Discriminating between copers and people with chronic ankle instability

Examining the diagnostic accuracy of common physical examination and functional tests in the diagnosis of patellofemoral pain syndrome among patients with anterior knee pain

PURPOSE

The aims of this study were to evaluate the diagnostic accuracy of common physical examination and functional evaluation tests, and to determine a set of tests with the highest diagnostic accuracy for diagnosing patellofemoral pain syndrome (PFPS) in patients with anterior knee pain.

METHODS

Based on careful evaluation of clinical findings and imaging methods by orthopedic physicians, 162 patients with anterior knee pain were classified into two groups of PFPS and non-PFPS. The physical examination and functional tests were performed by two physiotherapists. The accuracy of these measures was determined by calculating sensitivity, specificity, area under the receiver operating characteristic (ROC) curve (AUC), likelihood ratio (LR), and predictive value (PV).

RESULTS

Our results showed the most sensitive tests in identifying patients with PFPS were as follows: eccentric step test [0.82 (95%CI: 0.72-0.89)]; palpation test [0.81(95%CI: 0.70-0.88)]; and prolonged sitting [0.73 (95%CI: 0.62-0.82)]. The palpation test, patellar tilt test, eccentric step test, navicular drop test, squatting, and stair descending tests had an acceptable accuracy (AUC ≥ 70). The strongest combination of the physical examination and functional tests included pain severity between 3 and 10 during stair descending test and pain severity between 6 and 10 during prolonged sitting test. This combination showed a positive LR of 19.47 (95% CI: 6.36-59.65) and a posttest probability of 95%.

CONCLUSION

Our findings provide evidence for the good accuracy of the palpation test, patellar tilt test, eccentric step test, navicular drop test, squatting, and stair descending and prolonged sitting tests for diagnosing PFPS. Also, the combination of stair descending test and prolonged sitting test could be very useful for ruling in PFPS patients.

Accuracy to identify young adults with chronic ankle instability using a virtual reality - Balance error scoring system: A cross-sectional study

INTRODUCTION

The Balance Error Scoring System (BESS) assesses the ability to control postural stability by performing 3 different stances on two-type surfaces during closed eyes. Virtual reality technology combined with the BESS test (VR-BESS) may be used to disrupt visual inputs instead of closing the eyes, which may improve the sensitivity of diagnosing patients with chronic ankle instability (CAI).

OBJECTIVE

This study aimed to evaluate the accuracy to identify individuals with CAI of the VR-BESS test comparing with the original BESS test.

METHODS

The BESS and VR-BESS tests were administered to 68 young adults (34 participants with CAI and 34 without CAI). Frontal and lateral video views were used to measure the participant's performance errors. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was computed to determine the diagnostic test's overall accuracy.

RESULTS

The total score of the BESS test and the VR-BESS test were statistically significant in comparison to the AUC of no discrimination at 0.5, with AUC values of 0.63 and 0.64, respectively. The cut-off scores for the BESS and VR-BESS tests were 12 and 15, respectively. There was no significant difference between the ROC curves of the BESS and the VR-BESS test for identifying individuals with CAI.

CONCLUSION

The BESS and VR-BESS tests may be utilized interchangeably to identify individuals with CAI.

The influence of jump-landing direction on dynamic postural stability following anterior cruciate ligament reconstruction

BACKGROUND

Traditional testing prior to return to sport following anterior cruciate ligament reconstruction typically involves jump-landing tasks in the forward direction. As injury is most likely the result of multiplanar neuromuscular control deficits, assessment of dynamic postural stability using landing tasks that require multiplanar stabilization may be more appropriate. The purpose of this study was to examine how dynamic postural stability is affected when performing jump-landing tasks in three different directions.

METHODS

Fifteen athletes [11 females (18.0 ± 3.0 years) and 4 males (18.5 ± 3.1 years)] following anterior cruciate ligament reconstruction performed a series of single-limb jump-landing tasks in 3 directions. Individual directional stability indices and a composite dynamic postural stability index were calculated using ground reaction force data and were compared using separate one-way repeated measures ANOVAs.

FINDINGS

All directional stability indices demonstrated a significant main effect for jump-landing direction (medial-lateral P < 0.001, η2p = 0.95; anterior-posterior P < 0.001, η2p = 0.97; vertical P = 0.021, η2p = 0.24). The diagonal jump-landing direction produced increased medial-lateral stability and vertical stability scores, while the forward and diagonal jump-landing directions produced increased anterior-posterior stability scores. There was no significant effect for the composite dynamic stability index score.

INTERPRETATION

Jump-landing direction affects dynamic postural stability in all 3 planes of movement in athletes following anterior cruciate ligament reconstruction. Results indicate the potential need to incorporate multiple jump-landing directions to better assess dynamic postural stability prior to return to sport.

Examining accuracy of and determining the best cutoff point for photographic-based postural angles to discriminate between slight and moderate-to-severe forward head posture

PURPOSE

To evaluate the accuracy of and determine the best cutoff point for craniovertebral angle (CVA) and forward shoulder angle (FSA) in discriminating between two groups of individuals with different severities of forward head posture (FHP).

METHODS

A sample of 90 subjects aged 20-50 who had different severities of FHP was recruited. Participants were categorized into two groups based on observational method, namely individuals with slight FHP and those with moderate-to-severe FHP. The CVA and FSA were assessed using the photographic device. The accuracy of these measures was determined by calculation of sensitivity, specificity, area under the receiver operating characteristic curve, likelihood ratio (LR), and predictive value (PV).

RESULTS

Our results show that CVA has high sensitivity (0.93) and acceptable area under the curve (0.88) in discriminating between the two groups of FHP (P < .01), but FSA cannot discriminate between the two groups of FHP (P = .06). The LR and PV results show that the CVA has a low negative LR (0.13) and a large negative PV (0.93). The best cutoff point for CVA was determined at 45.5 degrees.

CONCLUSION

Overall, the results of the present study showed that CVA has a good accuracy in discriminating between two groups of individuals with slight and moderate-to-severe FHP. It can be valuable in correctly identifying the slight FHP and screening the moderate and severe grades of the FHP. Researchers and clinicians can also use the optimal cutoff point for the CVA obtained in this study to accurately quantify and classify the severity of the FHP.

EMG Analysis During Static Balance in Chronic Ankle Instability, Coper and Controls

Patients with chronic ankle instability (CAI) consistently display postural control alterations, which may result from sensorimotor dysfunction. This study aimed to compare muscle activity in the lower extremity and postural control among individuals with CAI, copers and uninjured controls during a static balance test. A total of 57 physically active participants were categorized into three groups (CAI, copers and controls) and performed a single-leg balance test with two visual conditions: eyes open and eyes closed. Muscle activity in six lower extremity muscles and center of pressure (CoP) variables were recorded and analyzed. Patients with CAI exhibited greater muscle activity in the medial gastrocnemius and gluteus maximus compared to controls or copers, regardless of the visual condition. Copers displayed increased gluteus medius activity compared to controls. Additionally, all groups demonstrated increased muscle activity and CoP variables when visual feedback was disrupted. These findings suggest that patients with CAI may have less effective recruitment of motor units during static balance. On the other hand, greater muscle activity in the gluteus medius in copers may represent a coping mechanism to avoid further ankle injuries. Further research on muscle activity during dynamic postural control is warranted to explore sensorimotor alterations in patients with CAI.

Chronic Ankle Instability - Mechanical vs. Functional

Chronic ankle instability arises from three interacting contributing factors: mechanical ankle instability, functional ankle instability, and perceived ankle instability. To decide on the most appropriate individual recommendation for therapeutic options, it is necessary to assess which of the two main aetiologies - functional vs. mechanical - is dominant in causing the perceived impairment. It is essential to perform a thorough analysis and diagnosis, even though quantifying mechanical ankle instability is still a challenge in the clinical approach to this common pathology. When diagnosing mechanical instability, the most established procedure is physical examination, although this unfortunately does not allow the deficit to be quantified. Additional options include stress-ultrasound, 3D stress-MRI (3SAM), ankle arthrometry, marker-based 3D motion analysis, and diagnostic ankle arthroscopy. Of these the latter is considered the gold standard, even though it is an invasive procedure, it may not be performed for diagnostic reasons only, and it also does not allow the mechanical instability to be quantified. For diagnosing functional instability there are non-instrumented tests such as the Star Excursion Balance Test or Y-Balance Test, posturography/stabilometry, and gait and running analysis, possibly combined with EMG acquisition and isokinetic strength testing.To date, the standard of care is conservative management of ankle instability, and the therapy should include sensorimotor training, strength training of the periarticular muscles, balance training, and gait and running exercises on different surfaces. However, it is increasingly clear that a certain degree of mechanical instability cannot be compensated for by functional training. Thus, it is the goal of differential diagnostics to identify those patients and guide them to mechanical therapy, including ankle bracing, taping, and surgical ligament reconstruction.

Disrupted vision impairs force steadiness and accuracy in chronic ankle instability patients

The primary purpose of this study was to examine the effect of visual disruption on submaximal force steadiness and accuracy among three groups including chronic ankle instability (CAI) patients, lateral ankle sprain copers, and healthy controls. Twenty patients with CAI, 20 copers, and 20 matched-healthy controls volunteered to participate in the study. Submaximal force steadiness and accuracy for evertors, invertors, and hip abductors (10% and 20% of their maximal voluntary isometric contraction) were measured with an isokinetic dynamometer. All groups performed the tasks with and without stroboscopic glasses. The CAI group showed worse steadiness and accuracy in evertors with visual disruption compared to nonvisual disruption (p < 0.0001 and = 0.02, respectively). Relative to the control group, the CAI group showed worse force steadiness and accuracy in evertors (p < 0.0001, both), worse force accuracy in hip abductors (p = 0.02), and the coper group also showed worse accuracy in evertors (p = 0.02). Individuals with CAI demonstrated impaired force steadiness and accuracy in evertors and hip abductors compared to healthy controls. In addition, they tended to rely more on visual feedback during the force steadiness task than copers and healthy controls.

Unexpected inversion perturbation during a single-leg landing in patients with chronic ankle instability

It remains unclear how unexpected perturbations during single-leg landings affect lower extremity kinematics and muscle activations in patients with chronic ankle instability (CAI). The purpose of this study was to identify the differences in lower extremity movement patterns among CAI subjects, copers, and healthy controls. Sixty-six people including 22 CAI subjects, 22 copers, and 22 healthy controls volunteered to participate in the study. Lower extremity joint kinematics and EMG activations from 200-ms pre to 200-ms post the initial contact during unexpected tilted landings were measured. Functional data analysis was used to evaluate between-group differences for outcome measures. Relative to copers and healthy controls, CAI subjects showed more inversion from 40-ms to 200-ms after initial contact. Relative to healthy controls, CAI subjects and copers showed more dorsiflexion. Relative to healthy controls, CAI subjects and copers showed more muscle activation in tibialis anterior and peroneus longus, respectively. In conclusion, CAI subjects demonstrated greater inversion angles and muscle activation before initial contact compared to LAS copers and healthy controls. This suggests that CAI subjects and copers prepare for their landing with protective movements, but the prepared movements shown by CAI subjects may be insufficient to reduce risk of recurrent injury.

Determining key clinical predictors for chronic ankle instability and return to sports with cost of illness analysis: protocol of a prospective cohort study

INTRODUCTION

Ankle sprains are common in sports and the general population. Although considered innocuous, a large proportion has residual complaints such as recurrent ankle sprains and develop chronic ankle instability. Although some predicting factors are identified, there is no unequivocality regarding the development of chronic ankle instability, nor about the optimal rehabilitation for an acute ankle sprain. Alongside the biomechanical impairments, ankle sprains are a burden on society due to substantial economic costs. Therefore, we aim to identify key clinical predictors of chronic ankle instability or recovery after acute lateral ankle sprain. Additionally, we aim to determine cost-of-illness of patients who developed chronic ankle instability.

METHODS AND ANALYSIS

This prospective cohort study (Clinicaltrials.gov: NCT05637008 - pre-results) aims to recruit adult (18-55 years) patients with an acute lateral ankle sprain who are active in sports. Clinical assessments and patient-reported outcome measures will be used to collect data at 7-14 days, 6 weeks, 12 weeks and 12 months after enrolment in the study. The primary outcome will be chronic ankle instability at 12-month follow-up. Salient outcomes will be analysed by logistic regression to determine association with the development of chronic ankle instability. Participants will fill in a cost diary containing direct and indirect costs related to their injury.

ETHICS AND DISSEMINATIONS

The ethical committee of the Antwerp University Hospital (B3002022000138) has given approval of the protocol and consent forms on 10 October 2022. We perform this study according to the Helsinki Declaration. We will present results at conferences or webinars and publish in peer-reviewed articles.NCT05637008.

Impairment-based assessments for patients with lateral ankle sprain: A systematic review of measurement properties

STUDY DESIGN

Systematic review.

BACKGROUND AND OBJECTIVE

The International Ankle Consortium developed a core outcome set for the assessment of impairments in patients with lateral ankle sprain (LAS) without consideration of measurement properties (MP). Therefore, the aim of this study is to investigate MPs of assessments for the evaluation of individuals with a history of LAS.

METHODS

This systematic review of measurement properties follows PRISMA and COSMIN guidelines. Databases Pubmed, CINAHL, Embase, Web of Science, Cochrane Library and SPORTDiscus were searched for eligible studies (last search: July 2022). Studies on MP of specific tests and patient-reported outcome measurements (PROMs) in patients with acute and history of LAS (>4 weeks post injury) were deemed eligible.

RESULTS

Ten studies of acute LAS and 39 studies of history of LAS patients with a total of 3313 participants met the inclusion criteria. Anterior Drawer Test (ADT) in supine position five days post injury and Reverse Anterolateral Drawer Test are recommended in acute settings in single studies. In the history of LAS patients, Cumberland Ankle Instability Tool (CAIT) (4 studies) as a PROM, Multiple Hop (3 studies) and Star Excursion Balance Tests (SEBT) (3 studies) for dynamic postural balance testing showed good MPs. No studies investigated pain, physical activity level and gait. Only single studies reported on swelling, range of motion, strength, arthrokinematics, and static postural balance. Limited data existed on responsiveness of the tests in both subgroups.

CONCLUSION

There was good evidence to support the use of CAIT as PROM, Multiple Hop, and SEBT for dynamic postural balance testing. Insufficient evidence exists in relation to test responsiveness, especially in the acute situation. Future research should assess MPs of assessments of other impairments associated with LAS.

Prabhakar A, Eapen C, Keogh JW. Ability of functional performance assessments to discriminate athletes with and without chronic ankle instability : a case-control study

Background

The decline in motor function associated with chronic ankle instability (CAI) can be assessed using Functional Performance tests. Ankle muscular strength, endurance and range of motion (ROM) has been assessed in previous studies but functional activities such as sprinting and change of direction are less well studied in athletes with CAI. Hence the aim of this study was to determine how sprint, change of direction, ankle isometric strength, endurance and ROM measures may be associated with discriminate athletes with and without CAI.

Methods

One hundred and six participants (CAI: n = 53 or no CAI: n = 53) provided informed consent to participate in this study. Participants performed three functional performance tests, (30-m sprint test, Modified Illinois change of direction test (MICODT)) and change of direction test. Range of motion for dorsiflexion was measured using weight bearing lunge test and inversion, eversion and plantarflexion using Saunders® digital inclinometer. Strength was assessed using Baseline® hand-held dynamometer for plantarflexors, dorsiflexors, invertors and evertors. Muscular endurance was assessed by single heel raise test and Modified single heel raise test. Between-group comparisons utilised Student's t-test and Mann-Whitney U-tests, with a number of unique variable and multivariable binomial logistic regression performed to determine which performance measures may discriminate participants with CAI.

Results

The CAI participants performed significantly worse in the three functional performance tests as well as multiple measures of ankle ROM, isometric strength and muscular endurance (p < 0.008). While several measures of ROM (plantarflexion and dorsiflexion), strength (inversion and eversion) and both muscular endurance tests were significantly associated with CAI in the univariable analysis, the strongest association was the functional performance tests, especially MICDOT time (odds ratio (95% CI): 0.06 [0.02-0.17], sensitivity 94.3%, specificity 88.7%). Multivariable regression analyses indicated that performance across the functional performance tests were more strongly associated with CAI than any ankle ROM, muscular strength or endurance test. Further, the inclusion of the best ankle range of motion, strength or muscular endurance tests did not significantly improve upon the association of the MICDOT with CAI.

Conclusions

Chronic ankle instability in athletic populations appears to be highly associated with declines in functional performance and to a somewhat lesser extent, ankle range of motion, strength and muscle endurance measures. This may suggest that optimal rehabilitation for athletes with CAI may require a greater focus on improving sprinting speed and change of direction ability in the mid to latter stages of rehabilitation, with regular assessments of these functional performance tests necessary to guide the progression and overload of this training.

Effects of Stroboscopic Vision on Postural Control in Individuals With and Without Chronic Ankle Instability

Objectives: Patients with chronic ankle instability (CAI) tend to increase their reliance on visual information, perhaps to compensate for proprioceptive deficits which appear after lateral ankle sprains. However, little is known about how limited visual feedback would alter static postural control in patients with CAI compared with copers and controls. The purpose of this study was to identify the effects of reduced visual feedback via stroboscopic glasses on static balance among CAI, coper, and uninjured control participants. Design: Controlled trial in a laboratory setting. Methods: Nineteen patients with CAI, 19 copers, and 19 controls participated in this study. Each participant performed a single-leg balance test with eyes open, stroboscopic vision, and eyes closed. Two-way analysis of variance (group × condition) was used to examine the differences between condition (eyes open, stroboscopic vision, and eyes closed) and group (CAI, coper, and control). Results: There were no significant interactions for static balance. Although there were no group effects among 3 groups for all static postural control measures, visual condition main effects were present (P < .01) for each dependent variable. Across all groups, anterior–posterior and mediolateral center of pressure path length and center of pressure velocity with stroboscopic vision were greater than the condition with eyes open (P < .01) and less than with eyes closed (P < .01). Conclusions: Stroboscopic glasses could be cost effective visual disruption equipment during static postural control regardless of ankle injury history. However, incorporating static balance with limited visual information via stroboscopic glasses could not display the differences in visual reliance in individuals with and without CAI.

Corticospinal activity during a single-leg stance in people with chronic ankle instability

PURPOSE

The aim of the study was to determine whether corticospinal excitability and inhibition of the tibialis anterior during single-leg standing differs among individuals with chronic ankle instability (CAI), lateral ankle sprain copers, and healthy controls.

METHODS

Twenty-three participants with CAI, 23 lateral ankle sprain copers, and 24 healthy control participants volunteered. Active motor threshold (AMT), normalized motor-evoked potential (MEP), and cortical silent period (CSP) were evaluated by transcranial magnetic stimulation while participants performed a single-leg standing task.

RESULTS

Participants with CAI had significantly longer CSP at 100% of AMT and lower normalized MEP at 120% of AMT compared to lateral ankle sprain copers (CSP_100%: p = 0.003; MEP_120%: p = 0.044) and controls (CSP_100%: p = 0.041; MEP_120%: p = 0.006).

CONCLUSION

This investigation demonstrate altered corticospinal excitability and inhibition of the tibialis anterior during single-leg standing in participants with CAI. Further research is needed to examine the effects of corticospinal maladaptations to motor control of the tibial anterior on postural control performance in those with CAI.

Hip and knee muscle torque is not impaired in the first three months of a first-time lateral ankle sprain

OBJECTIVES

The primary objective was to compare hip and knee isometric muscle strength between individuals with a first-time acute lateral ankle sprain and controls. A secondary objective was to investigate hip and knee isometric muscle strength three months post-injury.

DESIGN

Cross-sectional and prospective follow-up components.

SETTING

Laboratory environment.

PARTICIPANTS

Forty-two participants (21 acute lateral ankle sprain and 21 controls) matched for age, sex, physical activity and leg dominance participated.

MAIN OUTCOME MEASURES

Hip and knee isometric muscle torque was assessed using a rigidly fixated hand-held dynamometer. Testing in acute lateral ankle sprain participants was performed within four weeks of injury and three months post-injury. Controls were tested at one timepoint.

RESULTS

There were no differences in hip or knee isometric muscle torque between acute lateral ankle sprain and control participants (mean differences <0.08). Hip and knee isometric muscle torque in acute ankle sprain participants did not differ between baseline and three months post-injury testing (mean difference <0.06).

CONCLUSIONS

Proximal lower limb isometric strength is not impaired within the first three months of sustaining a first-time lateral ankle sprain injury. This implies that hip and knee isometric strength deficits in individuals with CAI may occur at some later stage.

Use of Backward Walking Speed to Screen Dynamic Balance and Mobility Deficits in Older Adults Living Independently in the Community

BACKGROUND AND PURPOSE

Older adults who live independently in the community are higher functioning and routinely ambulate in the community. Unrestricted community ambulation increases the likelihood of encountering precarious situations challenging balance. Sufficient dynamic balance is necessary to avoid falls. Currently used balance and mobility assessments may not sufficiently challenge dynamic balance to uncover mobility deficits in independent community-dwelling older adults. The purpose of this study was to investigate whether backward walking speed (BWS) can serve as an outcome measure to screen dynamic balance and mobility deficits in independent community-dwelling older adults.

METHODS

A convenience sample of 30 older adults (73.68 ± 6.54 years) participated in this cross-sectional study. Participants walked backward on an instrumented walkway to record BWS. Other outcomes included forward walking speed (FWS), Community Balance and Mobility (CB&M) Scale, Falls Efficacy Scale-International (FES-I), Timed Up and Go (TUG) test, and 7-day average step count (ASC). A multivariate analysis of variance investigated the overall group differences between older adults at fall risk and those not at risk and was followed up by univariate tests. Pearson and spearman coefficients investigated associations between study outcomes. Youden's index assessed diagnostic accuracy.

RESULTS AND DISCUSSION

Backward walking speed, CB&M, FES-I, ASC discriminated older adults at fall risk from those not at risk (P < .01) whereas FWS and TUG did not. Backward walking speed strongly correlated with challenging assessments of balance and mobility (CB&M, FES-I, and ASC) but only moderately correlated with the TUG. The CB&M Scale independently explained 53% variance in the BWS performance (P < .01). Youden's index was highest (Y = 0.6, sensitivity = 93%, and specificity = 67%) for BWS (0.73 m/s) compared with other study outcomes.

CONCLUSIONS

Preliminary results suggest that BWS can screen for dynamic balance and mobility deficits in independent community-dwelling older adults. Accurate screening is the first step to capture early decline in function for independent community-dwelling older adults. Longitudinal follow-up studies are warranted to validate BWS as a screening tool.

The Cut-Off Score of Four Clinical Tests to Quantify Balance Impairment in Individuals with Chronic Ankle Instability

Background

Balance impairment is a common consequence of chronic ankle instability (CAI). This study aimed to assess the discriminative validity of four clinical tests for quantifying balance impairment in individuals with CAI.

Methods

Participants were screened for their balance using the single-leg balance test (SLBT) and were assigned to either the positive or the negative SLBT groups. Fifty-four individuals with CAI (N = 27 per group) were recruited and completed four clinical tests including the foot-lift test (FLT), the time-in-balance test (TIBT), the modified star excursion balance test in the posteromedial (mSEBT-PM) direction and the side-hop test (SHT). The receiver operating characteristics (ROC) curve coupled with Youden index were calculated to determine the optimal cut-off scores of each test.

Results

We found significant differences in balance between groups for all tests, with good to excellent values for the area under the ROC curve (AUC). All four tests reached good to excellent sensitivity and specificity values and had significant cut-off scores to discriminate balance performance among CAI participants.

Conclusion

All four clinical tests can be conducted with their respective cut-off scores to quantify balance impairment in individuals with CAI.

The effects of visual feedback disruption on postural control with chronic ankle instability

OBJECTIVES

The purpose of this study was to identify the effects of reduced visual feedback via stroboscopic glasses on dynamic postural control among chronic ankle instability (CAI), lateral ankle sprain (LAS) coper and uninjured control participants.

DESIGN

Controlled trial in a laboratory setting.

METHODS

Twenty CAI patients, 20 copers, and 20 controls participated in this study. Each participant performed a single-leg hop stabilization test with eyes open (EO) and stroboscopic vision (SV). Two-way ANOVAs (group × condition) were used to examine the differences between group (CAI, coper, and control) and condition (EO and SV).

RESULTS

There was a significant group by condition interaction for DPSI scores. CAI patients displayed increased DPSI scores with SV compared to EO (p < 0.01), and CAI patients had increased DPSI scores only with SV when compared with controls. All participants displayed decreased dynamic postural control under the SV condition compared to the EO condition (p < 0.01) regardless of ankle group.

CONCLUSIONS

CAI patients rely more on visual feedback during dynamic postural control than copers and controls. However, they may not be as able to compensate for the disrupted visual feedback during a dynamic task. Regardless of ankle injury history, stroboscopic glasses could be cost-effective visual disruption devices during a dynamic balance task.

Reliability of musculoskeletal ultrasonography for peri-ankle muscles in subjects with unilateral chronic ankle instability

BACKGROUND

Ankle sprain is a common problem among active people and athletes. It causes reduces their activity of daily living and quality of life. Because of the impaired muscle strength and neuromuscular and postural control, it seems that the morphological criteria of peri-ankle muscles are changed.

OBJECTIVE

This study aimed to develop a reliable method for measuring tibialis anterior (TA) and peroneus longus (PL) muscles in the injured and intact side of lower limbs in people with unilateral chronic ankle instability (CAI).

STUDY DESIGN

Cross-sectional study.

METHOD

This study was intra-tester reliability by ultrasound imaging to measure ultrasonography characteristics contains thickness, width, fiber length, pennation angle, and cross-sectional area (CSA) of TA, and PL in both limbs of 25 subjects at three separate times. Intra-class correlation coefficients (ICC), limits of agreement (LOA), standard error of measurement (SEM), and minimal detectable change (MDC) were calculated to analyzed relative and absolute intra-tester reliability, respectively.

RESULTS

The present study showed good to excellent relative reliability for both injured and intact sides (ICC 0.88-0.98), less proportional measurement error (β coefficient of LOA≈ 0), and suitable absolute reliability.

CONCLUSION

Musculoskeletal ultrasonography is a reliable method for the measurement of peri-ankle muscle morphology such as thickness, width, CSA, fiber length, and pennation angle.

Psychological impairments in individuals with history of ankle sprain: a systematic review

Patient-reported outcomes (PROs) can be used to assess and monitor psychological health following musculoskeletal injury. Studies have reported decreased psychological health after lateral ankle sprain (LAS) using numerous PROs. The purpose of this systematic review was to critically evaluate individual studies, summarize PROs utilized to quantify psychological health, and examine the effect of ankle injury on psychological health between groups (1 LAS, >1 LAS, and healthy controls). Databases searched included: CINAHL, MEDLINE, SPORTDiscus, APA, Psychinfo and PubMed Central. All case-control studies were critically appraised using the modified Downs and Black. Effect sizes (ES) were calculated between the groups (1 LAS, >1 LAS, healthy control) for each of the identified studies, for each included PRO used to quantify psychological impairments. Nine high-quality manuscripts were included. Overall, individuals with history of > 1 LAS self-reported greater psychological impairments compared to healthy controls (ES range = -0.37-12.16), while those with 1 LAS had similar psychological health to healthy control groups (ES rang e = -0.65-0.65). Conclusion: The main findings from this systematic review were individuals with > 1 LAS have increased levels of injury-related fear and decreased psychological health compared to healthy controls. PROs can aid clinicians in identifying psychological health concerns during rehabilitation.

Recent Ankle Injury, Sport Participation Level, and Tests of Proprioception

OBJECTIVE

Assessing the effects of ankle injury and sport participation level on ankle proprioceptive sensitivity using a joint position reproduction (JPR) test and an inversion movement extent discrimination test.

DESIGN

Cross-sectional.

SETTING

Biomechanics lab.

PARTICIPANTS

Forty-five student athletes ages 21-30 (mean = 24.8 y).

MAIN OUTCOME MEASURES

Participants were tested for ankle inversion sensitivity using 2 devices; movement reproduction error was obtained from JPR in a non-weight-bearing (N-WB) state at 10° and 15° of inversion, and an ankle proprioceptive sensitivity score was obtained from the active movement extent discrimination apparatus (AMEDA), representing the ability to differentiate 5 inversion movement extents between 10.5° and 14.5°, with testing in both N-WB and weight-bearing (WB) states.

RESULTS

For the 34 athletes with no ankle injury in the previous 12 months, the sensitivity scores achieved on the AMEDA were significantly higher (P < .01) than those for the 11 athletes with ankle injury, and the injury effect was significantly greater in WB (P = .01). In JPR testing, the 2.96° error of reproduction for athletes with no recent ankle injury was not significantly different from the 3.36° error for those with ankle injury (P = .46). Correlation of current sport participation level with JPR showed less error for higher-level performers (r = .49, P = .001) but no significant relationship to WB or N-WB AMEDA scores (both P > .61). WB AMEDA scores were significantly higher for athletes who had competed at a higher level of sport competition when <18 years old (r = -.57, P < .001).

CONCLUSIONS

Previous ankle sprains affected proprioceptive scores on the WB AMEDA and N-WB AMEDA tests, indicating the sensitivity of the AMEDA movement discrimination test to the effects of ankle injury. The correlation between JPR scores and current level of sport participation suggests the sensitivity of the JPR test to current ankle use.

Lower-Extremity Motor Synergies in Individuals With and Without Chronic Ankle Instability

Current theoretical models suggest that ankle sprain copers exhibit movement adaptations contributing to the avoidance of chronic ankle instability. However, few studies have examined adaptations at the level of biomechanical motor synergies. The purpose was to examine characteristics of the support moment synergy between individuals with chronic ankle instability, copers, and healthy individuals. A total of 48 individuals participated in the study. Lower-extremity kinetics and variability in the moment of force patterns were assessed during the stance phase of walking trials. The copers exhibited reductions in the support moment during the load response and preswing phase compared with the chronic ankle instability group, as well as during the terminal stance and preswing phase compared the healthy group. The copers also exhibited reductions in the hip extensor moment and ankle plantarflexion moment compared with healthy and chronic ankle instability groups during intervals of stance phase. Variability of the support moment and knee moment was greater in the copers compared with the chronic ankle instability group. Dampening of the support moment and select joint moments exhibited by the copers may indicate an adaptive mechanism to mitigate loading perturbations on the previously injured ankle. Heightened motor variability in copers may be indicative of a more adaptable motor synergy compared with individuals with chronic ankle instability.

Response profile of fibular repositioning tape on ankle osteokinematics, arthrokinematics, perceived stability and confidence in chronic ankle instability

BACKGROUND

Preliminary evidence suggests that fibular repositioning tape reduces risk of recurrent ankle injuries, but the underlying mechanism has not been investigated.

OBJECTIVE

To investigate the effects of fibular repositioning tape on ankle osteokinematics, arthrokinematics and perceived stability and confidence in individuals with chronic ankle instability immediately post-tape and following exercise.

DESIGN

Cross-sectional repeated measures study.

METHOD

Passive ankle plantarflexion-inversion range of motion, weight-bearing dorsiflexion range of motion, anteroposterior translation, inversion-eversion tilt, and perceived ankle stability and confidence during hopping were assessed before and immediately after the application of fibular repositioning tape and after 15 min of exercise in 14 individuals with chronic ankle instability.

RESULTS

Ankle plantarflexion-inversion range of motion, inversion-eversion tilt and anteroposterior translation were reduced immediately after the application of tape compared to pre-tape (p < 0.01). After exercise, total inversion-eversion tilt was significantly lower than pre-tape (p = 0.01), but there were no differences for any of the other mechanical outcomes. Dorsiflexion range of motion did not differ between conditions (p > 0.11). Perceived ankle stability, ankle and task confidence were greater immediately post-tape and post-exercise compared to pre-tape (p < 0.01).

CONCLUSIONS

Fibular repositioning tape was associated with a restriction of ankle total inversion-eversion tilt and improved perceived ankle stability and confidence both immediately after application of tape and after participating in exercise. This data provides grounds for exploring mechanical and psychological mechanisms underpinning any clinical efficacy of fibular repositioning tape.

Is the fibula positioned anteriorly in weight-bearing in individuals with chronic ankle instability? A case control study

Background: Clinically, a discrepancy of fibular position in relation to the tibia has been proposed as a factor in the persistence of chronic ankle instability (CAI). Previous studies have produced conflicting findings, perhaps due to varying radiological methods and measurement of participants in non-weight-bearing positions.Objectives: To compare normalized-fibular position in weight-bearing in individuals with CAI with healthy controls.Design: A weight-bearing lateral X-ray was taken of the affected ankle of 33 adults with CAI and 33 matched controls. The distance between the anterior edges of the distal fibula and tibia was recorded, and then normalized as a proportion of maximal tibial width. Normalized-fibular position was compared between groups using independent t-tests. Intra-class correlation coefficients (ICC_2,1) were calculated to determine reliability of measurements. A receiver-operating characteristic (ROC) curve was used to determine sensitivity, specificity, and a cutoff score to differentiate individuals with CAI from controls using normalized-fibular position.Results: Normalized fibular position was significantly different (CAI, 29.7 (6.6)%; healthy, 26.7 (4.8)%) between the groups. Measurement of intra-rater (0.99, 95%CI = 0.98 to 1.00) and inter-rater (0.98, 95%CI = 0.96 to 0.99) reliability were both excellent. The threshold normalized-fibular position was 27%, with a score more than 27% indicating a greater chance of being in the CAI group. Sensitivity was 69.7% and specificity was 54.5% for this threshold.Conclusion: A slightly anteriorly positioned fibula in relation to the tibia was observed in people with CAI. Specificity/sensitivity scores for normalized-fibular position indicate that it has little ability to predict CAI alone.

Time-frequency analysis of muscle activation patterns in people with chronic ankle instability during Landing and cutting tasks

BACKGROUND

People with chronic ankle instability (CAI) exhibit neuromuscular deficits. Previous studies, however, only investigated magnitudes of muscle activation and not the time-frequency domain.

RESEARCH QUESTION

Do people with CAI exhibit differences in muscle activation patterns in the time-frequency domain during landing, anticipated cutting, and unanticipated cutting compared to matched controls?

METHODS

Eleven people with CAI and eleven healthy matched controls (CON) performed landing, anticipated cutting, and unanticipated cutting as surface EMG of the lateral gastrocnemius, medial gastrocnemius, fibularis longus, soleus, and tibialis anterior were recorded. The time-frequency domain of surface EMG data was analyzed with wavelet transformations and principal component analysis (PCA), PC scores were compared across group, task, and muscle with three-way ANOVAs.

RESULTS

The PCA extracted two PCs that captured the overall magnitude (PC1) of wavelet intensities across the time-frequency domain and a shift among the range of frequencies (PC2) where wavelet intensities were most prominent. A main effect for group indicated that people with CAI demonstrated smaller (p = 0.009) PC1 scores than people in the CON group across all muscles and tasks. An interaction between group and task indicated that people in the CAI group exhibited smaller (p = 0.041) PC2 scores than people in the CON group during only anticipated cutting.

SIGNIFICANCE

People with CAI exhibited neuromuscular deficits in the time-frequency domain of EMG during dynamic tasks. These deficits appear to reflect a neuromuscular strategy characterized by the recruitment of fewer motor units in ankle muscles regardless of task, and an inability to scale the recruitment of motor units in the frequency domain in response to different task demands. Rehabilitation for people with CAI should consider that this population exhibits differences in neuromuscular control that exist not only in the overall magnitudes, but also in the time-frequency domain, of muscle activation patterns.

Donor-Site Morbidity after Fibula Transplantation in Head and Neck Tumor Patients: A Split-Leg Retrospective Study with Focus on Leg Stability and Quality of Life

The free fibula flap has been one of the most important microvascular grafts for orofacial reconstruction for more than 30 years. The complication rates at the donor-site reported in literature are considered to be low, but the published data vary greatly in some cases. In particular, restrictions in the stability and balance of the involved leg and their effects on the quality of life have been described very inconsistently to date. Therefore, this study mainly focuses on the stability and balance of the affected leg in a split-leg design. Between December 2014 and January 2018, out of 119 subjects who underwent mainly jaw ablative tumor surgery and reconstruction using a fibula flap, 68 subjects were examined for donor site morbidity. Besides reporting general types of complications, two specific test procedures were used. The Star Excursion Balance Test (SEBT) as a practical test for ankle function and the Foot and Ankle Disability Index (FADI) as a questionnaire in order to assess quality of life, depending on the lower leg function. SEBT revealed an average of 55.3 cm with the operated leg as the supporting leg, which corresponds to 95.5% of 57.9 cm achieved with the healthy leg as the supporting leg. An average FADI score of 89.4% was recorded. SEBT and FADI seem to be suitable methods of examination for subjects post fibular transplantation and pointed out minimal limitations of the involved legs in comparison to the unaffected legs. These limitations were clinically not relevant and they had minor influence on the subjects’ quality of life and their daily activities.

Weight, BMI and stability are risk factors associated with lateral ankle sprains and chronic ankle instability: a meta-analysis

IMPORTANCE

Lateral ankle sprains (LAS) are common in the general population and may lead to chronic ankle instability (CAI). If patients at risk could be identified, they could receive adequate and on-time treatment.

OBJECTIVE

The purpose of the current review was to identify all reported intrinsic factors associated with sustaining a LAS or progressing to CAI after an initial sprain.

EVIDENCE REVIEW

PubMed, Embase, MEDline, Cochrane and PEDro were searched for studies published until July 2019. Articles were selected if they included intrinsic factors related to LAS or CAI, subjects of at least 16 years old, and contained a minimum of 10 patients and 10 controls. Studies were excluded if they concerned reviews or case reports, included patients with previous surgical interventions, concomitant injuries or joint pathology other than ankle instability. Quality of included studies was assessed using the Quality in Prognostic Studies tool and quality of evidence was assessed using the GRADEpro tool. In case outcomes were described by at least three studies, data were pooled and assessed by performing a meta-analysis. Based on the pooled data, either a fixed-effects model or random-effects model was selected to correct for the degree of heterogeneity.

FINDINGS

The search resulted in a total of 4154 studies. After title and abstract screening and subsequent full-text screening, 80 relevant studies were included. Results of the meta-analyses indicated that, compared with healthy controls, patients with LAS had a higher mean body mass index (BMI). In patients with CAI, a higher weight and a longer time to stabilise after performing a task (eg, jumping) were found compared with healthy controls. Other outcomes could not be compared using a meta-analysis due to heterogeneity in outcome measurement and the great number of different outcomes reported. Identification of the risk factors when patients present themselves after a LAS may help to determine which patients are at risk of recurrent sprains or developing CAI.

CONCLUSIONS AND RELEVANCE

Based on the findings in this review, a higher BMI, and a higher weight and neuromuscular stability deficits may be regarded risk factors for sustaining a LAS or developing CAI, respectively.

LEVEL OF EVIDENCE

III.

Anterior cruciate ligament reconstruction and dynamic stability at time of release for return to sport

OBJECTIVE

Examine dynamic stability using Dynamic Postural Stability Index (DPSI) in athletes following anterior cruciate ligament reconstruction (ACLR) at time of release for return-to-sport (RTS), compared to matched controls.

DESIGN

Cross-sectional case-control study.

SETTING

Sports medicine clinic.

SUBJECTS

Fifteen ACLR athletes who had completed post-operative rehabilitation and were within 6 weeks following release to RTS were age-, gender-, and activity-matched to 15 healthy controls.

MAIN OUTCOME MEASURES

Ground reaction forces (GRFs) were collected using a portable force plate during stabilization from three different single-leg landing tasks. A composite DPSI was calculated using GRFs.

RESULTS

Compared to matched controls, ACLR athletes within 6 weeks of release for RTS did not significantly differ in dynamic postural stability and there were no significant differences between the involved and uninvolved limbs in the ACLR group.

CONCLUSION

Current findings indicate that dynamic postural stability, as measured using the DPSI, is not significantly different in ACLR subjects at time of release for RTS compared to matched controls. In addition, the DPSI was not significantly different between the involved and uninvolved limbs in the ACLR subjects. The results suggest that the post-ACLR rehabilitation program utilized may have adequately restored postural stability in this particular sample.

Subgroup characteristics of patients with chronic ankle instability in primary care

OBJECTIVES

To 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.

DESIGN

Cross-sectional study.

METHODS

206 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.

RESULTS

A 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.

CONCLUSIONS

Sports 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.

Nonlinear Dynamic Measures for Evaluating Postural Control in Individuals With and Without Chronic Ankle Instability

This study aimed to compare time-to-boundary and sample entropy during a single-leg balance task between individuals with chronic ankle instability (CAI), lateral ankle sprain copers, and healthy controls. Twenty-two participants with CAI, 20 lateral ankle sprain copers, and 24 healthy controls performed a single-leg balance task during an eyes-closed condition. Participants with CAI exhibited lower time-to-boundary values compared with lateral ankle sprain copers and healthy controls. However, we did not find differences in sample entropy variables between cohorts. A decrease in time-to-boundary values in participants with CAI indicated that CAI may constrain the ability of the sensorimotor system to maintain the center of pressure within the boundaries of the base of support. However, the regularity of the center of pressure velocity time series appears not to be altered in the CAI cohort in this study.

Functional performance tests identify lateral ankle sprain risk: A prospective pilot study in adolescent soccer players

Determining the clinical utility of functional performance tests (FPTs) and establishing cutoff scores could be useful in identifying those athletes who could benefit from effective injury prevention interventions. Our purpose was to determine the accuracy of FPTs in identifying adolescent athletes who go on to experience lateral ankle sprain(s) and establish specific cutoff scores capable of identifying those who sustain a lateral ankle sprain in the near future. Sixty-four participants (age = 15.5 ± 1.3 years; height = 161.7 ± 7.7 cm; mass = 57.1 ± 8.4 kg) were recruited from a junior soccer club and tracked for 10 months. Participants performed the anterior (AN), posterior-medial (PM), and posterior-lateral (PL) reach directions of the Star Excursion Balance Test (SEBT) and the Single-Leg Hop Test (SLHT) in pre-season, and then were followed for the 10-month competitive season (12 injured, 52 uninjured). Significant Area Under the Curve (AUC) values and cutoff scores were found for the PM (AUC = 0.78; 95% CI 0.61-0.95; P = 0.003; Sn = 0.83; Sp = 0.77; cutoff = 76%) and the PL (AUC = 0.82; 95% CI 0.71-0.94; P = 0.001; Sn = 0.92; Sp = 0.65; cutoff = 70%) reach directions of the SEBT and the SLHT (AUC = 0.77; 95% CI 0.60-0.95; P = 0.003; Sn = 0.67; Sp = 0.94; cutoff = 15.4 seconds). The PM and PL reach directions of the SEBT and the SLHT may be useful as pre-season screening measures to help clinicians identify adolescents who will go on to experience a lateral ankle sprain.

Examining the diagnostic accuracy of static postural stability measures in differentiating among knee osteoarthritis patients with mild and moderate to severe radiographic signs

BACKGROUND

Clinicians need a reliable and accurate tools that can best identify and classify balance impairments between mild and moderate to severe grades of knee osteoarthritis (OA).

RESEARCH QUESTION

This study was designed to investigate the accuracy of postural measurements to discriminate between these two groups of knee OA.

METHODS

A total of 130 patients with knee OA based on the Kellgren-Lawrence (KL) grading scale were categorized into 65 patients with mild (a KL grade≤ 2) and 65 patient with moderate to severe (a KL grade≥3) radiographic sign. Static postural control was assessed on the force plate in three conditions of double leg stance with open (DO) and closed eyes (DC) and single leg stance with open eyes (SO). The accuracy for static postural control parameters was determined by calculation of sensitivity, specificity, area under the Receiver Operating Characteristic (ROC) curve (AUC) and likelihood ratios (LRs).

RESULTS

Our results showed that standard deviation (SD) of velocity in anterior-posterior (AP) direction had the highest sensitivity and specificity in conditions of DO and DC, respectively. ROC curve analysis indicated that measures of mean and SD velocity in medio-lateral (ML) direction in conditions of DO and DC had acceptable levels of accuracy (AUC > 0.70) in discriminating between the two groups of knee OA patients. Also, based on LR results, SD of velocity in AP direction had the best ability for ruling in and ruling out moderate to severe grade of knee OA patients in conditions of DC and DO, respectively.

SIGNIFICANCE

Our findings provide evidence for selection of mean velocity and SD of velocity in identifying and discriminating static postural performance in patients with mild and moderate to severe grades of knee OA.

Energy dissipation differs between females with and without chronic ankle instability

Chronic ankle instability (CAI) is associated with altered energy dissipation patterns, but comparisons to lateral ankle sprain (LAS) copers have not been explored. The purpose of this study was to examine differences in relative sagittal plane energy dissipation during a single-leg landing between female CAI and LAS coper participants. We separated 33 females (23.6 ± 4.6 years, 164.3 ± 6.2 cm, 69.4 ± 13.7 kg) into CAI (n = 17) and LAS coper (n = 16) groups. Participants completed 5 single-leg landings followed by a 5-second stabilization. We collected sagittal plane kinematics and joint moments at the ankle, knee, hip, and proximal joints (knee and hip) combined then calculated each joint's energy dissipation at 50, 100, 150, and 200 ms post-landing. We compared the percentage of total energy dissipated by the ankle, knee, hip, and proximal joints during each interval utilizing independent t tests and Cohen's d effect sizes. Statistical significance was set a priori at P < .05. The CAI group had lower relative energy dissipation from the ankle at 50 (24.7 ± 11.5% vs 39.2 ± 11.8%, P < .01, d = 1.25 [0.47, 1.95]), 100 (66.9 ± 19.4% vs 77.7 ± 6.5%, P = .04, d = 0.74 [0.01, 1.42]), and 150 ms (70.7 ± 17.8% vs 81.0 ± 5.7%, P = .03, d = 0.77 [0.04, 1.46]) compared to LAS copers. The CAI group had a greater hip contribution through 150 ms (17.9 ± 10.7% vs 11.7 ± 4.4%, P = .04, d =-0.75 [-1.44, -0.03]) and the proximal joints at 50 (75.3 ± 11.5% vs 60.8 ± 11.8%, P < .01, d = -1.25 [-1.96, -0.47]), 100 (33.1 ± 19.4% vs 22.3 ± 6.5%, P = .04, d = -0.74 [-1.42, -0.01]), and 150 ms (29.3 ± 17.8 vs 19.0 ± 5.7%, P = .03, d =-0.77 [-1.46, -0.04]) compared to LAS copers. Females with CAI may benefit from therapeutic exercises designed to correct a single-leg energy dissipation strategy that relies less on the ankle joint.

Military personnel with self-reported ankle injuries do not demonstrate deficits in dynamic postural stability or landing kinematics

BACKGROUND

The odds of sustaining non-contact musculoskeletal injuries are higher in Special Operations Forces operators than in infantry soldiers. The ankle is one of the most commonly injured joints, and once injured can put individuals at risk for reinjury. The purpose of this study was to determine if any differences in postural stability and landing kinematics exist between operators with a self-reported ankle injury in the past one year and uninjured controls.

METHODS

A total of 55 Special Operations Forces operators were included in this analysis. Comparisons were made between operators with a self-reported ankle injury within one-year of their test date (n=11) and healthy matched controls (n=44). Comparisons were also made between injured and uninjured limbs within the injured group. Dynamic postural stability and landing kinematics at the ankle, knee, and hip were assessed during a single-leg jump-landing task. Comparisons were made between groups with independent t-tests and within the injured group between limbs using paired t-tests.

FINDINGS

There were no significant differences in dynamic postural stability index or landing kinematics between the injured and uninjured groups. Anterior-posterior stability index was significantly higher on the uninjured limb compared to the injured limb within the injured group (P=0.02).

INTERPRETATION

Single ankle injuries sustained by operators may not lead to deficits in dynamic postural stability. Dynamic postural stability index and landing kinematics within one year after injury were either not affected by the injuries reported, or injured operators were trained back to baseline measures through rehabilitation and daily activity.

Time series of ground reaction forces following a single leg drop jump landing in elite youth soccer players consist of four distinct phases

The single leg drop jump landing test may assess dynamic and static balance abilities in different phases of the landing. However objective definitions of different phases following landing and associated reliability are lacking. Therefore, we determined the existence of possible distinct phases of single leg drop jump landing on a force plate in 82 elite youth soccer players. Three outcome measures were calculated over moving windows of five sizes: center of pressure (COP) speed, COP sway and horizontal ground reaction force (GRF). Per outcome measure, a Factor Analysis was employed with all windows as input variables. It showed that four factors (patterns of variance) largely (>75%) explained the variance across subjects/trials along the 12s time series. Each factor was highly associated with a distinct phase of the time series signal: dynamic (0.4-2.7s), late dynamic (2.5-5.0s), static 1 (5.0-8.3s) and static 2 (8.1-11.7s). Intra-class correlations (ICC) between trials were lower for the dynamic phases (0.45-0.68) than for the static phases (0.60-0.86). The COP speed showed higher ICC's (0.63-0.86) than COP sway (0.45-0.61) and GRF (0.57-0.71) for all four phases. In conclusion, following a drop jump landing unique information is available in four distinct phases. The COP speed is most reliable, with higher reliability in the static phases compared to the dynamic phases. Future studies should assess the sensitivity of information from dynamic, late dynamic and static phases.

Evidence review for the 2016 International Ankle Consortium consensus statement on the prevalence, impact and long-term consequences of lateral ankle sprains

Lateral ankle sprains (LASs) are the most prevalent musculoskeletal injury in physically active populations. They also have a high prevalence in the general population and pose a substantial healthcare burden. The recurrence rates of LASs are high, leading to a large percentage of patients with LAS developing chronic ankle instability. This chronicity is associated with decreased physical activity levels and quality of life and associates with increasing rates of post-traumatic ankle osteoarthritis, all of which generate financial costs that are larger than many have realised. The literature review that follows expands this paradigm and introduces emerging areas that should be prioritised for continued research, supporting a companion position statement paper that proposes recommendations for using this summary of information, and needs for specific future research.

INFLUENCE OF INJURY ON DYNAMIC POSTURAL CONTROL IN RUNNERS

BACKGROUND

Injury has been linked with altered postural control in active populations. The association between running injury and dynamic postural control has not been examined.

HYPOTHESIS/PURPOSE

The purpose of this study was to examine dynamic postural control in injured and uninjured runners using the Star Excursion Balance Test (SEBT), Time to Stabilization (TTS) of ground reaction forces following a single-leg landing, and postural stability indices reflecting the fluctuations in GRFs during single-leg landing and stabilization tasks (forward and lateral hop). It was hypothesized that dynamic postural control differences would exist between runners with a history of injury that interrupted training for ≥7 days (INJ) when compared to runners without injury (CON).

DESIGN

Case-control study.

METHODS

Twenty-two INJ (14 F, 8 M; 23.7 ± 2.1 y; 22.3 ± 2.8 kg/m2; 29.5 ± 16.3 mi/wk) currently running > 50% pre-injury mileage without pain were compared with twenty-two matched CON (14F, 8M; 22.7 ± 1.2 y; 22.7 ± 2.7 kg/m2; 31.2 ± 19.6 mi/wk). INJ group was stratified by site of injury into two groups (Hip/Thigh/Knee and Lower Leg/Ankle/Foot) for secondary analysis. Leg length-normalized anterior, posterolateral, and posteromedial reach distances on the SEBT, medial/lateral and anterior/posterior ground reaction force TTS, directional postural stability indices, and a composite dynamic postural stability index (DPSI), were assessed using mixed model ANOVA (α=0.05) and effect sizes (d).

RESULTS

No group X direction interaction or group differences were observed for the SEBT (p=0.51, 0.71) or TTS (p=0.83, 0.72) measures. A group X direction interaction was found for postural stability indices during the forward landing task (p<0.01). Both Hip/Thigh/Knee and Lower leg/Ankle/Foot INJ groups demonstrated a greater vertical postural stability index (VPSI) (p=0.01 for both, d=0.80, 0.95) and DPSI (p=0.01, 0.02, d=0.75, 0.93) when compared to CON suggesting impaired balance control. A group X direction interaction was also found for postural stability indices during the lateral landing task (p=0.03). Only the Hip/Thigh/Knee INJ runners displayed a greater VPSI (p=0.01, d=0.91) and DPSI (p=0.017, d=0.89) when compared to CON.

CONCLUSIONS

When compared to CON, INJ runners demonstrated impaired dynamic control of vertical forces when performing the single leg landing and stabilization tasks. Clinicians should consider addressing dynamic control of vertical loads through functional tasks during the rehabilitation of running injury.

LEVEL OF EVIDENCE

Level 3.

Neural Excitability and Joint Laxity in Chronic Ankle Instability, Coper, and Control Groups

CONTEXT

Neuromuscular and mechanical deficiencies are commonly studied in participants with chronic ankle instability (CAI). Few investigators have attempted to comprehensively consider sensorimotor and mechanical differences among people with CAI, copers who did not present with prolonged dysfunctions after an initial ankle sprain, and a healthy control group.

OBJECTIVE

To determine if differences exist in spinal reflex excitability and ankle laxity among participants with CAI, copers, and healthy controls.

DESIGN

Case-control study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty-seven participants with CAI, 30 participants categorized as copers, and 26 healthy control participants.

MAIN OUTCOME MEASURE(S)

We assessed spinal reflex excitability of the soleus using the Hoffmann reflex protocol. Participants' ankle laxity was measured with an instrumented ankle arthrometer. The maximum Hoffmann reflex : maximal muscle response ratio was calculated. Ankle laxity was measured as the total displacement in the anterior-posterior directions (mm) and total rotation in the inversion and eversion directions (°).

RESULTS

Spinal reflex excitability was diminished in participants with CAI compared with copers and control participants (P = .01). No differences were observed among any of the groups for ankle laxity.

CONCLUSION

Changes in the spinal reflex excitability of the soleus that likely affect ankle stability were seen only in the CAI group, yet no mechanical differences were noted across the groups. These findings support the importance of finding effective ways to increase spinal reflex excitability for the purpose of treating neural excitability dysfunction in patients with CAI.

Recovery From a First-Time Lateral Ankle Sprain and the Predictors of Chronic Ankle Instability: A Prospective Cohort Analysis

BACKGROUND

Impairments in motor control may predicate the paradigm of chronic ankle instability (CAI) that can develop in the year after an acute lateral ankle sprain (LAS) injury. No prospective analysis is currently available identifying the mechanisms by which these impairments develop and contribute to long-term outcome after LAS.

PURPOSE

To identify the motor control deficits predicating CAI outcome after a first-time LAS injury.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Eighty-two individuals were recruited after sustaining a first-time LAS injury. Several biomechanical analyses were performed for these individuals, who completed 5 movement tasks at 3 time points: (1) 2 weeks, (2) 6 months, and (3) 12 months after LAS occurrence. A logistic regression analysis of several "salient" biomechanical parameters identified from the movement tasks, in addition to scores from the Cumberland Ankle Instability Tool and the Foot and Ankle Ability Measure (FAAM) recorded at the 2-week and 6-month time points, were used as predictors of 12-month outcome.

RESULTS

At the 2-week time point, an inability to complete 2 of the movement tasks (a single-leg drop landing and a drop vertical jump) was predictive of CAI outcome and correctly classified 67.6% of cases (sensitivity, 83%; specificity, 55%; P = .004). At the 6-month time point, several deficits exhibited by the CAI group during 1 of the movement tasks (reach distances and sagittal plane joint positions at the hip, knee and ankle during the posterior reach directions of the Star Excursion Balance Test) and their scores on the activities of daily living subscale of the FAAM were predictive of outcome and correctly classified 84.8% of cases (sensitivity, 75%; specificity, 91%; P < .001).

CONCLUSION

An inability to complete jumping and landing tasks within 2 weeks of a first-time LAS and poorer dynamic postural control and lower self-reported function 6 months after a first-time LAS were predictive of eventual CAI outcome.

Individuals with both perceived ankle instability and mechanical laxity demonstrate dynamic postural stability deficits

BACKGROUND

Chronic ankle instability is a frequent and serious consequence of lateral ankle sprains. The contribution of perceived instability and potential for mechanical laxity to contribute to the overall deficit in dynamic postural stability is unclear. The purpose was to determine if those with mechanical laxity demonstrated significant differences in dynamic postural stability compared to controls, copers and those with perceived instability.

METHODS

Of 93 participants, 83 recreationally active individuals were divided into 4 groups: controls, copers, those with perceived instability, and those with both perceived instability and mechanical laxity. Injury history and the Cumberland Ankle Instability Tool were collected, and an instrumented arthrometer was applied. Participants completed a single limb jump landing, balancing upon completion. Ground reaction force data were collected, scaled to body mass, and the Dynamic Postural Stability Indices were calculated for anterior-posterior, medial-lateral, vertical and composite. One-way ANOVAs with Tukey post-hoc tests (α<0.05) were conducted on each of the stability indices among the four groups.

FINDINGS

The mechanically lax group had significantly greater mean (standard deviation) medial-lateral stability index scores 0.57 (0.62) than the coper group 0.24 (0.20; P=0.02) and significantly greater composite index scores 0.73 (0.57) than the perceived instability 0.49 (0.09) and coper groups 0.47 (0.12 P=0.05). No other indices were significantly different among groups.

INTERPRETATION

Individuals with perceived instability and mechanical laxity exhibited dynamic postural deficits compared to copers and those with perceived instability alone. Mechanical laxity may contribute to the deficits in dynamic postural stability.

Ankle ligament laxity and stiffness in chronic ankle instability

BACKGROUND

The contribution of mechanical laxity and ligament stiffness to chronic ankle instability is unclear, particularly when using the inversion laxity test, and may have implications for diagnosis, prognosis, and treatment. Our purpose was to determine if individuals with chronic ankle instability demonstrate greater mechanical ligament laxity and altered stiffness compared to controls and copers (those with a healed sprain) during an instrumented arthrometer inversion stress test.

METHODS

Recreationally active individuals were classified as those with chronic ankle instability (n = 16), copers (n = 16), or controls (n = 16) based on injury history and self-reported score on the Cumberland Ankle Instability Tool (CAIT). Three trials of an inversion stress test were applied with an instrumented arthrometer utilizing a reliable tester. Talocrural inversion (degrees) and stiffness values were extracted. One-way ANOVAs were calculated, and Tukey post hoc testing was applied (α ≤ .05).

RESULTS

Groups were not different in age, height, or weight. The chronic ankle instability group (19 ± 6) had significantly lower CAIT scores than the control (30 ± 1) and coper (29 ± 1) groups (P < .001). The chronic ankle instability group (23 ± 12 degrees) demonstrated significantly greater inversion than the controls (13 ± 9 degrees) (P = .04) but was not significantly different than the copers (17 ± 10 degrees). No significant differences were detected in stiffness between the groups.

CONCLUSION

The chronic ankle instability group demonstrated decreased self-reported ankle function and increased mechanical laxity utilizing an instrumented arthrometer for inversion compared to the control group but not the coper group. Laxity, but not stiffness, may be a factor affecting chronic ankle instability and self-reported function.

LEVEL OF EVIDENCE

Level III, comparative study.

Differences between mechanically stable and unstable chronic ankle instability subgroups when examined by arthrometer and FAAM-G

Background

The objective measurement of the mechanical component and its role in chronic ankle instability is still a matter of scientific debate. We analyzed known group and diagnostic validity of our ankle arthrometer. Additionally, functional aspects of chronic ankle instability were evaluated in relation to anterior talar drawer.

Methods

By manual stress testing, 41 functionally unstable ankles were divided as mechanically stable (n = 15) or mechanically unstable (n = 26). Ankle laxity was quantified using an ankle arthrometer. Stiffness values from the load displacement curves were calculated between 40 and 60 N. Known group validity and eta² were established by comparing manual and arthrometer testing results. Diagnostic validity for the ankle arthrometer was determined by a 2 × 2 contingency table. The functional ankle instability severity was quantified by the German version of the Foot and Ankle Ability Measure (FAAM-G). Stiffness (40–60 N) and FAAM-G values were correlated.

Results

Mechanically unstable ankles had lower 40–60 N stiffness values than mechanically stable ankles (p = 0.006 and <0.001). Eta for the relation between manual and arthrometer anterior talar drawer testing was 0.628. With 5.1 N/mm as cut-off value, accuracy, sensitivity, and specificity were 85%, 81%, and 93%, respectively.

The correlation between individual 40–60 N arthrometer stiffness values and FAAM-G scores was r = 0.286 and 0.316 (p = 0.07 and 0.04).

Conclusions

In this investigation, the ankle arthrometer demonstrated a high diagnostic validity for the determination of mechanical ankle instability. A clear interaction between mechanical (ankle arthrometer) and functional (FAAM-G) measures could not be demonstrated.

Electronic supplementary material

The online version of this article (doi:10.1186/s13018-015-0171-2) contains supplementary material, which is available to authorized users.

Reliability and validity of an accelerometry based measure of static and dynamic postural stability in healthy and active individuals

Postural stability is an important measure in both research and clinical practice. A portable, easy to use device that can provide higher resolution than current clinical tests may allow for better identification of patients or athletes with postural stability deficits. The purpose of this study was to evaluate the ability of a tri-axial accelerometer to quantify postural stability in a healthy athletic population. Ten subjects were recruited to determine the reliability of the accelerometer to measure dynamic postural stability and thirteen were recruited to compare the accelerometer measures across tasks of varying difficulty. Subjects were asked to complete four static postural stability tasks with eyes open and eyes closed and two dynamic postural stability tasks for a total of ten tasks. During each task postural stability was measured using a tri-axial accelerometer and force platform. Differences between postural stability scores between tasks and the correlation between the two measures were assessed. The accelerometer demonstrated moderate to good test-retest reliability (ICC=0.732 to 0.899). Only the medial-lateral axis of the accelerometer showed significant differences between static tasks but all directions were able to show significant differences between static and dynamic tasks. Additionally, Spearman's ranked correlations showed little to no correlation between the accelerometer and force platform scores. Accelerometers are a reliability tool for postural stability that measure low difficulty tasks best in the medial-lateral direction. Low correlation between the accelerometer and force platform suggest that these two methods are not measuring the same components of postural stability.

Inter-joint coordination strategies during unilateral stance 6-months following first-time lateral ankle sprain

BACKGROUND

Longitudinal analyses of participants with a history of lateral ankle sprain are lacking. This investigation combined measures of inter-joint coordination and stabilometry to evaluate eyes-open (condition 1) and eyes-closed (condition 2) static unilateral stance performance in a group of participants, 6-months after they sustained an acute, first-time lateral ankle sprain in comparison to a control group.

METHODS

Sixty-nine participants with a 6-month history of first-time lateral ankle sprain and 20 non-injured controls completed three 20-second unilateral stance task trials in conditions 1 and 2. An adjusted coefficient of multiple determination statistic was used to compare stance limb 3-dimensional kinematic data for similarity in the aim of establishing patterns of lower-limb inter-joint coordination. The fractal dimension of the stance limb centre of pressure path was also calculated.

FINDINGS

Between-group analyses revealed significant differences in stance limb inter-joint coordination strategies for conditions 1 and 2, and in the fractal dimension of the centre-of-pressure path for condition 2 only. Injured participants displayed increases in ankle-hip linked coordination compared to controls in condition 1 (sagittal/frontal plane: 0.15 [0.14] vs 0.06 [0.04]; η(2)=.19; sagittal/transverse plane: 0.14 [0.11] vs 0.09 [0.05]; η(2)=0.14) and condition 2 (sagittal/frontal plane: 0.15 [0.12] vs 0.08 [0.06]; η(2)=0.23), with an associated decrease in the fractal dimension of the centre-of-pressure path (injured limb: 1.23 [0.13] vs 1.36 [0.13]; η(2)=0.20).

INTERPRETATION

Participants with a 6-month history of first-time lateral ankle sprain exhibit a hip-dominant coordination strategy for static unilateral stance compared to non-injured controls.