Evaluation of joint position recognition measurement variables associated with chronic ankle instability: a meta-analysis

Classification of chronic ankle instability using machine learning technique based on ankle kinematics during heel rise in delivery workers

Objective

Ankle injuries in delivery workers (DWs) are often caused by trips, and high recurrence rates of ankle sprains are related to chronic ankle instability (CAI). Heel rise requires joint angles and moments similar to those of the terminal stance phase of walking that the foot supinates. Thus, our study aimed to develop, determine, and compare the predictive performance of statistical machine learning models to classify DWs with and without CAI using ankle kinematics during heel rise.

Methods

In total, 203 DWs were screened for eligibility. Seven predictors were included in our study (age, work duration, body mass index, calcaneal stance position angle [CSPA] in the initial and terminal positions during heel rise, calcaneal movement during heel rise [CMHR], and plantar flexion angle during heel rise). Six machine learning algorithms, including logistic regression, decision tree, AdaBoost, Extreme Gradient boosting machines, random forest, and support vector machine, were trained.

Results

The random forest model (area under the curve [AUC], 0.967 [excellent]; F1, 0.889; accuracy, 0.925) confirmed the best predictive performance in the test datasets among the six machine learning models. For Shapley Additive Explanations, old age, low CMHR, high CSPA in the initial position, high PFA, long work duration, low CSPA in the terminal position, and high body mass index were the most important predictors of CAI in the random forest model.

Conclusion

Ankle kinematics during heel rise can be considered in the classification of DWs with and without CAI.

Joint position sense error in the hip and knee without reference to the joint angle

BACKGROUND

Joint position reproduction measures the angle acuity of reference angle reproduction using an indicator angle. However, reference angles are often not available.

OBJECTIVE

This study aimed to examine joint position sense at three different targeted joint angles, which were estimated from the maximum range of motion (maxROM) without a reference angle at each targeted joint angle.

METHODS

The maxROM was measured in straight leg raise (SLR) and active knee extension (AKE) positions. In both positions, a targeted joint angle at 75% of the maxROM was assessed first, followed by that at 50% and 25% of the maxROM. A one-sample t-test was used to analyze differences between the targeted and reproduced angles in both positions.

RESULTS

All reproduced angles significantly differed from the targeted angle in both SLR and AKE positions except for the reproduced angle measured at 75% maxROM. Overall, position errors in the AKE position were higher than those in the SLR position.

CONCLUSIONS

Estimating the angle based on the maxROM without a matched reference angle may lead to significant discrepancies in comparison with the targeted joint angle. In clinical settings, if accurate reproduction of motions is required to improve proprioception, providing a reference angle might be helpful.

Modified proximal thigh kinematics captured with a novel smartphone app in individuals with a history of recurrent ankle sprains and altered dorsiflexion with walking

BACKGROUND

We examined sagittal-plane thigh angular kinematics in individuals with and without recurrent ankle sprains using a clinical smartphone app called AccWalker. Sagittal-plane ankle kinematics were also compared to ascertain that altered ankle dorsiflexion, which is typically displayed with chronic ankle instability, is also present in individuals with recurrent ankle sprains.

METHODS

Participants with (n = 22) and without (n = 22) recurrent ankle sprains were evaluated on average sagittal-plane ankle kinematics during walking and average sagittal-plane thigh angular kinematics during stepping-in-place with AccWalker.

FINDINGS

Significant group-by-limb interactions were found for sagittal-plane ankle kinematics (F_(1,42) = 63.786, P < .010) during walking and sagittal-plane average thigh angular range-of-motion (F_(1,42) = 6.166, P = .017) with AccWalker. Individuals with recurrent ankle sprains displayed more ankle dorsiflexion in affected (P < .001) and unaffected (P = .001) limbs during walking than healthy controls and exhibited more ankle dorsiflexion in their affected-limb compared to their unaffected-limb (P < .001). The average sagittal-plane thigh angular range-of-motion was lower in the unaffected-limb for recurrent ankle sprains compared to their affected-limb (P = .038) and the assigned unaffected-limb of healthy controls (P = .035).

INTERPRETATION

Increased dorsiflexion was present in both limbs of the recurrent ankle sprain group with walking. AccWalker does not assess ankle movement, but uniquely identified thigh motion impairments associated with recurrent ankle sprains in their unaffected-limb, potentially identifying central deficits associated with recurrent ankle sprains. This app has clinical implications for assessing potential pathological movement that can be corrected through rehabilitation.

Center of Pressure Deviation during Posture Transition in Athletes with Chronic Ankle Instability

Center of pressure (COP) tracking during posture transition is an ideal scale for determining the recurrence of an ankle injury, thereby preventing chronic ankle instability (CAI). However, the same is difficult to determine because the reduced ability of certain patients (who experienced sprain) to control posture at the ankle joint is masked by the chain of hip and ankle joint motion. Thus, we observed the effects of knee joint immobilization/non-immobilization on postural control strategies during the posture transition task and attempted to evaluate the detailed pathophysiology of CAI. Ten athletes with unilateral CAI were selected. To examine differences in COP trajectories in the CAI side and non-CAI legs, patients stood on both legs for 10 s and one leg for 20 s with/without knee braces. COP acceleration during the transition was significantly higher in the CAI group with a knee brace. The COP transition from the double- to single-leg stance phase was significantly longer in the CAI foot. In the CAI group, the fixation of the knee joint increased COP acceleration during postural deviation. This suggests that there is likely an ankle joint dysfunction in the CAI group that is masked by the hip strategy.

Ankle instability as a prognostic factor associated with the recurrence of ankle sprain: A systematic review

DESIGN

Systematic review using PRISMA guidelines.

PURPOSE

To explore Relationship between ankle instability and ankle sprain recurrence in preventing recurrence of ankle sprains and to provide appropriate treatment.

METHODS

MEDLINE (the Cochrane Library) and the Physiotherapy Evidence Database (PEDro) were explored using key words related to ankle instability and ankle sprains in for April 2022. According to the inclusion criteria, studies that 1) targeted patients with ankle sprains, 2) assessed ankle instability, and 3) investigated ankle sprain recurrence rates, were extracted. The author names, publication year, patient characteristics, comparison groups, intervention methods, and outcome data (ankle instability and recurrence) were extracted. A correlation analysis between recurrence rate and ankle instability was conducted. In addition, A meta-analysis was performed on the correlation coefficients within each article.

RESULTS

Eight studies were extracted from 149 studies. A correlation analysis was conducted on five studies and meta-analysis was on three studies with the same post-intervention follow-up period and the same assessment methods for ankle instability and recurrence rate. Strong positive correlations were found for the same follow-up periods (r = 0.95: 95%CI [0.62-0.99]; 3-month, r = 0.97: 95%CI [0.75-0.10]; 1 year, p < .05). The correlation became stronger as the follow-up period increased. Furthermore, the meta-analysis showed that ankle instability as well as the main symptoms of sprain, such as pain and swelling, tended to be positively correlated with the recurrent rate of ankle sprains. These results suggest that ankle instability is strongly related to recurrence, and the longer the time since onset, the stronger the relationship.

CONCLUSIONS

Ankle instability was a prognostic factor associated with recurrence of ankle sprains in patients with ankle sprains. Therefore, ankle instability is one of important factor in preventing recurrence of ankle sprains.

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.

A quantitative evaluation of the individual components contributing to the functional ankle instability in patients with modified Broström procedure

Residual functional ankle instability regardless of the restoration of mechanical stability after the lateral ligament repair or reconstruction can cause recurrent sprain. The purpose of this study was to identify the sequential changes of joint-position sense, peroneal strength, postural control, and functional performance ability after the modified Broström procedure (MBP) for chronic ankle instability. A total of 46 patients (46 ankles) underwent the MBP for chronic ankle instability were eligible for this study and were followed for 1 year postoperatively. The changes of joint-position sense and peroneal strength were periodically evaluated with an isokinetic dynamometer. Postural control ability was evaluated using a one-leg stance test with eyes closed. The functional performance ability examination comprised a one-leg hop test, a 6-meter hop test, and a cross 3-meter hop test. The error in joint-position sense significantly improved from a mean 4.3º to 2.8º (p < .001). Peak torque for eversion significantly improved from a mean 18.2 Nm to 21.2 Nm (p = .024). Balance retention time significantly improved from a mean 4.7 seconds to 6.4 seconds (p < .001). Among the functional performance tests, only the one-leg hop test showed a significant improvement postoperatively (p = .031). At 1 year postoperatively, the recovery ratios compared to the unaffected ankle were 67.9% in joint-position sense (p < .001), 86.9% in peroneal strength (p = .012), and 74.4% in postural control (p < .001) with significant side-to-side differences. Although joint-position sense, peroneal strength, postural control, and functional performance ability were significantly improved after the MBP, recovery ratios compared to the unaffected ankle were insufficient up to 1 year postoperatively.

Slower visuomotor reaction time in division-I collegiate athletes with a history of ankle sprain

The purpose of this study was to compare visuomotor reaction time (VMRT) in collegiate athletes based on ankle sprain history. Participants included athletes with ankle sprain history (n = 18) and athletes with no ankle sprain history (n = 33). Participants completed an upper-extremity VMRT task which was comprised of eight wireless light-emitting diode sensors. The difference between reaction time (sec) and the number of "Hits" and "Misses" were compared between groups. The ankle sprain history group had significantly slower VMRT compared to the no ankle sprain history group with moderate effect sizes. However, there was no difference in the number of "Hits" or "Misses" between groups, despite observing moderate effect sizes. This result suggests that VMRT may be a potential target for prevention and rehabilitation strategies in individuals with ankle sprains. However, further research is needed to better understand the role of VMRT on the risk of ankle sprains.

The changes of joint-position sense, peroneal strength, postural control, and functional performance ability after the modified Broström procedure for chronic ankle instability

Purpose: Residual functional ankle instability regardless of the restoration of mechanical stability after the lateral ligament repair or reconstruction can cause recurrent sprain. The purpose of this study was to identify the sequential changes of joint-position sense, peroneal strength, postural control, and functional performance ability after the modified Broström procedure (MBP) for chronic ankle instability. Methods: A total of 46 patients (46 ankles) who underwent the MBP for chronic ankle instability were eligible for this study and were followed up for 1 year postoperatively. The changes of joint-position sense and peroneal strength were periodically evaluated with an isokinetic dynamometer. Postural control ability was evaluated using a one-leg stance test with eyes closed. The functional performance ability examination comprised a one-leg hop test, a six-meter hop test, and a cross three-meter hop test. Results: The error in joint-position sense significantly improved from a mean 4.3° to 2.8° (p < 0.001). Peak torque for eversion significantly improved from a mean 18.2 Nm to 21.2 Nm (p = 0.024). Balance retention time significantly improved from a mean 4.7 s to 6.4 s (p < 0.001). Among the functional performance tests, only the one-leg hop test showed a significant improvement postoperatively (p = 0.031). At 1 year postoperatively, the recovery ratios compared to the unaffected ankle were 67.9% in joint-position sense (p < 0.001), 86.9% in peroneal strength (p = 0.012), and 74.4% in postural control (p < 0.001), with significant side-to-side differences. Conclusion: Although joint-position sense, peroneal strength, postural control, and functional performance ability were significantly improved after the MBP, recovery ratios compared to the unaffected ankle were insufficient up to 1 year postoperatively. Level of Evidence: Level IV (prospective case series).

Disrupted somatosensory input alters postural control strategies during the Star Excursion Balance Test (SEBT) in healthy people

BACKGROUND

Chronic adaptations, including persistent sensorimotor deficits, remain in individuals with a history of ankle instability, resulting in altered postural control strategies during functional tasks such as gait, running, or landing. However, we do not know the contribution of the altered somatosensory input on postural control strategies during a dynamic balance task such as the Star Excursion Balance Test (SEBT).

RESEARCH QUESTION

The purpose of this study was to characterize postural control strategies with and without disrupted somatosensory input during a dynamic balance task in people without chronic ankle sprain.

METHODS

This study was a crossover study design. Twenty healthy young adults (10 men, 10 women; age = 23.9 ± 3.0 years, height = 174.2 ± 7.4 cm, mass = 71.2 ± 16.7 kg) performed the posteromedial reach test during the SEBT while standing on the ground and on foam. We measured the maximum reach distance (MRD); joint angles of the ankle, knee, hip, and trunk in the sagittal, frontal, and transverse planes; and position and displacement of the center of mass (COM) and center of pressure (COP) during the posteromedial reach task.

RESULTS

The MRD was shorter when standing on the foam than on the ground (p < 0.001). There was a condition by phase interaction for ankle dorsiflexion; tibia internal rotation; and trunk flexion (p < 0.001; p = 0.03; p = 0.01, respectively). The COM and COP were positioned more laterally on the foam (p < 0.001). The COM and COP anterior-posterior displacements were more anterior during the foam condition (p = 0.017).

SIGNIFICANCE

By using a foam pad to disrupt somatosensory information, participants demonstrated altered strategies to control the joint kinematics, COM, and COP, as a function of posteromedial distance. Ankle and trunk movement strategies may influence the posteromedial reach distance. This model may simulate changes that occur with chronic ankle instability.

Lower limb joint position sense and prospective hamstring injury

BACKGROUND

The hamstrings remain the most injured muscle group within the Australian Football League (AFL).

OBJECTIVE

To investigate preseason measures of hip and knee joint position sense (JPS) and prospective hamstring injury in AFL players.

DESIGN

Prospective cohort study.

METHODS

A total of 116 AFL players were recruited for this study. JPS was assessed with 3-D sensors using mono-articular hip (45° flexion and 0°) and knee (90° and 45° flexion) joint reproduction tests conducted in the preseason. Hamstring injury data were collected prospectively in the following AFL season. Wilcoxon-signed rank tests were used to assess between the subsequently injured and uninjured limbs. Mann-Whitney U tests were used to assess between group differences and odds ratio (OR) were used to predict players at risk of hamstring injury.

RESULTS

Eight players with JPS data sustained a season hamstring injury and 108 players did not. JPS was not significantly different between the subsequently injured and uninjured limbs (all P values > 0.05). No significant differences for any JPS measure were found between the subsequently injured and uninjured players (all p's > 0.05). ORs did not achieve significance for AE (2.7, p = 0.21) or for RMSE (OR = 1.9, p = 0.44).

CONCLUSION

Lower limb JPS measures were not predictive of hamstring injury in AFL players.

Chronic ankle instability is associated with proprioception deficits: A systematic review and meta-analysis

BACKGROUND

Acute ankle injury causes damage to joint mechanoreceptors and deafferentation and contributes to proprioception deficits in patients with chronic ankle instability (CAI). We aimed to explore whether deficits of proprioception, including kinesthesia and joint position sense (JPS), exist in patients with CAI when compared with the uninjured contralateral side and healthy people. We hypothesized that proprioception deficits did exist in patients with CAI and that the deficits varied by test methodologies.

METHODS

The study was a systematic review and meta-analysis. We identified studies that compared kinesthesia or JPS in patients with CAI with the uninjured contralateral side or with healthy controls. Meta-analyses were conducted for the studies with similar test procedures, and narrative syntheses were undertaken for the rest.

RESULTS

A total of 7731 studies were identified, of which 30 were included for review. A total of 21 studies were eligible for meta-analysis. Compared with the contralateral side, patients with CAI had ankle kinesthesia deficits in inversion and plantarflexion, with a standardized mean difference (SMD) of 0.41 and 0.92, respectively, and active and passive JPS deficits in inversion (SMD = 0.92 and 0.72, respectively). Compared with healthy people, patients with CAI had ankle kinesthesia deficits in inversion and eversion (SMD = 0.64 and 0.76, respectively), and active JPS deficits in inversion and eversion (SMD = 1.00 and 4.82, respectively). Proprioception deficits in the knee and shoulder of patients with CAI were not statistically significant.

CONCLUSION

Proprioception, including both kinesthesia and JPS, of the injured ankle of patients with CAI was impaired, compared with the uninjured contralateral limbs and healthy people. Proprioception varied depending on different movement directions and test methodologies. The use of more detailed measurements of proprioception and interventions for restoring the deficits are recommended in the clinical management of CAI.

Assessments of Sensorimotor Deficits Used in Randomized Clinical Trials With Individuals With Ankle Sprains and Chronic Ankle Instability: A Scoping Review

The main purpose of this scoping review was to summarize the most common tasks and outcome measures in randomized control trials (RCTs) used to assess sensorimotor function following ankle sprain and chronic ankle instability (CAI). We also aimed to summarize the description of inclusion criteria used in articles. We searched for RCTs published between 2008 and 2018 using the following databases: MEDLINE, PubMed, SPORTDiscus, and Web of Science. Eligible studies included participants of either sex who had had at least one ankle sprain with/without subsequent CAI. All articles assessed sensorimotor function. The tasks, outcome measures, and inclusion criteria were categorized, and frequencies of use in each category were calculated. Of 272 publications, 31 met the eligibility criteria. The most common task was single-limb stance (58% of 31). The most common outcome measure was the posterior-medial reach distance of the Star Excursion Balance Test (SEBT) (13 of 16 articles, 81%). Different inclusion criteria for a history of ankle sprains or CAI were used. A wide range of sensorimotor assessments and inclusion criteria was used among studies involving individuals with a history of ankle sprain with or without CAI, which could make it difficult to compare and generalize study results. This scoping review provides a baseline for planning future studies exploring outcome measures to assess sensorimotor function of individuals with a history of ankle sprain with or without CAI.

Joint position reproduction and joint position discrimination at the ankle are not related

Purpose: Limited data in current literature can be found on the relation between the two commonly-used active proprioception assessment methods -active joint position reproduction (JPR) and active movement extent discrimination assessment (AMEDA). The current study compared the two active methods, JPR and AMEDA, to investigate their interrelationship over two studies that differed in task difficulty, using active ankle inversion movements made in weight-bearing to maximise ecological validity.Methods: 50 participants volunteered in this research, 20 of whom on a harder protocol and the other 30 on an easier protocol, were tested by both methods, JPR and AMEDA. Proprioceptive acuity was represented by absolute error (AE) and variable error (VE) for JPR and by AE and the area under the curve (AUC) for AMEDA.Results: Proprioceptive acuity scores are found to be significantly correlated within test methods but not between methods for either hard or easy tasks, where JPR AE and VE scores were not correlated with either AMEDA AE or AUC. Further, proprioceptive acuity scores were significantly higher on the easy task when tested with the AMEDA method, but not with JPR method.Conclusion: Scores obtained from the two active movement proprioception tests, movement extent discrimination and joint position reproduction, were not significantly correlated. Taken together with previous findings, these results show that for proprioception, scores from the three classical psychophysical methods for measuring sensitivity (adjustment, limits and constant stimuli) are not correlated with each other. This suggests that each proprioception measurement system assesses a different aspect of proprioception.

Ankle strength is not strongly associated with postural stability in patients awaiting surgery for chronic lateral ankle instability

PURPOSE

(1) To describe ankle strength and postural stability in patients with chronic lateral ankle instability and (2) to analyse the correlation between deficits in ankle strength and postural stability.

METHODS

Results of preoperative isokinetic and balance tests in 203 patients whose contralateral ankle was normal were retrospectively reviewed. Isokinetic peak torque values of eversion and inversion at 2 angular velocities (30°/s and 120°/s) were measured in the injured and normal ankles. In the balance test, the percent differences of 3 actual scores (overall, anterior-posterior, and medial-lateral) between the injured and normal ankles were calculated. Additional statistical analyses were performed to evaluate weakness of ankle strength, postural stability deficits, and their correlation.

RESULTS

Significant differences in 4 peak torque values and 4 relative peak torque values (peak torque/body weight) were found between the injured and normal ankles. All 8 values were significantly lower in the injured ankles. Weakness was severe during inversion and at 30°/s. In the balance test, 49 subjects (24.1%) had significant deficits in postural stability and 109 (53.7%) had favourable results. No strong association was found between weakness of ankle strength and deficits in postural stability.

CONCLUSIONS

Strength measurement alone is insufficient to evaluate preoperative functional deficits, and other functional tests are required to measure postural stability. The results of this study provide further evidence for a rehabilitation programme consisting of proprioceptive training as well as strengthening. The proprioceptive training must be an integral part of the rehabilitation programme in addition to strengthening exercise.

LEVEL OF EVIDENCE

Case series, Level IV.

Motoneuron Function Does not Change Following Whole-Body Vibration in Individuals With Chronic Ankle Instability

CONTEXT

Following a lateral ankle sprain, ∼40% of individuals develop chronic ankle instability (CAI), characterized by recurrent injury and sensations of giving way. Deafferentation due to mechanoreceptor damage postinjury is suggested to contribute to arthrogenic muscle inhibition (AMI). Whole-body vibration (WBV) has the potential to address the neurophysiologic deficits accompanied by CAI and, therefore, possibly prevent reinjury.

OBJECTIVE

To determine if an acute bout of WBV can improve AMI and proprioception in individuals with CAI.

DESIGN AND PARTICIPANTS

The authors examined if an acute bout of WBV can improve AMI and proprioception in individuals with CAI with a repeated-measures design. A total of 10 young adults with CAI and 10 age-matched healthy controls underwent a control, sham, and WBV condition in randomized order.

SETTING

Biomechanics laboratory.

INTERVENTION

WBV.

MAIN OUTCOME MEASURES

Motoneuron pool recruitment was assessed via Hoffmann reflex (H-reflex) in the soleus. Proprioception was evaluated using ankle joint position sense at 15° and 20° of inversion. Both were assessed prior to, immediately following, and 30 minutes after the intervention (pretest, posttest, and 30mPost, respectively).

RESULTS

Soleus maximum H-reflex:M-response (H:M) ratios were 25% lower in the CAI group compared with the control group (P = .03). Joint position sense mean constant error did not differ between groups (P = .45). Error at 15° in the CAI (pretest 0.8 [1.6], posttest 2.0 [2.8], 30mPost 2.0 [1.9]) and control group (pretest 0.8 [2.0], posttest 0.6 [2.9], 30mPost 0.5 [2.1]) did not improve post-WBV. Error at 20° did not change post-WBV in the CAI (pretest 1.3 [1.7], posttest 1.0 [2.4], 30mPost 1.5 [2.2]) or control group (pretest -0.3 [3.0], posttest 0.8 [2.1], 30mPost 0.6 [1.8]).

CONCLUSION

AMI is present in the involved limb of individuals with CAI. The acute response following a single bout of WBV did not ameliorate the presence of AMI nor improve proprioception in those with CAI.

Correlation Between Joint-Position Sense, Peroneal Strength, Postural Control, and Functional Performance Ability in Patients With Chronic Lateral Ankle Instability

BACKGROUND

The first aim of this study was to evaluate the side-to-side difference of joint-position sense, peroneal strength, postural control, and functional performance ability in patients with chronic lateral ankle instability. The second aim was to identify the correlation between various components contributing to the functional ankle instability (FAI).

METHODS

Thirty-five patients to be scheduled for the modified Broström procedure for chronic ankle instability were analyzed. Joint-position sense and peroneal strength were measured with an isokinetic dynamometer. Postural control ability was evaluated using the modified Romberg test. The functional performance test consisted of the 1-leg hop test, 6-meter hop test, and cross 3-m hop test. Spearman's correlation coefficient (r) was calculated to determine the linear association between the individual components of the FAI.

RESULTS

Except for the 6-m and cross 3-m hop tests, most examination tools for the FAI demonstrated significant side-to-side differences compared with the unaffected ankle. Spearman's correlation analysis revealed that individual components (joint-position sense, peroneal strength, postural control, and functional performance ability) of the FAI were significantly associated with one another, except between peroneal strength and postural control ability (r = 0.21, P = .195).

CONCLUSION

Joint-position sense, peroneal strength, postural control ability, and 1-leg hop test demonstrated significant side-to-side differences in patients with chronic lateral ankle instability. Individual components contributing to the FAI were significantly correlated with one another, except between peroneal strength and postural control ability. Postural control evaluation using the modified Romberg test could substitute for dynamometer testing, with convenience and economic advantage.

LEVEL OF EVIDENCE

Level IV, prospective case series.

Changes in Spinal and Corticospinal Excitability in Patients with Chronic Ankle Instability: A Systematic Review with Meta-Analysis

The objective of this systematic review with meta-analysis was to determine alterations in spinal and corticospinal excitability of ankle muscles in patients with chronic ankle instability (CAI) compared to uninjured controls. Independent researchers performed comprehensive literature searches of electronic databases and included studies that compared groups with and without CAI and investigated neural excitability with Hoffmann reflex (H-reflex) and/or transcranial magnetic stimulation (TMS). A fixed-effect meta-analysis was conducted to determine group differences for (1) soleus and fibularis maximal H-reflex (Hmax)/maximal M-wave (Mmax)-ratios, and (2) soleus and fibularis longus cortical motor thresholds (CMTs). Seventeen studies were included in the current meta-analysis. They showed that the Hmax/Mmax-ratios of the soleus and the fibularis longus in the CAI group were significantly lower than those in the uninjured control group (soleus: d = −0.41, p < 0.001; fibularis longus: d = −0.27, p = 0.04). There was no evidence for changes in the CMT. This systematic review is the first to demonstrate evidence that patients with CAI present decreased spinal reflex excitability in the soleus and fibularis longus. However, there is no evidence of changes in supraspinal excitability when considering only the CMT. The latter result needs to be interpreted with caution as all except one study demonstrate some changes at the supraspinal level with CAI.

The Ankle-Joint Complex: A Kinesiologic Approach to Lateral Ankle Sprains

Copious research exists regarding ankle instability, yet lateral ankle sprains (LASs) persist in being among the most common recurrent musculoskeletal injuries. Key anatomical structures of the ankle include a triform articulating structure that includes the inferior tibiofibular, talocrural, and subtalar joints. Functionally, force absorption and propulsion through the ankle complex are necessary for any task that occurs in weight bearing. For optimal ankle performance and avoidance of injury, an intricate balance between stability and mobility is necessary to ensure that appropriate force transfer occurs during sports and activities of daily living. Consideration for the many structures that may be directly or indirectly involved in LASs will likely translate into advancements in clinical care. In this clinical review, we present the structure, function, and relevant pathologic states of the ankle complex to stimulate a better understanding of the prevention, evaluation, and treatment of LASs.

An Updated Model of Chronic Ankle Instability

Lateral ankle sprains (LASs) are among the most common injuries incurred during participation in sport and physical activity, and it is estimated that up to 40% of individuals who experience a first-time LAS will develop chronic ankle instability (CAI). Chronic ankle instability is characterized by a patient's being more than 12 months removed from the initial LAS and exhibiting a propensity for recurrent ankle sprains, frequent episodes or perceptions of the ankle giving way, and persistent symptoms such as pain, swelling, limited motion, weakness, and diminished self-reported function. We present an updated model of CAI that aims to synthesize the current understanding of its causes and serves as a framework for the clinical assessment and rehabilitation of patients with LASs or CAI. Our goal was to describe how primary injury to the lateral ankle ligaments from an acute LAS may lead to a collection of interrelated pathomechanical, sensory-perceptual, and motor-behavioral impairments that influence a patient's clinical outcome. With an underpinning of the biopsychosocial model, the concepts of self-organization and perception-action cycles derived from dynamic systems theory and a patient-specific neurosignature, stemming from the Melzack neuromatrix of pain theory, are used to describe these interrelationships.

Effect of Lateral Ligament Augmentation Using Suture-Tape on Functional Ankle Instability

BACKGROUND:

Although lateral ligament augmentation using suture-tape has been effective for restoration of mechanical ankle stability, few data are available regarding changes of peroneal strength, proprioception, and postural control. The aim of this study was to determine effects of suture-tape augmentation on functional ankle instability (FAI).

METHODS:

Twenty-four patients who underwent suture-tape augmentation were eligible and were followed more than 2 years postoperatively. Functional outcomes were evaluated with the Cumberland Ankle Instability Tool (CAIT), Foot and Ankle Ability Measure (FAAM). Changes of peroneal strength, proprioception and postural control were analyzed with an isokinetic dynamometer and a modified Romberg test.

RESULTS:

CAIT and FAAM (average of daily and sports activity scores) significantly improved to average 27.2 points and 86.7 points, respectively, at final follow-up. Peak torque for eversion in 60 degrees/s angular velocity significantly improved to 10.6 Nm at final follow-up. Deficit ratio of peak torque for eversion significantly improved from mean 39.5% to 20.9%, and significant side-to-side difference was revealed ( P < .001). There were no significant differences in joint position sense. A significant improvement in balance retention time was revealed at final follow-up, and the relative deficit ratio compared to the unaffected side was 30.9%.

CONCLUSIONS:

Patient-reported functional outcomes significantly improved after lateral ligament augmentation using suture-tape. Although this procedure demonstrated significant effects on FAI based on improvement of isokinetic peroneal strength and postural control, recovery rates compared to the unaffected side were not significant at the intermediate-term follow-up. In addition, there was no positive effect on proprioception of the ankle.

LEVEL OF EVIDENCE:

Level IV, prospective case series.

Factors Contributing to Chronic Ankle Instability: A Systematic Review and Meta-Analysis of Systematic Reviews

BACKGROUND

Many factors are thought to contribute to chronic ankle instability (CAI). Multiple systematic reviews have synthesised the available evidence to identify the primary contributing factors. However, readers are now faced with several systematic reviews that present conflicting findings.

OBJECTIVE

The aim of this systematic review and meta-analysis was to establish the statistical significance and effect size of primary factors contributing to CAI and to identify likely reasons for inconsistencies in the literature.

METHODS

Relevant health databases were searched: CINAHL, MEDLINE, PubMed, Scopus and SPORTDiscus. Systematic reviews were included if they answered a focused research question, clearly defined the search strategy criteria and study selection/inclusion and completed a comprehensive search of the literature. Included reviews needed to be published in a peer-reviewed journal and needed to review observational studies of factors and/or characteristics of persons with CAI, with or without meta-analysis. There was no language restriction. Studies using a non-systematic review methodology (e.g. primary studies and narrative reviews) were excluded. Methodological quality of systematic reviews was assessed using the modified R-AMSTAR tool. Meta-analysis on included primary studies was performed.

RESULTS

Only 17% of primary studies measured a clearly defined CAI population. There is strong evidence to support the contribution of dynamic balance, peroneal reaction time and eversion strength deficits and moderate evidence for proprioception and static balance deficits to non-specific ankle instability.

CONCLUSIONS

Evidence from previous systematic reviews does not accurately reflect the CAI population. For treatment of non-specific ankle instability, clinicians should focus on dynamic balance, reaction time and strength deficits; however, these findings may not be translated to the CAI population. Research should be updated with an adequately controlled CAI population.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2016, CRD42016032592.

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

PURPOSE

The underlying cause of balance impairments in chronic ankle instability (CAI) patients remains unknown, but an altered use of sensory information has been hypothesized as a potential cause. The purpose of this systematic review with meta-analysis was to determine whether CAI patients use somatosensory information to the same extent as uninjured controls during static single limb stance.

METHODS

We searched PubMed, CINAHL, SPORTDiscus, and Scopus databases from origin to March 2016 using the combination of key words, including postural control, postural stability, single limb stance, single leg stance, single leg balance, single limb balance, and time to boundary (TTB). Eligible studies had to include instrumented single leg stance with both eyes open and eyes closed in healthy, CAI, or both groups as well as report TTB mean and SD values.

RESULTS

A total of 11 articles were identified. Effect sizes using eyes closed to eyes open standardized mean differences and 95% confidence intervals were calculated for all studies that were included in this investigation. Similarly, pooled estimates for each TTB outcome were compared between the CAI and the uninjured control groups. The mean (95% confidence interval) of the mediolateral TTB (control: -1.50 [-1.71 to -1.29]; CAI: -2.04 [-2.31 to -1.77]), anterioposterior mean (control: -2.19 [-2.43 to -1.96]; CAI: -2.82 [-3.13 to -2.52]), and anterioposterior SD (control: -1.81 [-2.03 to -1.58]; CAI: -2.50 [-2.79 to -2.22]) did not overlap, indicating significant differences between two groups.

CONCLUSION

On the basis of our systematic review with meta-analysis, it appears that CAI patients do not use somatosensory information to the same extent as uninjured controls and instead upregulate the use of visual information during single limb stance.

Proprioception retraining for a patient with chronic wrist pain secondary to ligament injury with no structural instability

STUDY DESIGN

Case report.

INTRODUCTION

Previously published studies demonstrate the importance of the sensory innervation of the carpal ligaments and the implication for the sensorimotor control of the wrist. In addition, this case considers key rehabilitation concepts to include the dart-throwing motion and the stabilizing effect of the forearm muscles.

PURPOSE OF THE STUDY

To describe the rehabilitation program for a patient with chronic wrist pain, diagnosed with a partial tear of the dorsal intercarpal ligament and a sprain of the scapholunate ligament of the right wrist.

METHODS

The patient participated in a staged treatment plan over a 3-month period (20 sessions), which began with a focus on proprioceptive awareness and joint position sense retraining. The treatment progressed to strengthening of specific muscles to enhance stability of the wrist joint. The patient completed the Quick Disabilities of the Arm, Shoulder and Hand and the patient-rated wrist evaluation on initial evaluation, re-evaluation at ninth session, and discharge at 20th session.

RESULTS

Raw scores in the Quick Disabilities of the Arm, Shoulder and Hand and the patient-rated wrist evaluation improved from 33 and 61.5 on initial evaluation to 18 and 17.5 on discharge, respectively.

CONCLUSIONS

Sensorimotor techniques including proprioceptive retraining may improve pain, neuromuscular control, and functional outcomes in patients with chronic wrist pain due to ligament injury. The effectiveness of proprioceptive retraining needs to be evaluated in a well-designed randomized controlled trial recruiting this patient population.

LEVEL OF EVIDENCE

5.

Predicting Manual Therapy Treatment Success in Patients With Chronic Ankle Instability: Improving Self-Reported Function

CONTEXT

  Therapeutic modalities that stimulate sensory receptors around the foot-ankle complex improve chronic ankle instability (CAI)-associated impairments. However, not all patients have equal responses to these modalities. Identifying predictors of treatment success could improve clinician efficiency when treating patients with CAI.

OBJECTIVE

  To conduct a response analysis on existing data to identify predictors of improved self-reported function in patients with CAI.

DESIGN

  Secondary analysis of a randomized controlled clinical trial.

SETTING

  Sports medicine research laboratories.

PATIENTS OR OTHER PARTICIPANTS

  Fifty-nine patients with CAI, which was defined in accordance with the International Ankle Consortium recommendations.

INTERVENTION(S)

  Participants were randomized into 3 treatment groups (plantar massage [PM], ankle-joint mobilization [AJM], or calf stretching [CS]) that received six 5-minute treatments over 2 weeks.

MAIN OUTCOME MEASURE(S)

  Treatment success, defined as a patient exceeding the minimally clinically important difference of the Foot and Ankle Ability Measure-Sport (FAAM-S).

RESULTS

  Patients with ≤5 recurrent sprains and ≤82.73% on the Foot and Ankle Ability Measure had a 98% probability of having a meaningful FAAM-S improvement after AJM. As well, ≥5 balance errors demonstrated 98% probability of meaningful FAAM-S improvements from AJM. Patients <22 years old and with ≤9.9 cm of dorsiflexion had a 99% probability of a meaningful FAAM-S improvement after PM. Also, those who made ≥2 single-limb-stance errors had a 98% probability of a meaningful FAAM-S improvement from PM. Patients with ≤53.1% on the FAAM-S had an 83% probability of a meaningful FAAM-S improvement after CS.

CONCLUSIONS

  Each sensory-targeted ankle-rehabilitation strategy resulted in a unique combination of predictors of success for patients with CAI. Specific indicators of success with AJM were deficits in self-reported function, single-limb balance, and <5 previous sprains. Age, weight-bearing-dorsiflexion restrictions, and single-limb balance deficits identified patients with CAI who will respond well to PM. Assessing self-reported sport-related function can identify CAI patients who will respond positively to CS.

Evidence of a different landing strategy in subjects with chronic ankle instability

The purpose of the study is to evaluate the discriminative validity of the multiple hop test (MHT) for chronic ankle instability (CAI). The dynamic postural control of 51 CAI subjects and 52 uninjured controls was assessed using the MHT. To evaluate dynamic postural control, the type and number of balance errors were analysed and the time to complete the MHT was measured. Between-group differences of time scores and balance errors, identified as being change-in-support strategy errors (CSS) or fixed-support strategy errors (FSS), were assessed. The area under curve of the outcomes was determined and likelihood ratios (LRs) were calculated based upon their most optimal cut off point. When compared to uninjured controls, CAI subjects needed significantly more time to perform the test (p<0.001) and made significantly more CSS errors (p<0.001). When 1 positive outcome (time score or CSS errors) was considered as a criterion, the LR⁺ was 2 and the LR^- 0.08. In the case of 2 positive outcomes (time score and CSS errors), the LR⁺ was 7.1 and the LR^- 0.49. CAI subjects have an impaired dynamic postural control and rely on a different postural strategy to restore balance. The MHT has good discriminative validity for CAI.

Response to Tendon Vibration Questions the Underlying Rationale of Proprioceptive Training

CONTEXT

Proprioceptive training on compliant surfaces is used to rehabilitate and prevent ankle sprains. The ability to improve proprioceptive function via such training has been questioned. Achilles tendon vibration is used in motor-control research as a form of proprioceptive stimulus. Using measures of postural steadiness with nonlinear measures to elucidate control mechanisms, tendon vibration can be applied to investigate the underlying rationale of proprioceptive training.

OBJECTIVE

To test whether the effect of vibration on young adults' postural control depended on the support surface.

DESIGN

Descriptive laboratory study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty healthy adults and 10 adults with chronic ankle instability (CAI; age range = 18-40 years).

INTERVENTION(S)

With eyes open, participants stood in bilateral stance on a rigid plate (floor), memory foam, and a Both Sides Up (BOSU) ball covering a force platform. We applied bilateral Achilles tendon vibration for the middle 20 seconds in a series of 60-second trials and analyzed participants' responses from previbration to vibration (pre-vib) and from vibration to postvibration (vib-post).

MAIN OUTCOME MEASURE(S)

We calculated anterior-posterior excursion of the center of pressure and complexity index derived from the area under multiscale entropy curves.

RESULTS

The excursion response to vibration differed by surface, as indicated by a significant interaction of P < .001 for the healthy group at both time points and for the CAI group vib-post. Although both groups demonstrated increased excursion from pre-vib and from vib-post, a decrease was observed on the BOSU. The complexity response to vibration differed by surface for the healthy group (pre-vib, P < .001). The pattern for the CAI group was similar but not significant. Complexity changes vib-post were the same on all surfaces for both groups.

CONCLUSIONS

Participants reacted less to ankle vibration when standing on the BOSU as compared with the floor, suggesting that proprioceptive training may not be occurring. Different balance-training paradigms to target proprioception, including tendon vibration, should be explored.

Sensory-Targeted Ankle Rehabilitation Strategies for Chronic Ankle Instability

INTRODUCTION

Deficient sensory input from damaged ankle ligament receptors is thought to contribute to sensorimotor deficits in those with chronic ankle instability (CAI). Targeting other viable sensory receptors may then enhance sensorimotor control in these patients. The purpose of this randomized controlled trial was to evaluate the effects of 2 wk of sensory-targeted ankle rehabilitation strategies (STARS) on patient- and clinician-oriented outcomes in those with CAI.

METHODS

Eighty patients with self-reported CAI participated. All patients completed patient-oriented questionnaires capturing self-reported function as well as the weight-bearing lunge test and an eyes-closed single-limb balance test. After baseline testing, patients were randomly allocated to four STARS groups: joint mobilization, plantar massage, triceps surae stretching, or control. Each patient in the intervention groups received six 5-min treatments of their respective STARS over 2 wk. All subjects were reassessed on patient- and clinician-oriented measures immediately after the intervention and completed a 1-month follow-up that consisted of patient-oriented measures. Change scores of the three STARS groups were compared with the control using independent t-tests and Hedges' g effect sizes with 95% confidence intervals.

RESULTS

The joint mobilization group had the greatest weight-bearing lunge test improvement. Plantar massage had the most meaningful single-limb balance improvement. All STARS groups improved patient-oriented outcomes with joint mobilization having the most meaningful effect immediately after the intervention and plantar massage at the 1-month follow-up.

CONCLUSION

Each STARS treatment offers unique contributions to the patient- and clinician-oriented rehabilitation outcomes of those with CAI. Both joint mobilization and plantar massage appear to demonstrate the greatest potential to improve sensorimotor function in those with CAI.

Extrinsic visual feedback and additional cognitive/physical demands affect single-limb balance control in individuals with ankle instability

AIM

To investigate the impact of extrinsic visual feedback and additional cognitive/physical demands on single-limb balance in individuals with ankle instability.

METHODS

Sixteen subjects with ankle instability participated in the study. Ankle instability was identified using the Cumberland Ankle Instability Tool (CAIT). The subject’s unstable ankle was examined using the Athletic Single Leg Stability Test of the Biodex Balance System with 4 different protocols: (1) default setting with extrinsic visual feedback from the monitor; (2) no extrinsic visual feedback; (3) no extrinsic visual feedback with cognitive demands; and (4) no extrinsic visual feedback with physical demands. For the protocol with added cognitive demands, subjects were asked to continue subtracting 7 from a given number while performing the same test without extrinsic visual feedback. For the protocol with added physical demands, subjects were asked to pass and catch a basketball to and from the examiner while performing the same modified test.

RESULTS

The subject’s single-limb postural control varied significantly among different testing protocols (F = 103; P = 0.000). Subjects’ postural control was the worst with added physical demands and the best with the default condition with extrinsic visual feedback. Pairwise comparison shows subjects performed significantly worse in all modified protocols (P < 0.01 in all comparisons) compared to the default protocol. Results from all 4 protocols are significantly different from each other (P < 0.01) except for the comparison between the “no extrinsic visual feedback” and “no extrinsic visual feedback with cognitive demands” protocols. Comparing conditions without extrinsic visual feedback, adding a cognitive demand did not significantly compromise single-limb balance control but adding a physical demand did. Scores from the default protocol are significantly correlated with the results from all 3 modified protocols: No extrinsic visual feedback (r = 0.782; P = 0.000); no extrinsic visual feedback with cognitive demands (r = 0.569; P = 0.022); no extrinsic visual feedback with physical demands (r = 0.683; P = 0.004). However, the CAIT score is not significantly correlated with the single-limb balance control from any of the 4 protocols: Default with extrinsic visual feedback (r = -0.210; P = 0.434); no extrinsic visual feedback (r = -0.450; P = 0.081); no extrinsic visual feedback with cognitive demands (r = -0.406; P = 0.118); no extrinsic visual feedback with physical demands (r = -0.351; P = 0.182).

CONCLUSION

Single-limb balance control is worse without extrinsic visual feedback and/or with cognitive/physical demands. The balance test may not be a valid tool to examine ankle instability.

Relationships between mechanical joint stability and somatosensory function in individuals with chronic ankle instability

BACKGROUND

Individuals with chronic ankle instability (CAI) have demonstrated alterations in ankle mechanics and deficits in sensory function. However, relationships between mechanical stability and somatosensory function have not been examined, nor have those between somatosensory function and injury history characteristics. Therefore, the objective of this study was to examine relationships between (1) somatosensory function and mechanical stability and (2) somatosensory function and injury history characteristics.

METHODS

Forty adults with CAI volunteered to participate. In a single testing session, participants completed mechanical and sensory assessments in a counterbalanced order. Dependent variables included anterior/posterior displacement (mm), inversion/eversion rotation (°), SWM index values, JPS absolute error (°), number of previous ankle sprains, and number of "giving way" episodes in the previous 3 months. Spearman's Rho correlations examined the relationships between somatosensory function and (1) mechanical stability and (2) injury history characteristics (p<0.05).

RESULTS

No significant correlations were identified between any variables (p>0.11), and all r-values were considered weak.

CONCLUSIONS

These results revealed somatosensory function was not significantly correlated to mechanical stability or injury history characteristics. This indicates peripheral sensory impairments associated with CAI are likely caused by factors other than mechanical stability and injury history characteristics.

Factors contributing to chronic ankle instability: a protocol for a systematic review of systematic reviews

BACKGROUND

Ankle sprains are a significant clinical problem. Researchers have identified a multitude of factors contributing to the presence of recurrent ankle sprains including deficits in balance, postural control, kinematics, muscle activity, strength, range of motion, ligament laxity and bone/joint characteristics. Unfortunately, the literature examining the presence of these factors in chronic ankle instability (CAI) is conflicting. As a result, researchers have attempted to integrate this evidence using systematic reviews to reach conclusions; however, readers are now faced with an increasing number of systematic review findings that are also conflicting. The overall aim of this review is to critically appraise the methodological quality of previous systematic reviews and pool this evidence to identify contributing factors to CAI.

METHODS

A systematic review will be conducted on systematic reviews that investigate the presence of various deficits identified in CAI. Databases will be searched using pre-determined search terms. Reviews will then be assessed for inclusion based on the set eligibility criteria. Two independent reviewers will assess the articles for inclusion before evaluating the methodological quality and presence of bias of the included studies; any disagreements will be resolved by discussion between reviewers to reach consensus or by a third reviewer. Data concerning the specific research question, search strategy, inclusion/exclusion criteria, population, method and outcomes will be extracted. Findings will be analysed with respect to the methodological quality of the included reviews.

DISCUSSION

It is expected that this review will clarify the cause of contradicting findings in the literature and facilitate future research directions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016032592 .

Plantar cooling does not affect standing balance: A systematic review and meta-analysis

The purpose of this systematic review with meta-analysis was to critically appraise and synthesize the literature to determine if cooling the plantar surface of the foot is an effective method of inducing postural control alterations in healthy individuals. Specific variables that were evaluated within the meta-analysis included (1) the duration of the plantar cooling intervention, (2) the stance type during postural control assessment, and (3) the role of visual input. A computerized search of four electronic databases from inception to March 2015 was performed to identify studies which examined the effects of plantar cooling on postural control in healthy individuals. A critical appraisal of the methodological quality of the included studies was performed using an appraisal criteria instrument previously used for assessing biomechanics studies. The literature search yielded 88 references of which 7 were deemed relevant and included in the systematic review and meta-analysis. A single, overall random-effects model meta-analysis of all study variables were performed; as well as, separate meta-analyses for each study variable. Across the 7 studies, the overall effect was 0.028 (95% CI=-0.177, 0.234; p=0.78) indicating that cooling the plantar surface had a very small effect on postural control. Similar results were obtained when data were examined based on study quality, plantar cooling intervention duration, stance type during postural control assessment, and the presence of visual input. Therefore, cooling the plantar surface of the foot had a very weak, non-significant effect on standing balance despite the anesthetic effects identified in each study.

Neuromuscular control and rehabilitation of the unstable ankle

Lateral ankle sprain is a common orthopedic injury with a very high recurrence rate in athletes. After decades of research, it is still unclear what contributes to the high recurrence rate of ankle sprain, and what is the most effective intervention to reduce the incident of initial and recurrent injuries. In addition, clinicians often implement balance training as part of the rehabilitation protocol in hopes of enhancing the neuromuscular control and proprioception of the ankle joint. However, there is no consensus on whether the neuromuscular control and proprioception are compromised in unstable ankles. To reduce the prevalence of ankle sprains, the effectiveness of engaging balance training to enhance the neuromuscular control and proprioception of the ankle joint is also questionable.

Plantar cutaneous sensitivity and balance in individuals with and without chronic ankle instability

OBJECTIVE

To determine if plantar cutaneous sensation and postural control differ between individuals with and without chronic ankle instability (CAI).

DESIGN

Case-control.

SETTING

Laboratory.

PARTICIPANTS

Ten subjects with CAI and 10 subjects with no ankle sprain history participated.

INTERVENTIONS

Light touch was evaluated at 3 sites (heel, base of fifth metatarsal, and head of first metatarsal) on the plantar aspect of the foot using Semmes-Weinstein Monofilaments (SWMs). Postural control was assessed using the single leg firm and foam conditions of the Balance Error Scoring System (BESS) and during eyes open and eyes closed static postural control on a force plate.

MAIN OUTCOME MEASURES

Semmes-Weinstein Monofilament detection thresholds, BESS errors, and the mean of time-to-boundary (TTB) minima (TTB-mean) and the SD of TTB minima (TTB-SD) in the anterior-posterior (AP) and medial-lateral directions were evaluated for each subject.

RESULTS

Subjects with CAI demonstrated increased SWM detection thresholds at the heel (P = 0.009), head of the first (P = 0.01), and base of the fifth metatarsal (P < 0.001) and postural control deficits on the BESS firm (P = 0.04) and foam (P = 0.001) conditions and with eyes open TTB-mean AP (P = 0.007) and TTB-SD AP (P = 0.02). When combining groups, a negative moderate correlation was observed between the base of the fifth metatarsal detection threshold and eyes open TTB-mean AP (r = -0.50; P = 0.03).

CONCLUSIONS

Light touch and postural control deficits were observed in individuals with CAI. The correlation between light touch over the base of the fifth metatarsal and eyes open TTB-mean AP suggests that there may be a relevant relationship between these measures.

CLINICAL RELEVANCE

Individuals with CAI demonstrated deficits in light touch over the plantar aspect of the foot. The relationship between base of the fifth metatarsal sensation and TTB-mean AP may provide a starting point to link plantar cutaneous sensory deficits to changes in other aspects of sensorimotor function.

Peroneal reaction time after ankle sprain: a systematic review and meta-analysis

BACKGROUND

Many studies have examined the temporal response of the peroneal muscles to sudden inversion perturbation in patients with a previous ankle sprain. The purpose of this systematic review with meta-analysis was to synthesize the evidence and determine whether peroneal reaction time (PRT) impairments are present after ankle sprain.

METHODS

An electronic search was conducted using PubMed Central and EBSCOhost (1965-January 2013). Articles were included if they 1) examined the PRT to sudden inversion perturbation in patients with a history of ankle sprain using a mechanical tilt platform, 2) made comparisons with a control group or contralateral limb with no history of ankle sprain, and 3) provided data for the calculation of effect sizes (ES). In addition to examining the overall effect of sustaining an ankle sprain on PRT, the effects of study design and subject characteristics on PRT were evaluated. Bias-corrected Hedges g ES and 95% confidence intervals (CI) were calculated to make comparisons across studies.

RESULTS

A total of 23 studies met the inclusion criteria. The overall ES was 0.67 (95% CI = 0.37-0.95, P < 0.001), indicating that a previous ankle sprain, regardless of study design or subject characteristics, resulted in moderate-to-strong PRT deficits. Further analyses determined studies with patients classified as having chronic ankle instability demonstrated large magnitude PRT deficits in between groups (ES = 0.72, 95% CI = 0.29-1.14, P = 0.001) and side-to-side (ES = 1.24, 95% CI = 0.70-1.79, P < 0.001) comparisons, whereas patients with all other ankle sprain histories demonstrated weak PRT alterations in between groups (ES = -0.21, 95% CI = -1.01 to 0.59, P = 0.61) and side-to-side (ES = 0.21, 95% CI = -0.19 to 0.60, P = 0.31) comparisons.

CONCLUSIONS

Overall, this meta-analysis determined that individuals with a previous ankle sprain exhibit delayed PRT. Further analyses determined that these deficits are more evident in patients with chronic ankle instability when compared with the contralateral uninvolved limb or a healthy control group.

Lateral Ankle Sprain and Chronic Ankle Instability: A Critical Review

Many studies investigated the contributing factors of chronic ankle instability, but a consensus has not yet been obtained. The objective of this critical review is to provide recent scientific evidence on chronic ankle instability, including the epidemiology and pathology of lateral ankle sprain as well as the causative factors of chronic ankle instability. We searched MEDLINE from 1964 to December 2013 using the terms ankle, sprain, ligament, injury, chronic, functional, mechanical, and instability. Lateral ankle sprain shows a very high recurrence rate and causes considerable economic loss due to medical care, prevention, and secondary disability. During the acute phase, patients with ankle sprain demonstrate symptoms such as pain, range of motion deficit, postural control deficit, and muscle weakness, and these symptoms may persist, leading to chronic ankle instability. Although some agreement regarding the effects of chronic ankle instability with deficits in postural control and/or concentric eversion strength exists, the cause of chronic ankle instability remains controversial.

LEVELS OF EVIDENCE

Therapeutic Level IV: Review of Level IV studies.

Effects of fatiguing treadmill running on sensorimotor control in athletes with and without functional ankle instability

BACKGROUND

Sensorimotor control is permanently impaired following functional ankle instability and temporarily decreased following fatigue. Little is known on potential interactions between both conditions. The purpose was to investigate the effect of fatiguing exercise on sensorimotor control in athletes with and without (coper, controls) functional ankle instability.

METHODS

19 individuals with functional ankle instability, 19 ankle sprain copers, and 19 non-injured controls participated in this cohort study. Maximum reach distance in the star excursion balance test, unilateral jump landing stabilization time, center of pressure sway velocity in single-leg-stance, and passive ankle joint position sense were assessed before and immediately after fatiguing treadmill running. A three factorial linear mixed model was specified for each outcome to evaluate the effects of group, exhausting exercise (fatigue) and their interactions (group by fatigue). Effect sizes were calculated as Cohen's d.

FINDINGS

Maximum reach distance in the star excursion balance test, jump stabilization time and sway velocity, but not joint position sense, were negatively affected by fatigue in all groups. Effect sizes were moderate, ranging from 0.27 to 0.68. No significant group by fatigue interactions were found except for one measure. Copers showed significantly larger prefatigue to postfatigue reductions in anterior reach direction (P≤0.001; d=-0.55) compared to the ankle instability (P=0.007) and control group (P=0.052).

INTERPRETATION

Fatiguing exercise negatively affected postural control but not proprioception. Ankle status did not appear to have an effect on fatigue-induced sensorimotor control impairments.