Lumbar extension peak-torque, muscle endurance and motor imagery in junior-elite basketballers with and without a history of low back pain: a pilot study.

Objectives: Low back pain (LBP) is common in elite athletes. Several peripheral and central factors have been identified to be altered in non-athletic LBP populations, however whether these alterations also exist in elite athletes with LBP is unknown. The aim of this study was to determine whether elite basketballers with a history of persistent LBP perform worse than those without LBP at a lumbar muscle endurance task, a lumbar extension peak-torque task, and a lumbar motor imagery task. Method: An observational pilot study. Twenty junior elite-level male basketballers with (n = 11) and without (n = 9) a history of persistent LBP were recruited. Athletes completed a lumbar extensor muscle endurance (Biering-Sorensen) task, two lumbar extensor peak-torque (modified Biering-Sorensen) tasks and two motor imagery (left/right lumbar and hand judgement) tasks across two sessions (48 hours apart). Performance in these tasks were compared between the groups with and without a history of LBP. Results: Young athletes with a history of LBP had reduced lumbar extensor muscle endurance (p < 0.001), reduced lumbar extension peak-torque (p < 0.001), and were less accurate at the left/right lumbar judgement task (p = 0.02) but no less accurate at a left/right hand judgement task (p = 0.59), than athletes without a history of LBP. Response times for both left/right judgement tasks did not differ between groups (lumbar p = 0.24; hand p = 0.58). Conclusions: Junior elite male basketballers with a history of LBP demonstrate reduced lumbar extensor muscle endurance and lumbar extension peak-torque and are less accurate at a left/right lumbar rotation judgement task, than those without LBP.

Diving Into the Health Problems of Competitive Divers: A Systematic Review of Injuries and Illnesses in Pre-elite and Elite Diving Athletes.

CONTEXT: The Olympic sport of diving involves the competitive disciplines of 3 m springboard and 10 m platform. Although it is generally accepted that lumbar spine injuries are common in diving athletes, the existing literature of health problems in diving athletes remains scarce. OBJECTIVE: To identify the incidence, prevalence, and type of health problems that occur in competitive diving athletes. DATA SOURCES: Medline, EMBASE, SportsDiscus, PsycINFO, and Google Scholar. STUDY SELECTION: Studies written in English investigating elite or pre-elite competitive diving (springboard, platform) injuries and/or illnesses were eligible. Two independent reviewers screened for inclusion by title, abstract, and full text in accordance with the eligibility criteria. STUDY DESIGN: Systematic review. LEVEL OF EVIDENCE: Level 4. DATA EXTRACTION: Data extraction was completed by 1 author using a structured form. A second author then independently reviewed and verified the extracted data, any discrepancies were resolved through consensus. RESULTS: The search identified 2554 potential articles, with 28 studies meeting eligibility criteria. The surveillance setting of most studies was restricted to competition-based events, with the reported injury incidence proportion ranging from 2.1% to 22.2%. The reported injury incidence rate ranged from 1.9 to 15.5 per 1000 athlete-exposures. Injuries to the shoulder, lower back/lumbar spine, trunk, and wrist/hand were reported most frequently. The prevalence of low back pain was reported as high as 89% (lifetime), 43.1% (period), and 37.3% (point). The illness incidence proportion ranged from 0.0% to 22.2%, with respiratory and gastrointestinal illness reported most frequently. CONCLUSION: Up to 1 in 5 diving athletes sustain an injury and/or illness during periods of competition. A reporting bias was observed, with most cohort studies limiting surveillance to short competition-based periods only. This limits the current understanding of the health problems experienced by diving athletes to competition periods only and requires expansion to whole-of-year surveillance.

Estimating the cost of sports injuries: A scoping review.

OBJECTIVES: Provide an overview of the methods used to estimate the cost of sports-related injury published to date, and to highlight considerations and opportunities for future research. DESIGN: Scoping review. METHODS: Scopus, MEDLINE and CINHAL were searched from 1st January 2000 to 1st January 2023. Studies were screened by two independent reviewers and were eligible if they reported on a cost analysis or cost estimation of sports related injury. RESULTS: Thirty-one studies fulfilled the inclusion criteria. Twenty-seven studies (87 %) were published since 2014. The type of costs included direct healthcare costs (12 studies), indirect costs (10 studies) and a combination of both (9 studies). Twenty-one studies (68 %) used a bottom-up costing approach to measure costs of sports injury and estimated direct costs from the service rates or fee schedules of health systems, hospital, insurance companies or national insurance boards. A top-down approach was used in seven studies (23 %) to estimate the indirect salary cost of time-loss injuries using data from publicly available resources. Ten studies were from the cost perspective of a sporting organisation (32 %). There was a lack of explicit reporting of the costing method used and the perspective of those bearing the costs. CONCLUSIONS: Estimating the cost of sports injuries is an emerging area of research, with publications increasing in recent years. However, there remains a lack of methodological guidance to inform or appraise these studies. The expansion of established cost of illness checklists with sport injury explanations to guide future cost of sports injury studies is recommended.

Chronic Ankle Instability and Neuromuscular Performance in Prerecruitment Infantry Soldiers.

CONTEXT: Ankle instability can describe various impairments, including perceived instability (PI), mechanical instability (MI), and recurrent sprains (RSs), alone or combined. OBJECTIVE: To examine the prevalence of 8 ankle impairment subgroups and their effect on neuromuscular performance in prerecruitment combat soldiers. DESIGN: Cross-sectional study. SETTING: Military infantry basic training base. PATIENTS OR OTHER PARTICIPANTS: A total of 364 infantry male combat soldiers entering basic training (aged 18-21 years). MAIN OUTCOME MEASURE(S): Participants were assessed for PI (via the Cumberland Ankle Instability Tool), MI (using the Anterior Drawer Test and Medial Talar Tilt Test), and RSs (based on history) of their dominant and nondominant legs. Injuries were categorized in 8 subgroups: PI, RSs, PI + RSs, MI, PI + MI, MI + RSs, PI + MI + RSs, and none. Participants were screened for neuromuscular performance (dynamic postural balance, proprioceptive ability, hopping agility, and triceps surae muscle strength) during the first week of military basic training. RESULTS: For the dominant and nondominant legs, RSs were reported by 18.4% (n = 67) and 20.3% (n = 74) of the participants, respectively; PI was reported by 27.1% (n = 99) and 28.5% (n = 104) of the participants, respectively; and MI was seen in 9.9% (n = 36) and 8.5% (n = 31) of the participants, respectively. A 1-way analysis of variance showed differences in the mean proprioceptive ability scores (assessed using the Active Movement Extent Discrimination Apparatus) of all subgroups with impairments in both the dominant and nondominant legs (F = 6.943, η2 = 0.081, P < .001 and F = 7.871, η2 = 0.091, P < .001, respectively). Finally, differences were found in the mean muscle strength of subgroups with impairment in the nondominant leg (F = 4.884, η2 = 0.056, P = .001). CONCLUSIONS: A high prevalence of ankle impairments was identified among participants who exhibited reduced abilities in most neuromuscular assessments compared with those who did not have impairments. Moreover, participants with 1 impairment (PI, MI, or RSs) exhibited different neuromuscular performance deficits than those with >1 impairment.

Injury and illness in short-course triathletes: A systematic review.

BACKGROUND: Determining the incidence and prevalence of injury and illness in short-course triathletes would improve understanding of their etiologies and therefore assist in the development and implementation of prevention strategies. This study synthesizes the existing evidence on the incidence and prevalence of injury and illness and summarizes reported injury or illness etiology and risk factors affecting short-course triathletes. METHODS: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies reporting health problems (injury and illness) in triathletes (all sexes, ages, and experience levels) training and/or competing in short-course distances were included. Six electronic databases (Cochrane Central Register of Controlled Trials, MEDLINE, Embase, APA PsychINFO, Web of Science Core Collection, and SPORTDiscus) were searched. Risk of bias was independently assessed by 2 reviewers using the Newcastle-Ottawa Quality Assessment Scale. Two authors independently completed data extraction. RESULTS: The search yielded 7998 studies, with 42 studies eligible for inclusion. Twenty-three studies investigated injuries, 24 studies investigated illnesses, and 5 studies investigated both injuries and illnesses. The injury incidence rate ranged 15.7-24.3 per 1000 athlete exposures, and the illness incidence rate ranged 1.8-13.1 per 1000 athlete days. Injury and illness prevalence ranged between 2%-15% and 6%-84%, respectively. Most injuries reported occurred during running (45%-92%), and the most frequently reported illnesses affected the gastrointestinal (7%-70%), cardiovascular (14%-59%), and respiratory systems (5%-60%). CONCLUSION: The most frequently reported health problems in short-course triathletes were: overuse and lower limb injuries associated with running; gastrointestinal illnesses and altered cardiac function, primarily attributable to environmental factors; and respiratory illness mostly caused by infection.

Gender and socioecological level differences in stakeholders' perceptions of athlete attrition factors in an Australian high-performance pathway system.

OBJECTIVES: This study aimed to build on previous work by the authors. It examines how socioecological level and gender influence high-performance sport system (HPSS) stakeholders' perspectives of the relative importance and feasibility to address athlete attrition factors within an Australian high-performance pathway system (HPPS). DESIGN: Mixed methods. METHODS: Sub-analysis was conducted of rating data from 30 participants who had contributed to identifying 83 statements in 13 clusters in a previous Concept Mapping study. The 13 clusters were statistically analysed in 'R' using cumulative link mixed models (CLMMs) to determine differences in perceived importance and feasibility between 1) socioecological levels, and 2) genders. RESULTS: Mean ratings for 11 and three of the 13 clusters were statistically significantly different between at least two of the five socioecological levels, for importance and feasibility, respectively. Athletes had the largest variation in mean ratings from the most (athlete health 4.59), to least (performance potential 2.83) important cluster, when compared to the other four socioecological levels. There were statistically significant differences between the ratings between genders (Men/Women) for two clusters for each rating scale: Importance: 'athlete health' (M3.33:W3.84 [p 0.012]); 'performance potential' (M3.35:W2.57; [p 0.001]), Feasibility: 'abuse and mismanagement of health' (M2.97:W3.68; [p 0.000]) and 'athlete health' (M2.54:W3.33; [p 0.000]). CONCLUSIONS: This study highlights the need to implement more robust athlete attrition monitoring protocols. It also highlights the importance of listening to youth athletes' voices, and enabling equal gender representation to ensure holistically tailored environments are created to retain talented athletes in high-performance pathway programmes.

Validation of an instrumented mouthguard in rugby union-a pilot study comparing impact sensor technology to video analysis.

Background: To better understand the biomechanical profile of direct head impacts and the game scenarios in which they occur in Rugby Union, there is a need for an on-field validation of a new instrumented mouthguard (IMG) against the reference standard. This study considers the potential of a combined biomechanical (IMG) and video analysis approach to direct head impact recognition, both of which in isolation have limitations. The aim of this study is to assess the relationship between an instrumented mouthguard and video analysis in detection of direct head impacts in rugby union. Design: Pilot Study - Observational Cohort design. Methods: The instrumented mouthguard was worn by ten (3 backs, 7 forwards) professional Rugby Union players during the 2020-21 Gallagher Premiership (UK) season. Game-day video was synchronized with timestamped head acceleration events captured from the instrumented mouthguard. Direct Head Impacts were recorded in a 2 × 2 contingency table to determine sensitivity. Impact characteristics were also collected for all verified head impacts to further the understanding of head biomechanics during the game. Results: There were 2018 contact events that were reviewed using video analysis. Of those 655 were categorized as direct head impacts which also correlated with a head acceleration event captured by the IMG. Sensitivity analysis showed an overall sensitivity of 93.6% and a positive predictive value (PPV of 92.4%). When false positives were excluded due to ball out of play, mouthguard removal or handling after a scoring situation or stoppage, PPV was improved (98.3%). Most verified head impacts occurred in and around the ruck contest (31.2%) followed by impacts to the primary tackler (28.4%). Conclusion: This pilot validation study demonstrates that this IMG provides a highly accurate measurement device that could be used to complement video verification in the recognition of on-field direct head impacts. The frequency and magnitude of direct head impacts derived from specific game scenarios has been described and allows for greater recognition of high-risk situations. Further studies with larger sample sizes and in different populations of Rugby Union players are required to develop our understanding of head impact and enable strategies for injury mitigation.

The effect of compression and combined compression-tactile stimulation on lower limb somatosensory acuity.

Background: Lower limb somatosensation and proprioception are important for maintaining balance. Research has shown that compression garments or exposure to textured surfaces, can enhance somatosensation however, little is known about the effect of combined compression and texture on somatosensory acuity in the lower limb. This study aimed to assess the effects of combined compression socks with a plantar textured sole, on lower limb somatosensory acuity. Methods: Thirty participants completed a somatosensory acuity task (active movement extent discrimination apparatus; AMEDA) under three conditions: barefoot (control condition), standard knee-high compression sock (compression sock), and knee-high compression sock with internal rubber nodules situated on the sole (textured-compression sock). Somatosensory acuity was assessed between the different sock conditions for the (i) entire group, (ii) high performers, and (iii) low performers. It was hypothesized that low performers would see gains wearing either sock, but the greatest improvement would be in the textured-compression sock condition. Results: AMEDA scores were not significantly different between conditions when the entire group was analyzed (p = 0.078). The low performers showed an improvement in somatosensory acuity when wearing the compression sock (p = 0.037) and the textured compression sock (p = 0.024), when compared to barefoot, but there was no difference between the two sock conditions (p > 0.05). The high performers did not show any improvement (p > 0.05 for all). Conclusion: These findings demonstrate that additional sensory feedback may be beneficial to individuals with lower baseline somatosensory acuity but is unlikely to provide benefit for those with higher somatosensory acuity.

Multimodal physiological sensing for the assessment of acute pain.

Pain assessment is a challenging task encountered by clinicians. In clinical settings, patients' self-report is considered the gold standard in pain assessment. However, patients who are unable to self-report pain are at a higher risk of undiagnosed pain. In the present study, we explore the use of multiple sensing technologies to monitor physiological changes that can be used as a proxy for objective measurement of acute pain. Electrodermal activity (EDA), photoplethysmography (PPG), and respiration (RESP) signals were collected from 22 participants under two pain intensities (low and high) and on two different anatomical locations (forearm and hand). Three machine learning models were implemented, including support vector machines (SVM), decision trees (DT), and linear discriminant analysis (LDA) for the identification of pain. Various pain scenarios were investigated, identification of pain (no pain, pain), multiclass (no pain, low pain, high pain), and identification of pain location (forearm, hand). Reference classification results from individual sensors and from all sensors together were obtained. After feature selection, results showed that EDA was the most informative sensor in the three pain conditions, 93.2±8% in identification of pain, 68.9±10% in the multiclass problem, and 56.0±8% for the identification of pain location. These results identify EDA as the superior sensor in our experimental conditions. Future work is required to validate the obtained features to improve its feasibility in more realistic scenarios. Finally, this study proposes EDA as a candidate to design a tool that can assist clinicians in the assessment of acute pain of nonverbal patients.

Use of Dual-Task Timed-Up-and-Go Tests for Predicting Falls in Physically Active, Community-Dwelling Older Adults-A Prospective Study.

This prospective study aimed to determine which specific mobility tests were the most accurate for predicting falls in physically active older adults living in the community. Seventy-nine physically active older adults who met the American College of Sports Medicine physical activity guidelines volunteered. Participants were assessed and followed up for 12 months. Mobility assessments included the 30-s sit-to-stand test, five times sit-to-stand test, single-task timed-up-and-go test (TUG), motor dual-task TUG (Mot-TUG), and cognitive dual-task TUG (Cog-TUG). Mot-TUG and Cog-TUG performances were moderately correlated with number of falls (r = .359, p < .01 and r = .372, p < .01, respectively). When Mot-TUG, Cog-TUG, or Age were included as fall predictors, discrimination scores represented by the area under the receiver operating characteristic curve (AUC) were AUC (Mot-TUG) = 0.843 (p < .01), AUC (Cog-TUG) = 0.856 (p < .01), and AUC (Age) = 0.734 (p < .05). The cutoff point for Cog-TUG was 10.98 s, with test sensitivity of 1.00 and specificity of 0.66. Fall predictors for different populations may be based on different test methods. Here, the dual-task TUG test more accurately predicted falls in older adults who met American College of Sports Medicine's physical activity guidelines.

A systematic review of neurophysiological sensing for the assessment of acute pain.

Pain is a complex and personal experience that presents diverse measurement challenges. Different sensing technologies can be used as a surrogate measure of pain to overcome these challenges. The objective of this review is to summarise and synthesise the published literature to: (a) identify relevant non-invasive physiological sensing technologies that can be used for the assessment of human pain, (b) describe the analytical tools used in artificial intelligence (AI) to decode pain data collected from sensing technologies, and (c) describe the main implications in the application of these technologies. A literature search was conducted in July 2022 to query PubMed, Web of Sciences, and Scopus. Papers published between January 2013 and July 2022 are considered. Forty-eight studies are included in this literature review. Two main sensing technologies (neurological and physiological) are identified in the literature. The sensing technologies and their modality (unimodal or multimodal) are presented. The literature provided numerous examples of how different analytical tools in AI have been applied to decode pain. This review identifies different non-invasive sensing technologies, their analytical tools, and the implications for their use. There are significant opportunities to leverage multimodal sensing and deep learning to improve accuracy of pain monitoring systems. This review also identifies the need for analyses and datasets that explore the inclusion of neural and physiological information together. Finally, challenges and opportunities for designing better systems for pain assessment are also presented.

Developing a multivariate prediction model of falls among older community-dwelling adults using measures of neuromuscular control and proprioceptive acuity: A pilot study.

OBJECTIVE: To examine whether measures of neuromuscular control and proprioceptive acuity were predictive of falls in an older community-dwelling population and to develop a multivariate prediction model. METHODS: Fifty-eight adults aged above 60 living independently in the community were recruited for a prospective falls study. On entry, they undertook a Sensory Organisation Test (SOT) and an Active Movement Extent Discrimination Assessment (AMEDA) and completed a short fall risk questionnaire. Participants were monitored for falls over the subsequent 12 months. Prior to analysis, falls were classified into three categories based on the difficulty of the activity being undertaken and the demands of the environment in which the fall occurred. Logistic regression was used to predict the probability of a fall. RESULTS: For falls occurring under the least challenging circumstances, the model fitted using the AMEDA score and two of the questions from the fall risk questionnaire, related to balance and confidence, achieved a specificity of 87% and sensitivity of 83%. Falls occurring in more challenging circumstances could not be predicted with any accuracy based on the variables recorded at inception. CONCLUSIONS: This study highlights the importance of considering the heterogeneous nature of falls. Poorer proprioceptive acuity appears to play a role in falls occurring where neither the environment nor the activity is challenging, but not in falls occurring in other circumstances. Falls in the least-challenging circumstances affected 15% of participants, but this group was considerably more likely to have multiple falls, increasing their vulnerability to adverse consequences.

Exercise in bushfire smoke for high performance athletes: A Position Statement from the Australian Institute of SportEndorsed by Australasian College of Sport and Exercise Physicians (ACSEP) and Sport Medicine Australia (SMA).

OBJECTIVES: The frequency of bushfires in Australia is increasing and it is expected bushfire smoke will become a more prevalent phenomenon impacting air quality. The objective of this position statement is to provide guidance to the sport sector regarding exercise in air affected by bushfire smoke. DESIGN: This is position statement from the Australian Institute of Sport, based on a narrative review of the literature regarding bushfire smoke and its effects on health and exercise performance. METHODS: A narrative review of scientific publications regarding the effects of bushfire smoke on health and exercise performance. RESULTS: Bushfire smoke has negative impacts on health and performance. Athletes exercising at high intensity over a prolonged duration will increase their exposure to air pollutants. Athletes with a history of elevated airway responsiveness are likely to be at increased risk of an adverse response to bushfire smoke exposure. CONCLUSIONS: Athletes, coaches, support staff and sport organisations should monitor air quality (PM2.5 concentration) and make appropriate adjustments to training duration and intensity.

The Function of the Proprioceptive, Vestibular and Visual Systems Following Fatigue in Individuals With and Without Chronic Ankle Instability.

To maintain postural balance, the proprioceptive, vestibular, and visual systems continuously provide body position and movement data to the central nervous system. In this study, our main aim was to examine, for the first time, the influence of anaerobically or aerobically induced fatigue on these separate functions in persons with and without chronic ankle instability (CAI). We obtained assessments pre- and post-fatigue protocols from 60 physical education students (Mage = 24.3, SD = 3.4) Twenty-seven students had CAI, and 33 students did not have CAI). To measure proprioception, we used the AMEDA device; for vision, we used near point of convergence (NPC); and, for vestibular function, we used subjective visual vertical (SVV). We found a pre-post proprioception (AMEDA) effect in the aerobic group (p < .001), and a visual (NPC) effect in both anaerobic and aerobic participant groups (both p < .001). There were no visual system (NPC) fatigue effect differences among aerobic or anerobic participants who had or did not have CAI (p = .047); there was a significant aerobic fatigue effect on proprioception (AMEDA) (p = .010) that favored participants without CAI. There was a significant interaction effect between time of testing and CAI for visual (NPC) (p = .003) in the aerobic group only. In both the anaerobic and aerobic groups, post-fatigue vestibular function (AMEDA) was significantly lower for those with than those without CAI (anaerobic: p = .030; and aerobic: p =.016). Thus, post-fatigue, participants with CAI showed worse proprioceptive, visual, and vestibular function than those without CAI. Future investigators should further examine each movement sense system in individuals with CAI.

Achilles Tendon and Patellar Tendon Structure in Combat Soldiers Following Prevention Exercises.

INTRODUCTION: Military training that increases physical stress on musculoskeletal morphology also increases the risk of orthopedic injuries. Somatosensory prevention programs that reduce stress and improve functionality could be beneficial for better organization of tendon structure. The aim of this study was to investigate the impact of a somatosensory prevention exercise on the tendon structure (percentage of echo-type fibers; A-P and M-L diameters and cross-sectional area) of the Achilles tendon and patellar tendon among combat soldiers. MATERIALS AND METHODS: These tendons of male Infantry soldiers aged 18-21 were screened before and after a 14-week training course. The intervention group, who performed preventative exercises, included 108 soldiers (BMI = 23.85 ± 2.76), while the control group, who participated in the same military course without these exercises, included 98 soldiers (BMI = 24.26 ± 4.03). Ultrasound scanning for tendon structure included percent of echo-type I-IV fibers, A-P diameter, M-L diameter, and cross-sectional area parameters. RESULTS: Time by group interaction was found for echo-type I and II in both tendons. No significant differences were found between the two groups in the pretesting percentage of echo-type IV fibers of the Achilles tendon (P = .522), in echo-type III fibers of the Achilles tendon (P = .833), and echo-type IV fibers of the patellar tendon (P = .162). Greater pre-post differences in echo-type III and IV fibers were found in the control group compared with the intervention group for both the Achilles tendon (P = .021, P = .002) and the patellar tendon (P < .001, P < .001). CONCLUSION: Increased damaged fibers (echo-type III and IV) of both tendons were found among the control group, yet not among soldiers who performed prevention exercises.

Another Look at Fatigued Individuals with and without Chronic Ankle Instability: Posturography and Proprioception.

Fatigue can impair function of the three sensory systems (vestibular, visual, and somatosensory) that control postural balance. Yet impairment may be greater among individuals with than those without chronic ankle instability (CAI). The present study used posturography assessment to extend previous findings demonstrating reduced function of the three systems in CAI participants following fatigue. Our aim in this study was to examine the influence of anaerobic and aerobic protocols on the function of these three sensory systems in individuals with and without CAI. We assessed 60 healthy physical education students (Mage = 24.3, SD = 3.4) by a Tetrax® Posturography device for Stability-Index and Fourier-frequencies [low sway (F1) visual input, medium-low sway (F2-F4) vestibular input, medium-high sway (F5-F6) somatosensory input] and by the Active Movement Extent Discrimination Assessment (AMEDA) for active ankle somatosensory ability, before and after performing anaerobic or aerobic protocols. Among participants, 45% were identified with CAI. We found significant Time effect (pre-post), CAI effect, and CAI X Time interactions for Fourier frequencies, Stability-Index, and AMEDA scores, indicating greater pre-post deterioration for those with CAI compared to those without CAI (p < .05). CI (95%) showed that, although there was a Time effect for F1, F2-F4, and F5-F6, only F5-F6 frequencies (i.e., somatosensory input) showed the CAI effect and the Time X CAI interaction. Thus, participants with and without CAI showed reduced visual, vestibular, and somatosensory ability following fatigue. While we found greater deterioration in both passive and active somatosensory ability (F5-6 and AMEDA) among individuals with CAI compared with those with no-CAI, we recommend intervention programs for improving vestibular abilities following fatigue in both those with and without CAI.

Can ankle proprioception be improved by repeated exposure to an ankle movement discrimination task requiring step-landing in individuals with and without CAI?

OBJECTIVES: To determine whether individuals with and without Chronic Ankle Instability (CAI) can improve their ankle movement discrimination sensitivity by repeated exposure to an ankle proprioceptive task requiring landing. DESIGN: A repeated-measures study. SETTING: University laboratory. PARTICIPANTS: 24 university students, 11 with CAI and 13 without CAI. MAIN OUTCOME MEASURES: Ankle proprioception was measured using the Ankle Inversion Discrimination Apparatus for Landing (AIDAL) over 3 occasions: AIDAL-1 and AIDAL-2 separated with a 10-min interval, and AIDAL-3 at 24 h post AIDAL-2. RESULTS: Better Cumberland Ankle Instability Tool (CAIT) questionnaire scores were correlated with higher AIDAL scores (rho = 0.465, p = 0.022). Two-way ANOVA showed a significant CAI main effect for step landing ankle inversion proprioception, with CAI worse (F = 8.410, p = 0.008), but the Time main effect across the 3 AIDAL tests was not significant (F = 1.552, p = 0.223). CONCLUSIONS: The AIDAL assessment was sensitive in terms of discriminating between individuals with or without CAI. However, the step-down component of the AIDAL proprioceptive task was possibly too challenging. For CAI, physical therapy exercises should take into account the difficulty of the training task, so that a demonstrable learning effect can be achieved.

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.

The impact of unexpected platform perturbation on ankle proprioception ability in static and dynamic starting positions.

AIMS: To examine the relationship between ankle proprioception and the ability to maintain balance with increased magnitudes of unexpected perturbations; and to compare the participants' ability to maintain balance following perturbations when starting from static and dynamic positions. METHODS: Sixty physical education students (average 24.6 years) were tested for proprioception ability (AUC scores) and balance challenges presented on a perturbation treadmill. The degree at which participants lost postural balance was recorded in seven starting positions: standing-eyes-open (SO), standing-eyes-closed (SC), tandem-dominant (TD), tandem non-dominant, (TND) single-leg lateral side perturbation (SLP), single-leg medial side perturbation (SMP), and walking. Perturbation scores were analysed divided by tertiles. Multidimensional Unfolding SPSS Statistics 25 (PREFSCAL) was used to examine the relationships between data sets. RESULTS: AUC scores of both dominant and non-dominant legs were significantly correlated with SO (r = 0.316; r = 0.445), SC (r = 0.364; r = 0.413), TD (r = 0.346; r = 0.308), and walking (r = 0.265; r = 0.439), respectively. In the dominant-leg, AUC scores of individuals with below-median SO scores were significantly worse compared to those with median SO scores (p = .046). In the non-dominant leg, individuals with above-median SC had significantly better AUC scores compared to those with lower-than-median SC (p = .008). Those with median and above-median SO and walking achieved better AUC scores than those with below-median (SO: p = .049, p = .004; walking: p = .016, p < .001, respectively). In dimension I, the SLP and SMP were located opposite one another; in dimension II, the TD and TND were located at the upper side, whereas SC, SO and walking were at the lowest side. CONCLUSIONS: AUC scores were significantly correlated with the level at which postural balance was lost, whereby the better the proprioception ability, the better the ability to maintain balance. As such, the ability to maintain balance is harder in tandem positions than in standing and walking positions. This ability differed when perturbations were to the lateral or medial sides.