asked to fill in a questionnaire and make a detailed subjective evaluation of current discomfort, stability, flexibility and sporting abilities. Eighty-eight percent of the patients reported satisfactory results; only 3% complained of persistent instability. In 71% the ability to take part in sports had improved after surgery, and 85% of the patients reported unrestricted walking abilities. Supination ability was impaired in 5% of the patients at the follow-up. The radiographic examination showed restored ankle stability with a significant reduction of talar tilt and talar translation; a postoperative increase in signs and symptoms of arthrosis was not observed. Dynamic pedography showed a large degree of symmetry of plantar pressure distribution after surgery. There were no significant differences in peroneal reaction time in the repaired and intact ankles. The results of the study show that it is possible to restore ankle stability with anatomical reconstruction without impairing the range of movement in the ankle joint complex. Progressive osteoarthrosis can be prevented.     

Subgroup characteristics of patients with chronic ankle instability in primary care

ObjectivesTo examine clinical and radiological characteristics of participants with an ankle sprain in general practice, classified into subgroups of a previously described chronic ankle instability (CAI) model.DesignCross-sectional study.Methods206 participants, who visited their general practitioner with a lateral ankle sprain 6–12 months before inclusion, completed a questionnaire, physical examination, radiography and magnetic resonance imaging. They were classified into three subgroups of the previously described CAI-model: mechanical instability (MI), perceived instability (PI) and recurrent sprains (RS). Regression analyses were applied to evaluate differences in subgroup characteristics.ResultsA total of 192 participants were eligible to be classified into the model. Of these participants, 153 participants were classified into the subgroups and 39 could not be classified. With overlap between the subgroups and patients falling into more than one subgroup, 59 were classified having MI, 145 having PI and 30 having RS. Participants with RS and PI were more often sports participants (OR 6.83;95%CI 1.35–34.56 and OR 4.44;95%CI1.06–18.63 respectively) than participants without RS and PI. Participants with MI more often had a tenderness on palpation of the anterior talofibular ligament (OR 4.09;95%CI 1.91–8.72) and a KL-score ≥ 1 in the talonavicular joint on X-ray (OR 2.24;95%CI 1.09–4.58), compared to participants without MI.ConclusionsSports participation, tenderness on palpation of the anterior talofibular ligament and early signs of osteoarthritis were variables that discriminated between subgroups of CAI. However, further research is mandatory in order to examine the usefulness of the CAI model in relation to prognosis and suitable intervention.     

Short-term and long-term effects of ankle joint taping and bandaging on balance,proprioception and vertical jump among volleyball players with chronic ankle instability

ObjectiveThis study hypothesized that the prolonged use of taping during athletic activities produces more significant increases in proprioception, balance, and vertical jump among volleyball players with CAI.DesignA randomized controlled study.ParticipantsOne-hundred participants with chronic ankle instability (CAI) participated in this study. Participants were distributed into 3-groups: taping group, bandaging group, and control group.Primary outcome measuresProprioception (ankle range of motion absolute error), balance(Y-balance test), and vertical jump (vertical jump tester).InterventionsThree interventions were performed: ankle rigid taping, ankle bandaging, and placebo taping. The measurements were performed at baseline, immediately, 2-weeks and 2-months after support.ResultsImmediately after supports, there were non-significant differences between all groups for proprioception, balance (P < .05). There was a significant difference between banding and control groups, and taping and control groups for the vertical jump (P < .05). After 2-weeks and 2-months, there were significant differences between bandaging and control groups, and taping and control groups for proprioception, balance, and vertical jump (P < .05). There were non-significant differences between taping and bandaging groups (P < .05) during all assessments.ConclusionThis study indicated that ankle taping and bandaging immediately improve vertical jump only; while they improve proprioception, balance, and vertical jump after 2-weeks and 2-months.     

Concomitant osteochondral lesions of the talus affect the stair descent biomechanics of patients with chronic ankle instability: A pilot study

BackgroundPrevious studies on the kinematics of patients with chronic ankle instability (CAI) that did not incorporate MRI and arthroscopic assessment could not differentiate between patients with CAI without osteochondral lesion of the talus (OLT) and patients with CAI and OLT and have thus presented contradictory results.Research questionThis study aimed to investigate the kinematic and electromyographic differences between patients with and without OLT.MethodsSixteen subjects with CAI (eight without OLT and eight with OLT confirmed through MRI and arthroscopic assessment) and eight healthy subjects underwent gait analysis in a stair descent setting. The three groups’ patient-reported outcomes; ankle joint range of motion in flexion, inversion and rotation; and muscle activation of the peroneus, tibialis anterior, and gastrocnemius during a gait cycle were analyzed and compared. A curve analysis, namely, one-dimensional statistical parametric mapping, was performed to compare the dynamic ankle kinematics and muscle activation curves over the entire normalized time series.ResultsThe patients with and without OLT had no difference in patient-reported outcomes. The maximal ankle plantarflexion of the patients without OLT and the healthy subjects was significantly larger than that of patients with OLT (p = 0.005). The maximal ankle internal rotation of patients without OLT was significantly larger than that of patients with OLT (p = 0.048). The peroneal activation during 0–6% of the gait cycle of patients with OLT was reduced compared with the healthy subjects.SignificancePatients with CAI and OLT and patients with CAI without OLT have no difference in patient-reported outcomes, but patients with OLT can be differentiated using the post-initial-contact peroneal activation deficit and the restriction of ankle plantarflexion and internal rotation during stair descent. These variables can be utilized to monitor the function of patients with CAI and their possibility of developing OLT.     

Effect of chronic ankle instability on lower extremity kinematics,dynamic postural stability,and muscle activity during unilateral jump-landing tasks: A systematic review and meta-analysis

ObjectiveTo determine if individuals with chronic ankle instability (CAI) demonstrate altered landing kinematics, muscle activity, and impaired dynamic postural stability during a unilateral jump-landing task.Methods21 studies were included from PubMed, MEDLINE, Embase and CINAHL searched on September 26, 2021. Mean differences in joint angles and muscle activity between CAI and controls were analysed as continuous variables and pooled using a random-effects model to obtain standardised mean differences and 95% confidence intervals. Dynamic postural stability measured using time to stabilisation (TTS) was assessed qualitatively.ResultsWe found greater plantarflexion (pooled SMD = 0.33, 95%CI [0.02,0.65]), reduced knee flexion (pooled SMD = −0.67, 95%CI [−0.97, −0.37]), and reduced hip flexion (pooled SMD = −0.52, 95%CI [−0.96, −0.07]) in CAI after landing. Regarding muscle activity, we observed reduced peroneus longus muscle activation (pooled SMD = −0.77, 95% CI [−1.17, −0.36]) in CAI prior to landing.ConclusionOur study provides preliminary evidence of altered landing kinematics in the sagittal plane and reduced peroneus muscle activity in CAI during a dynamic jump-landing task. These results may have clinical implications in the development of more effective and targeted rehabilitation programmes for patients with CAI.     

骨锚在慢性踝关节前外侧不稳手术中的临床应用

目的探讨和总结微型带线骨锚钉在治疗慢性踝关节前外侧不稳手术中的临床疗效和使用经验。方法选择2008年4月～2010年4月我院收治的慢性踝关节前外侧不稳患者38例。所有病例均采用强生Fastin RC带线锚钉手术解剖重建外踝韧带。本组男性25例,女性13例;年龄19～32岁,平均（24.1±6.4）岁。结果 38例均获得随访13～25个月,平均（16.8±6.7）个月,术后所有踝关节活动度基本恢复正常,均未出现复发性踝关节不稳。关节功能根据美国足踝骨科协会（AOFAS）足踝评分进行评估。术前与术后AOFAS后足评分有极显著性差异（P〈0.01）。结论运用微型带线骨锚钉解剖重建外踝韧带,有效恢复了踝关节外侧的稳定性,是治疗慢性踝关节前外侧不稳合理想有效的方法。     

The reliability,and discriminative ability of the identification of functional ankle instability questionnaire,Japanese version

ObjectiveTo assess the discriminability as well as the reliability, and internal consistency of the Identification of Functional Ankle Instability questionnaire translated into Japanese (IdFAI-J).DesignCross-sectional study.SettingCollegiate athletic training/sports medicine clinic.ParticipantsTwenty bilingual and sixty-five collegiate athletes including participants with and without functional instability (FI).Main outcome measuresThe sensitivity, specificity, test retest reliability, and internal consistency of IdFAI-J.ResultsThe optimal cutoff score between the FI and non-FI participants was >10, with an area under the curve of 0.92. We calculated high sensitivity (0.94) and specificity (0.77) at the cutoff point. For the test-retest reliability, the intraclass correlation coefficient value of the IdFAI-J was 0.96; the standard error of measurement and minimal detectable change value was 1.69 and 3.60, respectively. Cronbach's α was 0.87; there was no improvement when a particular item was deleted from the scale.ConclusionsThe IdFAI-J has excellent discriminability, test-retest reliability, and internal consistency. Hence, the IdFAI-J significantly contribute to clinical practice and future research related to ankle instability in Japan.     

A new approach of the Star Excursion Balance Test to assess dynamic postural control in people complaining from chronic ankle instability

The purpose of this study was to quantitatively and qualitatively assess dynamic balance with accuracy in individuals with chronic ankle instability (CAI). To this aim, a motion capture system was used while participants performed the Star Excursion Balance Test (SEBT). Reached distances for the 8 points of the star were automatically computed, thereby excluding any dependence to the experimenter. In addition, new relevant variables were also computed, such as absolute time needed to reach each distance, lower limb ranges of motion during unipodal stance, as well as absolute error of pointing. Velocity of the center of pressure and range of variation of ground reaction forces have also been assessed during the unipodal phase of the SEBT thanks to force plates. CAI group exhibited smaller reached distances and greater absolute error of pointing than the control group (p < 0.05). Moreover, the ranges of motion of lower limbs joints, the velocity of the center of pressure and the range of variation of the ground reaction forces were all significantly smaller in the CAI group (p < 0.05). These reduced quantitative and qualitative performances highlighted a lower dynamic postural control. The limited body movements and accelerations during the unipodal stance in the CAI group could highlight a protective strategy. The present findings could help clinicians to better understand the motor strategies used by CAI patients during dynamic balance and may guide the rehabilitation process.     

Arthrography of the ankle joint in chronic instability

Papers on arthrography of injuries of the lateral ligaments of the ankle relate mainly to recent distortion of the joint. Arthrography performed at a later stage after injury generally is considered useless. In fact, changes in chronic instability are observed; they are subtle and consist either of small recesses adjacent to the lateral malleolus or communication of the joint with the peroneal tendon sheaths. Arthrography was assessed in 61 cases of recurrent lateral sprains of the ankle more than 2 weeks after acute injury; 38 were considered as positive. Twenty-five patients had operative evaluation, with four false negative and one false positive results. Small recesses adjacent to the lateral malleolus or opacification of the peroneal tendon sheaths are sequelae of an acute sprain with tear of the anterior talofibular and/or the calcaneofibular ligaments. Although false negative results occur, arthrography is useful in the preoperative assessment of chronic ankle instability.