Sensorimotor deficits with ankle sprains and chronic ankle instability. Clin Sports Med. 2008;27:353-370, vii. [PMID: 18503872 DOI: 10.1016/j.csm.2008.03.006]

Soleus arthrogenic muscle inhibition following acute lateral ankle sprain correlates with symptoms and ankle disability but not with postural control

BACKGROUND

Acute lateral ankle sprains (ALAS) are associated with long-term impairments and instability tied to altered neural excitability. Arthrogenic muscle inhibition (AMI) has been observed in this population; however, relationships with injury-related impairments are unclear, potentially due to the resting, prone position in which AMI is typically measured. Assessing AMI during bipedal stance may provide a better understanding of this relationship.

METHODS

AMI was assessed in 38 young adults (19 ALAS within 72 h of injury: 10 males, 21.4 ± 2.7 years; 19 healthy controls: 10 males, 21.9 ± 2.2 years; mean ± SD) using the Hoffmann reflex (H-reflex) during bipedal stance. Electrical stimulation was administered to identify the maximal H-reflex (Hmax) and maximal motor response (Mmax) from the soleus, fibularis longus, and tibialis anterior muscles. The primary outcome measure was the Hmax/Mmax ratio. Secondary outcomes included acute symptoms (pain and swelling), postural control during bipedal stance, and self-reported function.

RESULTS

No significant group-by-limb interactions were observed for any muscle. However, a significant group main effect was observed in the soleus muscle (F(1,35) = 6.82, p = 0.013), indicating significantly lower Hmax/Mmax ratios following ALAS (0.38 ± 0.20) compared to healthy controls (0.53 ± 0.16). Furthermore, lower Hmax/Mmax ratios in the soleus significantly correlated with acute symptoms and self-reported function but not with postural control.

CONCLUSION

This study supports previous evidence of AMI in patients with ALAS, providing insight into neurophysiologic impacts of musculoskeletal injury. Our results suggest that assessing AMI in a standing position following acute injury may provide valuable insight into how AMI develops and guide potential therapeutic options to curb and offset the formation of joint instability.

Central imaging based on near-infrared functional imaging technology can be useful to plan management in patients with chronic lateral ankle instability

BACKGROUND

Near infrared brain functional imaging (FNIRS) has been used for the evaluation of brain functional areas, the imaging differences of central activation of cognitive-motor dual tasks between patients with chronic lateral ankle instability (CLAI) and healthy population remain unclear. This study aimed to evaluated the role of central imaging based on FNIRS technology on the plan management in patients with CLAI, to provide insights to the clinical treatment of CLAI.

METHODS

CLAI patients treated in our hospital from January 1, 2021 to June 31, 2022 were selected. Both CLAI patients and health controls were intervened with simple task and cognitive-motor dual task under sitting and walking conditions, and the changes of oxygenated hemoglobin concentration in bilateral prefrontal cortex (PFC), premotor cortex (PMC) and auxiliary motor area (SMA) were collected and compared.

RESULTS

A total of 23 participants were enrolled. There were significant differences in the fNIRS ΔHbO2 of barefoot subtractive walking PFC-R and barefoot subtractive walking SMA-R between experimental and control group (all P < 0.05). There was no significant difference in ΔHbO2 between the experimental group and the control group in other states (P > 0.05). There was no significant difference in ΔHbO2 between the experimental group and the control group in each state of the brain PMC region.

CONCLUSION

Adaptive alterations may occur within the relevant brain functional regions of individuals with CLAI. The differential activation observed between the PFC and the SMA could represent a compensatory mechanism emerging from proprioceptive afferent disruptions following an initial ankle sprain.

Differences in Cortical Activation During Dorsiflexion and Plantarflexion in Chronic Ankle Instability: A Task-fMRI Study

BACKGROUND

Chronic ankle instability is a common sports injury that often presents with increased plantarflexion and restricted dorsiflexion. The cumulative effect of peripheral injuries may induce neuroplasticity in the central nervous system. However, the relationship between dorsiflexion or plantarflexion and the central nervous system in patients with chronic ankle instability remains unknown.

QUESTIONS/PURPOSES

(1) Is there a difference in region and voxel (volume pixel) of cortical activation during plantarflexion and dorsiflexion between patients with chronic ankle instability and a control group with normal ankle function? (2) Is there a correlation between activation of sensorimotor-related brain regions and three clinical measurement scales of ankle function and disease severity in patients with chronic ankle instability?

METHODS

Between December 2020 and May 2022, we treated 400 patients who had chronic ankle instability. Ten percent (40 patients; mean ± standard deviation age 29 ± 7 years; 17 male patients) were randomly selected to participate in this study. We recruited 42 volunteers with normal ankle function (mean age 28 ± 5 years; 21 male participants) matched by age and education level. A total of 2.5% (1 of 40) of patients with bilateral chronic ankle instability and 30% (12 of 40) with left-sided chronic ankle injury did not meet our inclusion criteria and were excluded from the study. The control group underwent MRI with good image quality. Finally, 27 patients with chronic ankle instability (mean age 26 ± 5 years; 10 male patients) and 42 participants with normal ankle function were enrolled. Ankle function and disease severity were assessed using three clinical scales: the Cumberland Ankle Instability Tool, Karlsson-Peterson Ankle Function Score, and the American Orthopedic Foot and Ankle Society Score. A uniplanar and nonweightbearing ankle dorsiflexion-plantarflexion paradigm (a recognized model or pattern) was performed using a short-block design during the functional MRI scan. This experimental design included a series of on-off periods consisting of movement and a rest period. From 15° of plantarflexion to 15° of dorsiflexion, the manipulator allowed 30° of ankle rotation. The cerebral excitability patterns between patients with chronic ankle instability and controls were analyzed using t-tests. We retained voxels with p values less than 0.05 in a voxel-level family-wise error correction. Clusters with voxel numbers greater than 10 were retained. The Cohen d coefficient was used to calculate between-group effect sizes. Spearman analysis was performed to explore the correlation between activation regions and the three clinical assessment scales.

RESULTS

In the patient group, cortical activation was greater during plantarflexion than during dorsiflexion, which was different from that in the control group. The between-group comparison showed that patients with chronic ankle instability had reduced activation in the ipsilateral precuneus (cluster size = 35 voxels [95% CI -0.23 to 0.07]; p < 0.001) during dorsiflexion, whereas during plantarflexion, chronic ankle instability caused increased activation in the ipsilateral superior temporal gyrus (cluster size = 90 voxels [95% CI -0.73 to -0.13]; p < 0.001), precuneus (cluster size = 18 voxels [95% CI -0.56 to -0.19]; p < 0.001), supplementary motor area (cluster size = 57 voxels [95% CI -0.31 to 0.00]; p < 0.001), superior frontal gyrus (cluster size = 43 voxels [95% CI -0.82 to -0.29]; p < 0.001), medial part of the superior frontal gyrus (cluster size = 39 voxels [95% CI 0.41 to 0.78]; p < 0.001), and contralateral postcentral gyrus (cluster size = 100 voxels [95% CI -0.32 to 0.02]; p < 0.001). Patients with chronic ankle instability showed a large effect size compared with controls (Cohen d > 0.8). During plantarflexion, the number of activated voxels in the supplementary motor area had a modest, positive correlation with the Karlsson-Peterson Ankle Function Score (r = 0.52; p = 0.01), and the number of activated voxels in the primary motor cortex (M1) and primary sensory cortex (S1) had a weak, positive correlation with the American Orthopedic Foot and Ankle Society Score in patients with chronic ankle instability (M1: r = 0.45; p = 0.02, S1: r = 0.49; p = 0.01).

CONCLUSION

Compared with volunteers with normal ankle function, patients with chronic ankle instability had increased cortical activation during plantarflexion and decreased cortical activation during dorsiflexion. We analyzed the central neural mechanisms of chronic ankle instability in patients with sports injuries and provided a theoretical basis for the development of new central and peripheral interventions in the future.

CLINICAL RELEVANCE

Because there was a positive correlation between the neural activity in sensorimotor-related regions during plantarflexion and clinical severity, clinicians might one day be able to help patients who have chronic ankle instability with neuromuscular rehabilitation by applying electrical stimulation to specific targets (such as S1M1 and the supplementary motor area) or by increasing activation of sensorimotor neurons through ankle movement.

Effect of sensor location for modifying center of pressure during gait using haptic feedback in people with chronic ankle instability

BACKGROUND

Gait retraining using haptic biofeedback medially shifts the center of pressure (COP) while walking in orthopedic populations. However, the ideal sensor location needed to effectively shift COP medially has not been identified in people with chronic ankle instability (CAI).

RESEARCH QUESTIONS

Can a heel sensor location feasibly be employed in people with CAI without negatively altering kinematics? Does a heel sensor placement relative to the 5th metatarsal head (5MH) impact COP location while walking in people with CAI?

METHODS

In this exploratory crossover study, 10 participants with CAI walked on a treadmill with vibration feedback for 10 minutes with a plantar pressure sensor under the heel and 5MH. Separate 2×2 repeated measures analyses of covariances (rmANCOVAs) were used to compare the averaged COP location and 3-D lower extremity kinematics from the first 10% of stance before and after training and between sensor locations. Baseline measures served as covariates to adjust for baseline differences.

RESULTS

Feedback triggered by a heel sensor resulted in 40% of participants avoiding a heel strike. There were no significant main effects or interactions between time and sensor location on COP location when controlling for baseline COP (p>0.05). However, with the 5MH placement, participants displayed less ankle internal rotation(IR) (5MH/Heel: -4.12±0.00º/ -6.43±0.62º), less forefoot abduction (-4.29±0.00º/ -5.14±1.01º), more knee flexion (3.40±0.32º/ 0.14±0.57º), less knee external rotation (-10.95±0.00º/-11.24±1.48º), less hip extension (-0.20±0.00º/-1.42±1.05º), and less hip external rotation (3.12±0.00º/3.75±1.98º).

SIGNIFICANCE

A 5MH location may be more feasible based on difficulties maintaining heel strike when the sensor was under the heel. While no sensor location was statistically better at changing the COP, the 5MH location decreased proximal transverse plane motions making participants' gait more like controls. Individual response variations support comprehensive lower extremity assessments and the need to identify responder profiles using sensory feedback in people with CAI.

Patients with chronic ankle instability exhibit increased sensorimotor cortex activation and correlation with poorer lateral balance control ability during single-leg stance: a FNIRS study

Introduction

Chronic Ankle Instability (CAI) is a musculoskeletal condition that evolves from acute ankle sprains, and its underlying mechanisms have yet to reach a consensus. Mounting evidence suggests that neuroplastic changes in the brain following ankle injuries play a pivotal role in the development of CAI. Balance deficits are a significant risk factor associated with CAI, yet there is a scarcity of evidence regarding the sensorimotor cortical plasticity related to balance control in affected individuals. This study aims to evaluate the differences in cortical activity and balance abilities between patients with CAI and uninjured individuals during a single-leg stance, as well as the correlation between these factors, in order to elucidate the neurophysiological alterations in balance control among patients with CAI.

Methods

The study enrolled 24 patients with CAI and 24 uninjured participants. During single-leg stance, cortical activity was measured using a functional near-infrared spectroscopy (fNIRS) system, which included assessments of the pre-motor cortex (PMC), supplementary motor area (SMA), primary motor cortex (M1), and primary somatosensory cortex (S1). Concurrently, balance parameters were tested utilizing a three-dimensional force platform.

Results

Independent sample t-tests revealed that, compared with the uninjured individuals, the patients with CAI exhibited a significant increase in the changes of oxyhemoglobin concentration (ΔHbO) during single-leg stance within the left S1 at Channel 5 (t = 2.101, p = 0.041, Cohen's d = 0.607), left M1 at Channel 6 (t = 2.363, p = 0.022, Cohen's d = 0.682), right M1 at Channel 15 (t = 2.273, p = 0.029, Cohen's d = 0.656), and right PMC/SMA at Channel 11 (t = 2.467, p = 0.018, Cohen's d = 0.712). Additionally, the center of pressure root mean square (COP-RMS) in the mediolateral (ML) direction was significantly greater (t = 2.630, p = 0.012, Cohen's d = 0.759) in the patients with CAI. Furthermore, a moderate positive correlation was found between ML direction COP-RMS and ΔHbO2 in the M1 (r = 0.436; p = 0.033) and PMC/SMA (r = 0.488, p = 0.016), as well as between anteroposterior (AP) direction COP-RMS and ΔHbO in the M1 (r = 0.483, p = 0.017).

Conclusion

Patients with CAI demonstrate increased cortical activation in the bilateral M1, ipsilateral PMC/SMA, and contralateral S1. This suggests that patients with CAI may require additional brain resources to maintain balance during single-leg stance, representing a compensatory mechanism to uphold task performance amidst diminished lateral balance ability in the ankle joint.

Changes in Dynamic Balance Ability Among Firefighter Recruits: A Longitudinal Cohort Study

ABSTRACT

Cornell, DJ, Gnacinski, SL, and Ebersole, KT. Changes in dynamic balance ability among firefighter recruits: A longitudinal cohort study. J Strength Cond Res 38(4): 734-741, 2024-It has been suggested that enhanced balance ability may mitigate the high musculoskeletal injury (MSKI) rate among firefighters, but the longitudinal changes in dynamic balance ability within this tactical athlete population have yet to be characterized. The purpose of this study was to examine the changes in dynamic balance ability of a cohort population of firefighter recruits completing a training academy and their probationary period as active-duty firefighters. Twenty-seven male firefighter recruits completed the modified Star Excursion Balance Test (mSEBT) at the beginning (W1) and at the end of their training academy (W14) and after completing their probationary period as active-duty firefighters (W38). After controlling for age and changes in body fat (BF) over time, significant changes in mSEBTANT ( p < 0.001), mSEBTPL ( p = 0.015), mSEBTPM ( p < 0.001), and mSEBTCOMP ( p = 0.003) were observed across time. Although mSEBTPL performance significantly increased ( p = 0.033) in from W1 to W14, significant decreases in all mSEBT reach directions were observed from W14 to W38 ( p < 0.05), with mSEBTANT ( p < 0.001) and mSEBTCOMP ( p = 0.002) also significantly decreasing from W1 to W38. However, the frequency of right vs. left asymmetries (>4 cm) did not significantly change over time in any mSEBT reach direction ( p > 0.05). Irrespective of age or changes in BF, minimal changes in the dynamic balance ability of firefighter recruits were observed during their training academy, but significant decreases in balance ability were noted by the end of their probationary period.

Individuals With Chronic Ankle Instability Show Abnormalities in Maximal and Submaximal Isometric Strength of the Knee Extensor and Flexor Muscles

BACKGROUND

It has been shown that chronic ankle instability (CAI) leads to abnormalities in neuromuscular control of more proximal joints than the ankle. Although strength of the hip and the ankle muscles has been largely investigated providing concordant results, limited evidence with contrasting results has been reported regarding knee extensor and flexor muscles.

PURPOSE

To investigate maximal and submaximal isometric muscle strength in individuals with CAI.

STUDY DESIGN

Controlled laboratory study.

METHODS

Fifteen participants with unilateral CAI and 15 healthy matched controls were recruited. To quantify maximal strength, peak forces were recorded during a maximal isometric voluntary contraction of knee extensor and flexor muscles at 30° and 90° of knee flexion and normalized by the body weight of each participant. At both angles, submaximal isometric contractions at 20%, 50%, and 80% of the maximal voluntary isometric contraction were performed to analyze strength steadiness, in terms of coefficient of variation, and strength accuracy, in terms of absolute error. During all the assessments, knee extensor and flexor muscle activation was recorded by means of surface electromyography.

RESULTS

Knee flexor maximal isometric strength was significantly lower in the injured limb of individuals with CAI in comparison with healthy controls at both 30° (0.15 ± 0.05 vs 0.20 ± 0.05; P < .05) and 90° (0.14 ± 0.04 vs 0.18 ± 0.05; P < .05). Knee extensor and flexor steadiness was significantly lower (higher coefficient of variation) in both the injured and the noninjured limbs of individuals with CAI in comparison with healthy individuals at 90° and at 30° for knee flexor steadiness of the injured limb. Knee extensor and flexor accuracy was lower (higher absolute error) in both the injured and noninjured limbs of individuals with CAI in comparison with healthy individuals, mainly at 30°, while at 90° it was lower only in the injured limb. No differences between the 2 groups were found for maximal isometric strength of knee extensor muscles, as well as for muscle activations.

CONCLUSION

Individuals with CAI show abnormalities in maximal and submaximal isometric strength of knee flexor muscles, and submaximal strength of the knee extensor muscles. Further studies should deeply investigate mechanisms leading to these abnormalities.

CLINICAL RELEVANCE

Rehabilitation interventions should consider abnormalities of neuromuscular control affecting joints more proximal than the ankle in individuals with CAI.

REGISTRATION

NCT05273177 (ClinicalTrials.gov identifier).

The impact of whole-body vibration training and proprioceptive neuromuscular facilitation on biomechanical characteristics of lower extremity during cutting movement in individuals with functional ankle instability: A parallel-group study

BACKGROUND

We compared the effects of whole-body vibration training and proprioceptive neuromuscular facilitation on the biomechanical characteristics of the lower limbs in functional ankle instability patients during cutting movement to ascertain the superior rehabilitation method.

METHODS

Twenty-two male College students with unilateral functional ankle instability volunteered for this study and were randomly divided into whole-body vibration training group and proprioceptive neuromuscular facilitation group. Kinematics data and ground reaction forces were collected using infrared motion capture system and 3-D force plates synchronously during cutting. Repeated measures two-way ANOVA was performed to analyze the data.

FINDINGS

Both training methods reduced the maximum hip abduction angle (p = 0.010, effect size: proprioceptive neuromuscular facilitation = 0.69; whole-body vibration training = 0.20), maximum knee flexion angle (p = 0.008, effect size: proprioceptive neuromuscular facilitation = 0.39, whole-body vibration training = 1.26) and angular velocity (p = 0.014, effect size: proprioceptive neuromuscular facilitation = 0.62, whole-body vibration training = 0.55), maximum ankle inversion angular velocity (p = 0.020, effect size: proprioceptive neuromuscular facilitation = 0.52, whole-body vibration training = 0.81), and knee flexion angle at the time of maximum vertical ground reaction forces (p = 0.018, effect size: proprioceptive neuromuscular facilitation = 0.27, whole-body vibration training = 0.76), and increased the maximum ankle dorsiflexion moment (p = 0.049, effect size: proprioceptive neuromuscular facilitation = -0.52, whole-body vibration training = -0.22). Whole-body vibration training reduced the maximum ground reaction forces value in the mediolateral directions (p = 0.010, effect size = 0.82) during cutting movement.

INTERPRETATION

These findings suggested that the two types of training might increase neuromuscular conduction function around the ankle. After these two types of training, functional ankle instability patients showed a similar risk of injury to the lateral ankle ligaments during cutting.

Understanding the effects of a sudden directional shift in somatosensory feedback and increasing task complexity on postural adaptation in individuals with and without chronic ankle instability

BACKGROUND

Individuals with chronic ankle instability (CAI) present somatosensory dysfunction following an initial ankle sprain. However, little is known about how individuals with CAI adapt to a sudden sensory perturbation of instability with increasing task and environmental constraints to maintain postural stability.

METHODS

Forty-four individuals with and without unilateral CAI performed the Adaptation Test to a sudden somatosensory inversion and plantarflexion perturbations (environment) in double-, injured-, and uninjured- limbs. Mean sway energy scores were analyzed using 2 (group) × 2 (somatosensory perturbations) × 3 (task) repeated measures analysis of variance.

RESULTS

There were significant interactions between the group, environment, and task (P=.025). The CAI group adapted faster than healthy controls to a sudden somatosensory inversion perturbation in the uninjured- (P=.002) and injured- (P<.001) limbs, as well as a sudden somatosensory plantarflexion perturbation in the double- (P=.033) and uninjured- (P=.035) limbs. The CAI and healthy groups presented slower postural adaptation to a sudden inversion perturbation than a sudden somatosensory plantarflexion perturbation in double-limb (P<.001). Whereas both groups demonstrated faster postural adaptation to a sudden somatosensory inversion perturbation compared to somatosensory plantarflexion perturbation while maintaining posture in the injured- (P<.001) and uninjured- (P<.001) limbs. The CAI and healthy groups adapted faster to a sudden somatosensory inversion perturbation in the injured- (P<.001) and uninjured- (P<.001) limbs than in double-limb, respectively.

DISCUSSION

Postural adaptation in individuals with and without CAI depended on environmental (somatosensory perturbations) and task constraints. The CAI group displayed comparable and faster postural adaptation to a sudden somatosensory inversion and plantarflexion in double-, injured-, and uninjured- limbs, which may reflect a centrally mediated alteration in neuromuscular control in CAI.

Using clinician-oriented and laboratory-oriented assessments to study dynamic stability of individuals with chronic ankle instability

To compare the dynamic stability of lower extremities between Copers and individuals with chronic ankle instability (CAI) using clinician-oriented assessments (Y-balance test, YBT) and laboratory-oriented assessments (time to stabilization, TTS). 90 participants (Copers, 45; CAIs, 45) were recruited and measured by YBT and TTS to evaluate dynamic stability. The difference of dynamic stability between Copers and CAIs was examined using a two-factor MANOVA. Only for females in anterior direction, YBT scores for the AS side of Copers were significantly higher than that of CAIs. For males, the TTS of CAIs was significantly shorter than that of Copers in the anterior, lateral, and medial direction separately. For females, the TTS of CAIs is also significantly shorter than that of Copers in the anterior, lateral, and medial direction separately. There are opposite results when evaluating the dynamic stability difference between Copers and CAIs using YBT and TTS.

Anticipation of landing leg masks ankle inversion orientation deficits and peroneal insufficiency during jump landing in people with chronic ankle instability

Ankle inversion orientation and peroneal activation insufficiency may contribute to lateral ankle sprains during landing in chronic ankle instability (CAI); however, how anticipation alters these factors is neglected. This study aimed to assess the impact of anticipation on joint orientation and muscle activity during landing in individuals with CAI. Fifteen participants with CAI and 15 healthy participants (control) were recruited to perform single-leg landings after bilateral countermovement jumps when the landing limb was specified before (planned) or after (unplanned) take-off. Joint angle (hip, knee, and ankle) and electromyography (gluteus medius, rectus femoris, biceps femoris, gastrocnemius lateral head, tibialis anterior, and peroneal longus) were collected and analyzed with 2 (groups) × 2 (conditions) statistical parametric mapping ANOVA. In the unplanned condition, the CAI group demonstrated a less plantarflexed (maximum difference [MD] = 9.5°, p = 0.047) and more inverted ankle joint (MD = 4.1°, p < 0.001) before ground contact, along with lower peroneal activity at ground contact compared to the control group (MD = 28.9% of peak activation, p < 0.001). No significant differences between groups were observed in the planned condition. In conclusion, anticipation may mask jump landing deficits in people with CAI, including inverted ankle orientation and reduced peroneus longus activity pre- and post-landing, which were observed exclusively in unplanned landings. Clinicians and researchers need to recognize the impact of anticipation on apparent landing deficits and consider the implications for injury prevention and rehabilitation strategies.

Investigating the Combined Effects of Fascial Distortion Model Manual Therapy and Balance-Strength Training in Individuals with Chronic Ankle Instability

BACKGROUND

The Fascial Distortion Model (FDM) is a relatively new manual therapy approach in the field of musculoskeletal physical therapy, and its potential effectiveness in treating chronic ankle instability (CAI) remains unexplored.

METHODS

A randomized controlled trial with 23 participants was conducted. Patients were randomly assigned to either the FDM + balance-strength training (BST) group (n = 8), receiving extra FDM sessions weekly in addition to two sessions of BST, or the BST group (n = 7). Healthy controls (n = 8) did not receive any treatment and participated only in pre- and post-test measurements. Objective measurements including Y-Balance Test Lower Quarter (YBT-LQ), Flamingo Balance Test (FBT), Weight-Bearing Lunge Test (WBLT), ankle joint range of motion (ROM), and Cumberland Ankle Instability Tool (CAIT) were recorded at baseline and the end of the intervention. The results demonstrated significant differences between the FDM + BST and BST groups for supination ROM (p = 0.008) and similarly for WBLT (p = 0.041), FBT (p = 0.40), YBT-LQ (p = 0.023), and CAIT score (p = 0.008). Moreover, while both groups demonstrated significant improvement at the post-test compared with their pre-test for plantarflexion and pronation ROM, WBLT, and CAIT score, the FDM + BST group demonstrated significant improvements in supination ROM, FBT, and YBT-LQ.

CONCLUSION

Our study suggests that the addition of FDM concepts to a BST may lead to enhanced improvements in ankle ROM, static and dynamic balance, and self-reported outcomes in individuals with CAI compared to BST.

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

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

Association of Diaphragm Contractility and Postural Control in a Chronic Ankle Instability Population: A Preliminary Study

BACKGROUND

Altered reorganization of the sensorimotor system after an initial lateral ankle sprain may lead to a chronic neuromuscular maladaptation in multiple body locations. Specifically, decreased diaphragm contractility has been observed in patients with chronic ankle instability (CAI). The diaphragm has an essential role in postural control. Decreased diaphragm contractility could associate with diminished postural control commonly observed in patients with CAI. However, no study has determined if diaphragm contractility contributes to postural control in a CAI population.

HYPOTHESIS

Decreased diaphragm contractility would be negatively associated with static postural control in patients with CAI.

STUDY DESIGN

Cross-sectional study design.

LEVEL OF EVIDENCE

Level 4.

METHODS

A total of 15 participants with CAI participated voluntarily. An ultrasonography assessment was performed to quantify the right and left hemidiaphragm thickness at the end of resting inspiration and expiration in supine while breathing quietly. The degree of diaphragm contractility was calculated from the diaphragm thickness. Participants performed 3 eyes-open trials of a 20-second single-leg balance task on the involved limb. Static postural control measures included the center of pressure velocity (COPV) and mean of time-to-boundary (TTB) minima in the anteroposterior (AP) and mediolateral directions.

RESULTS

Moderate correlations of the right hemidiaphragm contractility were observed with COPV (ρ = -0.54) and TTB mean minima (ρ = 0.56) (P < 0.05) in the AP direction. The left hemidiaphragm contractility was moderately correlated with COPV (ρ = -0.56) and TTB mean minima (ρ = 0.60) (P < 0.05) in the AP direction.

CONCLUSION

Lower diaphragm contractility may be associated with diminished static postural control in the AP direction in patients with CAI.

CLINICAL RELEVANCE

This study highlights diaphragm contractility could be a potential connection with diminished static postural control in patients with CAI. Our data raise new avenues for future exploration including potential beneficial effects of implementation of diaphragm breathing exercises and techniques for restoring static postural control in patients with CAI.

In Vivo Characterization of Cerebellar Peduncles in Chronic Ankle Instability: A Single and Multishell Diffusion-Weighted Imaging Study

BACKGROUND

Ankle sprain causes proprioceptor injuries and prolonged joint deafferentation, which might lead to maladaptive neuroplasticity in patients with chronic ankle instability (CAI), especially in the cerebellum. Previous studies have indicated the impairment of superior cerebellar peduncle (SCP), but the inferior cerebellar peduncle (ICP) and middle cerebellar peduncle (MCP) have not been fully analyzed.

HYPOTHESIS

The cerebellar peduncles of participants with CAI would have altered fractional anisotropy (FA) and orientation dispersion index (ODI) in comparison with healthy controls without ankle injury history. In addition, FA and ODI would be correlated with the duration or severity of the sensorimotor deficits in CAI.

STUDY DESIGN

Cross-sectional study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A group of 27 participants with CAI and 26 healthy controls underwent diffusion-weighted imaging scanning, with the cerebellar peduncles as the regions of interest. The measures obtained by single-shell diffusion tensor imaging and the multishell neurite orientation dispersion and density imaging were used. Correlation analyses were performed to examine the potential relationship between the FA/ODI and both the normalized Y-balance scores and the durations of ankle instability.

RESULTS

The ipsilateral ICP of the injured ankle in participants with CAI showed significantly lower FA (Cohen d 95% CI, -1.33 to -0.21; P = 0.04) and marginally significant higher ODI (Cohen d 95% CI, 0.10 to 1.20, P = 0.08) when compared with the same measures in the control group, with the ODI being positively correlated with the duration of ankle instability (r = 0.42, P = 0.03).

CONCLUSION

The ICP in participants with CAI exhibited impaired integrity and a trend of abnormally organized neurites in comparison with a healthy control group.

CLINICAL RELEVANCE

The impairments of ICP might be an ongoing part of the pathological process of CAI, having the potential to become a target for the diagnostic evaluation of this clinical entity.

Weighting of visual and auditory inputs in dancers with and without previous ankle injury

Elite dance requires highly controlled balance performance in dynamic visual and auditory environments characterized by the use of stage lighting and music. Perturbing visual input is known to influence balance in dancers, but the effects of sounds have not been clearly established. Ankle inversion injuries are common in dancers and may also play a role in dancers' ability to respond to sensory perturbations. The aims of this study were to identify changes in static balance in response to visual or auditory perturbation in elite collegiate dancers with and without a history of ankle injury, and to describe coupling of measurements obtained from the waist and head during balance. Thirty-seven dancers: 22 controls and 15 with a history of ankle sprain, performed single-leg balance under static and dynamic visual and auditory conditions. Dancers demonstrated increased waist sway when viewing a dynamic visual scene and when presented with moving sounds and increased head sway with dynamic visuals. These results did not vary by history of ankle sprain. While dancers appear to dampen the impact of waist sway on head motion during single leg stance, even highly trained dancers may experience challenges controlling balance under perturbing visual and auditory conditions like those present during stage performance.

Running gait adaptations among adolescent runners with soft tissue impairments following lateral ankle sprains

BACKGROUND

Lateral ankle sprains (LAS) frequently lead to residual soft tissue impairments, often attributed to biomechanical dysfunction during movement.

OBJECTIVE

To compare running biomechanics between adolescent runners with soft tissue pathologies following LAS (injured) and healthy runners (control) and between limbs.

DESIGN

Retrospective cohort study.

SETTING

Hospital-affiliated sports injury prevention center.

PARTICIPANTS

Twenty-five adolescent runners with a history of LAS and current ankle impingement or tendinopathy (23 female, 2 male; age: 15 ± 2 years; body mass index [BMI]: 19.5 ± 2.5 kg/m2 ; symptom duration: 1.1 ± 0.9 years), and 23 healthy controls without any LAS history (19 female, 4 male; age: 15 ± 1 years; BMI: 19.2 ± 2.7 kg/m2 ) were included in this study.

INTERVENTIONS

All participants completed a clinical gait assessment in which they ran at a self-selected speed on a force-plate instrumented treadmill, while two video cameras recorded two-dimensional sagittal and coronal views.

MAIN OUTCOME MEASURES

Foot rotation, step width, contact time, and cadence were compared between groups and limbs (involved, uninvolved [or "better" for bilateral cases]) using a multivariate analysis of variance (MANOVA). Rearfoot landing and foot strike type were compared between groups and limbs using a chi-square analysis.

RESULTS

The injured group had significantly increased step width (F = 4.71, p = .04; mean difference [MD] with SE: 1.5 [0.7] cm) compared to controls. The injured groups' involved limb had longer contact time (F = 4.62, p = .03; MDgroup : 12 [7] ms, MDlimb : 22 [11] ms) with more internal foot rotation (F = 14.60, p < .001; MDgroup : 2.2 [1.2] degrees, MDlimb : 4.2 [1.3] degrees) compared to controls and their contralateral limb. There were no significant differences for cadence (F = 2.43, p = .13; MD: 4 [3] steps/min), foot landing (X2  = 1.28, p = .53), or foot strike (X2  = 1.24, p = .54).

CONCLUSIONS

Spatiotemporal and kinematic running adaptations may predispose young runners with initial LAS to secondary soft tissue dysfunction due to loss of stability from ligamentous structures and an overreliance on myotendinous control. Clinicians may consider targeting these maladaptations during gait-training interventions.

Balance and Muscle Synergies During a Single-Limb Stance Task in Individuals With Chronic Ankle Instability

The aim of this study was to investigate balance performance and muscle synergies during a Single-Limb Stance (SLS) task in individuals with Chronic Ankle Instability (CAI) and a group of healthy controls. Twenty individuals with CAI and twenty healthy controls were asked to perform a 30-second SLS task in Open-Eyes (OE) and Closed-Eyes (CE) conditions while standing on a force platform with the injured or the dominant limb, respectively. The activation of 13 muscles of the lower limb, hip, and back was recorded by means of surface electromyography. Balance performance was assessed by identifying the number and the duration of SLS epochs, and the Root-Mean-Square (RMS) in Antero-Posterior (AP) and Medio-Lateral (ML) directions of the body-weight normalized ground reaction forces. The optimal number of synergies, weight vectors, and activation coefficients were also analyzed. CAI group showed a higher number and a shorter duration of SLS epochs and augmented ground reaction force RMS in both AP and ML directions compared to controls. Both groups showed an increase in the RMS in AP and ML forces in CE compared to OE. Both groups showed 4 optimal synergies in CE, while controls showed 5 synergies in OE. CAI showed a significantly higher weight of knee flexor muscles in both OE and CE. In conclusion, muscle synergies analysis provided an in-depth knowledge of motor control mechanisms in CAI individuals. They showed worse balance performance, a lower number of muscle synergies in a CE condition and abnormal knee flexor muscle activation compared to healthy controls.

Ankle Sprain History Does Not Significantly Alter Single- and Dual-Task Spatiotemporal Gait Mechanics

CONTEXT

Single- and dual-task walking gait assessments have been used to identify persistent movement and cognitive dysfunction among athletes with concussions. However, it is unclear whether previous ankle sprain injuries confound these outcomes during baseline testing. The purpose of this study was to determine the effects of (1) ankle sprain history and (2) time since prior ankle sprain injury on single- and dual-task spatiotemporal gait outcomes and cognitive measures.

DESIGN

Cross-sectional study.

METHODS

We assessed 60 college Division-I athletes (31 with ankle sprain history; 13 females and 18 males, 19.3 [0.8] y; 29 with no ankle sprain history, 14 females and 15 males, 19.7 [0.9] y) who completed injury history forms and underwent concussion baseline testing. Athletes completed single- and dual-task gait assessments by walking back and forth along an 8-m walkway for 40 seconds. Athletes wore a smartphone with an associated mobile application on their lumbar spine to record spatiotemporal gait parameters and dual-task cognitive performance. Separate multivariate analyses of variance were used to assess the effects of ankle sprain injury history on spatiotemporal measures, gait variability, and cognitive performance. We performed a multivariate regression subanalysis on athletes who reported time since injury (n = 23) to assess temporal effects on gait and cognitive performance.

RESULTS

Athletes with and without a history of ankle sprains had comparable spatiotemporal and gait variability outcomes during single- (P = .42; P = .13) and dual-task (P = .75; P = .55) conditions. Additionally, ankle sprain injury history did not significantly influence cognitive performance (P = .35). Finally, time since ankle sprain did not significantly affect single- (P = .75) and dual-task gait (P = .69), nor cognitive performance (P = .19).

CONCLUSIONS

Ankle sprain injury history did not significantly alter spatiotemporal gait outcomes nor cognitive performance during this common clinical assessment. Future studies may consider including athletes with ankle sprain injury history during concussion assessments.

Effects of A Single Balance Training Session on Neural Excitability in Individuals With Chronic Ankle Instability

CONTEXT

Individuals with chronic ankle instability (CAI) demonstrate reduced spinal reflex modulation and corticospinal excitability of the soleus, which may contribute to decreased balance performance.

OBJECTIVE

To determine the effects of a single session of balance training on Spinal-reflexive excitability modulation and corticospinal excitability in those with CAI.

DESIGN

Randomized controlled trials.

SETTING

Research laboratory.

PARTICIPANTS

Thirty participants with CAI were randomly assigned to the balance training (BAL) or control (CON) group.

MAIN OUTCOME MEASURES

Modulation of soleus spinal-reflexive excitability was measured by calculating relative change in normalized Hoffmann reflexes (ratio of the H-reflex to the M-wave) from prone to single-leg standing. Corticospinal excitability was assessed during single-leg stance using transcranial magnetic stimulation, outcomes of which included active motor threshold (AMT), motor evoked potential, and cortical silent period (CSP). Balance performance was measured with center of pressure velocity in anterior to posterior and medial to lateral directions. Separate 2 × 2 repeated-measures analyses of variance were employed to determine the effect of group (BAL and CON) and time (baseline and posttraining) on each dependent variable.

RESULTS

There were significant group by time interactions in the modulation of soleus spinal-reflexive excitability (F1,27 = 4.763, P = .04); CSP at 100% AMT (F1,27 = 4.727, P = .04); and CSP at 120% AMT (F1,27 = 16.057, P < .01). A large effect size suggests increased modulation of spinal-reflexive excitability (d = 0.81 [0.03 to 1.54]) of the soleus in BAL compared with CON at posttest, while CSP at 100% (d = 0.95 [0.17 to 1.70]) and 120% AMT (d = 1.10 [0.29 to 1.84]) was reduced in BAL when compared with CON at posttest.

CONCLUSION

After a single session of balance training, individuals with CAI initiated increases in spinal reflex modulation and corticospinal excitability of the soleus. Thus, individuals with CAI who undergo balance training exhibit positive neural adaptations that are linked to improvements in balance performance.

The Accuracy of Ankle Eccentric Torque Control Explains Dynamic Postural Control During the Y-Balance Test

Background

The Y-Balance Test (YBT), especially the posteromedial (PM) reach direction (PM-YBT), is able to identify dynamic postural control deficits in those who have ankle instability. However, there still exists a need to understand how sensorimotor function at the ankle explains the performance during the PM-YBT.

Hypothesis/Purpose

The purpose of this study was to determine whether the ability to accurately control eccentric ankle torque explained PM-YBT performance. It was hypothesized that eccentric dorsiflexion/plantarflexion torque control would be positively related to the maximum reach distance (MRD) of PM-YBT.

Study Design

Cross-sectional study.

Methods

Twelve healthy subjects performed the PM-YBT, maximum voluntary isometric contractions (MVIC) for both dorsiflexion and plantarflexion muscle strength, and then the torque control testing of the ankle. The torque control testing provided a target torque level on a screen in front of the subject and passive rotations of the ankle joint in the sagittal plane at 10 deg/sec between plantarflexion to dorsiflexion. Subjects were then instructed to eccentrically contract the dorsiflexors and plantar flexors to generate torque while the ankle joint rotated. The accuracy of torque control during eccentric dorsiflexion and plantarflexion by calculating absolute errors, the area between the target torque and the produced torque were evaluated. Tibialis anterior and soleus muscle activities were simultaneously recorded during testing. A step-wise linear regression model was used to determine the best model predicted the MRD of the PM-YBT (PM-MRD).

Results

A step-wise linear regression developed a model explaining only eccentric dorsiflexion torque control predicted higher PM-MRD score (R2 = 44%, F1,10 = 7.94, β = -0.67, p = 0.02).

Conclusion

The accuracy of torque control during eccentric dorsiflexion predicts better performance in the PM-YBT.

Level of Evidence

3b.

Role of interventions targeting plantar cutaneous receptors in improving postural control in chronic ankle instability: A systematic review with meta-analysis

INTRODUCTION

Chronic ankle instability (CAI) is a disorder that occurs after one or more acute ankle sprains and is characterised by persistent symptoms which include episodes of ''giving way'' a sensation of instability, recurrent ankle sprains, and functional deficits. Despite of effective treatment strategies a comprehensive approach is needed that can break this continuum of disability and improve the postural control. A systematic review with meta-analysis assessing the effectiveness of interventions targeting plantar cutaneous receptors for improving postural control in individuals with chronic ankle instability.

METHODS

The systematic review with meta-analysis was performed following PRISMA guidelines. Outcome measure used to evaluate the improvement in which static postural control was assessed on SLBT (Single limb balance test) and COP (Centre of pressure) whereas dynamic postural control was assessed on SEBT (star excursion balance test) and scores expressed as mean ± SD and random-effects model were performed, and heterogeneity between the studies was calculated using the I2 statistic.

RESULTS

A total of 168 CAI populations were included among the 8 selected studies in the meta-analysis. In which,5 studies using Plantar massage and 3 studies using foot insole were assessed, with moderate to high quality on the Pedro scale (range 4-7). For single and six-sessions of plantar massage showed insignificant effect on SLBT COP and for the single session of custom moulded FO showed insignificant effect on SEBT.

CONCLUSION

The meta-analysis showed non-significant pooled results for plantar massage and foot orthotics on static and dynamic postural control when assessed on postural outcome measures. Further high-quality evidence-based trials would be required to highlight the importance of sensory targeted approaches to treat the postural instability in CAI patients.

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

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

Effects of whole-body vibration on sensorimotor deficits and brain plasticity among people with chronic ankle instability: a study protocol for a single-blind randomized controlled trial

BACKGROUND

Chronic ankle instability (CAI) is a form of musculoskeletal disease that can occur after a lateral ankle sprain, and it is characterized by pain, recurrent ankle sprains, a feeling of "giving way" at the ankle joint, and sensorimotor deficits. There has been increasing evidence to suggest that plastic changes in the brain after the initial injury play an important role in CAI. As one modality to treat CAI, whole-body vibration (WBV) has been found to be beneficial for treating the sensorimotor deficits accompanying CAI, but whether these benefits are associated with brain plasticity remains unknown. Therefore, the current study aims to investigate the effect of WBV on sensorimotor deficits and determine its correlation with plastic changes in the brain.

METHODS

The present study is a single-blind randomized controlled trial. A total of 80 participants with CAI recruited from the university and local communities will be divided into 4 groups: whole-body vibration and balance training (WBVBT), balance training (BT), whole-body vibration (WBV), and control group. Participants will be given the WBV intervention (25-38 Hz, 1.3-2 mm, 3-time per week, 6-week) supervised by a professional therapist. Primary outcome measures are sensorimotor function including strength, balance, proprioception and functional performance. Brain plasticity will be evaluated by corticomotor excitability, inhibition, and representation of muscles, as measured by transcranial magnetic stimulation. Activation of brain areas will be assessed through functional near-infrared spectroscopy. Secondary outcome measures are self-reported functional outcomes involving the Cumberland Ankle Instability Tool and the Foot and Ankle Ability Measure. All tests will be conducted before and after the WBV intervention, and at 2-week follow-up. Per‑protocol and intention-to-treat analysis will be applied if any participants withdraw.

DISCUSSION

This is the first trial to investigate the role of brain plasticity in sensorimotor changes brought by WBV for individuals with CAI. As plastic changes in the brain have been an increasingly important aspect in CAI, the results of the current study can provide insight into the treatment of CAI from the perspective of brain plasticity.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2300068972); registered on 02 March 2023.

Yoga as a balance intervention for middle-age and older adults with history of lateral ankle sprain: An exploratory study

INTRODUCTION

Balance deficiencies are common among aging adults. Musculoskeletal injuries such as lateral ankle sprains (LAS) also contribute to compromised balance; potentially amplifying the postural insufficiencies in these age groups with a history of LAS. Yoga has emerged as an effective balance training intervention for aging adults; but limited application exists in these age cohorts with LAS history. This study may provide important guidance for the implementation of this intervention in these populations.

METHODS

In this cohort design study, middle-age and older adults with a history of LAS completed an 8-week beginner-level yoga class. Balance was measured before and after the yoga intervention statically (force plate) and dynamically (star excursion balance test [SEBT]) using single-limb balance tasks.

RESULTS

Following the yoga intervention, older adults improved static postural control in the anterior-posterior direction, as well as dynamic postural control in selected reach directions of the SEBT relative to the middle-age adults.

CONCLUSION

This is an important step in exploring how to help the aging population that likely has amplifications in balance deficiencies due to a common musculoskeletal injury, LAS. While more work is needed to determine how to optimize and document balance improvements in aging adults with LAS history, yoga appears to be a promising form of intervention, particularly for older adults.

Effects of plantar-sensory treatments on postural control in chronic ankle instability: A systematic review and meta-analysis

OBJECTIVE

This study aimed to examine the effects of plantar-sensory treatments on postural control in individuals with chronic ankle instability (CAI).

METHODS

This study was registered in PROSPERO (registration number CRD42022329985) on May 14, 2022. An extensive search was performed in Pubmed, Embase, Cochrane, Web of Science, and Scopus to identify the potential studies on plantar-sensory treatments affecting postural control before May 2022. The methodological quality of involved studies was assessed using the scale of Physiotherapy Evidence Database (PEDro). The Cochrane Tool and the Risk of Bias in Non-randomized Studies of Interventions assessment tool were used to evaluate the risk of bias in randomised controlled trials (RCTs) and non-RCTs respectively. RevMan 5.4 was utilised to calculate the standardised mean difference (SMD), with 95% confidence interval (CI).

RESULTS

Eight RCTs with a mean PEDro rating of 6 and four non-RCTs with a mean PEDro rating of 4.75 were included in the quantitative analysis. The types of plantar-sensory treatments included plantar massage, whole-body vibration and textured surface-stimulation treatment. A significant effect of static balance with eyes open (SMD = -0.54; 95% CI: -0.81 to -0.27; p < 0.001) was found and subgroup analysis showed that plantar massage (SMD = -0.49; 95% CI: -0.84 to -0.14; p = 0.006) and whole-body vibration (SMD = -0.66; 95% CI: -1.12 to -0.19; p = 0.005) had positive effects. In the subgroup analysis of anterior dynamic balance, whole-body vibration revealed a significant increase (SMD = 0.60; 95% CI: 0.06-1.14; p = 0.03). The pooled results or subgroup analysis including eyes-closed static balance and other directions of dynamic balance indicated no significant difference (p > 0.05).

CONCLUSIONS

This meta-analysis indicated that plantar-sensory treatments could improve postural control in CAI, especially the treatments of plantar massage and long-term whole-body vibration.

Lower Extremity Muscle Activation during the Star Excursion Balance Test in Patients with Chronic Ankle Instability and Copers

Background and Objectives: The aim of this study was to assess the impact of ankle muscles on performance of the Star Excursion Balance Test (SEBT) among individuals with stable ankles, a history of ankle sprain, and chronic ankle instability (CAI). Materials and Methods: Sixty subjects (twenty per group) performed the SEBT in each of the anterior (A), posteromedial (PM), and posterolateral (PL) directions. Normalized maximum reach distance (NMRD) and normalized mean amplitude of the tibialis anterior (NMA_TA), fibularis longus (NMA_FL), and medial gastrocnemius (NMA_MG) were measured during performance of the SEBT. Results: Copers have greater NMRD than subjects with stable ankles and those with CAI, and subjects with stable ankles also have greater NMRD than those with CAI in only the PL direction. Subjects with stable ankles and those with CAI showed greater NMA_TA than copers. The A direction showed greater NMA_TA than the PM and PL directions. Copers showed greater NMA_FL than subjects with stable ankles. Subjects with CAI showed greater NMA_MG than copers and subjects with stable ankles. The A and PL directions showed greater NMA_MG than the PM direction. Conclusions: Overall, copers and/or subjects with CAI demonstrated altered neuromuscular function by compensating for their ankle muscles when compared to subjects with stable ankles due to a history of ankle sprain.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

Effects of foot intensive rehabilitation (FIRE) on clinical outcomes for patients with chronic ankle instability: a randomized controlled trial protocol

BACKGROUND

Lateral ankle sprains account for a large proportion of musculoskeletal injuries among civilians and military service members, with up to 40% of patients developing chronic ankle instability (CAI). Although foot function is compromised in patients with CAI, these impairments are not routinely addressed by current standard of care (SOC) rehabilitation protocols, potentially limiting their effectiveness. The purpose of this randomized controlled trial is to determine if a Foot Intensive REhabilitation (FIRE) protocol is more effective compared to SOC rehabilitation for patients with CAI.

METHODS

This study will use a three-site, single-blind, randomized controlled trial design with data collected over four data collection points (baseline and post-intervention with 6-, 12-, and 24-month follow-ups) to assess variables related to recurrent injury, sensorimotor function, and self-reported function. A total of 150 CAI patients (50 per site) will be randomly assigned to one of two rehabilitation groups (FIRE or SOC). Rehabilitation will consist of a 6-week intervention composed of supervised and home exercises. Patients assigned to SOC will complete exercises focused on ankle strengthening, balance training, and range of motion, while patients assigned to FIRE will complete a modified SOC program along with additional exercises focused on intrinsic foot muscle activation, dynamic foot stability, and plantar cutaneous stimulation.

DISCUSSION

The overall goal of this trial is to compare the effectiveness of a FIRE program versus a SOC program on near- and long-term functional outcomes in patients with CAI. We hypothesize the FIRE program will reduce the occurrence of future ankle sprains and ankle giving way episodes while creating clinically relevant improvements in sensorimotor function and self-reported disability beyond the SOC program alone. This study will also provide longitudinal outcome findings for both FIRE and SOC for up to two years. Enhancing the current SOC for CAI will improve the ability of rehabilitation to reduce subsequent ankle injuries, diminish CAI-related impairments, and improve patient-oriented measures of health, which are critical for the immediate and long-term health of civilians and service members with this condition. Trial Registration Clinicaltrials.gov Registry: NCT #NCT04493645 (7/29/20).

Effects of Whole-Body Vibration Exercise on Athletes with Ankle Instability: A Systematic Review

OBJECTIVE

Chronic Ankle Instability (CAI) or Functional Ankle Instability (FAI) is a condition characterized by laxity and mechanical instability in the ankle joint. This instability interferes with the activities and physical-functional parameters of athletes, which leads to repetitive ankle sprains. The current systematic review was carried out to identify the effects of whole-body vibration exercise (WBVE) in athletes with CAI.

METHODS

We conducted electronic searches in Pubmed, the Cochrane Library, Embase, Web of Science, Scopus, Science Direct, Allied Health Literature (CINAHL) and Academic Search Premier (ASP) (EBSCO) databases on 26 February 2022. Registers were identified, and studies were selected for inclusion according to the eligibility criteria. The methodological quality was assessed by the Physiotherapy Evidence Database (PEDro) scale.

RESULTS

Seven studies were included with a mean methodological quality score of 5.85, considered 'regular' quality on the PEDro scale. WBVE interventions in athletes with CAI showed that this exercise contributes to a better response on parameters of neuromuscular performance, muscle strength and consequently in balance and postural control, variables that are for the management of CAI.

CONCLUSION

WBVE interventions in sports modalities promote physiological responses that may lead to positive effects in several parameters. The protocols proposed in each modality can be carried out in practice and are considered effective additional exercise and training methods beyond traditional types of training for athletes. However, more studies are needed on athletes with this condition, with specific protocols, to highlight the possible physiological and physical-functional responses. Protocol study registration: PROSPERO (CRD42020204434).

Effectiveness of the SMART training intervention on ankle joint function in patients with first-time acute lateral ankle sprain: study protocol for a randomized controlled trial

BACKGROUND

The lateral ankle sprain (LAS) is the most common injury in the field of everyday and sports-related activities. There is a high rate of patients with LAS who will develop chronic ankle instability (CAI). A possible explanation for this high rate is an insufficient rehabilitation and/or a premature return to intense exercise and workloads. Currently, there are general rehabilitation guidelines for LAS but there is a lack of standardized evidenced-based rehabilitation concepts for LAS, which effectively reduce the high CAI rate. The primary aim of the study is to investigate the effectiveness of a 6-week sensorimotor training intervention (SMART-Treatment, SMART) in contrast to standard therapy (Normal Treatment, NORMT) after an acute LAS on perceived ankle joint function.

METHODS

This study will be a prospective, single-center, interventional randomized controlled trial with an active control group. Patients (14-41 years) with an acute LAS and a MRI confirmed lesion or rupture of at least one ankle ligament will be included. Exclusion criteria are acute concomitant injuries of the ankle, pre-injuries of the ankle, serious lower-extremity injuries of the last 6 months, lower-extremity surgery, and neurological diseases. The primary outcome measure will be the Cumberland Ankle Instability Tool (CAIT). Secondary outcomes include the Foot and Ankle Ability Measurement (FAAM), isokinetic and isometric strength diagnostics, joint repositioning sense, range of motion, measurements of postural control, gait and run analysis, and jump analysis. This protocol will follow the SPIRIT guidance.

DISCUSSION

Current management of LAS rehabilitation lacks since there is a high rate of patients developing a CAI. It has been shown that exercise therapy improves ankle function in acute LAS as well as in patients with CAI. It is further recommended to address specific impairment domains in ankle rehabilitation. However, empirical data for such a holistic treatment algorithm is missing. Therefore, this study has the potential to improve the healthcare for LAS patients and might be used for a future standardized evidence-based rehabilitation concept.

TRIAL REGISTRATION

"Prospectively registered" ISRCTN - ISRCTN13640422 17/11/2021; DRKS (German Clinical Trials Register) - DRKS00026049.

Mechanical and Sensorimotor Outcomes Associated With Talar Cartilage Deformation After Static Loading in Those With Chronic Ankle Instability

CONTEXT

Those with chronic ankle instability (CAI) demonstrate deleterious changes in talar cartilage composition, resulting in alterations of talar cartilage loading behavior. Common impairments associated with CAI may play a role in cartilage behavior in response to mechanical loading.

OBJECTIVE

To identify mechanical and sensorimotor outcomes that are linked with the magnitude of talar cartilage deformation after a static loading protocol in patients with and those without CAI.

DESIGN

Cross-sectional study.

SETTING

Laboratory setting.

PATIENTS OR OTHER PARTICIPANTS

Thirty individuals with CAI and 30 healthy individuals.

MAIN OUTCOME MEASURES(S)

After a 60-minute off-loading period, ultrasonographic images of the talar cartilage were acquired immediately before and after a 2-minute static loading protocol (single-legged stance). Talar cartilage images were obtained and manually segmented to enable calculation of medial, lateral, and overall average talar thickness. The percentage change, relative to the average baseline thickness, was used for further analysis. Mechanical (ankle joint laxity) and sensorimotor (static balance and Star Excursion Balance Test) outcomes were captured. Partial correlations were computed to determine associations between cartilage deformation magnitude and the mechanical and sensorimotor outcomes after accounting for body weight.

RESULTS

In the CAI group, greater inversion laxity was associated with greater overall (r = -0.42, P = .03) and medial (r = -0.48, P = .01) talar cartilage deformation after a 2-minute static loading protocol. Similarly, poorer medial-lateral static balance was linked with greater overall (r = 0.47, P = .01) and lateral (r = 0.50, P = .01) talar cartilage deformation. In the control group, shorter posterolateral Star Excursion Balance Test reach distance was associated with greater lateral cartilage deformation (r = 0.42, P = .03). No other significant associations were observed.

CONCLUSIONS

In those with CAI, inversion laxity and poor static postural control were moderately associated with greater talar cartilage deformation after a 2-minute static loading protocol. These results suggest that targeting mechanical instability and poor balance in those with CAI via intervention strategies may improve how the talar cartilage responds to static loading conditions.

EFEITOS DO EXERCÍCIO DE REABILITAÇÃO ACELERADA DEPOIS DE TBM SOBRE A FUNÇÃO E A FORÇA NA INSTABILIDADE DO TORNOZELO

RESUMO Introdução: Os atletas de taekwondo com instabilidade lateral crônica do tornozelo (ILCT) podem apresentar dificuldades com propriocepção e força muscular do tornozelo. Depois da cirurgia, um programa de exercícios de reabilitação convencional pode ser ineficaz, porque a propriocepção ou a força muscular podem não se restaurar e, portanto, resultar em melhora mínima. Objetivos: Este estudo teve como objetivo avaliar os efeitos de um programa de ERA depois de TBM sobre a propriocepção, força isocinética e resistência do tornozelo. Métodos: Trinta atletas com diagnóstico de ILCT foram submetidos à TBM. Eles foram divididos em grupo ERA (n=15) e grupo controle CON (n = 15). O grupo ERA realizou exercícios ERA precoces seis vezes por semana durante 4 semanas. Os parâmetros aplicados para testar a força muscular do tornozelo foram velocidade angular de 30°/s e 180°/s (inversão: Inv e eversão: Eve, respectivamente). A propriocepção foi medida pela capacidade de sentir a posição articular de 15° de Inv e 5° de Eve Resultados: Foram observadas diferenças significativas entre os grupos ERA e CON na força do tornozelo 30°/s (Inv: p < 0,001, Eve: p < 0,001), 180°/s (Inv: p < 0,001, Eve: p < 0,001), e propriocepção a 15° (Inv: p < 0,001) e 5° (Eve: p < 0,001). Conclusões: Registramos efeitos de curto prazo significativos com ERA precoce em atletas de taekwondo com ILCT depois da TBM. Os resultados fornecem dados de referência para o reabilitador esportivo ou ATC (Certified athletic trainer) na avaliação da fase de reabilitação e informar os pacientes sobre as expectativas depois da TBM em termos de condições de desempenho e momento de retorno ao esporte. Nível de evidência III; Estudos terapêuticos – Investigação dos resultados do tratamento - Estudo de caso-controle.

EFFECTS OF ACCELERATED REHABILITATION EXERCISE AFTER MBO ON ANKLE FUNCTION AND STRENGTH IN ANKLE INSTABILITY

ABSTRACT Background: Taekwondo athletes with lateral chronic ankle instability (LCAI) may experience difficulties with proprioception and ankle muscle strength. After surgery, a conventional rehabilitation exercise program can be ineffective, as it may not restore proprioception or muscle strength and, thus, result in minimal improvement. Objective: This study aimed to assess the effects of an ARE program following MBO on the proprioception, isokinetic strength, and endurance of ankle. Methods: Thirty athletes diagnosed with LCAI underwent MBO. They were divided into the ARE group (n=15) and the control group (CON, n=15). The ARE group performed early ARE exercises six times per week for 4 weeks. The parameters applied to test ankle muscle strength were angular speed of 30°/sec and 180°/sec (inversion: Inv. and eversion: Eve., respectively). Proprioception was measured as being able to sense a joint position of 15° of Inv. and 5° of Eve. Results: Significant differences were observed between the ARE and CON groups in ankle strength 30°/sec (Inv.: p<0.001, Eve.: p<0.001), 180°/sec (Inv.: p<0.001, Eve.: p<0.001), and proprioception at 15° (Inv.: p<0.001) and 5° (Eve.: p<0.001). Conclusions: We recorded significant short-term effects from early ARE in Taekwondo athletes with LCAI after MBO. The results provide reference data for the sports rehabilitator or ATC in evaluating the rehabilitation phase and informing patients about expectations after MBO in terms of performance status and the timing of return to sports. Level of evidence III; Therapeutic studies–Investigation of treatment outcomes - Case-control Study.

Comparison of the Effectiveness of Kinesiology Taping and Rigid Taping on Ankle Kinematics During Drop Landing in Individuals with Lateral Ankle Injury

BACKGROUND

Lateral ankle sprain is an injury that often occurs during sports or daily life activities. Athletic tape and kinesiology tape applications are among the external support treatment options especially for athletes to support the ankle and protect it from recurrent sprains. We sought to compare the kinematic stabilization effects of different ankle taping applications on the ankle joint during drop landing in individuals with a history of unilateral lateral ankle injury.

METHODS

In this randomized controlled study, 30 volunteers with unilateral ankle injury were evaluated. The participants were asked to land on one leg on the involved side and the contralateral side from a 30-cm-high platform. The same practice was repeated after applying kinesiology tape and rigid tape to the injured foot. Kinematic analysis of the foot and ankle was performed by recording three-dimensional spatial position information at a speed of 240 frames per second using infrared cameras.

RESULTS

The highest inversion angles of the involved foot at initial contact and 150 msec after initial contact were higher than those of the uninvolved side (P = .03 and P = .04, respectively). There was no significant difference in ankle kinematic values in the involved foot among kinesiology taping, athletic taping, and no taping applications (P = .74).

CONCLUSIONS

People with lateral ankle sprains show reduced inversion during landing. There were no significant differences among kinesiology taping, athletic taping, and no taping on the injured foot in terms of ankle kinematics. Care should be taken when using taping materials as protective measures for sports activities.

Foot and Shank Coordination During Walking in Copers Compared With Patients With Chronic Ankle Instability and Controls

BACKGROUND

Chronic ankle instability (CAI) alters sensorimotor function and joint coordination, but ankle coordination during walking in copers (patients with a history of ankle sprain without any residual symptoms of CAI) remains unknown.

PURPOSE

To identify foot and shank coordination patterns that discriminate among individuals with CAI, copers, and healthy controls and to investigate whether copers display a different strategy to overcome altered sensorimotor function after a lateral ankle sprain compared with individuals with CAI and healthy controls.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 51 participants (17 participants with CAI, 17 copers, 17 healthy controls) walked on an instrumented treadmill at a fixed speed of 1.20 m/s for a 10-second trial, from which 8 consecutive gait cycles were extracted for analysis. Heel strike and toe-off were identified for each stance phase, and each stance phase was normalized to 100 time frames. A curve analysis was performed to detect group mean differences in vector coding coupling angles and coordination variabilities for sagittal plane ankle motion/transverse plane tibial plane motion (SAK/TT) and frontal plane ankle motion/transverse plane tibial motion (FAK/TT) with 90% CIs.

RESULTS

During the terminal stance, CAI and coper groups demonstrated an inversion-tibial external rotation coupling, while controls displayed a dorsiflexion-tibial internal rotation strategy. During midstance, there were no differences between the coper, CAI, or control groups. At 0% to 20% of stance, the CAI group showed the most variability, while copers showed the least. During midstance, both copers and controls displayed an increase in variability earlier than the CAI group. The CAI group displayed a peak in variability from 39% to 43% of stance, which was greater than copers. During the propulsive phase (from heel-off to toe-off), the CAI group showed greater SAK/TT variability than both copers and controls. Similar to SAK/TT variability, the CAI group showed an earlier peak in FAK/TT variability compared with controls.

CONCLUSION

The CAI, coper, and control groups displayed different ankle joint coupling patterns and coordination variability during a walking gait cycle.

CLINICAL RELEVANCE

Copers may have the ability to alter their coordination during walking, which may help us understand the underlying mechanism of CAI.

Effects of lateral instability on ankle coupled motions in vivo using 3D fluoroscopy

Lateral ankle instability (LAI) compromises the normal kinematics of the ankle, affecting activities of daily living. In vitro kinematics of ankles with LAI during single-plane motions are available, but the active control stability of these motions remains unclear. The current study measured the 3D ankle kinematics during unresisted single-plane motion tests using a bi-plane fluoroscope with a CT model-based 2D/3D registration method in 12 patients with LAI and 14 healthy peers. The coupling of the kinematic components at the talocrural and subtalar joints was quantified by the path difference between the forward and return paths of the coupled motion. Significantly increased path differences were found in the subtalar dorsiflexion/plantarflexion and inversion/eversion components during internal/external rotation tests (p < 0.05). During inversion/eversion, significantly reduced tibiocalcaneal ranges of motion and the path differences in the talocrural and subtalar dorsiflexion/plantarflexion components were noted (p < 0.05). The current results suggest that chronic LAI had compromised control stability at the subtalar joint during internal/external rotation tests and a conservative motion control strategy with significantly reduced ranges of motion to maintain good control of out-of-plane motion components in response to direct challenges of the anterior talofibular ligament during inversion/eversion tests. The current results also suggest that, compared to kinematic patterns of individual components, the path difference of the coupled motion may serve as a better measure of the motion control stability of the ankle in differentiating LAI from healthy controls.

Impact of Sub-Clinical and Clinical Compression Socks on Postural Stability Tasks among Individuals with Ankle Instability

Compression socks are used by a very diverse group of individuals and may potentially have a greater impact on physically diminished or impaired individuals as opposed to healthy individuals. The purpose of this study was to compare the effects of sub-clinical (SC) and clinical (CL) compression socks among healthy (CON), copers (COP), and individuals with chronic ankle instability (CAI). Postural stability was evaluated in 20 participants (11 males and 9 females) using Balance Tracking System Balance platform (BTrackS™) during the modified clinical test of sensory integration in balance (mCTSIB) and limits of stability (LOS) tests. Postural sway parameters were analyzed using a mixed model repeated measures analysis of variance 3 (group: CON, COP, and CAI) by 3 (compression condition: BF, SC, and CL) × 4 (balance condition: EO, EC, EOF, and ECF) for mCTSIB and a 3 (group: CON, COP, and CAI) by 3 (compression condition: BF, SC, CL) × 4 (balance condition: FL, BL, BR, FR) for LOS. Results revealed significantly greater postural stability with both SC and CL compression socks when compared to barefoot conditions. However, no significant differences were observed among groups for compression socks grades. Both SC and CL compression socks may be effective in increasing postural stability.

Spinal Reflex Excitability of Lower Leg Muscles Following Acute Lateral Ankle Sprain: Bilateral Inhibition of Soleus Spinal Reflex Excitability

Neural changes in the ankle stabilizing muscles following ankle sprains are thought to be one contributing factor to persistent ankle dysfunction. However, empirical evidence is limited. Therefore, we aimed to examine spinal reflex excitability of lower leg muscles following acute ankle sprains (AAS). We performed a case-control study with 2 groups consisting of 30 young adults with AAS and 30 aged-matched uninjured controls. Hoffmann reflex (H-reflex) testing was performed to estimate spinal reflex excitability of lower leg muscles: soleus, fibularis longus (FL), tibialis anterior (TA). Maximal H-reflex (H_max) and motor responses (M_max) were determined by delivering a series of electrical stimuli at the sciatic nerve. H_max/M_max ratios were calculated to represent normalized spinal reflex excitability. Separate group-by-limb analyses of variance (ANOVA) with repeated measures found there were no significant interactions for any of the muscles (SL: F_1,56 = 0.95, p = 0.33, FL: F_1,51 = 0.65, p = 0.42, TA: F_1,51 = 1.87, p = 0.18), but there was a significant main effect of group in the soleus (F_1,56 = 6.56, p = 0.013), indicating the H_max/M_max ratio of soleus in the AAS group was significantly lower bilaterally (AAS = 0.56 ± 0.19, control = 0.68 ± 0.17, p = 0.013), with no significant group differences in the other muscles (FL: F_1,51 = 0.26, p = 0.61, TA: F_1,51 = 0.93, p = 0.34). The bilateral inhibition of the soleus spinal reflex excitability following AAS may be significant in that it may explain bilateral sensorimotor deficits (postural control deficits) following unilateral injury, and provide insights into additional therapies aimed at the neural change.

Alterations in Cortical Activation among Soccer Athletes with Chronic Ankle Instability during Drop-Jump Landing: A Preliminary Study

Background: Chronic ankle instability (CAI) is a common peripheral joint injury and there is still no consensus on the mechanisms. It is necessary to investigate electrocortical parameters to provide clinical insight into the functional alterations of brain activity after an ankle sprain, which would greatly affect the implementation of rehabilitation plans. The purpose of this study was to assess cortical activation characteristics during drop-jump landing among soccer athletes with CAI. Methods: A total of 24 participants performed the drop-jump landing task on a force platform while wearing a 64-channel EEG system. The differences of power spectral density (PSD) in theta and alpha (alpha-1 and alpha-2) bands were analyzed between two groups (CAI vs. CON) and between two limbs (injured vs. healthy). Results: CAI participants demonstrated significantly higher theta power at the frontal electrode than that in healthy control individuals (F(1,22) = 7.726, p = 0.011, η2p = 0.260). No difference in parietal alpha-1 and alpha-2 power was found between groups (alpha-1: F(1,22) = 0.297, p = 0.591, η2p = 0.013; alpha-2: F(1,22) = 0.118, p = 0.734, η2p = 0.005). No limb differences were presented for any frequency band in selected cortical areas (alpha-1: F(1,22) = 0.149, p = 0.703, η2p = 0.007; alpha-2: F(1,22) = 0.166, p = 0.688, η2p = 0.007; theta: F(1,22) = 2.256, p = 0.147, η2p = 0.093). Conclusions: Theta power at the frontal cortex was higher in soccer athletes with CAI during drop-jump landing. Differences in cortical activation provided evidence for an altered neural mechanism of postural control among soccer athletes with CAI.

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

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

The effect of whole body vibration on sensorimotor deficits in people with chronic ankle instability: A systematic review and meta-analysis

OBJECTIVE

To investigate the effects of whole body vibration on chronic ankle instability-associated sensorimotor deficits in balance, strength, joint position sense and muscle activity.

DATA SOURCES

Electronic databases including Cochrane Library, PubMed, Embase, Web of Science, EBSCO, China National Knowledge Infrastructure and WanFang were searched from database inception up to 31 March 2022.

METHODS

The risk of bias and methodological quality of included studies were assessed using the Cochrane tool and Physiotherapy Evidence Database (PEDro) scale respectively. Standardized mean difference (SMD) and mean differences (MD) with 95% confidence interval (CI) were calculated using the RevMan 5.3 software. Meta-regression was conducted with Stata 16.

RESULTS

Eight studies, with 315 subjects were eventually included in this review with an average PEDro score of 6.1/10. Significant effects of whole body vibration on balance (SMD = 0.61, 95% CI: 0.12 to 1.09, P = 0.01), and on the posterolateral direction (MD = 5.52, 95% CI: 1.02 to 10.01, P = 0.02) and medial direction (MD = 3.90, 95% CI: 0.87 to 6.94, P = 0.01) of the star excursion balance test were found. Whole body vibration significantly improved the peak torque (SMD = 0.36, 95% CI: 0.04 to 0.69, P = 0.03), joint position sense (SMD = 0.60, 95% CI: 0.10 to 1.11, P = 0.02), and muscle activity in tibialis anterior (SMD = 0.46, 95% CI: 0.04 to 0.88, P = 0.03) and gastrocnemius (SMD = 0.68, 95% CI: 0.14 to 1.23, P = 0.01).

CONCLUSIONS

The current evidence supports the use of whole body vibration to improve sensorimotor deficits involving balance, strength, joint position sense, and muscle activity in people with chronic ankle instability.

Center of pressure position in the touches of the star excursion balance test in healthy individuals

BACKGROUND

The Star Excursion Balance Test (SEBT) is a clinical test that aims to assess postural control. Its interpretation is related to the understanding of the motor specificities required. Adjustments must be made to the center of pressure (COP) to maintain balance during testing movements. Comprehend the specifics of these adjustments for each direction can allow the development of more suitable exercises for balance training. The aim was to compare the positions of the COP on the different directions of the SEBT and correlate the reachs obtained in the SEBT with the distances from the COP to the borders of the base of support (BOS).

METHODS

Sixteen healthy subjects participated in the study. Measurements were made by performing the SEBT over the force platform. The Kruskal-Wallis test followed by Bonferroni's post hoc test was used to compare directions. The Pearson correlation test was used to check the correlation of parametric variables and Spearman correlation test for the nonparametric ones.

RESULTS

The position of the COP at the touch differs from the anterior direction to the other directions of the SEBT and the performance in this direction is correlated with the proximity of the COP to the anterior limit of the support base. The performances in the other directions did not correlate with the COP position.

CONCLUSION

The requirements of the compensation mechanisms for postural control are different between the directions of the SEBT.

Linking Pain and Motor Control: Conceptualization of Movement Deficits in Patients With Painful Conditions

When people experience or expect pain, they move differently. Pain-altered movement strategies, collectively described here as pain-related movement dysfunction (PRMD), may persist well after pain resolves and, ultimately, may result in altered kinematics and kinetics, future reinjury, and disability. Although PRMD may manifest as abnormal movements that are often evident in clinical assessment, the underlying mechanisms are complex, engaging sensory-perceptual, cognitive, psychological, and motor processes. Motor control theories provide a conceptual framework to determine, assess, and target processes that contribute to normal and abnormal movement and thus are important for physical therapy and rehabilitation practice. Contemporary understanding of motor control has evolved from reflex-based understanding to a more complex task-dependent interaction between cognitive and motor systems, each with distinct neuroanatomic substrates. Though experts have recognized the importance of motor control in the management of painful conditions, there is no comprehensive framework that explicates the processes engaged in the control of goal-directed actions, particularly in the presence of pain. This Perspective outlines sensory-perceptual, cognitive, psychological, and motor processes in the contemporary model of motor control, describing the neural substrates underlying each process and highlighting how pain and anticipation of pain influence motor control processes and consequently contribute to PRMD. Finally, potential lines of future inquiry-grounded in the contemporary model of motor control-are outlined to advance understanding and improve the assessment and treatment of PRMD.

IMPACT

This Perspective proposes that approaching PRMD from a contemporary motor control perspective will uncover key mechanisms, identify treatment targets, inform assessments, and innovate treatments across sensory-perceptual, cognitive, and motor domains, all of which have the potential to improve movement and functional outcomes in patients with painful conditions.

Copers adopt an altered dynamic postural control compared to individuals with chronic ankle instability and controls in unanticipated single-leg landing

BACKGROUND

Several prior studies involving "expected" single-leg landings have not succeeded in establishing a difference between copers and a control group.

RESEARCH QUESTION

Does expected and unanticipated single-leg landing affect dynamic postural stability in lateral ankle sprain individuals with chronic ankle instability (CAI), copers, and controls?

METHODS

In this prospective cross-sectional study, physically active adults with CAI (n = 12), copers (n = 12), and controls (n = 12) were included. Participants performed expected single-leg landing by stepping off a 30-cm box. They also performed unanticipated landings including side-step cutting, side-step cutting at 60°, single-leg landing, and forward stepping. The expected and unanticipated conditions of each groups were compared in terms of time to stabilization (TTS) and center of pressure (COP) for the anterior-posterior (AP) and medial-lateral (ML) conditions. To analyze the data, a mixed-model one-way analysis of variance and a Tukey-Kramer post hoc test were performed.

RESULTS

A significant condition × group interaction was observed in only TTS ML, with the CAI group demonstrating a significantly longer TTS ML than the coper (p < 0.001) and control (p < 0.001) groups during unanticipated trials. In addition, group interaction effects were observed for COP AP and TTS AP. The coper group demonstrated significantly longer COP AP and TTS AP than the control group (p < 0.001).

SIGNIFICANCE

The CAI group demonstrated a significantly longer TTS ML than the coper and control groups during the unanticipated condition, and the coper group demonstrated significantly longer TTS AP and COP AP than the control group. Thus, longer COP AP and TTS AP sway time in the coper group may be a protection mechanism, allowing greater freedom in the AP plane while quickly controlling ML sway and preventing lateral ankle sprains. These findings can help in the prevention of lateral ankle sprains and assessment of dynamic postural control.

Optical flow balance perturbations alter gait kinematics and variability in chronic ankle instability patients

BACKGROUND

Individuals with chronic ankle instability (CAI) have known balance impairments thought to be the result of an inability to reweight sensory information. CAI patients place greater emphasis on visual information during single-limb stance than healthy controls but this evidence is based on removing visual information during static conditions.

RESEARCH QUESTION

Does perturbed optical flow effect step kinematics and variability in those with CAI differently than healthy controls? What is the relationship among ankle laxity, plantar cutaneous sensation, and susceptibility to perturbed optical flow in those with CAI?

METHODS

17 CAI patients and 17 healthy individuals participated in a crossover experimental study. Participants walked on a treadmill at 1.25 m/s while watching a speed-matched virtual hallway with and without continuous mediolateral (ML) optical flow perturbations. Three-dimensional pelvic and foot kinematics were recorded at 100 Hz for at least 300 consecutive steps in each condition. Step width (SW) and step length (SL) values were calculated from consecutive heel positions. Gait variability was characterized as the standard deviation of step width (SWV), step length (SLV), and ML sacrum motion (SMV) across all steps performed in each condition.

RESULTS

The CAI group exhibited a greater change in SWV (p = 0.037), SLV (p = 0.040), and ML SMV (p = 0.047) from the perturbed to unperturbed conditions relative to the healthy controls. A condition main effect was also noted for SW (p < 0.001) and SL (p < 0.001) as ML optical flow perturbations resulted in significant changes in SW and SL relative to the normal walking condition.

SIGNIFICANCE

Walking with ML optical flow perturbations induced greater variability changes in those with CAI relative to controls. When combined with the existing literature, this finding suggests that CAI individuals have a greater reliance on visual information in both static and dynamic (i.e. walking gait) conditions relative to healthy individuals.