Which Functional Tests and Self-Reported Questionnaires Can Help Clinicians Make Valid Return to Sport Decisions in Patients With Chronic Ankle Instability? A Narrative Review and Expert Opinion.

Lateral ankle sprain is the most common injury in sports, with up to 40% of patients developing chronic ankle instability (CAI). One possible cause underlying this high rate of recurrence or feeling of giving way may be a premature return to sport (RTS). Indeed, except for time-based parameters, there are no specific criteria to guide clinicians in their RTS decisions in patients with CAI. A recent international consensus highlighted the relevance and importance of including patient-reported ankle function questionnaires combined with functional tests targeting ankle impairments in this population. Thus, the aim of this narrative review and expert opinion was to identify the most relevant functional performance tests and self-reported questionnaires to help clinicians in their RTS decision-making process following recurrent ankle sprains or surgical ankle stabilization. The PubMed (MEDLINE), PEDro, Cochrane Library and ScienceDirect databases were searched to identify published articles. Results showed that the single leg stance test on firm surfaces, the modified version of the star excursion balance test, the side hop test and the figure-of-8 test appeared to be the most relevant functional performance tests to target ankle impairments in patients with CAI. A combination of the Foot and Ankle Ability Measure (FAAM) and the Ankle Ligament Reconstruction-Return to Sport after Injury (ALR-RSI) questionnaires were the most relevant self-reported questionnaires to assess patient function in the context of CAI. Although these functional tests and questionnaires provide a solid foundation for clinicians to validate their RTS decisions in patient with CAI, objective scientific criteria with cut-off scores are still lacking. In addition to the proposed test cluster, an analysis of the context, in particular characteristics related to sports (e.g., fatigue, cognitive constraints), to obtain more information about the patient's risk of recurrent injury could be of added value when making a RTS decision in patients with CAI. In order to evaluate the strength of evertors under ecological conditions, it would also be interesting to assess the ability to control weight-bearing ankle inversion in a unipodal stance. Further studies are needed to assess the relevance of this proposed test cluster in RTS decision-making following lateral ankle sprain injury and CAI.

Validity and reliability of video analysis to evaluate ankle proprioceptive reintegration during postural control.

BACKGROUND: The ability to dynamically reintegrate proprioceptive signals after they have been perturbated is impaired in certain pathologies. Evaluation of proprioceptive reintegration is useful for clinical practice but currently requires expensive laboratory tools. We developed a simple method, accessible to clinicians. RESEARCH QUESTION: Is two-dimensional (2D) video analysis of earlobe displacement a valid and reliable tool for the evaluation of ankle proprioceptive reintegration following muscle vibration? METHODS: Thirty-eight healthy individuals underwent vibration of the triceps surae while standing on a force plate (FP). Anterior (sagittal plane) earlobe displacement ('overshoot') was recorded at vibration cessation using 2D video analysis and rated by 3 blind examiners. Correlation analysis was performed between earlobe and center of pressure displacement (dCoP, recorded with the FP) to determine validity. Intra and interrater reliability were determined by calculation of the intraclass correlation coefficient (ICC), change in the mean (CiM), standard error of measurement (SEM) and the minimal detectable change (MDC). RESULTS AND SIGNIFICANCE: Strong positive correlations (r = 0.82-0.94, p < .001) were found between video and FP data. Intra- and interrater reliability were excellent (ICC from 0.99 to 1.00 and from 0.90 to 0.97 respectively). For intrarater analysis, the CiM was 0.01 cm, SEM were 0.27 cm (95% CI: 0.23-0.33) and 3.43% (95% CI: 2.92-4.20) and the MDC was 0.74 cm. For interrater reliability, the CiM ranged from - 0.81-0.55 cm, the SEM from 0.61 to 1.12 cm and the MDC from 1.69 to 3.10 cm. 2D video analysis of anterior (sagittal) earlobe displacement is therefore a valid and reliable method to assess postural recovery following muscle vibration. This simple method could be used by clinicians to evaluate the ability of the central nervous system to reintegrate proprioceptive signals from the ankle. Further studies are needed to assess its validity in individuals with proprioceptive impairment.

Assessment of evertor weakness in patients with chronic ankle instability: Functional versus isokinetic testing.

BACKGROUND: Ankle sprain is the most common sport-related injury and eccentric weakness of ankle evertors is regarded as a significant muscular deficit related to chronic ankle instability. However, the eccentric performance of the evertors is rarely assessed by clinicians because procedures used for research purposes (i.e. isokinetic tests) are not easily applicable in daily practice. METHODS: The present study assessed the ability of two different testing procedures to distinguish between groups of 12 healthy subjects or 12 patients suffering from chronic ankle instability. On the one hand, the strength of evertors was assessed with a goldstandard isokinetic procedure. On the other hand, we assessed the ability of the subjects to control ankle inversion during weight bearing (functional standing test). FINDINGS: Data showed no significant difference between groups for isokinetic peak torque values normalized to body weight. Conversely, the functional test revealed a significantly impaired ability to control ankle inversion during weight bearing in subjects with chronic ankle instability. INTERPRETATION: This suggests that this easy-to-apply functional test is better suited compared to isokinetic testing procedures to assess weakness of evertors in patients suffering from chronic ankle instability. Moreover, this test may also be used to objectively monitor improvements during rehabilitation or progression in prevention protocols.

Rehabilitation after anatomical ankle ligament repair or reconstruction.

The selection, implementation of and adherence to a post-operative regimen are all essential in order to achieve the best outcomes after ankle ligament surgery. The purpose of this paper is to present a best-evidence approach to this, with grounding in basic science and a consensus opinion from the members of the ESSKA-AFAS Ankle Instability Group. Basic science and clinical evidence surrounding tissue healing after surgical repair or reconstruction of the ligaments as well as around the re-establishment of sensorimotor control are reviewed. A consensus opinion based on this evidence as to the recommended rehabilitation protocol after ankle ligament surgery was then obtained from the members of the ESSKA-AFAS Ankle Instability Group. Rehabilitation recommendations are presented for the initial post-operative period, the early recovery phase and a goal-orientated late rehabilitation and return-to-sport phase. This paper presents practical, evidenced-based guidelines for rehabilitation and return to activity after lateral ankle ligament surgery.

Muscle fatigue as an investigative tool in motor control: A review with new insights on internal models and posture-movement coordination.

Muscle fatigue is a common phenomenon experienced in everyday life which affects both our force capacity and movement production. In this paper, we review works dealing with muscle fatigue and motor control and we attempt to demonstrate how the Central Nervous System deals with this particular state. We especially focus on how internal models--neural substrates which can estimate the current state as well as the future state of the body--face this internal perturbation. Moreover, we show that muscle fatigue is an interesting investigative tool in understanding the mechanisms involved in posture-movement coordination.

Ankle muscular proprioceptive signals' relevance for balance control on various support surfaces: an exploratory study.

OBJECTIVE: The purpose of this study was to test the effect of various unstable support surfaces on the relevance of muscular proprioceptive signals originating from the ankle joint. DESIGN: Ten healthy subjects were instructed to stand as still as possible on a force plate during 40 secs on three different surfaces: (1) stable, (2) unstable-unspecific (foam), and (3) unstable-specific (inspired from rearfoot anatomy). Muscular vibration was applied on the paraspinals and fibularis muscles. The effects of vibrations on postural stability as well as fibularis longus and tibialis anterior electrical activities for each support condition were investigated. RESULTS: The unstable-specific support surface was associated with higher fibularis muscular activity and greater postural perturbations when fibularis muscles were vibrated than the unspecific-unstable surface. CONCLUSION: Balance control on unstable-specific support surface maintains the relevance on muscular proprioceptive signals originating from ankle and increases ankle evertor muscle activity.

Hand-head coordination changes from discrete to reciprocal hand movements for various difficulty settings.

The parameters dictating the temporal hand-head coordination during visually corrected movements remain elusive. Here we examine the effects of the nature (discrete vs reciprocal) and the difficulty (ID of 4.7, 5.7 and 6.7 bits) of the task on the temporal hand-head coordination during a Fitts' like paradigm. Subjects aimed at a single target (discrete movement) or alternately to two targets (reciprocal movements). Head movements were unaffected by the ID during discrete movements. This was not the case during reciprocal movements where they were (1) smaller in duration and amplitude than during discrete movements and (2) increased in duration and amplitude with an increasing ID. To measure the temporal hand-head coordination, hand-head latencies were calculated at the onset, peak speed and offset of each movement. Offset latencies remained positive (i.e. the hand reached the target after the head stopped) for all IDs during reciprocal but not during discrete movements. Altogether, different patterns of temporal hand-head coordination were observed between discrete and reciprocal movements as well as between IDs, suggesting the hand-head coordination does not follow a fixed rule but is adjusted to task requirements.

Effect of terminal accuracy requirements on temporal gaze-hand coordination during fast discrete and reciprocal pointings.

BACKGROUND: Rapid discrete goal-directed movements are characterized by a well known coordination pattern between the gaze and the hand displacements. The gaze always starts prior to the hand movement and reaches the target before hand velocity peak. Surprisingly, the effect of the target size on the temporal gaze-hand coordination has not been directly investigated. Moreover, goal-directed movements are often produced in a reciprocal rather than in a discrete manner. The objectives of this work were to assess the effect of the target size on temporal gaze-hand coordination during fast 1) discrete and 2) reciprocal pointings. METHODS: Subjects performed fast discrete (experiment 1) and reciprocal (experiment 2) pointings with an amplitude of 50 cm and four target diameters (7.6, 3.8, 1.9 and 0.95 cm) leading to indexes of difficulty (ID = log2[2A/D]) of 3.7, 4.7, 5.7 and 6.7 bits. Gaze and hand displacements were synchronously recorded. Temporal gaze-hand coordination parameters were compared between experiments (discrete and reciprocal pointings) and IDs using analyses of variance (ANOVAs). RESULTS: Data showed that the magnitude of the gaze-hand lead pattern was much higher for discrete than for reciprocal pointings. Moreover, while it was constant for discrete pointings, it decreased systematically with an increasing ID for reciprocal pointings because of the longer duration of gaze anchoring on target. CONCLUSION: Overall, the temporal gaze-hand coordination analysis revealed that even for high IDs, fast reciprocal pointings could not be considered as a concatenation of discrete units. Moreover, our data clearly illustrate the smooth adaptation of temporal gaze-hand coordination to terminal accuracy requirements during fast reciprocal pointings. It will be interesting for further researches to investigate if the methodology used in the experiment 2 allows assessing the effect of sensori-motor deficits on gaze-hand coordination.

Cognitive cost of motor reorganizations associated with muscular fatigue during a repetitive pointing task.

Muscular fatigue is known to impair motor performance and to catalyse the development of upper limb musculoskeletal disorders. In order to delay the deleterious effects of muscular fatigue, the central nervous system (CNS) employs compensatory strategies. The cognitive cost of such compensatory strategies was assessed in 10 male subjects who alternatively performed two dual-task protocols before and immediately after an exhaustion procedure specific to upper arm abductor musculature. The main motor tasks were an isometric force-matching and a rapid multi-joint pointing. A secondary probe reaction time (RT) task was performed during both protocols and served as an indicator of attentional demands. Overall motor task performance was maintained despite fatigue. Kinematic and electromyographic data revealed that subjects used motor reorganization during the pointing task when fatigued. The RT increased with fatigue in both dual-task protocols, but this increase was significantly higher during the pointing task than during the force-matching task. The results highlight that the motor reorganization used by the CNS under muscular fatigue states require higher attentional demands than the initial motor organization. Finally, the capacity to delay the deleterious effects of muscular fatigue seems to depend on the proportion of cognitive resources available to plan the compensatory motor strategy.