Directional deficits in reactive postural control during perturbations among groups of chronic ankle instability, ankle sprain coper, and healthy control

doi:10.21203/rs.3.rs-4829344/v1

Unanticipated postural control measures may better identify mechanisms of ankle sprains in real-life situations. The purpose of this study was to identify directional deficits in reactive postural control during horizontal perturbations among groups of chronic ankle instability (CAI), ankle sprain coper, and healthy control. Sixty-eight volunteers (24 CAI patients, 23 ankle sprain copers, and 21 healthy controls) participated in this study. The participants performed a single-leg stance with unanticipated horizontal perturbations in four random directions of anterior, posterior, medial, and lateral. Anterior-posterior time to stabilization (APTTS) and medial-lateral time to stabilization (MLTTS) were calculated as an indicator of reactive postural control during horizontal perturbations. A significant interaction effect of the group x perturbation directions (3 x 4) was found. Both CAI and coper groups showed longer APTTS and MLTTS during medial and lateral horizontal perturbations compared to the control group. However, no difference was found in APTTS and MLTTS during anterior and posterior horizontal perturbations between three groups. Directional deficits in reactive postural control during medial and lateral perturbations could result from reflexive sensorimotor deficits as consequences of lateral ankle sprains in the coper and CAI groups.

lateral ankle sprain

time to stabilization

reflex

balance

motor response

Chronic ankle instability (CAI) is a condition of chronic residual symptoms resulting from the interaction of pathomechanical, sensory-perceptual, and motor-behavioral impairments following a lateral ankle sprain (LAS).¹ However, some individuals with a history of LAS show no chronic residual symptoms following their initial LAS, who are called ankle sprain copers.² Up to 70% of individuals with LAS develop into CAI,³ and up to 78% of CAI patients would have ankle articular cartilage degradation like posttraumatic ankle osteoarthritis after 10 years post LAS.⁴

A postural control deficit is one of the six components in the motor-behavioral impairment domain.¹ Importantly, postural control deficits are one of the strongest predictors and risk factors for LAS and CAI.⁵ Time to stabilization (TTS) has been the most reliable measure to identify postural control deficits in individuals with and without CAI.⁶ The TTS is the ability to maintain the equilibrium condition as quickly as possible following anticipated postural sway during jump landing and/or drop landing.⁷ The longer TTS during landing could be a result of sensorimotor control deficits.⁷

CAI patients showed longer TTS during single-leg jump landing compared to ankle sprain copers and/or healthy controls while no postural control deficit in TTS was observed during single-leg drop landing in ankle sprain copers.^6,8,9 However, postural control measures of TTS in the previous studies were conducted under a controlled, anticipated, and predicted condition where a participant could predict and prepare for their jump landing and/or drop landing tasks.^6,8,9 In addition, a single-leg stance (SLS) test was widely used to assess one’s postural control capacity in CAI and ankle sprain coper studies.^10–12 The ankle sprain copers show no postural control deficits during the SLS test.^10–12

Here are some limitations in the current literature. Both static (SLS) and dynamic (jump landing) postural control tasks may not replicate the actual mechanisms of LAS injury. The task demand of the static SLS task may be too easy to identify postural control deficits in ankle sprain copers. The dynamic jump landing task for TTS was conducted in anticipated condition. These two measures may not replicate actual LAS mechanisms as the ankle sprain occurs during sudden, uncontrolled, unanticipated situations in real-life. As LAS injury occurs in a combination of foot adduction, inversion, and/or internal rotation,¹³ it could be reasonable that individuals with a history of LAS would have directional deficits in postural control.

To fill the current research gaps, postural control measures should be more challenging and unanticipated by giving sudden horizontal perturbations in several directions. Identifying directional postural control deficits during perturbations could help better understand mechanisms of the LAS. Therefore, the purpose of this study was to identify directional deficits in reactive postural control during horizontal perturbations in SLS among groups of CAI, coper, and control. Based on the previous study,⁶ we hypothesized that only CAI patients would show directional deficits in reactive postural control (longer TTS) in four perturbation directions compared to copers and controls.

Interaction effect (group x perturbation direction) and main effect

The results of an interaction effect and a main effect are shown in Table 3. We found a significant interaction between the group and the perturbation direction. In addition, we found a significant main effect for the group and the perturbation direction. The results of post-hoc pairwise comparisons are shown in Fig. 2 and Table 3.

CAI group vs. healthy control group

Compared to the healthy control group, the CAI group showed longer APTTS and MLTTS during medial perturbation. Compared to the healthy control group, the CAI group showed longer APTTS and MLTTS during lateral perturbation. However, no significant interaction effect was found in the APTTS and MLTTS during anterior and posterior perturbation, respectively.

Ankle sprain coper group vs. healthy control group

Compared to the healthy control group, the ankle sprain coper group showed longer APTTS and MLTTS during medial perturbation. Compared to the healthy control group, the ankle sprain coper group showed longer APTTS and MLTTS during lateral perturbation. However, no significant interaction effect was found in the APTTS and MLTTS during anterior and posterior perturbation, respectively.

CAI group vs. ankle sprain coper group

No significant interaction effect was found in the APTTS and MLTTS during anterior, posterior, medial, and lateral perturbation, respectively.

This study was designed to examine reactive postural control among groups of CAI, ankle sprain coper, and healthy control. This study used a customized robotic-based force plate platform to identify directional deficits in reactive postural control by giving sudden, unanticipated horizontal perturbations into a direction of anterior, posterior, medial, and lateral, respectively (Fig. 1). Reactive postural control was identified by APTTS and MLTTS from anterior-posterior GRF and medial-lateral GRF as how quickly a participant was able to stabilize their balance following the horizontal perturbations during SLS. We hypothesized that CAI patients would show directional postural control deficits in both APTTS and MLTTS during horizontal perturbations compared to coper and control groups. Overall, current results partially support our hypotheses. First, CAI patients demonstrated longer APTTS and MLTTS during medial and lateral horizontal perturbations (Fig. 2). Second, as opposed to our hypothesis, ankle sprain copers who had a history of ankle sprains also show the same sensorimotor deficits (Fig. 2). Third, both CAI and ankle sprain coper groups show no sensorimotor deficits in APTTS and MLTTS during anterior and posterior horizontal perturbations (Fig. 2). These findings suggest that individuals with a history of ankle sprains (CAI patients and ankle sprain copers) appear to have directional balance deficits during horizontal perturbations in the frontal-plane, but not in the sagittal-plane.

Our finding is consistent with previous literature that CAI patients demonstrated longer TTS compared to healthy controls.^6,8,9 Most previous studies used single-leg jump-landing or drop landing tasks to identify dynamic postural control, which is defined as the ability to exert ongoing adjustment of center of mass when the base of support changes.^6,8,9 However, conflicting results exist in directional deficits of postural control in individuals with and without CAI.^14–20 For example, three studies^14–16 reported longer TTS in both anterior-posterior and medial-lateral directions in CAI patients during single-leg jump landing or drop landing tasks while two studies reported longer TTS in the anterior-posterior^17,18 and medial-lateral directions,^19,20 respectively. In contrast to previous findings,^14–20 we found reactive postural control deficits in the frontal-plane only during sudden, unanticipated horizontal perturbations in CAI patients. This finding has important clinical implications. Clinicians often utilize various dynamic balance training in clinical settings using a foam pad, wobble board, BAPS board, and/or BOSU ball for ankle sprain injury patients. However, no specific balance training guidelines have been reported in the literature associated with directional deficits in reactive postural control for this injured population. Thus, clinicians need to improve postural control deficiencies in the frontal-plane by giving sudden, unanticipated perturbations to improve reactive sensorimotor responses.

In this study, the ankle sprain copers demonstrated reactive postural control deficits during medial and lateral horizontal perturbations. Previous studies on postural control with ankle sprain copers show conflicting results.^20–23 A recent systematic review reports that ankle sprain copers show a postural control ability similar to healthy individuals during static SLS, dynamic SEBT, and gait termination tasks.²¹ On the other hand, several studies reported sensorimotor deficits in ankle sprain copers during dynamic single-leg jump landing or drop landing tasks.^20,22,23 For example, Wikstrom et al.²² reported that coper and CAI groups show greater anterior-posterior stability index and dynamic postural stability index during forward single-leg jump landing compared to the control group. The coper group show the greatest scores (impaired postural control) for all dynamic postural stability variables among three groups. In addition, Wright et al.²⁰ reported ankle sprain copers show sensorimotor deficits in the sagittal-plane during forward single-leg drop landing compared to the CAI and control groups, but not in the frontal-plane. Similarly, Watabe et al.²³ reported that coper group found longer APTTS and anterior-posterior maximal COP excursion during forward, lateral, and diagonal single-leg drop landing compared to the control group. These findings suggest that ankle sprain copers may potentially have sensorimotor deficits in the sagittal-plane rather than the frontal-plane. However, sensorimotor deficits in the sagittal-plane may result from the jump-landing direction in which the task is performed. For example, Wikstrom et al.²⁴ found that in healthy individuals, lateral and diagonal jump-landings produced increased medial-lateral stability index scores and forward jump-landing produced increased vertical stability index scores. They suggest that jump-landing protocol direction affects dynamic postural control. This effect could be compounded in individuals with lower limb impairments.²⁴ Further, this idea is supported by previous studies demonstrated the effect of jump-landing direction on dynamic postural control in healthy individuals,^24,25 as well as in patients with CAI²⁶ and anterior cruciate ligament reconstruction.²⁷ In this sense, sensorimotor deficits in the frontal-plane during horizontal perturbation were a result of a novel testing protocol. Importantly, unanticipated perturbation could be key to differentiating whether ankle sprain copers would have reactive postural control deficits or not.

Observed directional deficits in reactive postural control in both CAI and ankle sprain coper groups could be associated with a common continuum of disability following LAS injury.²⁸ Cascading events following LAS injury include ligament damage (anterior talofibular ligament [ATFL] and calcaneofibular ligament [CFL]), impaired sensory pathways to the brain, surrounding ankle structural changes, inhibition of spinal reflexes, and/or impaired sensorimotor control.²⁸ Importantly, impaired reactive postural control during frontal-plane perturbations could result from consequences of structural ligament damage in the frontal-plane for individuals with LAS injury. To support the current finding the underlying potential mechanisms of LAS injury is required. LAS injury results in damage of static stabilizers of the ankle such as ATFL and CFL.^13,29 These ligaments provide static stability of the ankle in the frontal-plane.^13,29 Unfortunately, this could result in increased pathologic talocrural joint and ligament laxity (ATFL and CFL) in both the anterior-posterior direction and medial-lateral directions.^30–32 This mechanical ankle instability could, in turn, lead to sensorimotor control deficiencies.^1,13,28 This idea is supported by previous studies demonstrated postural control deficits after lateral ankle ligamentous structures (ATFL, CFL, lateral ankle capsule, and peroneal tendons) anesthesia in healthy individuals.^33,34 In addition, a sensorimotor postural control deficit was reported in CAI patients with mechanical ankle instability during SLS (increased center of pressure [COP] excursion and area)^35,36 and single-leg jump landing (greater dynamic postural stability index scores).³⁷ Further, increased anterior and posterior joint laxity of the ankle was correlated with increased COP area during SLS and a shorter posterolateral reach during the SEBT.³⁸ Based on previous studies,^33–38 impaired postural control during medial and lateral horizontal perturbations in this study could be linked with the structural damage associated cascade of events related to LAS injury.^1,13,28

Impaired reactive postural control in the medial and lateral perturbations is likely a result of somatosensory dysfunction in CAI patients.¹ Besides mechanical structural alterations of the ankle in the frontal-plane, associated sensorimotor deficits could explain why both CAI and ankle sprain coper groups would have directional deficits in reactive postural control during medial and lateral perturbations. For example, the peroneus longus and brevis can play a key role in protective ankle dynamic stabilization in the frontal-plane through the fast reactive sensorimotor response.³⁹ Reactive sensorimotor response is modulated by a short latency spinal reflex.⁴⁰ As no study has investigated the effect of directional perturbations on TTS during SLS the current finding of postural control deficits in the frontal-plane may be supported by other similar studies using perturbations during walking⁴⁰ and standing.⁴¹ For walking, Hopkins et al.⁴⁰ used customized trapdoor walkway platforms where sudden, unanticipated inversion perturbations were applied to CAI patients during walking. The CAI patients show a delayed motor response and electromechanical delay of the peroneal longus and brevis compared to the uninjured leg in CAI patients and healthy controls.⁴⁰ For standing, Mitchell et al.⁴¹ also reported slowed motor response of the peroneus longus and brevis in CAI patients. Reduced spinal neural excitability and/or reactive motor responses of ankle musculature in the frontal-plane seem to be evident in CAI patients, and this sensorimotor deficit in the frontal-plane is strongly supported by a recent systematic review with meta-analyses.^39,42 In addition, reduced motor activation of frontal-plane muscle groups is also evident during walking⁴³ and jump landing and cutting⁴⁴ in which the distal (peroneus longus) and proximal (gluteus medius) muscle activation were both negatively affected in the frontal-plane. The recent systematic review with meta-analysis also supports sensorimotor deficits in the frontal-plane muscles including ankle evertors and hip abductors in CAI patients.⁴⁵ Therefore, observed postural control deficits during frontal-plane perturbations could be due to consequences of LAS injury.^39–45

This study has some limitations. First, we did not collect biomechanical data using motion capture systems (force plates, high-speed cameras, and EMG sensors), which would limit a view of neuromuscular control deficits. Second, as the current research was conducted in a university setting with collegiate students, current findings shouldn’t be inferred to other adolescent and/or older age populations.

In conclusion, TTS is a reliable measure to assess one’s postural control ability. However, most previous studies in postural control examined COP based variables during static SLS. This study is novel as we used the robotic-based perturbation force plate platform, which enables us to create sudden, unanticipated horizontal perturbations in four directions. As such this study examined directional postural control deficits in CAI, ankle sprain coper, and control groups. Our results show that CAI and coper groups had longer APTTS and MLTTS only during medial and lateral perturbations, but not anterior and posterior perturbations. These findings indicate directional deficits in reactive postural control for those who had a history of LAS injury (CAI and coper). For clinicians, individuals with a history of LAS injury (CAI patients and ankle sprain copers) would have sensorimotor dysfunction in reactive postural control, especially in the frontal-plane. Therefore, clinicians should provide perturbation balance training to increase sensorimotor deficits in the frontal-plane.

Research design

The research design was a case-control laboratory trial. Participants completed a single data collection session in a biomechanics laboratory. The independent variables were group (CAI, ankle sprain coper, and healthy control) and perturbation directions (anterior, posterior, medial, and lateral). The dependent variables were anterior-posterior time to stabilization (APTTS) and medial-lateral time to stabilization (MLTTS) from x- and y-axis of ground reaction force (GRF).

Participants

A total of 68 physically active individuals: 24 CAI patients, 23 ankle sprain copers, 21 healthy controls were recruited with an age of 18 to 45 years (Table 1). A priori sample size was calculated using G*Power ver. 3.1.9.4 (Franz Faul, Universität Kiel, Germany; Test family = t-tests; Statistical test = Means: Difference between two independent means; Type of power analysis = α priori). Based on a previous study investigating postural control among groups of CAI, coper, and control,¹⁰ a feasible sample size of 68 participants was selected based on Cohen’s d = 0.70, α error probability = 0.05, and power (1-β error probability) = 0.80. Inclusion and exclusion criteria for the CAI and ankle sprain coper groups were based on the suggested criteria from the International Ankle Consortium.⁴⁶ Participants were identified using the Foot and Ankle Ability Measure⁴⁷ and the Modified Ankle Instability Instrument⁴⁸ questionnaires. Specific inclusion and exclusion criteria for each group are presented in Table 2. All participants provided written informed consent prior to their participation as approved by the University Institutional Review Board. This study was conducted in accordance with the Declaration of Helsinki.

Table 1

Participant demographics. *ADL* activities of daily living, *FAAM* foot and ankle ability measure, *MAII* modified ankle instability instrument, *No.* number, SD standard deviation. ^a Indicates a significant difference between the chronic ankle instability and healthy control group. ^b Indicates a significant difference between the chronic ankle instability and ankle sprain coper group. ^c Indicates a significant difference between the ankle sprain coper and healthy control group.
Characteristic	Group, Mean (SD)			F_2,65	P
Characteristic	Chronic Ankle Instability	Ankle Sprain Coper	Healthy Control	F_2,65	P
Sex (male/female)	12/12	12/11	10/11
Age (years)	30.08 (4.21)	29.30 (4.11)	31.05 (4.30)	0.95	0.39
Height (cm)	172.67 (8.50)	169.83 (7.87)	170.86 (8.50)	0.71	0.50
Mass (kg)	69.33 (13.83)	68.00 (15.36)	65.81 (12.58)	0.36	0.70
FAAM ADL (%)	80.33 (9.31)	98.30 (2.20)	100	85.17	< 0.01^a,b
FAAM Sport (%)	60.42 (13.91)	94.43 (5.15)	100	137.00	< 0.01^a,b
MAII (No. yes)	3.50 (1.06)	0	0	237.79	< 0.01^a,b
Ankle sprains (No.)	5.63 (3.92)	1.17 (0.94)	0	35.31	< 0.01^a,b
Failed trials (No.)	4.29 (1.55)	3.91 (1.38)	1.24 (0.94)	34.34	< 0.01^a,c

Table 2

Inclusion and exclusion criteria for patients with chronic ankle instability and/or ankle sprain coper. *ADL* activities of daily living, *FAAM* foot and ankle ability measure, *LAS* lateral ankle sprain, *MAII* modified ankle instability instrument.
Inclusion criteria
Chronic ankle instability	Ankle sprain coper	Healthy control
1. A history of at least ≥ 1 severe LAS, which was associated with inflammatory symptoms like pain, swelling, loss of function, etc. 2. The initial LAS must have occurred at least 12 months prior to the study. 3. The initial LAS was required immobilization and/or non-weight bearing for ≥ 3 days or external supports for ≥ 7 days or both. 4. The most recent LAS must have occurred more than 3 months prior to the study. 5. Participants should report at least 2 ‘giving way’ episodes in the 6 months prior to the study. 6. MAII: ≥2 ‘yes’ answers on questions 4 to 8. (self-reported ankle instability) 7. FAAM ADL: <90% (self-reported ankle function) 8. FAAM Sport: <80% (self-reported ankle function)	1. A history of at least ≥ 1 severe LAS, which was associated with inflammatory symptoms like pain, swelling, loss of function, etc. 2. The initial LAS must have occurred at least 12 months prior to the study. 3. The initial LAS was required immobilization and/or non-weight bearing for ≥ 3 days or external supports for ≥ 7 days or both. 4. A return to moderate levels of weight-bearing physical activity without chronic residual symptoms within 12 months. 5. MAII: No ‘yes’ answers on questions 4 to 8. (self-reported ankle instability) 6. FAAM ADL: ≥90% (self-reported ankle function) 7. FAAM Sport: ≥80% (self-reported ankle function)	1. No history of LAS. 2. MAII: No ‘yes’ answers on questions 4 to 8. 3. FAAM ADL: 100% 4. FAAM Sport: 100%
Exclusion criteria
1. A history of previous surgeries (eg., bones, joint structures, and/or nerves). 2. A history of fractures in the lower extremity. 3. A history of neurological disorders. 4. Acute injury to musculoskeletal structures in the lower extremity in the past 3 months.

Experimental procedures

Anthropometric data including age, height, and mass were recorded for each participant (Table 1). We examined reactive postural control during the SLS by giving sudden, unanticipated horizontal perturbations in four random directions (anterior, posterior, medial, and lateral) using a robotic-based force plate platform (XY stage). The XY stage was customized and developed to allow the platform to perform linear translation into 8 directions (the same directions of the star excursion balance test [SEBT]) by the Department of Robotics and Mechatronics at XXX.⁴⁹ The magnitude of the robotic-based perturbation device was controlled by time (0.1–2.0 sec), frequency (0.5–5.0 Hz), and a maximal distance of 90 mm. Testing protocols were selected based on pilot data collection with a time of 0.4 sec, 2.5 Hz, and distance of 30 mm. Prior to actual data collection, participants performed at least 3 practice trials in each of four perturbation directions to reduce learning effects in postural control measures. Participants performed 20 sec trials of SLS with barefoot on a force plate platform with eyes open. Participants maintained their hands on their iliac crest, their non-weight-bearing leg of 30 deg of hip flexion, and 90 deg of knee flexion.⁵⁰ The weight-bearing leg was fully extended at the knee, and the foot was in a neutral position with the second toe and the center of the heel aligned vertically. They were instructed to remain as motionless as possible while focusing on a visual target placed 5 m in front of them (Fig. 1). We examined a total of 15 trials, including 12 successful trials (three trials per four perturbation directions) and 3 dummy trials to ensure that participants could not predict the perturbation directions. The perturbation directions were randomized for each participant using a random function in Excel. The onset of initial perturbation was given to participants within 5–10 sec once the participant set their SLS position. The participants hold their SLS position for 10–15 sec after the end of the perturbation. There was a 60 sec rest period between each trial to minimize fatigue effects. The current testing protocol took us around and/or over 1-hour per participant including the practice (12 trials) and testing (15 trials) sessions with a 60-sec resting period and failed trials (1–7 trials per participant). We followed failed trials based on the balance error scoring system including (i) moving the hands off of the iliac crest, (ii) a step, stumble, or fall, (iii) abduction or flexion of their hip or trunk more than 30°, (iv) lifting the forefoot or heel off from the force plate, and (v) being unable to remain a SLS position less than 20 seconds.⁵⁰ If failed trials occurred, the testing trial was repeated until 3 successful testing trials were obtained in all four directions. An average of failed trials in each group is presented in Table 1.

Data analysis

Raw GRF data of x- and y-axis were analyzed using a custom-written MATLAB code (MathWorks Inc., Natick, MA, US). Sampling rate for GRF data was set at 1000 Hz. APTTS and MLTTS were calculated through the technique of sequential estimation, using an algorithm to calculate a cumulative average of the data points from the SLS trials in series by successively adding in one point at a time.⁵¹ This cumulative average was then compared against the overall series mean of the GRF.⁵¹ The series consists of all data points collected during the 10-second period after the end of perturbation.⁵¹ The participant was considered to stable position when the sequential average remained within 0.25 standard deviations of the overall series mean.⁵¹ An average of three successful trials in each of four perturbation directions were used for statistical analyses.

Statistical analysis

All data analyses were performed using JMP Pro 17 software (SAS Institute Inc., Cray, NC, US). A 3x4 two-way repeated measures analysis of variances were used to examine an interaction of the group (CAI, ankle sprain coper, and healthy control) by perturbation direction (anterior, posterior, medial, and lateral). Tukey honest significant difference post-hoc tests were used for pairwise comparisons. The effect sizes of repeated measures analysis of variances were calculated as partial eta squared. Effect sizes were interpreted as ≥ 0.01 was small, ≥ 0.06 was medium, and ≥ 0.14 was large.⁵² A significant level was set at < 0.05.

Acknowledgements

The authors thank the participants for their contributions.

Author contributions

M.K. wrote the manuscript, S.K. collected the data, J.K., W.C., and S.O. analyzed and interpreted the data, J.T.H. reviewed and edited the manuscript, S.J.S. designed the study. All authors critically revised and approved the final manuscript.

Data available statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

Additional information

The authors declare no competing interests.

Hertel, J. & Corbett, R. O. An updated model of chronic ankle instability. J Athl Train 54, 572-588, doi:10.4085/1062-6050-344-18 (2019).
Wikstrom, E. A. & Brown, C. N. Minimum reporting standards for copers in chronic ankle instability research. Sports Med 44, 251-268, doi:10.1007/s40279-013-0111-4 (2014).
Herzog, M. M., Kerr, Z. Y., Marshall, S. W. & Wikstrom, E. A. Epidemiology of ankle sprains and chronic ankle instability. J Athl Train 54, 603-610, doi:10.4085/1062-6050-447-17 (2019).
Valderrabano, V., Hintermann, B., Horisberger, M. & Fung, T. S. Ligamentous posttraumatic ankle osteoarthritis. Am J Sports Med 34, 612-620, doi:10.1177/0363546505281813 (2006).
Delahunt, E. & Remus, A. Risk factors for lateral ankle sprains and chronic ankle instability. J Athl Train 54, 611-616, doi:10.4085/1062-6050-44-18 (2019).
Thompson, C. et al. Factors contributing to chronic ankle instability: A systematic review and meta-analysis of systematic reviews. Sports Med 48, 189-205, doi:10.1007/s40279-017-0781-4 (2018).
Fransz, D. P., Huurnink, A., de Boode, V. A., Kingma, I. & van Dieën, J. H. Time to stabilization in single leg drop jump landings: an examination of calculation methods and assessment of differences in sample rate, filter settings and trial length on outcome values. Gait Posture 41, 63-69, doi:10.1016/j.gaitpost.2014.08.018 (2015).
Simpson, J. D., Stewart, E. M., Macias, D. M., Chander, H. & Knight, A. C. Individuals with chronic ankle instability exhibit dynamic postural stability deficits and altered unilateral landing biomechanics: A systematic review. Phys Ther Sport 37, 210-219, doi:10.1016/j.ptsp.2018.06.003 (2019).
Chan, L. Y. T., Sim, Y. T. N., Gan, F. K. & Bin Abd Razak, H. R. Effect of chronic ankle instability on lower extremity kinematics, dynamic postural stability, and muscle activity during unilateral jump-landing tasks: A systematic review and meta-analysis. Phys Ther Sport 55, 176-188, doi:10.1016/j.ptsp.2022.04.005 (2022).
Wikstrom, E. A., Fournier, K. A. & McKeon, P. O. Postural control differs between those with and without chronic ankle instability. Gait Posture 32, 82-86, doi:10.1016/j.gaitpost.2010.03.015 (2010).
Terada, M. et al. Nonlinear dynamic measures for evaluating postural control in individuals with and without chronic ankle instability. Motor Control 23, 243-261, doi:10.1123/mc.2017-0001 (2019).
Mohamadi, S. et al. Attentional demands of postural control in chronic ankle instability, copers and healthy controls: A controlled cross-sectional study. Gait Posture 79, 183-188, doi:10.1016/j.gaitpost.2020.03.007 (2020).
Hertel, J. Functional anatomy, pathomechanics, and pathophysiology of lateral ankle instability. J Athl Train 37, 364-375 (2002).
Ross, S. E. & Guskiewicz, K. M. Examination of static and dynamic postural stability in individuals with functionally stable and unstable ankles. Clin J Sport Med 14, 332-338, doi:10.1097/00042752-200411000-00002 (2004).
Ross, S. E. & Guskiewicz, K. M. Effect of coordination training with and without stochastic resonance stimulation on dynamic postural stability of subjects with functional ankle instability and subjects with stable ankles. Clin J Sport Med 16, 323-328, doi:10.1097/00042752-200607000-00007 (2006).
Ross, S. E., Guskiewicz, K. M., Gross, M. T. & Yu, B. Balance measures for discriminating between functionally unstable and stable ankles. Med Sci Sports Exerc 41, 399-407, doi:10.1249/MSS.0b013e3181872d89 (2009).
Brown, C., Ross, S., Mynark, R. & Guskiewicz, K. Assessing functional ankle instability with joint position sense, time to stabilization, and electromyography. J Sport Rehabil 13, 122-134, doi:10.1123/jsr.13.2.122 (2004).
Gribble, P. A. & Robinson, R. H. Alterations in knee kinematics and dynamic stability associated with chronic ankle instability. J Athl Train 44, 350-355, doi:10.4085/1062-6050-44.4.350 (2009).
Marshall, P. W., McKee, A. D. & Murphy, B. A. Impaired trunk and ankle stability in subjects with functional ankle instability. Med Sci Sports Exerc 41, 1549-1557, doi:10.1249/MSS.0b013e31819d82e2 (2009).
Wright, C. J., Arnold, B. L. & Ross, S. E. Altered kinematics and time to stabilization during drop-jump landings in individuals with or without functional ankle instability. J Athl Train 51, 5-15, doi:10.4085/1062-6050-51.2.10 (2016).
Yu, P., Mei, Q., Xiang, L., Fernandez, J. & Gu, Y. Differences in the locomotion biomechanics and dynamic postural control between individuals with chronic ankle instability and copers: A systematic review. Sports Biomech 21, 531-549, doi:10.1080/14763141.2021.1954237 (2022).
Wikstrom, E. A. et al. Dynamic postural control but not mechanical stability differs among those with and without chronic ankle instability. Scand J Med Sci Sports 20, e137-144, doi:10.1111/j.1600-0838.2009.00929.x (2010).
Watabe, T., Takabayashi, T., Tokunaga, Y. & Kubo, M. Copers adopt an altered dynamic postural control compared to individuals with chronic ankle instability and controls in unanticipated single-leg landing. Gait Posture 92, 378-382, doi:10.1016/j.gaitpost.2021.12.014 (2022).
Wikstrom, E. A., Tillman, M. D., Schenker, S. M. & Borsa, P. A. Jump-landing direction influences dynamic postural stability scores. J Sci Med Sport 11, 106-111, doi:10.1016/j.jsams.2007.02.014 (2008).
Liu, K. & Heise, G. D. The effect of jump-landing directions on dynamic stability. J Appl Biomech 29, 634-638, doi:10.1123/jab.29.5.634 (2013).
Wikstrom, E. A., Tillman, M. D., Chmielewski, T. L., Cauraugh, J. H. & Borsa, P. A. Dynamic postural stability deficits in subjects with self-reported ankle instability. Med Sci Sports Exerc 39, 397-402, doi:10.1249/mss.0b013e31802d3460 (2007).
Head, P. L. et al. The influence of jump-landing direction on dynamic postural stability following anterior cruciate ligament reconstruction. Clin Biomech (Bristol, Avon) 112, 106195, doi:10.1016/j.clinbiomech.2024.106195 (2024).
Wikstrom, E. A., Hubbard-Turner, T. & McKeon, P. O. Understanding and treating lateral ankle sprains and their consequences: A constraints-based approach. Sports Med 43, 385-393, doi:10.1007/s40279-013-0043-z (2013).
Hubbard, T. J. Ligament laxity following inversion injury with and without chronic ankle instability. Foot Ankle Int 29, 305-311, doi:10.3113/fai.2008.0305 (2008).
Cordova, M. L., Sefton, J. M. & Hubbard, T. J. Mechanical joint laxity associated with chronic ankle instability: A systematic review. Sports Health 2, 452-459, doi:10.1177/1941738110382392 (2010).
Croy, T., Saliba, S. A., Saliba, E., Anderson, M. W. & Hertel, J. Differences in lateral ankle laxity measured via stress ultrasonography in individuals with chronic ankle instability, ankle sprain copers, and healthy individuals. J Orthop Sports Phys Ther 42, 593-600, doi:10.2519/jospt.2012.3923 (2012).
Wright, C. J. et al. Clinical examination results in individuals with functional ankle instability and ankle-sprain copers. J Athl Train 48, 581-589, doi:10.4085/1062-6050-48.3.15 (2013).
Hertel, J. N., Guskiewicz, K. M., Kahler, D. M. & Perrin, D. H. Effect of lateral ankle joint anesthesia on center of balance, postural sway, and joint position sense. J Sport Rehabil 5, 111-119, doi:10.1123/jsr.5.2.111 (1996).
McKeon, P. O., Booi, M. J., Branam, B., Johnson, D. L. & Mattacola, C. G. Lateral ankle ligament anesthesia significantly alters single limb postural control. Gait Posture 32, 374-377, doi:10.1016/j.gaitpost.2010.06.016 (2010).
Chen, H., Li, H. Y., Zhang, J., Hua, Y. H. & Chen, S. Y. Difference in postural control between patients with functional and mechanical ankle instability. Foot Ankle Int 35, 1068-1074, doi:10.1177/1071100714539657 (2014).
Wenning, M. et al. Functional deficits in chronic mechanical ankle instability. J Orthop Surg Res 15, 304, doi:10.1186/s13018-020-01847-8 (2020).
Brown, C. N., Ko, J., Rosen, A. B. & Hsieh, K. Individuals with both perceived ankle instability and mechanical laxity demonstrate dynamic postural stability deficits. Clin Biomech (Bristol, Avon) 30, 1170-1174, doi:10.1016/j.clinbiomech.2015.08.008 (2015).
Hubbard, T. J., Kramer, L. C., Denegar, C. R. & Hertel, J. Correlations among multiple measures of functional and mechanical instability in subjects with chronic ankle instability. J Athl Train 42, 361-366 (2007).
Labanca, L. et al. Muscle activations during functional tasks in individuals with chronic ankle instability: A systematic review of electromyographical studies. Gait Posture 90, 340-373, doi:10.1016/j.gaitpost.2021.09.182 (2021).
Hopkins, J. T., Brown, T. N., Christensen, L. & Palmieri-Smith, R. M. Deficits in peroneal latency and electromechanical delay in patients with functional ankle instability. J Orthop Res 27, 1541-1546, doi:10.1002/jor.20934 (2009).
Mitchell, A., Dyson, R., Hale, T. & Abraham, C. Biomechanics of ankle instability. Part 1: Reaction time to simulated ankle sprain. Med Sci Sports Exerc 40, 1515-1521, doi:10.1249/mss.0b013e31817356b6 (2008).
Suttmiller, A. M. B. & McCann, R. S. Neural excitability of lower extremity musculature in individuals with and without chronic ankle instability: A systematic review and meta-analysis. J Electromyogr Kinesiol 53, 102436, doi:10.1016/j.jelekin.2020.102436 (2020).
Son, S. J., Kim, H., Seeley, M. K. & Hopkins, J. T. Altered walking neuromechanics in patients with chronic ankle instability. J Athl Train 54, 684-697, doi:10.4085/1062-6050-478-17 (2019).
Son, S. J., Kim, H., Seeley, M. K. & Hopkins, J. T. Movement strategies among groups of chronic ankle instability, coper, and control. Med Sci Sports Exerc 49, 1649-1661, doi:10.1249/mss.0000000000001255 (2017).
Dejong, A. F., Koldenhoven, R. M. & Hertel, J. Proximal adaptations in chronic ankle instability: Systematic review and meta-analysis. Med Sci Sports Exerc 52, 1563-1575, doi:10.1249/mss.0000000000002282 (2020).
Gribble, P. A. et al. Selection criteria for patients with chronic ankle instability in controlled research: A position statement of the International Ankle Consortium. Br J Sports Med 48, 1014-1018, doi:10.1136/bjsports-2013-093175 (2014).
Carcia, C. R., Martin, R. L. & Drouin, J. M. Validity of the foot and ankle ability measure in athletes with chronic ankle instability. J Athl Train 43, 179-183, doi:10.4085/1062-6050-43.2.179 (2008).
Docherty, C. L., Gansneder, B. M., Arnold, B. L. & Hurwitz, S. R. Development and reliability of the ankle instability instrument. J Athl Train 41, 154-158 (2006).
Park, Y., Paine, N. & Oh, S. Development of force observer in series elastic actuator for dynamic control. IEEE Trans Ind Electron 65, 2398-2407, doi:10.1109/TIE.2017.2745457 (2018).
Bell, D. R., Guskiewicz, K. M., Clark, M. A. & Padua, D. A. Systematic review of the balance error scoring system. Sports Health 3, 287-295, doi:10.1177/1941738111403122 (2011).
Colby, S. M., Hintermeister, R. A., Torry, M. R. & Steadman, J. R. Lower limb stability with ACL impairment. J Orthop Sports Phys Ther 29, 444-451; discussion 452-444, doi:10.2519/jospt.1999.29.8.444 (1999).
Richardson, J. T. E. Eta squared and partial eta squared as measures of effect size in educational research. Educ Res Rev6, 135-147, doi:10.1016/j.edurev.2010.12.001 (2011).

No competing interests reported.

Directional deficits in reactive postural control during perturbations among groups of chronic ankle instability, ankle sprain coper, and healthy control

Status:

Version 1

Abstract

Figures

Introduction

Results

Interaction effect (group x perturbation direction) and main effect

CAI group vs. healthy control group

Ankle sprain coper group vs. healthy control group

CAI group vs. ankle sprain coper group

Discussion

Methods