Age-related changes in proprioception of the ankle complex across the lifespan

Effects of chronic ankle instability after grade I ankle sprain on the post-traumatic osteoarthritis

BACKGROUND

Untreated acute ankle sprains often result in chronic ankle instability (CAI) and can ultimately lead to the development of post-traumatic osteoarthritis (PTOA). At present, a typical animal model of ankle instability in mice is established by transecting the ligaments around the ankle joint. This study aimed to establish a grade I acute ankle sprain animal model by rapid stretching of peri-ankle joint ligaments. Furthermore, we tried to explore the pathophysiological mechanism of ankle osteoarthritis.

METHODS

In all, 18 male C57BL/6 J mice (7 weeks) were randomly divided into three groups: calcaneofibular ligament (CFL) laxity group, deltoid ligament (DL) laxity group, and SHAM group. One week after the surgical procedure, all mice were trained to run in the mouse rotation fatigue machine daily. The mice were tested on the balance beam before surgery and three days, 4 weeks, 8 weeks, and 12 weeks after surgery. Footprint analyses were performed on each mouse before surgery and 12 weeks after surgery. Micro-CT scanning was then performed to evaluate the degeneration of ankle joints and histological staining was performed to analyze and evaluate PTOA caused by ankle joint instability.

RESULTS

After surgery, the mice in the CFL and DL laxity groups took longer to cross the balance beam and slipped more often than those in the SHAM group (p < 0.05). The step length and width in the CFL and DL laxity groups were significantly shorter and smaller than those in the SHAM group 12 weeks after surgery (p < 0.05). There was a significant increase in the bone volume fraction (BV/TV) in the CFL and DL laxity groups compared with the SHAM group (p < 0.05). Histological staining results suggested obvious signs of PTOA in the CFL and DL laxity groups.

CONCLUSIONS

Based on CFL and DL laxity in a mouse ankle instability model, this study suggests that grade I ankle sprain can contribute to chronic ankle instability, impair motor coordination and balance, and eventually lead to PTOA of ankle with significant degeneration of its adjacent joints.

Ankle inversion proprioception measured during stair descent can identify chronic ankle instability

BACKGROUND

Individuals with chronic ankle instability (CAI) may experience recurrent ankle sprains and symptoms during daily activities such as stair descent, where the associated proprioceptive deficit is largely unevaluated.

OBJECTIVES

To evaluate the reliability and validity of an ankle inversion discrimination apparatus for stair descent, and examine whether proprioceptive scores from this apparatus are associated with patient-reported symptoms.

DESIGN

Cross-sectional study.

METHOD

Sixty-six participants volunteered in this study. The ankle inversion discrimination apparatus was purpose-built to assess ankle proprioception across four positions of ankle inversion (10°, 12°, 14°, and 16°) during stair descent. The Area Under the Receiver Operating Curve (AUC) was employed as the ankle proprioceptive discrimination score.

RESULTS

Test-retest reliability ICC (3,1) for the whole group was 0.825, with 0.747 for the non-CAI group (95%CI = 0.331-0.920) and 0.701 for CAI (95%CI = 0.242-0.904). The CAI group performed at a significantly lower level than non-CAI on the ankle inversion discrimination apparatus for stair descent assessment (0.769 ± 0.034 vs. 0.830 ± 0.035, F = 33.786, p < 0.001). CAIT scores were strongly and significantly correlated with scores from this apparatus (Spearman's rho = 0.730, p < 0.001).

CONCLUSIONS

The ankle inversion discrimination apparatus for stair descent is reliable and valid for assessing task-specific ankle proprioceptive impairments in CAI. The strong and significant relationship found between ankle proprioception during stair descent and the severity of CAI suggests that rehabilitation programs focusing on deficits in ankle inversion proprioception during stair descent may improve self-reported instability in CAI.

Keeping up with ourselves: Multimodal processes underlying body ownership across the lifespan

The sense of a bodily self is thought to depend on adaptive weighting and integration of bodily afferents and prior beliefs. While the physical body changes in shape, size, and functionality across the lifespan, the sense of body ownership remains relatively stable. Yet, little is known about how multimodal integration underlying such sense of ownership is altered in ontogenetic periods of substantial physical changes. We aimed to study this link for the motor and the tactile domain in a mixed-realty paradigm where participants ranging from 7 to 80 years old saw their own body with temporally mismatching multimodal signals. Participants were either stroked on their hand or moved it, while they saw it in multiple trials with different visual delays. For each trial, they judged the visuo-motor/tactile synchrony and rated the sense of ownership for the seen hand. Visual dependence and proprioceptive acuity were additionally assessed. The results show that across the lifespan body ownership decreases with increasing temporal multisensory mismatch, both in the tactile and the motor domain. We found an increased sense of ownership with increasing age independent of delay and modality. Delay sensitivity during multisensory conflicts was not consistently related to age. No effects of age were found on visual dependence or proprioceptive accuracy. The results are at least partly in line with an enhanced weighting of top-down and a reduced weighting of bottom-up signals for the momentary sense of bodily self with increasing age.

Impaired motor skills and proprioceptive function in Mandarin-speaking children with developmental language disorder

This study examined proprioceptive acuity and its relationship with motor function in Mandarin-speaking children with and without developmental language disorder (DLD). Fifteen children aged 9-12 years with DLD and 15 age- and sex-matched typically developing (TD) children participated in this study. Children's motor function was assessed using the second edition of the Movement Assessment Battery for Children (MABC-2). Their proprioceptive acuity was measured based on the absolute error (i.e., proprioceptive bias) and variable error (i.e., proprioceptive precision) when performing joint position matching tasks. Compared with the TD group, the DLD group exhibited impaired motor function and poorer proprioceptive acuity, as evidenced by the lower scores on the MABC-2 and the higher rates of absolute and variable errors in the joint position matching tasks. A significant association between the proprioceptive bias (absolute error) and the MABC-2 total score was also observed in the combined cohort of children with and without DLD. We conclude that DLD is associated with proprioceptive dysfunction.

Tai Chi counteracts age-related somatosensation and postural control declines among older adults

Objective

To investigate the effect of a 16-week Tai Chi practice on strength, tactile sensation, kinesthesia, and static postural control among older adults of different age groups.

Methods

This is a quasi-experimental study. Thirteen participants aged 60-69 years (60-69yr), 11 aged 70-79 years (70-79yr), and 13 aged 80-89 years (80-89yr) completed 16 weeks of 24-form Tai Chi practice. Their ankle and hip peak torque, tactile sensation, ankle and knee kinesthesia, and the root mean square of the center of pressure (Cop-RMS) were measured before (week 0) and after (week 17) practice.

Results

80-89yr showed less ankle plantar/dorsiflexion and hip abduction peak torques (p = 0.003, p < 0.001, p = 0.001), and a greater ankle plantar/dorsiflexion kinesthesia (p < 0.001, p = 0.002) than 60-69yr and 70-79yr. Greater ankle plantar/dorsiflexion and hip abduction torques (p = 0.011, p < 0.001, p = 0.045), improved arch and heel tactile sensation (p = 0.040, p = 0.009), and lower knee flexion/extension kinesthesia (p < 0.001, p = 0.044) were observed at week 17. The significant group*practice interaction for the fifth metatarsal head tactile sensation (p = 0.027), ankle plantar/dorsiflexion kinesthesia (p < 0.001, p = 0.004), and the CoP-RMS in the mediolateral direction (p = 0.047) only in 80-89yr revealed greater improvement at week 17.

Conclusion

Tai Chi practice increased strength, tactile sensation, kinesthesia, and static postural control among older adults. Tai Chi practice improved tactile, kinesthesia sensations, and static postural control among older adults over 80, who presented with worse strength and kinesthesia than their younger counterparts. Tai Chi practice offers a safe exercise option for those aged over 80 to encourage improvements in sensorimotor control.

Ankle proprioception in children with cerebral palsy

PURPOSE

There is no established clinical standard to evaluate ankle proprioception in children with cerebral palsy (CP). This study compared ankle position sense of children with CP to age-matched children who are typically developing (TD).

METHODS

Children aged 6-17 years participated (15 CP, 58 TD). Using a custom-built device, the ankle was passively rotated to two positions for 25 trials. Using a psychophysical forced-choice paradigm, participants indicated which position was more plantarflexed. A psychometric function was fitted to the response data to determine the just noticeable difference (JND) threshold and the associated uncertainty (random error) for ankle position sense.

RESULTS

Median JND thresholds for the CP group were elevated (CP: 4.3°, TD: 3.0°). Three children with CP exceeded the 95th percentile of TD. No differences in random error were found.

CONCLUSION

This method assessed ankle proprioception relative to norm data and identified position sense impairments in children with CP. Using this method can provide data on proprioceptive status in CP, augmenting the assessment of motor impairment.

A Physically Active Lifestyle Can Protect against Age-Related Decline in Ankle Proprioception

This study examined whether physically active middle-aged (50-64 years) and older adults (65-80 years) demonstrate age-related ankle proprioceptive decline relative to younger counterparts. Empirical data indicate that ankle proprioception declines with aging and such sensory decline negatively affects balance. Using a passive motion apparatus, we employed a psychophysical forced-choice paradigm in which the ankle was passively plantarflexed to a reference position (15° or 25°) and a comparison position that was always smaller than the reference. Subsequently, participants indicated which position was more plantarflexed. As outcome measures of ankle position sense acuity, a just-noticeable-difference (JND) threshold and the uncertainty area (UA) were derived from the psychometric stimulus-response difference function for each participant. The JND threshold is a measure of proprioceptive bias and UA constitutes a measure of precision. The main results are: First, at the 15° reference, most middle-aged (74%) and older adults (71%) had thresholds within the range of the young adults. The respective median JND threshold of young adults was statistically lower when compared to both older groups. Second, no differences between age groups were observed at the 25° reference. Third, no age-related differences were found for UA at either reference. These data indicate that physically active aging adults may be spared from age-related decline in ankle position sense and that age-related differences emerge for small ankle displacements. The findings underscore the importance of remaining active during aging.

Ageing and joint position sense of the asymptomatic shoulder: An observational study

PURPOSE

This study aimed to quantify the extent to which age was associated with joint position sense (JPS) of the asymptomatic shoulder as measured by joint position reproduction (JPR) tasks and assess the reproducibility of these tasks.

METHODS

120 Asymptomatic participants aged 18-70 years each performed 10 JPR-tasks. Both contralateral and ipsilateral JPR-tasks were evaluated on accuracy of JPR under active- and passive conditions at two levels within the shoulder forward flexion trajectory. Each task was performed three times. In a subgroup of 40 participants, the reproducibility of JPR-tasks was assessed one week after initial measurement. Reproducibility of JPR-tasks was evaluated by both reliability (intra-class correlation coefficients (ICC's)) and agreement (standard error of measurement (SEM)) measures.

RESULTS

Age was not associated with increased JPR-errors for any of the contralateral or ipsilateral JPR-tasks. ICC's ranged between 0.63 and 0.80 for contralateral JPR-tasks, and from 0.32 to 0.48 for ipsilateral tasks, except for one ipsilateral task where the reliability was similar to contralateral tasks (0.79). The SEM was comparable and small for all JPR-tasks, ranging between 1.1 and 2.1.

CONCLUSION

No age-related decline in JPS of the asymptomatic shoulder was found, and good agreement between test and re-test measurements for all JPR-tasks as indicated by the small SEM.

Ankle Inversion Proprioception Impairment in Persons with Chronic Ankle Instability Is Task-Specific

While investigators have often compared ankle proprioception between groups with and without chronic ankle instability (CAI), findings have been inconsistent. Possibly this is because ankle proprioceptive impairment in this population is task-specific. Thus, we aimed to compare ankle inversion proprioception in individuals with and without CAI in two task conditions: (i) when standing (not challenging) and (ii) when on a step-down landing (minimally-challenging). Ankle inversion proprioception was measured in both conditions for 38 recreational sport player volunteers with CAI (n = 19) and without CAI (n = 19). We used the Active Movement Extent Discrimination Apparatus (AMEDA) for the standing condition and the Ankle Inversion Discrimination Apparatus-Landing (AIDAL) for step-down landing. From analysis of variance (ANOVA) tests, CAI and non-CAI participants performed equally well on the AMEDA when standing; but the CAI group performed significantly worse than the non-CAI group on the AIDAL step-down landing task (p = 0.03). Within the non-CAI group, the AIDAL proprioceptive scores, as area under the receiver operating characteristics curve (AUC), were significantly higher than their AMEDA AUC scores (p = 0.03), while there was no significant difference between AIDAL and AMEDA AUC scores in the CAI group. Cumberland Ankle Instability Tool CAIT scores were significantly correlated with AIDAL scores (Spearman's rho = 0.391, p = 0.015), but not with the AMEDA scores; and there was no significant correlation between the AIDAL and AMEDA scores. Thus, an ankle inversion proprioceptive deficit was evident for persons with CAI on the step-down AIDAL, and in a dose-response way, but not evident on the standing AMEDA, suggesting that ankle proprioceptive impairment is task-specific. Selected proprioceptive tests must present some minimal degree of challenge to the ankle joint in a functional task in order to differentiate CAI from non-CAI participants.

Impaired ankle inversion proprioception during walking is associated with fear of falling in older adults

Background

Ankle proprioception plays a critical role in lower limb movement control. However, the relationship between ankle proprioception and fear of falling (FOF) in older people is still unclear.

Objective

(1) This study aims to develop a new device for measuring ankle inversion proprioceptive discrimination sensitivity during walking, i.e., the Ankle Inversion Discrimination Apparatus–Walking (AIDAW), and assess the test–retest reliability of the AIDAW in both young and older adults; (2) to evaluate the discriminant validity of the measure by comparing ankle proprioception during walking between the two groups; and (3) to explore convergent validity by determining to what extent the AIDAW proprioceptive scores correlate with Fall Efficacy Scale-International (FES-I) scores.

Materials and methods

The AIDAW was purpose-built to test ankle inversion proprioceptive discrimination sensitivity during walking. The area under the receiver operating curve (AUC) was calculated as the proprioceptive discrimination score. In total, 54 adults volunteered. Test–retest reliability was evaluated in 12 young and 12 older adults, and another 15 young and 15 older adults completed the comparison study. FOF was assessed by using the FES-I.

Results

The test–retest reliability intraclass correlation coefficient ICC _(3,1) value for the whole group was 0.76 (95% CI: 0.52–0.89). The ICC values of the young and older groups were 0.81 (95% CI: 0.46–0.94) and 0.71 (95% CI: 0.26–0.91), respectively. The Minimal Detectable Change with 90% confidence (MDC₉₀) values for the young and older groups were 0.03 and 0.11, respectively. There was a significant difference between the AIDAW proprioceptive sensitivity scores for the young and older groups (0.78 ± 0.04 vs. 0.72 ± 0.08, F = 5.06, p = 0.033). Spearman’s correlation analysis showed that the FES-I scores were significantly and negatively correlated with the AIDAW scores (rho = −0.61, p = 0.015), with higher FOF associated with worse ankle proprioception.

Conclusion

The AIDAW is a reliable and valid device for measuring ankle proprioception during walking in both young and older adults. Ankle inversion proprioceptive discrimination sensitivity during walking was found to be impaired in the elderly compared to young adults. This impairment was found to be strongly associated with FOF, suggesting that assessment and intervention for ankle proprioception in this population are needed to reduce the risk of falls.

Chronic non-specific low back pain and ankle proprioceptive acuity in community-dwelling older adults

BACKGROUND

For people above 65 years old, low-back pain (LBP) is associated with balance problems and falls. Down-weighting of proprioception due to ageing and LBP may cause such balance problems. While lumbar proprioceptive deficits have been shown in LBP and indications for more generalized deficits have been found, ankle proprioception, which is crucial for balance control, has not been studied in people with LBP.

RESEARCH QUESTION

Is there any difference in ankle proprioceptive acuity between community-dwelling older adults with and without LBP? We hypothesized that ankle proprioception was impaired in community-dwelling older adults with LBP compared to those without LBP.

METHODS

Thirty participants over 65 years old volunteered. Fifteen had LBP (M/F = 2/13, age = 72.0 (4.6) years), fifteen were healthy controls without back pain (control group) (M/F = 2/13, age = 72.1 (4.8) years). Ankle proprioception was measured in normal weight-bearing conditions, using the Active Movement Extent Discrimination Apparatus (AMEDA). Accuracy on the ankle proprioceptive test was expressed as absolute error (AE), constant error (CE) and variable error (VE).

RESULTS

AE was significantly larger (P = 0.029, 95 % CI = [0.00, 0.90]) in the LBP group, CE was also significantly larger (P = 0.046, 95 % CI = [-0.91, -0.01]), indicating an underestimation of ankle inversion in participants with LBP compared to controls. VE was not different between the two groups (P = 0.520, 95 % CI = [-0.20, 0.59]). No significant correlation was found between pain intensity and AE, CE or VE (P > 0.05).

CONCLUSION

Ankle proprioception decreased in older people with LBP compared to healthy peers, suggesting impaired central proprioceptive processing. Older people with LBP underestimate the extent of ankle inversion, which may increase fall risk. Thus, evaluation and training of ankle proprioception may be useful in older people with LBP.

The Non-Concordance of Self-Reported and Performance-Based Measures of Vestibular Dysfunction in Military and Civilian Populations Following TBI

As a predominately young, physically active, and generally healthy population, service members (SMs) with vestibular dysfunction (VD) following a TBI may not be accurately represented by the current civilian reference ranges on assessments of VD. This study enrolled SMs who were referred for vestibular rehabilitation following a mild/moderate TBI. The participants self-reported VD using the Activities-specific Balance Confidence (ABC) scale and the Dizziness Handicap Inventory (DHI) followed by evaluation of vestibular performance using computerized dynamic posturography sensory organizational test (CDP−SOT). Retrospective analysis of these outcomes comparing the study sample of SMs to the reported civilian samples revealed SMs self-reported lower VD with significantly higher balance confidence (ABC: 77.11 ± 14.61, p < 0.05) and lower dizziness (DHI: 37.75 ± 11.74, p < 0.05) than civilians. However, the SMs underperformed in performance-based evaluations compared to civilians with significantly lower CDP−SOT composite and ratio scores (COMP: 68.46 ± 13.46, p < 0.05; VIS: 81.36 ± 14.03, p < 0.01; VEST: 55.63 ± 22.28, p < 0.05; SOM: 90.46 ± 10.17, p < 0.05). Correlational analyses identified significant relationships between the ABC and CDP−SOT composite (r = 0.380, p < 0.01) and ratio scores (VIS: r = 0.266, p < 0.05; VEST: r = 0.352, p < 0.01). These results highlight the importance of recognizing and understanding nuances in assessing VD in SMs to ensure they have access to adequate care and rehabilitation prior to returning to duty.

Can therapeutic exercises improve proprioception in chronic ankle instability? a systematic review and network meta-analysis

OBJECTIVE

To assess exercise therapies that aim to enhance proprioception in individuals with chronic ankle instability (CAI).

DATA SOURCES

Five databases (PubMed, Embase, Cochrane Library, Web of Science, and EBSCO) were searched in October 2021.

STUDY SELECTION

Randomized controlled trials involving exercise therapy conducted on individuals with CAI were included.

DATA EXTRACTION

Data were extracted by two independent reviewers using a standardized form. Methodological quality and risk of bias were assessed with the PEDro scale.

DATA SYNTHESIS

The end-trial weighted mean difference and standard deviations were analyzed, and the synthetic value for the improvement in error scores of ankle joint position sense (JPS) in multiple directions was evaluated.

RESULTS

Eleven trials with 333 participants were eligible for inclusion in this systematic review and were included in the Network Meta-Analysis. Foot and ankle muscle strengthening exercise showed the highest probability of being among the best treatments (surface under the cumulative ranking (SUCRA)=74.6%). The next two were static balance exercise only (SUCRA=67.9%) and corrective exercise (SUCRA=56.1%). The SUCRA values of proprioceptive exercise, dynamic balance exercise only, aquatic exercise, rehabilitation exercise with brace, mixed static/dynamic balance exercise, and control were at relatively low levels, and scored at 49.6%, 48.8%, 47.8%, 47.7%, 44.0%, and 13.5%, respectively.

CONCLUSIONS

Foot and ankle muscle strengthening exercise may have a good effect when used to improve JPS in individuals with CAI. Probably, the more complex balance exercise intervention becomes, the less effective the proprioceptive outcome.

PROSPERO REGISTRATION NUMBER

CRD42021240331.

Daily surveillance of falls is feasible and reveals a high incidence of falls among older adults

Objective

To ensure accurate data capture for a fall study through a system of daily contact with participants.

Methods

Fifty‐eight adults older than 60 years of age and living independently in the community in Canberra, Australia, were recruited for a prospective fall study. We adopted a system of daily contact with study participants for at least 12 months, either by email or by text, asking whether they had suffered a fall in the previous 24 h. At the final testing session, we asked participants whether they had experienced a fall during the previous twelve months.

Results

We found no evidence that the daily reporting regime led to excess participant attrition. Only three participants withdrew over the course of the study, and the burden of responding was not cited as a factor in any of these cases. Of the 55 participants who completed the full twelve‐month study period, 38 (69%) experienced at least one fall. We also identified inconsistencies between recall of falls occurring during the last twelve months of the study and the contemporaneously recorded data.

Conclusions

Previous studies have found that increasing the reporting demands on fall study participants will lead to higher attrition. This study demonstrates that it is possible to maintain participant engagement and minimise attrition with appropriate design of reporting procedures. We confirm existing evidence regarding the unreliability of retrospective recall of falls. The study highlights the importance of comprehensive and accurate data capture and points to the possibility of under‐reporting of fall incidence.

A mouse model of ankle-subtalar joint complex instability induced post-traumatic osteoarthritis

BACKGROUND

Ankle-subtalar joint complex instability is not uncommonly presented in the clinic, but symptoms and signs similar to other conditions can easily lead to its misdiagnosis. Due to the lack of appropriate animal models, research on ankle-subtalar joint complex instability is limited. The aims of the present study were to establish an animal model of ankle-subtalar joint complex instability in mice and to explore its relationship with post-traumatic osteoarthritis (PTOA).

METHODS

Twenty-one male C57BL/6J mice were randomly divided into three groups: SHAM group (sham surgery group), transected cervical ligament + anterior talofibular ligament (CL+ATFL) group, and transected cervical ligament + deltoid ligament (CL+DL) group. Two weeks after surgery, all mice underwent cage running training. Balance beam and gait tests were used to evaluate the changes in self-movement in the mice after ankle-subtalar ligament injury. Micro-CT and histological staining were used to evaluate the progress of PTOA.

RESULTS

Compared with the SHAM group, balance and gait were affected in the ligament transection group. Twelve weeks after surgery, the time required to cross the balance beam in the CL+ATFL group was 35.1% longer and the mice slipped 3.6-fold more often than before surgery, and the mean step length on the right side was 7.2% smaller than that in the SHAM group. The time required to cross the balance beam in the CL+DL group was 32.1% longer and the mice slipped 3-fold more often than prior to surgery, and the average step length on the right side was 5.6% smaller than that in the SHAM group. CT images indicated that 28.6% of the mice in the CL+DL group displayed dislocation of the talus. Tissue staining suggested that articular cartilage degeneration occurred in mice with ligament transection 12 weeks after surgery.

CONCLUSIONS

Transected mice in the CL+ATFL and CL+DL groups displayed mechanical instability of the ankle-subtalar joint complex, and some mice in the CL+DL group also suffered from talus dislocation due to ligament injury leading to loss of stability of the bone structure. In addition, as time progressed, the articular cartilage displayed degenerative changes, which affected the ability of animals to move normally.

Assessing Proprioception in an Older Population: Reliability of a Protocol Based on Active Movement Extent Discrimination

Proprioceptive ability - the sense of where body parts are located in space - is one of many factors thought to affect falls risk among the elderly. Active movement extent discrimination is an approach to measuring proprioception that is administered in an ecologically valid testing environment to better reflect the exercise of proprioceptive skills in daily life. The Active Movement Extent Discrimination Apparatus (AMEDA) was developed to objectively measure this proprioceptive discrimination. However, the current absolute identification testing protocol is cognitively demanding, and it yields results that are insufficiently reliable to assess performance at the individual level. The objectives of this pilot study were to test the reliability and feasibility of a proposed new AMEDA testing protocol and to explore how performance related to cognitive ability and any perceived dysfunction in the foot or ankle. We tested 42 participants (aged 19 - 94 years) three times on the ankle AMEDA using a newly developed protocol that asked participants to report whether a given angle of ankle inversion was shallower or deeper than the immediately preceding inversion. Participants also completed the Stroop test, as a measure of cognitive ability, and two validated questionnaires for identifying foot or ankle dysfunction (the Cumberland Ankle Instability Tool and the Foot and Ankle Ability Measure). The proportion of correct responses for the AMEDA test showed the expected sigmoid shape of the psychometric function as signal strength increased. The intraclass correlation coefficient measured over the three tests was 0.65 (95% confidence interval: 0.49 - 0.78), suggesting moderate reliability. We found a positive and statistically significant correlation between AMEDA performance and Stroop results but no relationship between the AMEDA score and questionnaire-measured foot or ankle dysfunction. This study confirmed that the alternative testing protocol was simple to administer and easily understood by participants.

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

BACKGROUND

Research evidence has suggested that a more sensitive ankle proprioceptive testing method with higher ecological validity is needed for assessing proprioceptive deficits in individuals with chronic ankle instability (CAI).

OBJECTIVES

(1) To determine the test-retest reliability of a novel ankle proprioception assessment tool, the Ankle Inversion Discrimination Apparatus for Landing (AIDAL); (2) To assess whether AIDAL scores were sufficiently sensitive to detect proprioceptive deficits in chronic ankle instability (CAI); and (3) To examine whether AIDAL scores correlated with Cumberland Ankle Instability Tool (CAIT) scores.

DESIGN

Cross-sectional study.

METHODS

The AIDAL was purpose-built to assess ankle discrimination in four positions of ankle inversion (10°, 12°, 14° and 16°) upon landing from a 10cm drop. Area Under the Receiver Operating Curve (AUC) was employed as the ankle proprioceptive discrimination score. Seven-day test-retest reliability was evaluated with 23 university students (12 CAI and 11 non-CAI), and another 36 university students (18 CAI and 18 non-CAI) were in the comparison study.

RESULTS

The test-retest reliability ICC score for the whole group was 0.763 (95% CI=0.519-0.892), which showed an excellent reliability level. ICC _(3,1) was 0.701 for the non-CAI group (95%CI=0.210-0.910) and 0.804 for the CAI group (95%CI=0.451-0.939). The CAI group performed at a significantly lower level on the AIDAL assessment than the non-CAI group (0.777±0.05 vs. 0.815±0.05, F=5.107, p=0.03). The discriminative AUC value for the AIDAL test was 0.756 with a cut point of 0.819 (sensitivity=0.733, specificity=0.800). The MDC₉₀ scores for CAI and non-CAI groups were both 0.04. Spearman's correlation showed that the CAIT scores were significantly correlated with the ankle proprioceptive discrimination scores (rho=0.401, p=0.015).

CONCLUSION

The AIDAL showed good test-retest reliability for both non-CAI and CAI groups. Measuring ankle inversion proprioception during landing may be important for assessing the outcomes of CAI rehabilitation, as proprioceptive performance obtained from the AIDAL was significantly correlated with severity of functional ankle instability CAIT scores.

Vibration of calf muscles has reverse effects on right and left ankle proprioception in high and low proprioceptive performer groups

PURPOSE

Previous research has found hemispheric asymmetries in the utilization of proprioceptive information. It is undetermined, however, if there is any change in asymmetry in proprioceptive function when external stimulation, such as vibration, is presented. The present study was to investigate the immediate effects of vibration stimulation (VS) on bilateral ankle proprioception.

MATERIALS AND METHODS

Forty-six recreational male basketball players were included. Proprioception was assessed by using the active movement extent discrimination apparatus (AMEDA) in standing, and vibration was provided by using a vibrating form roller on the peroneal or gastrocnemius muscles.

RESULTS

When participants were divided into high score and low score groups, according to the median of the baseline proprioceptive performance, VS (irrespective of whether vibrating the peroneal or gastrocnemius muscles) significantly improved left non-dominant ankle proprioception in the low proprioceptive performer group (p = 0.019), while significantly deteriorated right dominant ankle proprioception in the high proprioceptive performer group (p = 0.011).

CONCLUSIONS

The results found that external stimuli reversely affect proprioception in better and worse performing groups. This suggests that there are differences in the processing of external stimulus signals on different bilateral hemispheres and in different groups (high score vs low score groups), which may be related to hemispheric asymmetry and stochastic resonance. Therefore, it is necessary to explore more specific interventions in the future.

Ipsilateral vs Contralateral Presentation of Familiarization Trials in a Lower-Limb Proprioception Test

We examined the effect of pretest familiarization with ipsilateral or contralateral limbs on the performance in a proprioception test conducted afterwards. Sixty adults were randomly assigned to six different familiarization-session patterns. Ankle proprioception was tested using active movement extent discrimination assessment. The results reflected a beneficial effect of familiarization session on performance in the subsequent proprioception test (ES = 0.777). However, no significant difference was found between proprioceptive acuity scores when familiarization and test happened with either ipsilateral or contralateral limbs (ES= 0.361), or between the tested left and right foot no matter which side was familiarized (ES = 0.343). These results suggest that proprioceptive information from the familiarization session facilitates the subsequent proprioception test and is equally available to both hemispheres without loss of quality.