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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., Competing Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The aim of this study was to evaluate stride-to-stride variability of the lower extremity during walking in individuals with and without chronic ankle instability (CAI) using a nonlinear analysis. Twenty-five participants with self-reported CAI and 27 healthy control participants volunteered for this study. Participants walked on a motor-driven treadmill for 3 min at their selected speed. Lower extremity kinematics in the sagittal and frontal planes were recorded using a passive retroreflective marker motion capture system. The temporal structure of walking variability was analyzed with sample entropy (SampEn). The CAI group produced lower SampEn values in frontal-plane ankle kinematics compared to the control group (P=.04). No significant group differences were observed for SampEn values of other kinematics (P>.05). Participants with CAI demonstrated less stride-to-stride variability of the frontal plane ankle kinematics compared to healthy controls. Decreased variability of walking patterns demonstrated by participants with CAI indicates that the presence of CAI may be associated with a less adaptable sensorimotor system to environmental changes. The altered sensorimotor function associated with CAI may be targets for clinical interventions, and it is critical to explore how interventions protocols affect sensorimotor system function., (Copyright © 2014 Elsevier B.V. All rights reserved.)

We investigated the influence of ankle dorsiflexion range of motion (DF-ROM) and self-reported patient outcomes on dynamic postural control assessed with the Star Excursion Balance Test (SEBT) in individuals with chronic ankle instability (CAI). Twenty-nine participants with self-reported CAI volunteered. The primary outcome measurements were categorized into clinician-and patient-generated. Clinician-generated outcome measurements included anterior (SEBT-A), posteriormedial (SEBT-PM) and posteriorlateral (SEBT-PL) reach distances (cm) normalized by leg length (cm) of the SEBT, maximum weight-bearing dorsiflexion (WB-DF) (cm), and open-chain DF-ROM (°). Self-reported patient-generated outcome measures included the foot and ankle ability measure and the level of perceived pain, stiffness, stability, and function of their involved ankle on a 10-cm visual analog scale (VAS). Pearson product moment correlations were used to examine the relationship of the SEBT performances with DF-ROM and self-reported patient outcome measures. A multiple linear regression was performed to determine the influence of patient- and clinician-generated measures on the SEBT. SEBT-A performance was significantly and fairly correlated with WB-DF (r=0.410, p=0.014), perceived ankle stiffness (r=0.477, p=0.014), and open-chain DF-ROM (r=0.404, p=0.015). The strongest predictor of the variance in SEBT-A was the combination of the variance in WB-DF and VAS-stiffness (R2=0.348, p=0.004). There were no significant correlations with the SEBT-PM and SEBT-PL. WB-DF and VAS-stiffness may represent targets for intervention that need to be addressed to produce the best outcome in participants with CAI when altered dynamic postural control is detected on the SEBT-A., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Context: Static postural control deficits are commonly documented among individuals with chronic ankle instability (CAI). Evidence suggests individuals with CAI who seek medical attention after an ankle sprain report fewer subjective symptoms. It is unknown if seeking medical attention and receiving supervised physical rehabilitation has a similar effect on objective outcomes, such as static postural control. Objective: To compare measures of single-limb postural control and center of pressure (COP) location between participants with CAI who did or did not self-report attending supervised rehabilitation at the time of their first lateral ankle sprain. Design: Retrospective cohort. Setting: Laboratory. Patients (or Other Participants): Twenty-nine participants with CAI who did (n = 14) or did not (n = 15) self-report attending supervised rehabilitation. Intervention(s): Self-reported attendance or not of supervised rehabilitation at the time of initial injury. Main Outcome Measures: Participants performed three 20-second trials of single-limb stance on a force plate with eyes open. Main outcome measures included the COP velocities, time-to-boundary (TTB) absolute minima, mean of TTB minima, and SD of TTB minima in the anteroposterior and mediolateral directions. The spatial distribution of the COP data points under the foot was quantified within 4 equally proportional sections labeled anteromedial, anterolateral, posteromedial, and posterolateral. Results: Participants who reported attending supervised rehabilitation after their initial ankle sprain had a lower COP velocity in the anterior–posterior direction (P =.030), and higher TTB anterior–posterior absolute minimum (P =.033) and mean minima (P =.050) compared with those who did not attend supervised rehabilitation. Conclusions: Among individuals with CAI, not attending supervised rehabilitation at the time of initial injury may lead to worse static postural control outcomes. Clinicians should continue advocating for patients recovering from an acute ankle sprain to seek medical attention and provide continued care in the form of physical rehabilitation. [ABSTRACT FROM AUTHOR]

Lateral ankle sprains are a commonly incurred injury in sports. They have a high recurrence rate and can lead to the development of persistent injury associated symptoms. We performed a quantitative synthesis of published case reports documenting the kinematics of acute lateral ankle sprains and episodes of 'giving-way' of the ankle joint to provide a comprehensive description of the mechanisms. A systematic literature search was conducted to screen records within MEDLINE® and EMBASE®. Additional strategies included manual search of specific journals, as well as contacting researchers in relevant communities to retrieve unpublished data. Twenty-four cases were included in the quantitative synthesis, 11 from individual case reports and 13 from four separate case series. Two authors independently reviewed all the articles and extracted ankle joint kinematic data. Excessive ankle inversion was the most pronounced kinematic pattern observed across all included cases, with a mean peak inversion angle of 67.5° (range 2.0 to 142) and a mean peak inversion velocity of 974°/s (range 468 to 1752). This was followed by internal rotation and plantar flexion, respectively. A homogeneous linear function revealed a mean inversion velocity across all cases of 337°/s (range 117 to 1400; R2 = 0.78; p < 0.0001). [ABSTRACT FROM AUTHOR]

CONTEXT: Altered neuromuscular function and decreased dorsiflexion range of motion (DFROM) have been observed in patients with chronic ankle instability (CAI). Joint mobilizations are indicated for restoring DFROM and dynamic postural control, yet it remains unknown if a mobilization can alter neuromuscular excitability in muscles surrounding the ankle. OBJECTIVE: To determine the immediate effects of a Maitland grade III anterior-to-posterior joint mobilization on spinal-reflex and corticospinal excitability in the fibularis longus (FL) and soleus (SOL), DFROM, and dynamic postural control. DESIGN: Single-blinded randomized control trial. SETTING: Research laboratory. PATIENTS: 30 patients with CAI randomized into a mobilization (n = 15) or control (n = 15) group. INTERVENTION: Maitland grade III anterior-to-posterior joint mobilization. MAIN OUTCOME MEASURES: Spinal-reflex excitability was measured with the Hoffmann reflex, while corticospinal excitability was evaluated with transcranial magnetic stimulation. DFROM was measured seated with the knee extended, and dynamic postural control was quantified with the Star Excursion Balance Test. Separate 2 × 2 repeated-measures ANOVAs were performed for each outcome measure. Dependent t tests were used to evaluate individual differences within groups in the presence of significance. RESULTS: Spinal-reflex and corticospinal excitability of the SOL and FL were not altered in the mobilization or control group (P > .05). DFROM increased immediately after the mobilization (P = .05) but not in the control group, while dynamic postural control was unchanged in both groups (P > .05). CONCLUSION: A single joint-mobilization treatment was efficacious at restoring DFROM in participants with CAI; however, excitability of spinal reflex and corticospinal pathways at the ankle and dynamic postural control were unaffected. [ABSTRACT FROM AUTHOR]

Context: People with chronic ankle instability (CAI) display a lower regional and global health-related quality of life (HRQoL). Examinations of HRQoL outcomes associated with CAI have addressed younger adults, restricting our understanding of the long-term consequences of CAI. Objective: To compare ankle regional and global HRQoL in middle-aged participants with and those without CAI. Design: Cross-sectional study. Setting: Laboratory. Patients or other participants: A total of 59 middle-aged volunteers, consisting of 18 with CAI (age = 50.2 ± 9.3 years), 17 who were ankle-sprain copers (age = 54.5 ± 8.7 years), and 24 uninjured controls (age = 56.7 ± 10.0 years). Main outcome measure(s): Participants completed the Foot and Ankle Disability Index (FADI) and the Patient-Reported Outcomes Measurement Information System Adult Profile. Regional HRQoL was assessed using the FADI Activities of Daily Living and Sport subscales. Global HRQoL was measured using the 43-item Patient-Reported Outcomes Measurement Information System Adult Profile, which contains 7 short forms-Physical Function, Pain Interference, Fatigue, Depression, Sleep Disturbance, Anxiety, and Ability to Participate in Social Roles and Activities. Separate Kruskal-Wallis tests were used to determine between-groups differences. Results: Middle-aged participants with CAI had lower scores on both subscales of the FADI than the coper and control groups (all P values <.001). Participants with CAI scored lower on the Physical Function (U = 116.0, z = -2.78, P = .005) and Ability to Participate in Social Roles and Activities (U = 96.0, z = -3.09, P = .002) subscales but higher on the Pain Interference (U = 144.0, z = -2.36, P = .02), Fatigue (U = 110.0, z = -2.72, P = .006), and Depression (U = 110.5, z = -2.91, P = .004) subscales than the control group. Participants with CAI also scored lower on the Physical Function (U = 74.5, z = -2.79, P = .005) and Ability to Participate in Social Roles and Activities (U = 55.0, z = -3.29, P = .001) subscales but higher on the Fatigue (U = 90.0, z = -2.09, P = .04) and Depression (U = 96.5, z = -1.97, P = .048) subscales than the coper group. Conclusions: Middle-aged participants with CAI displayed worse ankle regional and global HRQoL than their age-matched healthy counterparts and copers. These results demonstrated that CAI can affect HRQoL outcomes in middle-aged adults. [ABSTRACT FROM AUTHOR]

The aim of the current study was to assess movement strategies during a single leg balance in chronic ankle instability individuals with unstable postural control strategy identified by Nyquist and Bode analyses in conjunction with sample entropy. Thirty-three participants with self-reported chronic ankle instability and 22 healthy controls performed single-leg eyes closed static balance trials. The sagittal and frontal plane kinematics in the lower extremity and trunk as well as center of pressure trajectories were recorded during three, 20-second trials. The Nyquist and Bode stability analyses, which classify center of pressure waveforms as stable based on the resulting gain and phase margins, were performed to identify the presence of postural control deficits. Sample entropy was implemented to analyze movement strategies during the task. Based on the Nyquist and Bode stability analyses, we included 19 out of 33 chronic ankle instability participants with unstable postural control strategy and 16 out of 22 controls with stable postural control strategy in the final analyses. Chronic ankle instability participants demonstrated a significantly lower sample entropy value in sagittal and frontal plane trunk kinematics and sagittal plane hip kinematics compared to the controls. No between-group differences existed in other kinematic measures. The lower sample entropy values in participants with chronic ankle instability indicates that those with postural control deficits may increase reliance on the trunk and hip joint contributions to the maintenance of postural control, reflecting changes in the sensorimotor constraints on movement patterns during the task. • Ankle and postural instability were associated with decreased kinematic variability. • Ankle and postural instability were related to a hip-and-trunk-locked movement. • Postural instability is critical prior to determining altered movement strategies. • Identifying the disablement exhibited is critical to design rehabilitation programs. • Nyquist/Bode criteria are a potential tool for ankle instability homogeneity. [ABSTRACT FROM AUTHOR]

Background: Chronic ankle instability (CAI) is associated with hip strength deficits and altered movement in the lower extremity. However, it remains unclear how hip strength deficits contribute to lateral ankle sprain (LAS) mechanisms. We aimed to compare lower extremity landing kinematics and isometric hip strength between individuals with and without CAI and examine associations between hip kinematics and strength. Methods: Seventy-six individuals completed 5 single-leg landings, during which we collected three-dimensional ankle, knee, and hip kinematics from 200 milliseconds pre–initial contact to 50 milliseconds post–initial contact. We calculated average peak torque (Nm/kg) from 3 trials of isometric hip extension, abduction, and external rotation strength testing. One-way analyses of variance assessed group differences (CAI, LAS coper, and control) in hip strength and kinematics. Pearson product moment correlations assessed associations between hip kinematics and strength. We adjusted the kinematic group comparisons and correlation analyses for multiple comparisons using the Benjamini-Hochberg method. Results: The CAI group exhibited less hip abduction during landing than LAS copers and controls. The CAI group had lower hip external rotation strength than LAS copers (P =.04, d = 0.62 [0.05, 1.17]) and controls (P <.01, d = 0.87 [0.28, 1.43]). Effect sizes suggest that the CAI group had deficits in EXT compared with controls (d = 0.63 [0.06, 1.19]). Hip strength was not associated with hip landing kinematics for any group. Conclusion: Altered landing mechanics displayed by the CAI group may promote mechanisms of LAS, but they are not associated with isometric hip strength. However, hip strength deficits may negatively impact other functional tasks, and they should still be considered during rehabilitation. Level of Evidence: Level III, case-control study. [ABSTRACT FROM AUTHOR]

Considering the high recurrent injury rates, athletes may receive clearance for return to play (RTP) from a lateral ankle sprain (LAS) before impairments and activity limitations are resolved. The purpose of this study was to examine residual structural and functional impairments and activity limitations at RTP in athletes with a LAS. We found that athletes demonstrated increased ankle ligamentous laxity and reduced self-reported function, dorsiflexion range of motion, and dynamic postural control at RTP. Athletes with a LAS likely require more extensive care to resolve impairments and activity limitation before RTP. [ABSTRACT FROM AUTHOR]

The current study aimed to examine postural control performance during a single-leg balance task in elderly individuals with and without a previous history of lateral ankle sprain (LAS). Eighteen adults with a previous history of LAS (mean age = 66 years old) and 12 healthy controls (mean age = 65 years old) were included in the study. Participants performed three trials of a single-leg balance task during an eyes-opened condition for 20-s. Center of pressure (COP) trajectories in the anteroposterior (AP) and mediolateral (ML) directions were collected with a force plate. The following postural control measures were calculated in the AP and ML directions: 1) Sample Entropy (SampEn); 2) Approximate Entropy (ApEn); 3) mean of Time-to-Boundary minima (mean TTB); and 4) COP velocity (COPV). Older-age participants with a history LAS exhibited lower ApEn-AP, SampEn-AP, and SampEn-ML values compared to healthy controls (p < 0.05). The information gained from this investigation indicates more rigid postural control patterns, less adaptability, and more difficulty maintaining COP during a single-leg balance task in adults with a previous history of LAS. Our data suggest that there is a need to consider history of musculoskeletal injury when evaluating factors for postural control and fall risk in the elderly. Future investigations are needed to assess the effect of LAS on age-related declines in postural control and discern associations between potential risk factors of fall-related injuries and LAS in an elderly population. [ABSTRACT FROM AUTHOR]

Sensorimotor brain connectivity is often overlooked when determining relationships between postural control and motor performance following musculoskeletal injury. Thalamocortical brain connectivity is of particular interest as it represents the temporal synchrony of functionally and anatomically linked brain regions. Importantly, adults over the age of 60 are especially vulnerable to musculoskeletal injury due to age-related declines in postural control and brain connectivity. Is there a relationship between thalamocortical connectivity and static postural control in older adults with a history of LAS? Data were analyzed from twenty older adults (mean age = 67.0 ± 4.3 yrs; 13 females) with a history of LAS. The sensorimotor network (SMN) was identified from resting-state MRI data, and a priori thalamic and postcentral gyri regions of interest were selected in order to determine left and right hemisphere thalamocortical connectivity. Balance was assessed for the involved and non-involved limbs via center of pressure velocity (COPV) in the medial-lateral (ML) and anterior-posterior (AP) directions. Contralateral thalamocortical connectivity was significantly associated with COPV_ML COPV_ML (r = −0.474, P = 0.05) and COPV_AP (r = −0.622, P = 0.008) in the non-involved limb. No significant association was observed between involved limb balance and contralateral thalamocortical connectivity (COPV_ML: r = −0.08, P = 0.77; COPV_AP: r = 0.12, P = 0.63). A significant relationship between thalamocortical connectivity and static postural control was observed in the non-involved, but not the involved limb in older adults with a history of LAS. Findings suggest that thalamocortical connectivity may lead to or be the product of LAS. • Thalamocortical connectivity is related to postural control in non-injured ankles. • Changes in thalamocortical activity may be the result or product of LAS. • Thalamocortical connectivity may be a target for future postural control studies. [ABSTRACT FROM AUTHOR]

Objective: To identify which therapeutic intervention may be most effective for improving self-reported function in patients with chronic ankle instability (CAI).Design: Systematic literature review. Articles were appraised using the Downs and Black Checklist by 3 reviewers.Data Sources: PubMed along with CINAHL, MEDLINE and SPORTDiscus within EBSCOhost for pertinent articles from their inception through August 2016.Eligibility Criteria For Selected Studies: Articles included were required to (1) be written in English, (2) report adequate data to calculate effect sizes, (3) identify patients with CAI, (4) use some form of therapeutic intervention and (5) use a self-reported questionnaire as a main outcome measurement.Results: A broad spectrum of therapeutic interventions were identified related to balance training, multimodal rehabilitation, joint mobilisation, resistive training, soft-tissue mobilisation, passive calf stretching and orthotics. All of the articles included in the balance training category had moderate-to-strong Hedges g with none of the 95% CIs crossing 0. Hedges g effect sizes ranged from -0.67 to -2.31 and -0.51 to -1.43 for activities of daily living and physical activity, respectively. The multimodal rehabilitation category also produced moderate-to-strong Hedges g effect sizes but with large CIs crossing 0. Hedges g effect sizes ranged from -0.47 to -9.29 and -0.62 to -24.29 for activities of daily living and physical activity, respectively.Conclusions: The main findings from this systematic review were balance training provided the most consistent improvements in self-reported function for patients with CAI. [ABSTRACT FROM AUTHOR]

Background: Understanding the mechanisms of neurophysiological alterations with chronic ankle instability (CAI) may be essential in the development of the most-effective intervention programs to treat neuromuscular dysfunction in patients with CAI. Specifically, the presence of CAI may be associated with an altered supraspinal mechanism within the central nervous system to inhibit neural drive to the undamaged soleus surrounding the injured ankle joint.Objective: To investigate the influence of CAI on corticospinal excitability and inhibition of the soleus.Design: A single-blinded, case-control study.Setting: Research laboratory.Participants: Sixteen participants with self-reported CAI and 17 healthy control participants volunteered.Methods: Transcranial magnetic stimulation was used to assess corticospinal excitability and inhibition of the soleus muscle. Active motor threshold (AMT), defined as the lowest stimulator intensity required to elicit a peak-to-peak motor-evoked potential (MEP) amplitude ≥100 μV in at least four of 8 trials, was found to assess corticospinal excitability of the soleus. Eight stimuli were delivered at 120% of AMT, and peak-to-peak MEP amplitudes were recorded for each trial. The amplitude of 8 MEPs at 120% of AMP were averaged and normalized to the maximum M-response. Cortical silent period (CSP) was measured as the distance from the end of the MEP to a return of the mean electromyographic signal plus 2 times the standard deviation of the baseline (prestimulus) electromyographic signal. The ratio of the CSP to the MEP at 120% AMT (CSP:MEP120) were calculated to assess corticospinal inhibition.Results: The CAI group had a greater CSP:MEP120 ratio compared with the control group (P = .02). No significant differences between groups were observed for AMT (P = .67) and normalized MEP at 120% of AMT (P = .42).Conclusions: The greater CSP:MEP120 ratio in participants with CAI suggests an altered balance in corticospinal inhibition and excitability to the soleus of the CAI cohort. Future research is needed to determine the role of corticospinal inhibition in physical and self-reported function in patients with CAI.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

The purpose of this investigation was to examine the effects of the combination of chronic ankle instability (CAI) and altered visual focus on strategies for dynamic stability during a drop-jump task. Nineteen participants with self-reported CAI and 19 healthy participants performed a drop-jump task in looking-up and looking-down conditions. For the looking-up condition, participants looked up and read a random number that flashed on a computer monitor. For the looking-down condition, participants focused their vision on the force plate. Sagittal- and frontal-plane kinematics in the hip, knee and ankle were calculated at the time points of 100 ms pre-initial foot contact to ground and at IC. The resultant vector time to stabilisation was calculated with ground reaction force data. The CAI group demonstrated less hip flexion at the point of 100 ms pre-initial contact (P < 0.01), and less hip flexion (P = 0.03) and knee flexion at initial contact (P = 0.047) compared to controls. No differences in kinematics or dynamic stability were observed in either looking-up or looking-down conditions (P > 0.05). Altered visual focus did not influence movement patterns during the drop-jump task, but the presence of CAI did. The current data suggests that centrally mediated changes associated with CAI may lead to global alterations in the sensorimotor control. [ABSTRACT FROM AUTHOR]

The article discusses a case-control study which investigates the effect of chronic ankle instability (CAI) on the location of center of mass (COM) during a bilateral stop-jump task. A recreationally active 20 year old male with unilateral CAI volunteered for the study and reported to the motion analysis research laboratory. It cites the association between altered preparatory movement and energy dissipation patterns with higher location of COM with a documented recurrent ankle sprain.

Background Alterations in sagittal plane landing biomechanics in the lower extremity have been observed within the chronic ankle instability (CAI) population. Interestingly, a potential link between the risk of anterior cruciate ligament (ACL) injury and ankle sprain history has been proposed. However, it is not known if the observed biomechanical changes associated with CAI could mimic factors related to the mechanism of ACL injury. We investigated the influence of CAI on anterior tibial shear force (ATSF), lower extremity sagittal plane kinematics, and posterior ground reaction force (GRF) in a jump landing task. Methods Nineteen participants with CAI and 19 healthy control participants performed a vertical stop jump. Peak ATSF was calculated during the first landing of the stop jump, with sagittal-plane kinematics and posterior GRF measured at peak ATSF. Independent t-tests, multiple linear regression, and Pearson bivariate correlation were used for statistical analysis. Findings Participants with CAI demonstrated less knee flexion at peak ATSF compared to the controls (P = .026). No group-differences were found for peak ATSF or the other biomechanical variables. Knee flexion was moderately correlated with peak ATSF (r = −0.544, P = .008); however, the contributing factor that most explained the variance in ATSF was posterior GRF (R2 = 0.449; P = .002) in the CAI group. Interpretation Our findings indicate that the CAI group may be exhibiting altered knee function during functional movement. Screening knee movement patterns in individuals with CAI may help develop preventative measures for future joint injury throughout the kinetic chain. [ABSTRACT FROM AUTHOR]

Context: Few authors have assessed neuromuscular kneestabilization strategies in individuals with chronic ankle instability (CAI) during functional activities. Objective: To investigate the influence of CAI on neuromuscular characteristics around the knee during a stop-jump task. Design: Case-control study. Setting: Research laboratory. Participants or Other Participants: A total of 19 participants with self-reported unilateral CAI and 19 healthy control participants volunteered for this study. Intervention(s): Participants performed double-legged, vertical stop-jump tasks onto a force plate, and we measured muscle activation around the knee of each limb. Main Outcome Measure(s): We calculated the integrated electromyography for the vastus medialis oblique, vastus lateralis, medial hamstrings, and lateral hamstrings muscles during the 100 ms before and after initial foot contacts with the force plate and normalized by the ensemble peak electromyographic value. Knee sagittal-plane kinematics were also analyzed during a stop-jump task. Results: Compared with control participants, the CAI group demonstrated greater prelanding integrated electromyographic activity of the vastus medialis oblique (CAI = 52.28 ± 11.25%⋅ms, control = 43.90 ± 10.13%⋅ms, t36 = 2.41, P = .021, effect size = 0.78, 95% confidence interval = 0.11, 1.43) and less knee-flexion angle at the point of initial foot contact (CAI = 7.818 6 8.27°, control = 14.09° ± 8.7°, t36 =-2.2°, P = .029, effect size = -0.74, 95% confidence interval = -1.38, -0.07) and at 100 ms post-initial foot contact (CAI = 51.36° ± 5.29°, control=58.66° ± 7.66°, t36=-3.42, P=.002, effect size =-1.11, 95% confidence interval=-1.77,-0.40). No significant results were noted for the other electromyographic measures. Conclusions: We found altered feed-forward patterns of the vastus medialis oblique and altered postlanding knee sagittalplane kinematics in the CAI group. These observations may provide insight regarding sensorimotor characteristics that maybe associated with CAI. [ABSTRACT FROM AUTHOR]

Context: Clinicians perform therapeutic interventions, such as stretching, manual therapy, electrotherapy, ultrasound, and exercises, to increase ankle dorsiflexion. However, authors of previous studies have not determined which intervention or combination of interventions is most effective. Objective: To determine the magnitude of therapeutic intervention effects on and the most effective therapeutic interventions for restoring normal ankle dorsiflexion after ankle sprain. Data Sources: We performed a comprehensive literature search in Web of Science and EBSCO HOST from 1965 to May 29, 2011, with 19 search terms related to ankle sprain, dorsiflexion, and intervention and by cross-referencing pertinent articles. Study Selection: Eligible studies had to be written in English and include the means and standard deviations of both pretreatment and posttreatment in patients with acute, subacute, or chronic ankle sprains. Outcomes of interest included various joint mobilizations, stretching, local vibration, hyperbaric oxygen therapy, electrical stimulation, and mental-relaxation interventions. Data Extraction: We extracted data on dorsiflexion improvements among various therapeutic applications by calculating Cohen d effect sizes with associated 95% confidence intervals (CIs) and evaluated the methodologic quality using the Physiotherapy Evidence Database (PEDro) scale. Data Synthesis: In total, 9 studies (PEDro score = 5.22 6 1.92) met the inclusion criteria. Static-stretching interventions with a home exercise program had the strongest effects on increasing dorsiflexion in patients 2 weeks after acute ankle sprains (Cohen d = 1.06; 95% CI = 0.12, 2.42). The range of effect sizes for movement with mobilization on ankle dorsiflexion among individuals with recurrent ankle sprains was small (Cohen d range = 0.14 to 0.39). Conclusions: Static-stretching intervention as a part of standardized care yielded the strongest effects on dorsiflexion after acute ankle sprains. The existing evidence suggests that clinicians need to consider what may be the limiting factor of ankle dorsiflexion to select the most appropriate treatments and interventions. Investigators should examine the relationship between improvements in dorsiflexion and patient progress using measures of patient self-reported functional outcome after therapeutic interventions to determine the most appropriate forms of therapeutic interventions to address ankle-dorsiflexionlimitation. [ABSTRACT FROM AUTHOR]